Request for Classification
of a Natural Site
the World Heritage List
The coral reefs
Table of Contents
1. Site Description*
1.1. General description of New Caledonia*
·New Caledonia is a sparsely populated tropical archipelago, with 210,000 inhabitants very unevenly distributed in space *
·New Caledonia’s status is highly unusual *
·New Caledonia’s economy is heavily assisted *
·Almost all resource exportation is linked to nickel exploitation *
·Finally, New Caledonia has a young population, demographically dynamic, but culturally, socially and economically very heterogenous *
1.2. Description of the coral reef*
·Geographical characteristics *
·Ecosystems represented *
2. Reasons for the classification of the coral reef on the World Heritage List*
2.2. Comparisons with other, similar sites*
·Australia’s Great Barrier Reef *
·The reefs of French overseas territories *
2.3. The site’s authenticity and classification criteria*
3. Description of Caledonian marine biodiversity and of the site*
3.1. The various Caledonian marine environments*
3.2. Marine ecosystem typology and distribution*
·Coral reefs *
·Spermatophyta seagrass beds *
·Sandy areas *
3.3. Site description*
·State of the coral reefs *
·Rare or threatened species *
3.4 Conservation and protection*
·Protected areas *
·The institutions in charge of protected areas management *
4. Site management*
4.1 Protection measures, management tools*
·Protection measures against erosion and sedimentation *
·Measures against domestic, agricultural and industrial pollution *
·Resource management measures *
·Measures against the impact of tourism *
·Information and education *
·Monitoring and research networks *
·Regulatory tools *
·Financial tools (development contract, etc.) *
4.2 Organisations likely to become involved in site management*
·Central government offices *
·The Territory *
·The Provinces *
·The municipalities *
·Consultative organisations *
·Research and/or educational organisations *
·Nature protection associations *
5. Factors affecting the site*
5.1 Natural factors*
·Coral bleaching *
·Other organisms *
5.2 Human impacts*
·Mines and sedimentation due to industrial wastes *
·Coastal development (embankments, dredging, aquaculture) *
·Industrial, agricultural and domestic pollution *
·Resource use (corals, shellfish) *
·Introductions of exotic species *
·Tourism and recreational activities *
With an area of 18,575 km2, New Caledonia is located in the Western South Pacific at 21o latitude South and 165o longitude East, a three hours’ flight from Australia or New Zealand. It includes a main island (Grande Terre) that stretches along a northwest/southeast axis. This island is about 400 km long and 50 km wide, and is surrounded by a lagoon and several islands of a variety of sizes: the Loyalty Islands archipelago to the east (Ouvéa, Lifou, Tiga, Maré), the Isle of Pines to the south, and the Bélep archipelago to the north (to cite only the inhabited islands).
The Caledonian archipelago has a tropical island environment, and this fact has consequences for mining operations: rainfall is abundant, most often in the form of violent storms, which leads to serious erosion. In the hot season (November to April), cyclones and tropical depressions hit the territory, sometimes severely disturbing the local economy: blocked roads, interrupted mining activities and waterlogged work-sites, and considerable material damage all result from cyclones. The lagoon, which almost entirely surrounds Grande Terre, is particularly vulnerable during these rainy seasons as the high turbidity of the water can lead to significant coral mortality. Moreover, deforestation linked to mining activity and to bush fires further accentuates erosion. Thus, all of the territory’s large-scale town and country planning operations must account for these climatic hazards and this erosion.
The population currently consists of 210,000 inhabitants, of whom 60% are concentrated in the territory’s only urban area: Nouméa and its surroundings. This region regroups approximately 125,000 inhabitants, distributed between the city of Nouméa and its three main suburbs: Dumbéa, Mont Dore and Païta.
The rest of the territory appears empty, particularly the central mountain chain which forms the spine of Grande Terre. Nouméa is commonly distinguished from the rest of the territory, nicknamed "the Bush and the Islands".
New Caledonia is a part of the French Republic and has a unique political status since 1999. Before this date, New Caledonia was a T.O.M. (Overseas Territory) just like French Polynesia and Wallis and Futuna. This gave it a special legal position in relation to Metropolitan France.
The term that is becoming used to refer to New Caledonia is "Overseas Country", an ambiguous term that clearly demonstrates the ambivalence of its status.
On one hand, New Caledonia is not a "country" in the sense of an independent state, insofar as the French government, represented by the High Commissioner of the Republic, retains a certain number of powers.
On the other hand, New Caledonia is in the process of acquiring the prerogatives of an independent state: the ability to vote "national laws", a Caledonian citizenship, and the ability to take action on the international stage.
Political ties with Metropolitan France are also materialized by the size of the financial transfers that Metropolitan France allows New Caledonia to receive, particularly since the signature of the Matignon Accords in 1988.
These transfers are carried out in the form of grants of equipment and infrastructure which are intended to contribute to the economic readjustment of the Territory, for the benefit of the Bush and the Islands. Considerable sums have been invested in the modernisation of the road network as well as the health and education sectors, so as to reduce the gap between New Caledonia and Metropolitan France. Efforts have similarly been made to improve the housing situation.
To these grants must be added the substantial salaries paid to civil servants and government officials who reside in the Territory. These people represent 27% of the employed population. In order to compensate for a cost of living that is superior to that of Metropolitan France, the salaries and pensions of government employees are multiplied by 1.73 in Nouméa and 1.94 in the Bush, in comparison to salaries in Metropolitan France.
It is thus evident that the Caledonian economy is heavily assisted by these transfers from Metropolitan France. Its only significant exportable resources are linked to the exploitation of Grande Terre’s very abundant nickel reserves. This ore is either directly exported, to Australia and Japan, or processed in the Doniambo metallurgical refinery in Nouméa. Nickel exports reached 3.8 million tons in 1999 and represent 94% of the value of all exports.
Although nickel exploitation only represents a relatively small percentage of the GDP (8%) and of local employment (just over 5% of direct employment), it plays an important psychological role in New Caledonia and the saying, "when nickel goes well, all is well" is the Territory’s most widely shared economic creed.
The Melanesians (or Kanak), the indigenous population, are the most numerous ethnic group but only constitute 44% of the total population. The rest is composed of immigrants and their descendants who have arrived in the Territory since the middle of the 19th century from a variety of backgrounds: mainly Metropolitan France but also Wallis and Futuna, French Polynesia, Indonesia, Vietnam, Vanuatu, etc. Over time, these groups intermarried but never formed a "creole" population like that of the D.O.M.s (Overseas Departments).
Important differences exist between the lifestyles of the Melanesians who continue to live in villages in a fairly traditional manner, and the rest of the population: Melanesians who live outside of the village, Wallisians, Europeans, etc., who live in towns and in larger Nouméa, and are integrated into a modern economic system.
The relationships among these different populations are complex. They were particularly tense from 1984 to 1988 during the period that the Caledonians euphemistically refer to as the "Events". Since 1989, the social climate has become more relaxed. The signing of the Nouméa Accords in May 1999 was, on the whole, well received. Certain social problems are nonetheless still present in the workaday world, where there are frequent strikes, as well as in daily life, where problems include road accidents, alcoholism and marijuana consumption.
Along the shores of New Caledonia’s Grande Terre, coral reefs were formed during the Miocene and constructed an almost continuous barrier stretching for approximately 1,600 km.
This submerged barrier reef is continuous (except in the Southwest), has an area of 8,000 square km, and is at a distance from the coast of a few kilometers to about 65 km.
This large New Caledonian lagoon can be divided into several geographical entities: the Southwestern Lagoon, between Téremba to the north and the Isle of Pines to the south; the Eastern Lagoon, between the Havanah Canal to the south and the Amos Pass to the north; the Northern Lagoon, between the Diahot estuary to the south and the Great Passage to the north which separates the Northern Lagoon as such from the Surprise Atoll; and the Northwestern Lagoon, between Poya and the Isle of Yandé. These lagoons are very different in structure, shape, area, and bathymetry.
In New Caledonia’s dependencies are found other lagoons: in the Loyalty Islands, there are the lagoons of Ouvéa and of Beautemps-Beaupré; the Entrecasteaux Reefs including the Huon and Surprise Atolls; the two big atolls of Chesterfield and Bellona; and the submerged "atolls" of Fairway and Lansdowne.
In New Caledonia’s Economic Zone, there are numerous guyots, vestiges of sunken atolls (Scott and Rotondo, 1983; Richer de Forges et al., 1987b), the summits of which are situated in the euphotic zone.
The lagoon’s boundaries are defined by the 100 m isobath, which corresponds approximately to the lower limit of hermatypic coral development.
This immense coral barrier demarcates, around Grande Terre, lagoons with an area estimated at 23,400 square km. The average width of these entities is 10 km (and reaches 30 km in the southwest). The average depth is 25 m in the west and 40 m in the east with a maximum measured at 80 m.
When we add the coral barrier itself, the total lagoon/reef area represents almost 40,000 square km.
It is included in the ZEE of 200 nautical miles, of which the area is estimated to be 1.74 million square km. The ratio of reef : dry land is 70 : 30.
Originally a part of Gondwanaland, New Caledonia separated from the Australian coast about 80 million years ago. For geological, geographical and hydro-climatic reasons, this island has a very high rate of terrestrial and marine biodiversity. Around the main island, one of the world’s longest barrier reefs demarcates vast lagoons that shelter numerous coral islets, fringing reefs, Spermatophyta and Caulerpa seagrass beds, and mangrove zones. These diverse ecosystems are home to a high level of biodiversity, including many species still largely or entirely unknown to science.
The reef area is very geomorphologically diverse.
In morphological terms, New Caledonia’s Grande Terre is a continental island with a barrier reef.
The Caledonian barrier reef is the planet’s second largest coral reef, after Australia’s Great Barrier Reef. It is also one of the very few true double barrier reefs.
The reef also constitutes a rampart against the sea’s violence and plays a role as a natural protection for the coasts, especially during the cyclone season.
Constructed by coral, which creates its own mineral substrate, and grouping thousands of species in a single place, the reef is, along with tropical forests, the most diverse and complex ecosystem on the planet. It is also one of the most productive ecosystems and in the particularly biomass-poor tropical ocean environment, coral reefs are often considered to be like an oasis in the desert.
Species diversity is at its highest on the reefs of the French overseas territories. Certain isolated zones have a particular biogeographical interest (such as the Chesterfield Reef) where rare endemic species are found. They can also provide special turtle nesting sites.
The reef provides one of the world’s most beautiful marine panoramas and one of the planet’s most fabulous undersea landscapes. Thus, it is the basis of tourism and of recreational and sailing activities, which are essential for the local economy.
This is the world’s largest barrier reef and a large part of it is protected as a nature reserve (GBRMP: Great Barrier Reef Marine Park).
Australia’s eastern coast is bordered by almost 2,000 km of coral reefs that mark the boundaries of its continental plateau and define an immense lagoon (Maxwell, 1968). This is the world’s largest coral system and although the reefs only form a true "barrier" north of Cairns, these formations were named the Great Barrier Reef (GBR). This very coast is the site of the first scientific descriptions of coral reefs, particularly during the Great Barrier Reef Expedition led by Sir Maurice Yonge in 1928-29 (Younge, 1931).
In 1972, UNESCO classified the GBR as a "world heritage" site by including it on the World Heritage List. In 1975, a national park was created to protect all the reef formations along the east coast, and was named the Great Barrier Reef Marine Park. Two institutions are responsible for guarding this gigantic "reserve": the Australian government and the Queensland state government. This situation has created some disagreements over the application of regulations. The zone under the Great Barrier Marine Park Authority’s jurisdiction extends from Fraser Island in the south (24o30’S) to Cape York in the north (10o41’S) and covers an area of 348,700 square km. It includes approximately 2,500 reefs, each measuring between 100 and 10,000 ha, and 71 sand keys. The very numerous scientific studies of the GBR’s ecology that have been conducted to date are inventoried in Frankel’s bibliography (1988).
Many activities take place within this park, including tourism, fishing, and sea traffic. Different geographical sections have been defined, allowing regional management. The four largest sections are: the Northern section (83,000 km2); the Cairns section (35,000 km2); the Central section (77,000 km2); the Capricorn section (137,000 km2); and a "small" zone surrounding the Capricorn Islands group, the Capricornia section (11,800 km2), defined in 1979. The GBR contains practically all the existing types of reef formations: fringing reefs around high islands or coasts, submerged banks, sand keys, barrier reefs with terrigenous deposit zones and others that are totally oceanic, the closest reefs being situated in some places at more than 100 km from the coast. Environmental conditions are variable from one end to the other of the reserve, the southern reefs being bathed in temperate waters while the northern part is subjected to equatorial waters. In addition, the tidal range reaches several meters in some places, which causes very violent currents (>8 knots), particularly in the zone near the Torres Strait. The influx of fresh water and terrestrial elements varies from south to north. On the whole, the central and southern sections are more subjected to the influence of large rivers although the lagoon is wider there than in the northern section. The width of the continental plateau varies from 290 km offshore from Cape Townshend to 24 km near Cape Melville, where there are fossilized traces of barrier reefs that followed the changes in sea level linked to climatic fluctuations (Hopley, 1982).
The tourism value of these coral reefs rose by a factor of 40 between 1940 and 1980 and reached 140,000 visitors per year in 1984. A hotel infrastructure has been developed, offering outings to the reefs by boat or even by submersible. There was even an attempt made to place a floating hotel directly on the reef offshore from Townsville.
The Hawaiian archipelago is the result of volcanic activity linked to a hot spot currently situated near the island of Hawaii and the SE-NW movement of the Pacific Tectonic Plate (Menard, 1986; MacDonald et al., 1990). The Midway Atoll, the oldest of the atolls, is dated at 27 (+ or – 0.6) million years old while the youngest island is Hawaii, 0.8 million years old. This row of islands constitutes a state of the United States of America and an abundant literature has been dedicated to its environment, its natural history and in particular its marine species (Carlquist, 1980; Kay, 1994; Eldredge and Miller, 1995). These islands cover a total area of 16,749 km2, spread over 8 principal islands of which Hawaii is the largest (100,451 km2) but the most populated is Oahu (1,600 km2) where the capital, Honolulu, is located. The biodiversity of these very isolated islands, stretching over 2,300 km between Hawaii and the Kure Atoll, is characterised by a high rate of endemic species.
A very complete set of laws protects Hawaii’s environment: the Federal Land Policy and Management Act of 1976 for the terrestrial fauna and flora, and the Fish and Wildlife Act of 1956 and the Coastal Zone Management Act of 1972 for the marine section. In addition, the species are protected by the Endangered Species Act of 1973.
The National Park of Hawaii was created on the 1st of August, 1916, on the islands of Hawaii and Maui. The Hawaii Natural Areas Reserves System was established to "preserve in perpetuity specific land and water areas which support communities, as relatively unmodified as possible, of the natural flora and fauna, as well as geological sites of Hawaii." The main goal of the multiple reserved zones is the protection of the terrestrial flora and fauna; however, these reserves sometimes include coastal zones that protect, for example, an area of dunes where green turtles nest (Mo’omomi on the island of Moloka’i).
The coral reefs are well developed but have poor species diversity (43 species); however, it is on the reefs that the highest percentage of stony coral endemism is found (Grigg, 1983; Veron, 1995).
The Hawaiian Islands National Wildlife Refuge was created in 1966 and covers 122,443 ha of marine zones, including the Pacific’s northern-most coral reefs (27o50’N). This reserve includes rocks and volcanic islets as well as coral atolls (Pearl and Hermes) and coral banks (French Frigate Shoals). This zone is often visited by cetaceans, pinnipeds (Monachus schauinslandi), green turtles and numerous species of sea birds, sterns, boobies, puffins, frigate birds and albatrosses (Diomedea albatrus, D. immutabilis, D. nigripes). About 99 fish families, including 585 species, have been inventoried (Paine, 1991; Pyle, 1995; Randall, 1995).
The coral formations of the inhabited islands are heavily disturbed by human presence. Deforestation linked to agricultural development has caused soil erosion and led to water turbidity, which is harmful to coral growth. The effects of urban pollution are also felt in certain bays (such as Kaneohe Bay) (Smith et al., 1973). Coastal development was the main cause of reef destruction in certain zones, particularly during the construction of ports, channels, and airports. Despite good scientific knowledge of the Hawaiian Islands’ marine fauna and an arsenal of conservation measures, there is no real management program designed to evaluate the causes and consequences of the reefs’ decline. About 20 marine protected areas exist in Hawaii but the reef zones are not sufficiently protected (Maragos, 1993).
New Caledonia alone represents nearly 75% of the area of the reefs and lagoons of French overseas territories. In this capacity, New Caledonia makes France one of the world’s most coral-rich nations.
New Caledonia is the only area of France where all the known types of reef are located: barrier reefs, double barrier reefs, fringing reefs, atolls and coral banks.
The lagoon also provides habitat for numerous internationally protected marine species such as nautiluses and turtles.
New Caledonia’s most well-known lagoon space is situated within the Southwestern Lagoon between Téremba in the North and the great southern "valley", beyond the island of Ouen.
New Caledonia’s Southwestern Lagoon was the site of several investigations of which the most important for the knowledge of its biodiversity were:
In addition, a sedimentological study of the Southwestern Lagoon allowed the elaboration of a four-page map of the sea bottom (Dugas and Debenay, 1978, 1980, 1981, 1982) which shows the granulometry and the carbonate levels.
On the whole, these studies were concerned essentially with the Southwestern Lagoon and more particularly with the area around the Nouméa peninsula; in other words, they covered only a small fraction of the total area of the lagoons of New Caledonia’s economic zone.
The southwestern reefs are thus well known. The Ouvéa atoll is also relatively well known. As for the farther reefs and Grande Terre’s other lagoons, they are described as "poorly known". The overall knowledge of the Caledonian lagoon is thus estimated to be around 20%.
New Caledonia’s marine biodiversity is estimated at 15,000 species, although certain sectors still remain unexplored.
Coral reefs, mangroves and seagrass beds are believed to occupy approximately one third of the world’s tropical coastal regions. These ecosystems are extremely important in tropical regions. Hydrodynamic movements and trophic networks link these different ecosystems very closely.
Coral reefs’ principal biotopes are muddy seabeds, gray sand seabeds (lagoon plain), white sand sea beds (back reef) and coral constructions (including seaweed reefs, atoll reefs, and fringing reefs).
Fringing reefs, in particular, offer first-rate hatcheries for numerous species of fish, notably those with commercial value.
The presence and good health of these reefs are thus primordial.
New Caledonia’s most-represented moist areas are the mangroves that mainly occupy salty and muddy soils along the intertidal zone. These zones are intimately linked to reef ecosystems, as they have an essential biological value: they act as nurseries for a certain number of fish species and provide a land/sea interface, capturing terrestrial sediments and limiting the impacts of storms and coastal erosion.
The formations are low and the vegetation is composed of common species.
Approximately 50% of the coastline is bordered by mangroves, covering an area estimated at 200 square km for the whole island; they are particularly well developed in the bays along the west coast (Thollot, 1989, 1996a).
The mangrove is severely damaged in the Nouméa region where 23 to 28% of its area has been destroyed since 1960.
These are feeding grounds, especially for threatened species such as turtles and dugongs. They are also hatcheries and nurseries, and act to stabilise the sedimentary substrate and to oxygenate the water.
The shifting beds of New Caledonia’s lagoons are composed of sediments from two sources: one part comes from soil deposits from Grande Terre, due to the pluvial erosion of the lateritic crust; the other part is due to the degradation of the coral reefs, composed of carbonates, which undergo erosion from storms and from the biogenic production of organisms with a calcareous skeleton (mollusks, calcareous seaweeds, foraminifers, echinoderms, crustaceans, bryozoans, etc.). Two sedimentary gradients can thus be observed: carbonated sediments that decrease from the barrier towards the coast, and silicated terrestrial sediments decreasing from the coast towards the reef. From this double source of particulate matter results a zonation of the lagoon bottoms, which can be distinguished not only in the sediments but also in the benthic communities: a coastal muddy zone, a carbonated, "white bottomed" zone on the back reef, and a mixed zone (gray bottom) between the former two.
3.3. Site description
The state of the coral reefs’ health is poorly known and not quantified. However, it is estimated that the great majority of the coral reefs are in good condition, other than the areas of reef that are downstream from mining operations, especially on the east coast, and certain reefs around Nouméa.
In these zones, the coast and the marine environment are affected: disappearance of the mangrove and the fringing reefs, often poor bacteriological quality of swimming areas, coral mortality due to asphyxiation and light reduction, eutrophication, modification of ichthyological populations, etc.
Coral constructions provide shelter for a rich diversity of species. It is estimated that 15,000 species make their home on the reef, including 10,000 species of crustaceans and mollusks. Nearly 2,000 species of fish are also found there, as well as a few reptiles and rare or threatened mammals (leatherback turtles, dugongs, etc.).
Considering the hydrodynamic exchanges and the geographical characteristics, the rate of endemism of the marine biocenosis is low, estimated at 5%. However, it must be kept in mind that knowledge of the Caledonian marine biodiversity is still very limited.
The quantitatively dominant groups are the mollusks, the sponges, and the echinoderms.
The presence of dugong is a primordial component of the conservation value of the Caledonian lagoon.
The presence of 8 other mammal species can also be noted, including the humpback whale, the great dolphin, the pilot whale, and the minke whale.
The dugong or "sea cow" is listed in Appendix I of the Washington Convention. This protection from international commerce thus extends to the French Territory of New Caledonia. Hunting this species is strictly forbidden; however, in order to respect the traditions of indigenous populations, villages are authorised to catch dugong for certain "customary feasts". Theoretically, the villages must inform the local police of the capture of a dugong and fill in a form that describes the animal’s measurements. According to the official statistics from these forms, 16 specimens were caught between 1978 and 1984 (Sylvestre and Richer de Forges, 1985). Since the creation of the provinces, in 1988, the supervision of these captures seems to have been relaxed and there is no more reliable data. In the Northern Province, customary chiefs protested certain abuses in the capture and use of dugong flesh. Despite some poaching, however, human predation remains very limited and it seems that this species is not locally threatened by fishing. Nonetheless, the survival of this species depends on the health of the spermatophytic seagrass beds which constitute the basis of their diet. The extreme sedimentation linked to mining activities has already destroyed the seagrasses of the east coast, thus reducing the dugongs’ grazing grounds. In addition, New Caledonia is located at the edge of the dugong habitat zone, which doubtlessly makes it more vulnerable to natural and human disturbances.
Dugong are also disturbed by the noises from motor boats (and jet skis) and are becoming rare in areas where the traffic is too intense, eg. within a 10 mile radius around the Nouméa peninsula.
Awareness campaigns are regularly organised by environmental protection groups and more recently by the Southern Province’s Fisheries Department (Garrigue, 1994b).
In the Pacific, turtles are traditionally fished for their meat and their shells. Throughout the Pacific, turtle species are threatened by a demand for their meat for Asian markets and by a rise in "accidental" captures in drifting nets. Certain countries (such as Indonesia) commercially harvest turtle eggs and process turtle shells. In the past, tortoiseshell was often used in carpentry for inlays on valuable furniture and for the manufacture of jewelry, boxes and bottles, fans and combs. This practice continued until the 1950s. Despite the existence of plastic materials as substitutes, there is still a high demand for true tortoiseshell for the restoration of old furniture and for spectacle frames (Anonymous, 1997a, b).
Legislation on the capture of turtles in the Territory is currently the following:
Dispensations may be granted for scientific collections or for customary feasts. These regulations have never been recognized or applied in the Islands Province where turtles are captured all year long without authorisation and the eggs are consumed.
Four species of turtles from two different families are common in New Caledonia’s waters: Chelonidae, Eretmochelys imbricata (commonly called the "hawksbill turtle"), Chelonia mydas ("green turtle"), Caretta caretta ("loggerhead turtle"); Dermochelidae, Dermochelys coriacea ("leatherback").
Data on the biometry and the egg laying of these turtles (mainly the green turtle) were acquired during expeditions to the Huon and Surprise Islands (Pritchard, 1987; Laboute, 1989b; Hamel, 1991, 1992; Garrigue, 1994). The principal egg-laying areas are located in the north of New Caledonia, in the "Entrecasteaux Reefs" (Huon and Surprise Islands), on sandy islets (motu) of the Surprise atolls (Surprise, Fabre, Le Leizour) and on the island of Huon (Haeberle, 1952; Pisier, 1979; Richer de Forges and Bargibant, 1985; Hamel, 1992). It appears that this is one of the primary egg-laying areas in the entire Pacific for the green turtle. This discovery alone should lead to the classification of these two atolls as reserves.
In November-December, during the egg-laying season, up to 300 turtles per night have been observed on Surprise Island and 105 per night in January on Huon Island. Fishermen from the Belep Islands go there to catch turtles and during each trip they take 15 to 30 individuals, without considering the regulations. It is generally the medium-sized individuals, easier to transport, that are consumed (Hamel, 1992). Surprise Island, the closer of the two to Grande Terre and to the Belep Islands, is visited by both fishermen and recreational sailing vessels. The turtles there are less numerous than on Huon Island and it appears that they are more often disturbed (Laboute, 1989; ASNNC, 1989). During scientific expeditions to these islands, turtles have been marked and recaptures will allow a better understanding of the relationships between the stocks of green turtles that lay their eggs in New Caledonia and those of Australia and the Fiji Islands. Forty-eight turtles were marked in January 1989, 265 in December 1991 and 140 in December 1992 (ASNNC, 1993).
Natural mortality is very high: young turtles’ natural predators include birds (Fregata minor, F. ariel), crabs (Ocypode sp.), and sharks (Carcharinus melanopterus). In addition to this natural mortality, the turtles themselves frequently destroy other nests in trying to dig their own. The plates of "beach rock" found along the beaches of these islets constitute difficult obstacles for these turtles, who are already exhausted by egg-laying; some, caught by the low tide, die before having passed over these rocky barriers.
The "motu" of the Chesterfield Atoll (Loop Island, Longue Island, Renard Island) are also turtle egg-laying sites but they are much less well known because of their isolation (Rancurel, 1973; Condamin, 1977; Sintes, 1991). During the 1991 expedition, 425 turtle tracks were observed on the Mouillage Islets, Loop Island and Longue Island (Geermans, 1993).
Several times, tutles marked in Australia (Heron Island) were found on Surprise Island. The destination of the turtles that hatch in New Caledonia remains totally unknown (Pritchard, 1987).
These marine turtles are all listed in Appendix I of the CITES list under the Washington Convention. It would appear, however, that poaching is common (ASSNC, 1991).
It appears that the species Caretta caretta nests on the Beautemps-Beaupré Atoll, on the islets off the west coast, on the Isle of Pines, and on the islets of the Ouvéa Atoll (Pritchard, 1987).
The second meeting and workshop of the regional marine turtle conservation program (RMTCP), held in Nouméa in August 1991, led to the adoption of several resolutions. For New Caledonia, these involve: the encouragement of information campaigns led by the Association for the Preservation of New Caledonian Nature (ASNNC), the continuation of research on the important nesting sites within this Territory, the strict application of conservation laws, and the struggle against poaching.
Most of the reports from scientific expeditions to study turtles on the Surprise Islands, Huon Island or the Chesterfield Islands recommend that these exceptional places be designated as nature reserves. This advice has not yet been taken into consideration by the French government which is directly responsible for these small dependencies of the Territory of New Caledonia.
Everywhere in the world, mollusks are overexploited by humans. New Caledonia is home to several particularly threatened species. This threat is linked to collectors’ passion for their shells. In the most highly sought-after groups, which are the cowries, cone shells, and volutes, enthusiasts seek to expand their collections with endemic or rare species from distant islands. The threat to New Caledonia’s species is thus a direct consequence of the global market.
Potentially threatened species
Volutes are gasteropod marine mollusks which have an unusual reproductive style; their larvae are non-planktotrophic. There are no long-term planktonic larval stages to ensure the dispersion of the species. This reproductive strategy means that the species’ habitats are very restricted in size, which makes them more vulnerable than the others to variations in ecological conditions or to human predation. Moreover, since these species are relatively rare, large, and have very attractive shells, they are among the families most sought-after by collectors.
New Caledonia’s economic zone includes thirteen species of the Volutidae family, of which four are found on the Chesterfield Islands and nine around Grande Terre and the Loyalty Islands (Bouchet and Poppe, 1988, 1995). All these species are potentially in demand from collectors and merchants, and some have high market values. Most benefit from natural protection since they are deep sea species:
However, others live in shallow waters or even in the intertidal zone:
The most threatened species are:
Among the numerous species of cowries present in New Caledonia, some have special shapes and colours that give them a significant value. These are in fact anomalies, the origin of which has not been clearly identified. Two phenomena seem to be correlated, rostration and nigerisation. These monstrous specimens generally have an abnormally large size, a dark color (sometimes even charcoal black), rostrated extremities and sometimes sealed lips. Juvenile specimens are always normal and these modifications appear with age. For C. caurica, it has been demonstrated that the dark layer is a thin film under which persist the tiger markings characteristic of this species (Pierson and Pierson, 1975).
It has been suggested that water temperatures influence the development of such anomalies (Rougerie, 1980). In fact, the phenomenon is only observed in the south of New Caledonia and on the Queensland coast at the latitude of the Tropic of Capricorn. These two locations are bathed in winter by waters colder than 21.5oC, and it is believed that this thermal stress on populations that are already at the edges of their habitat zones may provoke a disturbance of their metabolism with hypercalcification and melanisation. However, other hypotheses suggest a pathology that may or may not be linked to the presence of heavy metals in the water and sediments (Pierson and Pierson, 1975).
Individuals with this type of anomaly are highly sought-after by collectors who take large numbers of the animals and also destroy their habitat. Some unscrupulous "shell seekers" do not hesitate to break coral with metal rods or even to dump pesticides into the water, in the hope of forcing some niger cowries to come out of hiding.
The range of niger cowries is exclusively limited to the southern coast of Grande Terre, between St. Vincent’s Bay and the Havannah Canal. Specimens have been found along the edges of coral islets but never on the barrier reef and never deeper than 12 m.
The species affected by these transformations in New Caledonia are: Cyprea arabica, C. cylindrica, C. caurica, C. eglantina, C. mappa, etc. In Australia (Keppel Bay), species include C. arabica, C. felina, C. erosa, and other, endemic, species. The most beautiful niger cowrie is undoubtedly Cypraea mappa which is very rare (Pierson and Pierson, 1975; Cavard, n.d.; Chatenay, 1977). According to Chatenay (1977), 38 species of cowrie in New Caledonia have been observed to have undergone rostration and/or melanisation.
If these anomalies are due to a disease caused by environmental conditions and not to genetic malformations, their incidence among the population could only be observed in a reserved area. Whatever the origin of these anomalies, these niger cowries represent only a small percentage of the populations of the species concerned, and do not themselves represent threatened species. However, Pierson and Pierson (1975) pointed out that even by the 1970s, fishing pressure on these cowries, and especially the niger variety, was threatening to cause the disappearance of these abnormal specimens.
The species Nautilus macromphalus Sowerby, 1849 is endemic to New Caledonia’s waters. It is very abundant on the external reef fronts and around the Loyalty Islands where it lives at depths of between 30 and 700 m but optimally between 300 and 400 m (Intes, 1978; Ward and Martin, 1980; Granperrin and Duflo, unpublished). It appears that its habitat range extends west to the Chesterfield Atoll (Richer de Forges et al., 1988a; Rancurel, 1990a,b).
Nautilus species have a different reproductive strategy from other cephalopods: the number of eggs is very limited, a dozen eggs per season (N. macromphalus may only produce eggs once a year) during only a few reproductive years. These very large eggs (25-35 mm) are individually fixed to the substrate. In an aquarium environment, the incubation period lasts several months (8-9) and as of yet, only the Waikiki Aquarium at Honolulu has managed to hatch a viable juvenile (Joannot, 1991). This very low reproductive rate makes these species vulnerable to overfishing (Ward, 1987, 1988; Würtz, 1989). The life expectancy of these nautiluses is on the order of 20 years and their growth is slow as they only attain maturity after 4 years.
On Grande Terre, the species is captured in traps and the shells are sold in souvenir boutiques at 50 to 150 FF each. It is difficult to estimate the number of captures since these are generally incidental catches by snapper fishermen. The demand increases proportionally with tourist activities on the Territory and the impact from fishing is already considerable on this species, whose biological characteristics remain largely unknown. Between 1976 and 1989, an average of 2.6 individuals were captured per trap with a maximum recorded capture of 44 individuals in a single trap (Grandperrin and Duflo, unpublished).
There is the danger that the exploitation of this species may rise even further as it is sold on the home aquarium market. The nautilus is a resistant animal, easy to transport and particularly attractive in aquariums. For the moment, only public aquariums request it but it is likely that the private market will soon take an interest in the species. In 1995, the Nouméa Aquarium contacted the provincial authorities to request that the capture and commercialisation of this "living fossil" be regulated and monitored, but until now no decision has been made.
In the Indo-Pacific, certain holothurians commonly known as "bêches-de-mer" or "trepang" are eaten. The main consumers of these echinoderms are Asians who use the integuments, the longitudinal muscles and certain organs, either raw or cooked and dried (Conand, 1994). Among the 300-odd species identified for the Indo-Pacific region, a dozen are commercially exploited (Anonymous, 1995e).
In New Caledonia, local communities have been fishing bêche-de-mer on a small scale since the 19th century. The commercial species are, in decreasing order: Holothuria (Microthele) fuscogilva, H. (Microthele) nobilis, H. scabra, Actinopyga miliaris, A. echinites, A. mauritania, Thelenota ananas, Holothuria atra, H. fuscopunctata, Thelenota anax.
The biology and population dynamics of all these species have been studied to determine the parameters necessary for the management of this resource (Intes and Menou, 1979; Conand, 1989). Most of them are sedentary and stay on the shifting lagoon beds where they play a very important role in sediment development. They are mainly detritivores and use the upper layer of the sediment, although some species burrow into it (Bohadschia). The bioturbation from their movements and from their continual ingestion of sediments (about 50 to 100 g of sediments per individual per day), in which they digest detritus, mesofauna, microflora and microfauna, modifies the physico-chemical characteristics of the sea bottom. Overfishing this species would thus have direct consequences on the whole lagoon bed ecosystem.
Holothurians are collected either on foot or in free dives, and thus their capture requires almost no investment. The preparation of trepang requires several operations: evisceration, smoking, and drying. The main importers are Hong Kong, Singapore and Taiwan.
In New Caledonia, about 100 fishermen currently harvest this species, especially on the northeast coast of Grande Terre. Since 1984, annual production has been around 100 tons of dried holothurians and it is unclear whether the lagoons can long withstand such levels. The "maximum sustainable harvest" levels estimated for the lagoons are on the order of a few dozen kilograms per hectare. "These levels clearly demonstrate the limited, and thus fragile, nature of these resources," (Conand, 1994). However, there is no regulation of the bêche-de-mer fishery.
Deep sea fish:
The 1980 campaign of the Japanese fishing boat, the "Kaimon maru", demonstrated the existence of significant deep sea fish stocks on the summits of seamounts on the Norfolk Ridge. The exploration campaign CHALCAL 2 confirmed the abundance of certain species on the Aztèque (now named Antigonia on marine maps), Éponge (= B Mountain) and Kaimon-maru Banks. The results were spectacular and completely unusual for a tropical zone: 94 tons/day on C Mountain and 34.7 tons/day on Éponge Mountain. The species of commercial interest are Beryx splendens, Pseudopentaceros richardsoni and Hyperoglype antarctica. These species were fished from 1988 to 1991 by a Franco-Japanese outfit. A halieutic study from 1991 to 1993 improved biological knowledge of Beryx splendens and allowed for a definition of the parameters for exploitation of the stocks (Lehodey, 1994).
Deep sea fish have only recently begun to be harvested, and in the region the largely untouched stocks consist of cold water species with slow growth rates. In addition, these fish are concentrated on the summits of small seamounts where their capture perturbs the ecosystem. Trawler fishing, extremely destructive of the benthic communities (jellyfish, anthipatharia, porifera), could not be maintained without destroying the resource. Longline deep sea fishing, practiced by the fishing industry, is not directly destructive of the benthos, but the impact of taking fish from such geographically restricted communities has not been adequately studied.
With the hypothesis that the Beryx splendens captured on the Norfolk Ridge’s seamounts belong to a single stock, the untouched, harvestable biomass has been estimated at approximately 2,000 tons (Lehodey, 1994). Since the stocks began to be fished, the maximum sustainable catch has been between 395 and 468 tons / year and no significant decline in yields, which would be a sign of overfishing, has been observed. The HALIPRO 2 campaign demonstrated that this species could be found on the slopes of seamounts to a depth of 900 m (Grandperrin et al., 1997a, b).
Just like everywhere else in the Indo-Pacific, sharks are fished in New Caledonia by tuna longliners. The Navimon company harvests 150 to 200 kg of shark fins per week and its competitor, Calédonie Toho, takes 120 kg per week. Dried and treated locally, these products are exported to Hong Kong and Taiwan. The Mako shark is the only species used for its flesh. The possibility of using the shark skins and livers was considered at one time, but it seems that this is not profitable in New Caledonia where labour is very expensive; the sharks are thus most often thrown back into the sea, with their fins amputated. In addition, tiger sharks are actively sought out for their teeth, which are used for jewelry.
All the species of stony coral that compose coral reefs are listed on Appendix II of the CITES list.
In several Indo-Pacific regions, stony corals are or have been harvested, either to extract the lime, used as a construction material (lime kilns on Reunion); as decorative objects, sold to tourists as souvenirs; or as "aquarium furnishings" (Wells et al., 1994). Coral exploitation is a very destructive activity and, along with natural disturbances (cyclones, Acanthaster, bleaching), can kill a reef. It is highly unlikely that the short-term gains from such exploitation can justify the degradation of a reef with the concomitant long-term consequences for biodiversity, sedimentation equilibrium, and aesthetic quality!
The main genera affected by the sale of corals in souvenir shops are: Acropora, Fungia, Heliopora, Tubipora, Stylophora, Seriatopora, Pectinia and Pavona. The particular commercialised species vary according to the regions of the Pacific and the clientele: in the Philippines there are 30 species and in Fiji 56 species of which most are branching corals (Acropora); on the other hand, in Australia, the species Pocillopora damicornis is the most affected. Worldwide, it was estimated in 1990 that 1.5 x 106 corals per year are taken for decorative purposes and are mainly exported to the United States, Europe and Japan (Wells et al., 1994). These statistics come from the monitoring of exports, but it is difficult to quantify the direct sales to tourists that occur on most islands. The use of living corals to decorate aquariums is a new trend coming into fashion. The main genera concerned are Catalaphyllia, Euphyllia, Goniopora and Favites. The main importers are located in the United States and in Europe, and the imported quantities are rapidly increasing.
Coral exploitation is rapidly reaching the level of overfishing because the species concerned have very low growth rates, a dozen centimetres per year for branching corals, but only about one centimetre per year for massive corals (Montastrea, Platygyra). The recolonisation of an exploited area can take decades.
In New Caledonia, an attempt to regulate these collections was made in 1982 by regulating coral harvests and trade, and by assuring scientific monitoring of all authorised exploitation (Joannot, 1990). Coral harvests increased from 1980 onwards with the collection of branching corals sold in souvenir shops. From 1981-83, the Sepal Exotic Fishing company was the main commercial unit. In 1983, regulations were designed to forbid the harvest, the transportation, and the commercialisation of corals (with the exception of the genuses Fungia and Acropora, under 300 g) in the Territory of New Caledonia (decree no83-003/CG). However, this decree was not respected and the coral trade continued. From 1984 to 1990 the number of harvesting authorisations, delivered by the Department of the Merchant Marine and Maritime Fishing, did not surpass 5 per year. However, the annual production during this same period is believed to have varied between 101 and 280 tons per year. During this period, the Acropora company, based on the Uitoe peninsula, exploited mainly Faviidae (Platygyra, Leptoria, Favia, Favites).
In 1984, an experimental harvesting area was created along the inside of the Southwestern Lagoon’s barrier reef, the Tetembia Reef, and scientific monitoring was established. In 1985, in view of the first scientific results, the list of authorised genera was modified and the trade in species from the Faviidae family was forbidden, whether the coral was in its untreated form, bleached, or cleaned. In fact, it was demonstrated that this is the most-harvested family (280 tons in 1988). These massive corals, whose skeletons form maze-like designs, are processed to end up on bookshelves as decorative balls or lamps. In 1987, the regulations were supplemented by fixing a minimum size of 25 cm for the harvest of Favidae colonies and prohibiting harvests during the breeding season, from October to December. According to the decrees no84-180/CG of 9/5/84 and no87-220/CE of 12/11/87, the genera of corals that can be professionally harvested from the Tetembia Reef are: Acropora, Seriatopora, Pocillopora, Stylohora, Millepora, Montipora, Acrhelia, Hydnophora, Merulina, Pavona, Porites, Fungia, Herpolitha, Polyphyllia, Leptoria and Platygyra.
The results from monitoring the Acropora company’s activities were the following (Joannot, 1990):
Year Production Catch per Unit Effort (C.U.E.)
1985 182 t 63 kg/hr/diver
1988 280 t 99.7 kg/hr/diver
Studies of the population dynamics of the Faviidae family allowed an estimation of the stock for the Tetembia Reef (520 ha) of 2,795 tons and an exploitable biomass of 655 tons. The collections were thus very significant since they reached a (declared) level of about 10% of the biomass. Moreover, the growth of massive coral colonies is very slow, on the order of 0.5 to 1.5 cm per year in diameter and the age of the large exploitable colonies is estimated at 60 years. In light of these results, a fishing quota for Faviidae was fixed at 30 tons/year and luckily this exploitation came to a halt on its own in 1990, before the destruction of the Faviidae stock on this reef.
In certain other coral countries (Philippines, Maldives, etc.), the harvest of living coral is now totally prohibited (Wood and Wells, 1988). In New Caledonia, a new type of demand for coral has just made its appearance. This involves "living stones" to decorate aquariums. These are generally encrusted Lithothaminium, fixed on dead corals. The demand is considerable, about 25 t /year, and no legislation regulates the harvest of calcareous algae. On the other hand, dead corals are subject to the same rules as living corals in international trade.
The coconut crab, Birgus latro, is an enormous (>3 kg) anomuran crustacean of the Coenobitidae family. It spends the great majority of its life on land and uses the marine environment only for its larval phase. It is highly valued for its meat, and its capture is easy and requires no material investment, which has led to an overexploitation of the populations of this species in numerous locations (Vanuatu, Guam) within its Indo-West-Pacific habitat range (Schiller et al., 1991).
In New Caledonia, it lives only on the Loyalty Islands, on the Isle of Pines and on the south of Grande Terre in areas of uplifted reefs, and it sometimes penetrates several kilometres inland. The decline of this species is due to its overexploitation, directly linked to the population growth on these islands. On the Loyalty Islands, the crabs are baited with coconut meat and then captured by hand at night during a "fishing" season that lasts about 8 months per year. On Lifou, the annual harvest is estimated at between 39,000 and 51,000 crabs for an estimated stock of 780,000 individuals + or – 105, or 27.5 crabs / ha (El Kadiri-Jan, 1995). This author demonstrates that on the island of Lifou, the coconut crab is not overexploited, thanks undoubtedly to the uneven relief of the fishing areas and to the limited number of inhabitants. All the same, attention is drawn to the vulnerability of this species.
In New Caledonia, spiny lobsters and slipper lobsters are fished on a small scale by local people, principally by the Polynesian community on Grande Terre and by the Melanesians of the Loyalty Islands and on the Isle of Pines (Prescott, 1980). "Recreational" fishing probably has as much of an effect as "professional" fishing. Nonetheless, no study or statistics exist to describe these fishing practices. The area that is easily accessible by recreational sailboats, within a radius of 10 nautical miles around greater Nouméa, seems overexploited. The current regulations set a minimum size of 9 cm for the length of the cephalothorax, and the fishing of egg-laden spiny lobsters is prohibited at all times. Preliminary studies carried out by Chauvet and Weil (1991), Joop (1992), Grandin and Chauvet (1994), Chauvet and Farman (1994) and maritime fishing statistics (Anonymous, 1990) allow a rough estimate of spiny lobster exploitation in New Caledonia. According to these documents, in 1989 New Caledonia fished 24.7 tons of spiny lobsters and imported 1.2 tons, and for 1994 these figures are 12.4 and 3.3 tons. Pitcher (1993) cites New Caledonia’s production as 10 tons for 1987.
If we extrapolate the data on Panulirus penicillatus from Enewetak to New Caledonia, for 1,600 km of reef, 120 individuals per kilometre, and an average weight of 500 g, we obtain a stock of 96 tons. This must be taken only as a very rough estimate since no count has ever been done for New Caledonia; this potential tonnage is probably underestimated (Richer de Forges and Laboute, 1995). A better estimation would account for the four main species present on the reef front and their competition for this space.
In general, the spiny lobster fishing regulations in use in different Pacific regions include:
These measures, if respected, are sufficient to protect the stock, especially since the larvae dispersal is significant and recruitment is practically independent of local fishing pressure.
On the other hand, capture techniques are poorly regulated. Spiny lobsters are most often fished at night, in free dives (the presence of scuba diving equipment on board the ship is punishable by a fine), with a speargun, and the extrication of the animal from its shelter often results in damage to the coral. This technique, which injures the animal, is also detrimental to the quality of its flesh, as a spiny lobster that has bled loses part of its flavour. The deterioration of the reef is, in the long term, harmful to fishermen because when the habitat is degraded, ciguatera tends to appear.
3.4 Conservation and protection
About 30 sites have been designated as protected areas, of which 4 are marine areas. These include strict nature reserves, territorial parks and special reserves.
Marine protected areas represent 2.8% of the lagoon’s surface area (52,270 ha). These are:
In all these places, fishing and the collection of marine organisms, hunting, and the capture of terrestrial animals are all prohibited. The vegetation is also protected.
These zones are monitored by boat and are under the authority of the provinces.
In addition, a 1,000 m wide protected zone, stretching from the high tide level, has been created all along the coasts of Grande Terre, the Isle of Pines, the Loyalty Islands, the Belep archipelago and all the inhabited islands situated less than 19 km from Grande Terre. Within this zone, professional fishing and collection of marine organisms is prohibited while subsistence fishing and gathering is permitted.
There are also protected wetlands such as the mangroves on Leprédour Islet and Pam Island.
In the Southern Province, marine protected areas are managed by the Marine Office of the Natural Resources Department.
The equivalent does not yet exist in the other two provinces. In the Northern Province, environmental matters are within the competence of the Economic Development Department.
In the Islands Province, environmental issues are addressed by the Topography and Urban Planning Office.
The reserves that are the responsibility of the central government are managed by the DAFE (the Agriculture, Forest and Environment Department), a central government/territorial joint organisation. This organisation is also the representative of the French Environmental Ministry and, as such, is in charge of the application of international conventions that have been ratified by France and are thus in force in New Caledonia.
Finally, there is a committee for environmental protection in the Southern Province which includes IRD and the associations for the protection of nature, among others, and acts as an advisor to the Province.
See the "site management" chapter below.
4. Site management
4.1 Protection measures, management tools
New extraction techniques are being implemented for nickel exploitation. These techniques aim to limit erosion by stocking overburden and slag in stable stockpiles. The mining sites are divided into sectors that correspond to watersheds, and the water collection and settling works are sized according to the watersheds’ area. This has allowed the erosion from rain water to be considerably reduced. In addition, efforts at rehabilitating and revegetating former mining sites has allowed slope stabilisation in many instances, but these actions are not yet systematic as the required investment is considerable.
Ultimately, these measures should aim to address all harmful activities from extraction zones, including roads, stockpiles, water courses, decanting basins, and loading ports.
Environmental impact statements are required for mining operations and quarries in all three provinces.
Management of domestic pollution is within the jurisdiction of the municipalities, which may adopt regional sanitation programs (Nouméa, Hienghène, Koumac, etc.). Currently, individual sanitation (when it exists) is the norm in most municipalities. The number of treatment stations is still limited, or insufficient (in greater Nouméa, only 50% of inhabitant equivalents are treated).
Each province’s marine office is responsible for the creation, the management, and the monitoring of reserves. They are also competent to manage lagoon areas and to apply fishing regulations. They can also deliver fishing licenses and participate in the monitoring of fish stocks.
Based on studies of the population dynamics and the biology of species, management rules (quotas, size, periods and fishing zones) exist for a certain number of species: mangrove crabs, spiny lobsters, trochus, sea cucumbers, sponges, bryozoans, aquarium fish. Outside greater Nouméa and a few other municipalities, surveillance efforts are limited to terrestrial monitoring, most often carried out by the local police. All professional fishermen are submitted to strict regulations; poaching is thus performed mainly by amateurs.
In addition, customary reserves, recognized by French law, correspond to traditional fishing zones and may be assimilated into protected areas.
Other than planning, these actions involve mainly the management of protected areas (placement of anchoring buoys in popular areas, dissemination of information pamphlets, etc.).
Contemporary societies are able to gauge the importance of protecting sites, especially marine ecosystems. These areas include educational and recreational values:
The means implemented to achieve these goals have included the creation of organisations and associations, the dissemination of explanatory pamphlets (destined mainly for recreational sailors), and awareness campaigns:
These are composed of various structures, which are explained in further detail in the following chapter.
Among others, they include:
The marine fauna includes several rare or threatened species listed in the IUCN Red Book and by CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). Among these may be cited the humpback whale, the sperm whale, the great dolphin, the dugong, the coconut crab, and certain spiny lobster species.
In order for the Territory to limit the impact of human pressures on these vulnerable species with an adequate set of regulations, and to determine whether or not to request the inclusion of certain species in Appendix II of the CITES list, scientific knowledge of these species must be improved. Required data includes: habitat areas, breeding seasons, population densities, growth rates, fishing pressures, commercialisation, etc.
The means of protecting these species should be determined on a case-by-case basis. The protection of holothurian stocks could be achieved by one of the following methods:
It should be noted that periodical closed seasons cannot be envisaged because all species do not have the same breeding seasons.
However, none of these solutions is feasible for New Caledonia where the harvesting activity is performed in villages. The only realistic regulations would cover the processing of the sea cucumbers; it would be possible to require a professional license and to set export quotas.
Similarly, spiny lobster management is problematic because there is only one set of regulations for several species with different biological and ecological characteristics (George, 1972).
Thus, in New Caledonia, the "Bourail spiny lobster" (Panulirus homarus) should be totally protected because it is particularly vulnerable due to its very restricted habitat; it is found only at the "Pierced Rock". (Although this species is not formally protected, the creation of the Poé Reserve now totally protects its habitat.) In contrast, the existing legislation, size restrictions and a prohibition on capturing egg-laden females, appears to be adequate for P. ornatus, P. penicillatus, P. versicolor and P. lognipes femoristriga. There are no regulations concerning slipper lobster fishing, unless the legislators consider them to be equivalent to the spiny lobsters?
Finally, the creation of zones where fishing is totally prohibited would present numerous advantages:
The management of such reserves would be relatively simple because it would suffice to establish a monitoring program which would ensure the respect of the total prohibition on fishing. In addition, the replenished ecosystems could lend themselves to ecotourism development (Fonteneau, 1996).
It appears that the numerous halieutic studies and stock management models established for tropical fisheries have rarely (if ever?) been applied in practice, and that the stocks experiencing very high fishing pressure have been maintained simply because of the existence of naturally protected zones.
Coastal seas are divided into several zones, each with its own set of regulations: a coastal protected area, the shore, inland waters, and territorial waters. Article 7 of the Referendum Act is applicable to these coastal seas and gives the competence for management of the marine environment to the Provinces. The EEZ is under the jurisdiction of the central government.
Although it appears simple, the application of these regulations is actually quite difficult and the design of these multiple levels of responsibilities gives the impression of sloppy legislation. The fact that the Administrative Tribunal was obliged to decide in favour of the Provinces and against the Territory, for reserve management jurisdiction, is a sign of this legislation’s lack of rigour! Inextricable complications originate from the fact that overlapping responsibilities are granted to the Territory, the Provinces, and the Municipalities. This is particularly the case for disturbances to the marine environment linked to maritime traffic or to mining activities. The Referendum Act makes no reference to coastal fishing, an activity that is very disturbing to the environment. In addition, no provincial maritime boundaries have been established.
The first development contracts, aimed at economic readjustment, were signed in 1990. The portion allocated to the environment in a broad sense was, in 1993, 32% by the Provinces and 52% by the central government, for a total sum of over 10 billion CFP.
4.2 Organisations likely to become involved in site management
The central government is represented by the High Commissioner of the Republic who ensures that all local authorities remain within the law.
Among other responsibilities, he is in charge of the application of international conventions ratified by France and in force in New Caledonia (currently, there are 7 of these). He also responsible for the Exclusive Economic Zone (200 mile zone). The struggle against accidental marine pollution as well as the guarantee of civil security is also within his province.
Ever since the application of the Organic Law of 1998, the Territory is in charge of: public health and hygiene (territorial hospitals), the regulation and the organisation of veterinary services and food sanitation, road transportation, ports and airports, as well as the production and transportation of electrical energy. It is also in charge of the creation of statistics, as well as the organisation of meteorological services. It should also be emphasised that the Territory owns the majority of the unexploited forests, surface waters and ground waters.
It is important to point out that the Territory also provides significant technical support to the Provinces, notably in the domain of the industrial environment (industrial pollution, etc.), through the Mines and Energy Office (SME) which thus plays a similar role to the DRIRE of Metropolitan France in many respects.
The Provinces are most often the favoured spokespersons as far as the environment is concerned. Since the 1st of January, 2000, they have been in charge of site protection, flora and fauna, minerals and corals, the lagoon out to the reef front, roadsteads, watercourses, and saltwater ponds, as well as a protected strip along the coast. They are also in charge of the management of forest spaces (including fires), fishing and hunting, agricultural or livestock development projects, as well as land tenure laws.
In terms of the industrial environment, the provinces prepare the files on construction permits, monitor everything concerning public hygiene and health, and are in charge of town-planning laws (Urban Agencies). They are also in charge of waste management.
Finally, the Provinces are also responsible for quarries and for the mining sector, including reserved materials such as nickel, cobalt, and chrome, which formerly were under the control of the central government.
The municipalities are partially responsible for the water distribution system (drinking water and sewage systems). The Municipal Code also grants them responsibilities in terms of security, public health, and fire fighting; often, several municipalities join together to create associations which allow them to reduce their high installation and operating costs.
The Customary Council is made up of the Great Chiefs and represents New Caledonia’s Customary Areas. It is consulted on projects and propositions, deliberated on by the relevant Provinces, concerning special local laws and land tenure laws.
The Economic and Social Committee is composed of the principal economic representatives of the territory. It is consulted for economic, social and cultural projects.
The Consultative Mining Committee includes representatives of the central government as well as of professional organisations and trade unions. It is consulted on issues relating to mining and metalworking legislation.
Along with these institutional bodies, other organisations, public or quasi-public, which specialise in research and development or awareness and information, may be sollicited for logistical, technical or financial support. These include IRD (Research for Development Institute), IAC (Caledonian Agronomic Institute, formerly CIRAD), IFREMER (French Institute for the Exploitation of the Sea), the Pasteur Institute, the University of New Caledonia, Météo-France and CNRS (National Centre of Scientific Research), as well as ADEME (Environment and Energy Management Agency) and soon WWF (World Wildlife Fund), among others. CIE (Centre for an Introduction to the Environment), under provincial jurisdiction, has played a role in increasing environmental awareness since 1996, like CPIE in Metropolitan France.
Each of these groups carries out scientific activities related to biodiversity: scientific knowledge, awareness, resource use, conservation, or restoration. It must also be mentioned that the Nouméa Aquarium, while not a research institution, welcomes numerous researchers and plays an important role in the dissemination of information about the marine environment.
IRD is by far the most important research institution in terms of its size, the diversity of disciplines and its seniority (active since 1946). Marine biodiversity research takes place within oceanographic and pharmacological programs. This almost always involves the acquisition of knowledge about species or ecosystems; conservation is not part of their stated goals. Nonetheless, researchers sometimes participate in impact studies for the marine environment (Chevillon et al., 1993) or contribute to the study of a reserve (Letourneur et al., 1997). Numerous studies have been dedicated to the evaluation of marine resources in the effort to improve and to regulate the exploitation of marine species: trochus (Bour, 1989), sea cucumbers (Conand, 1989), mangrove crabs (Delathiere, 1990), small pelagic fishes (Conand, 1988), coral fishes (Kulbicki et al., 1987), deep-sea fishes (Grandperrin, 1975). This organisation has great human and technical potential for a small island Territory, but its marine programs rarely concern New Caledonia or even the Southwest Pacific. Joining forces with regional organisations such as the Secretariat of the Pacific Community (fisheries program) and especially SPREP would allow this extraordinary knowledge base, accumulated over the past 50 years, to be put to work. It is essentially thanks to IRD, which often collaborates with the MNHN (National Natural History Museum), that the region’s marine fauna is practically the best known in the Southwest Pacific.
IFREMER is in charge of developing methods of exploiting aquatic resources (penaeid shrimp, oysters). Its experimental St. Vincent Station, in place since 1963, perfects shrimp farming techniques, produces post-larvae for the farmers and provides them with technical assistance. For the last few years, IFREMER, along with IRD, has been concerned about the aquatic stations’ environment and in particular the dumping of wastes laden with organic matter.
UNC (the University of New Caledonia, formerly UFP), was established in Nouméa in 1987 and since 1991 possesses a laboratory for its biology courses, LERVEM (Laboratory for the Study of Living Resources and the Marine Environment). The main studies conducted in this laboratory (most often by students) concern: spiny lobster and coconut crab stocks, the impacts of recreational fishing, marine reserves, the impact of coastal development, trochus aquaculture and Pectinidae.
CNRS’s activities in New Caledonia hardly concern the marine environment at all. However, it has often collaborated with IRD’s pharmacological department as part of SNOM (Natural Substances from Marine Organisms) and SMIB (Marine Substances of Biological Interest) programs.
The Pasteur Institute specialises in medicine but collaborates with IRD and CNRS in studying the antibacterial or antiviral activities of substances extracted from marine organisms.
Although it focuses on agronomy, CIRAD is nonetheless also involved in projects concerning the environment and terrestrial "wild fauna". Thus, it collaborates with IRD on the mine site revegetation program.
The Nouméa Aquarium, created in 1956 by Dr René Catala, introduces the public to the lagoon’s flora and fauna. It functions as an open system, with water pumped from Citrons Bay, which provides it with water full of plankton and the larvae of benthic organisms which then grow to maturity in the Aquarium. It is in this aquarium that coral fluorescence was discovered (Catala, 1958, 1959, 1960). For the last few years it has also possessed remarkable specimens of deep sea fauna (Nautilus, Bathynomus). It receives approximately 65,000 visitors per year and offers them a panorama of marine biodiversity.
This Aquarium has always been closely associated with IRD and it frequently welcomes researchers or allows doctoral students to conduct experiments. Because it offers the possibility of the collection of marine species or the maintenance of specimens in flowing seawater, it is used by many visiting researchers, French or foreign, for physiological or behavioural studies.
One of the Aquarium’s primary roles is pedagogical. Field trips to the Aquarium are a regular part of school curricula, and the students benefit from guided visits by specialists. Thus, it makes a great contribution to a better awareness of marine biodiversity and environmental problems.
Plans to create a new Aquarium on the same site are currently in the works and this building should soon see the light of day, thanks to funding from the European Development Fund. A visitors’ laboratory will allow this organisation to continue to act as a Marine Biology Laboratory.
The researchers from these various organisations participate in official meetings about the environment, thus allowing decision makers to benefit from their expertise. Nonetheless, they have only a consultative role and the studies that they propose, in order to give a scientific response to public policy issues, are often considered to be too long and too complex. One of their major difficulties lies in getting policy makers to understand that environmental problems are complex and that Science has no immediate response to offer. In addition, scientists are often suspected of trying to halt development through excessive caution. Dialogue between the two parties is difficult, irrational, or even non-existent.
SPREP, received in 1978 at the SPC headquarters in Nouméa, has been based in Apia, Samoa, since 1992. It is a regional organisation, created by the governments of 22 states and territories (Federated States of Micronesia, Fiji, Guam, Cook Islands, Northern Mariannas, Solomon Islands, Kiribati, Nauru, Niue, New Caledonia, Palau, Papua New Guinea, French Polynesia, Marshall Islands, Pitcairn, Samoa, American Samoa, Tokelau, Tonga, Tuvalu, Vanuatu, Wallis and Futuna). Australia, the United States, France, and New Zealand are associated members.
This organisation was created to help these states and territories of the South Pacific to protect and improve their environment for present and future generations. Its actions concern: biodiversity conservation and coastal zone management. It receives financial aid from UNDP (United Nations Development Program) and from various other international sources. In 1992 its budget was $US 5.2 x 106 and it was 5.9 x 106 in 1994.
This organisation is interested in problems experienced by Oceanians due to climatic variations, the rise in sea level, and the prevention and monitoring of pollution. It thus attempts to help develop national strategies for environmental management and especially to inform and educate citizens, with the ultimate goal of sustainable development. Environmental programs are defined by NEMS (National Environmental Management Strategies) in each state. These programs have, to date, been created for the following states: Cook Islands, Federated States of Micronesia, Marshall Islands, Solomon Islands, Tonga. The implementation of these national strategies presupposes the realisation of systematic environmental impact studies for any development project.
Recently, SPREP has addressed the theme of biodiversity preservation, considering small island ecosystems’ great species diversity and their vulnerability. SPREP has decided to support biodiversity data collection projects, conservation zone creation, threatened species and ecosystem protection, and the recognition of traditional knowledge and techniques that guarantee sustainable resource use.
SPREP has the secretaryship of two regional conventions:
SPREP is also involved in the application of other international conventions: the Convention on the Prevention of Marine Pollution By Dumping of Wastes and Other Materials, commonly known as the London Dumping Convention (1972); the Framework Convention on Climate Change (Rio, 1992); the Convention on Biological Diversity (Rio, 1992); the Washington Convention on International Trade in Endangered Species (1975); and the Ramsar Convention on Wetlands (1975).
During the United Nations Conference on Environment and Development (UNCED) at Rio de Janeiro, SPREP approved the global action strategy for sustainable development, "Agenda 21".
In 1993, SPREP launched the regional Population and Environment project which intends to address demographic problems which are particularly worrisome on certain small islands.
One of SPREP’s current programs is called the South Pacific Biodiversity and Conservation Program. It has defined conservation areas in the following countries: Fiji, Federated States of Micronesia, Kiribati, Niue, Palau, Solomon Islands, Tonga, Tuvalu, Vanuatu, Samoa. It has also carried out actions to protect turtles, sea birds and marine mammals as part of another natural resource conservation program.
While these actions are praiseworthy, SPREP is a complex, politicised organisation, bogged down in its "action plans" and "legal statutes" and for the time being it is inefficient and curiously absent from scientific gatherings that discuss biodiversity in the Indo-Pacific (DIWPA; BIONET; the conference entitled Marine and Coastal Biodiversity in the Tropical Island Pacific Region, organised in 1994 in Honolulu; the conference of the Pacific Science Association in Beijing in 1995, the 8th Pacific Science Congress in Suva in 1997, etc.).
One of the oldest nature protection associations is the Association for the Preservation of New Caledonian Nature (ASNNC) which has existed since 1971. In 1994 it had 400 members including many schoolteachers. It plays an important role in providing information and education, and produces the "Journal Vert", distributed free of charge with 3,000 copies. Its goal is to make New Caledonia’s natural heritage known and to draw attention to environmental disturbances (fires, mines, pollution, etc.). ASNNC has carried out "research" operations on a few emblematic species such as the Cagou and marine turtles as well as reforestation and litter collection campaigns. Unfortunately, the reforestation was done with introduced species, shocking for an association which claims to protect nature! Most often, this association uses volunteer labour but for certain operations such as turtle marking, it has obtained the support of SPREP and the Provinces.
Action Biosphère was created in 1992 with the goal of the protection of nature for sustainable development. It is very active in the field and hopes to obtain the creation of an "environmental watchdog". Its actions against the extraction of lagoon sands played a role in forcing this activity to be abandoned.
These two associations, ASNNC and Action Biosphère, each have the flaw of having a clear political orientation, which, in such a small island nation, sometimes leads to exaggerated attitudes that are detrimental to effective conservation action.
The Caledonian Ornithological Society, created in 1965, aims to study and protect avifauna and, more generally, terrestrial vertebrates. It especially contributes to the inventorying and monitoring of the populations of the lagoon’s nesting birds. It currently has about 30 members.
Corail Vivant was created in 2000 with the goal of the protection of the coral reef and its inclusion on UNESCO’s World Heritage List….
- d'obtenir l'insciption des massifs coralliens de Nouvelle-Calédonie sur la liste des patrimoines mondiaux de l'humanité (UNESCO). L'association pense qu'il y a lieu de protéger cet éco-système et les éco-systèmes associés dans les eaux de Nouvelle-Calédonie parcequ'ils ne sont pas encore trop affectés.
-d'améliorer la qualité de la vie des habitants de la Nouvelle-Calédonie. L'association veut, à travers ces actions, animer des réflexions au sein de la population locale sur son environnement marin et dégager des projets de nature éducative, socio-culturelle et socio-économique afin que, progressivement, une prise de conscience globale s'agglomère autour de la notion de développement durable.
-favoriser l’émergence d’une réelle loi de l’environnement.
5.1 Natural factors
With the destructive power of their enormous swells, the exceptionally high tides that they cause, and the very heavy rains that are associated with them, cyclones disturb coral reefs (Le Borgne, 1986).
Cyclones are isolated events, apparently unpredictable, and follow erratic trajectories. They nonetheless obey certain "laws" and do not occur everywhere. In the Southwest Pacific, almost all of them form along the coast of Papua New Guinea, near the "warm pool" (a large area of warm water) where surface temperatures are permanently above 27oC; the presence of large islands or continental land masses deflects tropical depressions. If we place on a single map the trajectories of all the cyclones since 1908 in the area around Australia, we obtain two tangles of tracks along the coasts, demonstrating that the coral regions of the South Pacific often suffer from these disturbances (Done, 1993). In the central Pacific region, cyclones are rarer but even more devastating.
However, the occurrence of cyclone disturbances is necessary for the development of certain reef structures, such as islets and sand keys, since the destructive action of the high swells causes an accumulation of debris (detritus) which raises the coasts and shields them from ordinary wave erosion (Scoffin, 1993). In addition, these detritus levees form cave-like structures that provide habitat for a great diversity of fauna (porifera, bryozoans, ascidians, crustaceans, mollusks, etc.).
Coral bleaching is a phenomenon that corresponds to a rejection of symbiotic zooxanthelle by coral colonies. It is generally observed following a stressful event and involves several genera (Acropora, Pocillopora, Montipora, Porites, etc.). Colonies without zooxanthelle are white and are slowly dying. This situation has been observed in many places (Polynesia, New Caledonia, the Caribbean, the Red Sea) and several interpretations of the causes of this bleaching have been proposed. Some believe it to be a pathological reaction to thermal stress (Rougerie et al., 1992; Jokiel and Coles, 1990) and others believe it to be simply an attempt at adaptation to poor environmental conditions (Buddemeier and Fautin, 1993). Mass bleachings have recently been observed. The first observation occurred in 1931, and in 1979 there were only about 20 observations of bleached corals. It would thus seem logical to link this currently significant, world-wide phenomenon to human impact and especially to global changes such as the rise in atmospheric CO2 levels. The host/symbiont relationship is disturbed, preventing photosynthesis and CaCO3 fixation.
In addition, stony corals are not the only species affected by bleaching and symbiotic zooxanthelle rejection has also been observed for Zoantharia (Palythoa caribaeorum), actinians and large species of foraminifers (Lesser et al., 1990). Thus, all the various components of coral ecosystems are under stress.
The most significant coral bleaching events in New Caledonia were observed in 1996, following unusually high seawater temperatures, and affected corals and certain Alcyonaria. Around Nouméa, coral mortality rates of 80 to 90% have been noted on certain shallow reef flats. This phenomenon also affected the exterior reef front, down to 60 m in depth. Since 1997-98, no similar phenomenon has been observed.
On the global scale, numerous hypotheses have been put forward, and many refer to changes in physico-chemical parameters due to "Global Warming". The consequences of the extinction of the coral reefs, for marine biodiversity and even for the existence of certain Indo-Pacific states, are incalculable.
The echinoderm Acanthaster planci is a stony coral predator, and feeds on polyps of various genera (Porites, Diploastrea, etc.). This starfish has been observed throughout the Indo-Pacific, from the Red Sea to the Eastern Pacific. Periods of proliferation have caused significant destruction of corals on the GBR during the 1960s and the 1980s. Kenchington (1987) provides a synthesis of the knowledge about Acanthaster populations on Australia’s Great Barrier Reef. The experts do not agree as to the origins of the phases of proliferation, and it is not known whether these phenomena are a normal part of the life of coral ecosystems. A great number of scientific studies have tried to understand these Acanthaster population explosions and to find ways of limiting its impact on the reefs. The abundance of Acanthaster larvae has been correlated to high precipitation levels which enrich the waters with nutrients. It would therefore appear that this phenomenon is not directly linked to human activity. However, humans have contributed to this natural process by overharvesting one of Acanthaster’s predators, the mollusk Charonia tritonis, and especially by disturbing the vegetation cover that regulated the water cycle. The effects of changes to the coastal terrestrial environment have probably been underestimated. Not only does deforestation increase erosion and cause flooding, but agricultural development introduces an excess of nutritive salts into the area. These salts end up in the lagoons where they lead to a proliferation of larvae (Birkeland, 1982; Brodie, 1990). The theory that Acanthaster proliferation is due to human influence is currently questioned by geologists who have found accumulations of Acanthaster spines in sediments dated at 200-300 years before the present (Sapp, 1996).
Reefs require 5 to 10 years to recover from an episode of heavy Acanthaster predation. However, massive coral species are even slower to regenerate and the impact of Acanthaster long leaves its mark on the community’s composition (Veron, 1993).
Certain Caledonian reefs were affected by this starfish in 1980, but it would appear that the effects were limited. Occasional cases of degradation were observed, but no scientific evaluation has been made of them. A new instance was observed in 1998.
Numerous other organisms contribute to the bio-erosion of reefs. These include micro-organisms (bacteria, cyanobacteria, fungi, and micro-algae), sponges, polychaetes, bivalves, cirripeds, sipunculids, bryozoans, mollusks, crustaceans and the group of parrotfish (Scaridae). Thus, certain mollusks of the Drupella genus damage reefs in southern Japan and in Micronesia. In some areas, it would appear that these damages are on the same order as those caused by Acanthaster (Moyer et al., 1982; Carpenter, 1997). There are as of yet no scientific data on this subject for New Caledonia.
5.2 Human impacts
As a large, sparsely populated island governed by a wealthy country, New Caledonia should be able to avoid the global biodiversity crisis. The territory’s population distribution is very uneven with 60% of New Caledonia’s population concentrated on about 1% of its area (Gabrie, 1995). However, one must not conclude that environmental problems occur only in this urban area. Large-scale mining development has led to extensive destruction of the vegetation cover with profound consequences for the terrestrial and marine ecosystems. The terrestrial biodiversity is highly threatened and numerous species have already disappeared; species have been and are still being introduced, contrary to common sense (crayfish, oysters, mussels, etc.); fires, very frequent in the dry season, accelerate the decrease in terrestrial biodiversity, and cause soil erosion and the sedimentation of coastal zones.
It must be hoped that the 1995 report on the state of the environment (Gabrie), the growth in international environmental awareness, and the recent examples of pollution (oil tanker spills) will awaken the public authorities, who tend to promote an idyllic image of New Caledonia’s environment, and will direct them on the path to sustainable development.
The most serious threats to terrestrial biodiversity are excessive deforestation and the introduction of exotic species (Gargominy et al., 1997).
The marine environment also suffers from the effects of human disturbances to the terrestrial environment. Fringing reefs and lagoons experience higher levels of run-off, leading to a increase in coral mortality due to an excess of fresh water and particulate matter.
The impact of mining on the lagoons: In New Caledonia, open-cast nickel mining generates an enormous quantity of lateritic overburden which ends up in watercourses and fills rivers with solid matter that is partially deposited in the lagoons (Bird et al., 1984). In areas affected by mining activity, the fringing reefs have been destroyed by the suffocation of stony corals. The fine particulate matter that is transported to the barrier reef makes the water turbid and thus disturbs productivity. Although mining companies have made efforts to stabilise their overburden, the momentum of this mining activity means that enormous quantities of material will to continue to appear in the lagoons for many years to come. During 120 years of exploitation, over 110 million tons of ore have been extracted, which implies that the quantities of slag must be at least 5 times as great and, as a result, the volume of unstable material is estimated at 300 x 106 m3.
There has been a lack of research on chemical pollution from heavy metals contained in these wastes, but it is known that certain filtering organisms such as ascidians concentrate metals, especially iron, chrome, cobalt and nickel (Monniot et al., 1994).
The effects of mining exploitation on the environments of high islands are described by Dupon (1986). The impacts of open-cast mining, such as that found in New Caledonia, are complex:
Stabilisation measures for slag rubble have only recently come on the scene and involve only the largest company (SLN). The numerous "small miners" are not subjected to any constraints concerning environmental protection. Mining operators’ current awareness of environmental concerns has provided opportunities to study possibilities for the revegetation of former mines in order to reduce the impact (Jaffre et al., 1993).
Bird et al. (1984) count 40 New Caledonian watercourses that have been modified by the deposits from extraction, about 2/3 of the total.
Some watersheds, such as the Ouenghi (245 km2), have been totally disturbed by mining activities and have formed a "manmade delta" because of a sediment deposit in the lagoon estimated at 106 m3. These deltas progress towards the lagoon’s interior, at a rate of 300-400 m in 28 years in the case of the Ouenghi, where the delta is 3 km long. In these zones, the fringing reefs have been killed and have even completely disappeared underneath several meters of sediments.
Chevillon (1997) demonstrated that in the case of the large rivers of the east coast, mud plugs the rivers, slowing the deposit of fine particulate matter in the lagoon.
Mining exploitation thus has an impact that goes far beyond the extraction sites and disturbs both terrestrial and marine ecosystems in the long term (several decades). It is thus impossible to dissociate processes of erosion and disturbances to terrestrial ecosystems from their effects on the marine environment. Beyond the unsightly appearance of mining degradation, the most serious impacts have been a reduction in biodiversity. In the terrestrial environment, the flora and fauna have been totally destroyed over large areas so that certain species with limited geographical distributions have undoubtedly disappeared. In the marine environment, estuaries have been disturbed in long-lasting ways.
A very large-scale mining project is in the process of being implemented in the south of Grande Terre. In October 1997, the construction of the pilot refinery began and the commercial refinery is planned to be built in the next five years. The Canadian company, INCO, plans to extract about 30,000 tons of nickel per year for 20 years, from lateritic deposits. The average mineral content of the ore is 1.60% of nickel and 0.16% of cobalt. The extractive process, known as percolation or leaching, consists of dissolving the metallic salts with sulfuric acid. This acidic mud is then neutralised before being replaced in the excavations. When the refinery is fully active, after the experimental stage, this neutralisation will require about 500,000 tons of calcium carbonate per year, which the company hopes to extract from the uplifted coral atolls of the Loyalty Islands. Although this company claims to take good care of the environment, the disturbances will be numerous and permanent. First, the vegetation, which is to a large degree composed of endemic species, will be destroyed not only at the extraction sites but also at the waste deposit sites and the refinery construction site, not to mention the damage to be caused by roads and the port that will be built at Prony Bay. The leaching of stripped lateritic soils will increase erosion and lagoon sedimentation, threatening to destroy the coastal coral formations that border the Koué estuary (see Rapport de l’Étude d’impact, Anonymous, 1995b).
This example is fairly characteristic of the serious terrestrial and marine environmental disturbances linked to the destruction of the vegetation cover in several Pacific islands (Papua New Guinea, Fiji, Solomon Islands, and Vanuatu). It is a very common problem which demonstrates that the degradation of the coastal marine environment is inseparable from terrestrial activities. It is clear that the heritage value of landscapes and ecosystems has not be taken into account in the evaluation of mining projects.
New Caledonia has carried out mining activities since 1877 and is the world’s 5th largest nickel producer. The main mines currently exploited are found along the island’s east coast and the raw ore is transported by boat to the Nouméa refinery.
On the 26th of October, 1992, the ore carrier "Manylad U" ran aground in the shallows of the Havannah Channel. A breach in the hull allowed ore to escape. This coral zone has strong currents capable of carrying pollutants to the nearby Merlet Reserve.
A complaint against persons unknown was lodged at the Nouméa Tribunal for "marine pollution following the immersion of materials or substances from a ship". The investigation requested by the Tribunal led to an impact study conducted by ORSTOM’s sedimentologist (Chevillon, 1992).
47% of the spilled ore was composed of fine particles (<63 microns), very prone to being diluted and rapidly transported by currents. Maps were made of the distribution of the large particles deposited on the sea bottom, such as sand, gravel, and blocks of ore. The volume of such particles spilled into the surroundings was estimated at 1,750m3 or approximately 2,450 tons.
It would appear that the ecological impacts were limited to the immediate area around the stranded boat, where the fauna was buried over an area of 4,500m2. No trace of the 1,880 tons of fine particulate matter was observed in the surrounding area.
The impact of this maritime accident was thus very limited but it draws attention to the risks of transportation by large carriers in a poorly mapped coral zone and via channels with strong currents. In this instance, there was only particulate pollution but an accident involving a leak of chemical substances (petroleum, acids, etc.) would have catastrophic consequences.
The development of the coastal zone around Nouméa’s urban area and the construction of certain coastal roads to the sea, by confinement of watercourses and the construction of enbankments, has led to the destruction of very large portions of mangroves and fringing reefs all around the urban area.
New Caledonia’s coasts have about 200 km2 of mangroves (Thollot, 1996a). Using SPOT satellite images, the southwest region was mapped; that area’s mangroves cover 80.3 km2.
According to French law, the mangrove is part of the public domain (Le Noel, pers. comm.).
Around the Nouméa peninsula, mangroves were destroyed in numerous places, the coast was banked up with slag from the Doniambo refinery, and roads or housing developments were constructed on these lands reclaimed from the sea. This process currently continues to the south near Tina and Mont Dore (Allenbach and Thollot, 1997). The only mangrove area that still exists within Nouméa’s urban perimeter is that of Ouémo which is being eaten away by housing developments, and road-building plans threaten to destroy it entirely.
In 1997, a complaint against persons unknown was lodged for "willful destruction of the mangrove" of the Tina golf course. This golf course was constructed in large part on the central government’s private lands and on the public maritime area (territorial waters and interior waters and sea channels). Approximately 32 ha of this area were mangroves. After the golf course’s construction, only 12 ha of mangrove remained. Finally, in August 1997, an evaluation carried out at the request of the Department of Agriculture and Forestry determined that 3 to 4 ha of the residual mangrove was totally dead for two reasons: the closing off of sea water circulation by a sand bank, and the use of herbicides on the bank bordering the golf course. In this case, not only was the mangrove ecosystem destroyed but the aesthetic result is a complete failure since this very beautiful site now has a dead forest right in the middle of the "green".
Overall, it is estimated that between 1955 and 1993, 380 ha of mangroves and other biological systems have been filled in or dug up.
In New Caledonia, a marine aquaculture industry was developed in the 70s and rapidly became specialised in the production of penaeid shrimp (Anonymous, 1972). After several trials with Penaeus monodon, P. japonicus, P. indicus, P. merguiensis, P. semisulcatus et Metapenaeopsis ensis, the Mexican species P. stylirostris was chosen for its performance and especially the rapidity of its growth, even in the cool season. The wild species of New Caledonia’s lagoons have never been the object of an exhaustive inventory, but according to the LAGON program’s collections, it would seem that there are at least: P. semisulcatus, P. longistylus, P. latisulcatus, P. monodon, P. canaliculatus et P. merguiensis (Crosnier, pers. comm.)
In 1994, shrimp production reached 700 tons for 280 ha of aquatic basins. In 2000, 10 operations, with a total of 440 ha of basins, produced 1,800 tons of shrimp (Shrimp News International, 2000). The most appropriate sites for the installation of aquatic basins behind the mangroves were evaluated by satellite teledetection and were estimated at around 6,000 ha (Lemonnier et al., 1997). In December 2000, a study by the Aquaculture Development group (jointly financed by the Northern Province and the Southern Province) allowed an evaluation of the sites favourable for the installation of aquaculture basins, estimated at approximately 1,500 ha (pers. comm.).
The type of aquaculture practiced is semi-intensive and requires food supplements. In fact, natural production in the basins (phytoplankton, zooplankton, herbivores, etc.) does not nearly satisfy the shrimps’ feeding requirements.
The farming basins’ water is renewed at a rate of 15 to 30% of the volume per day. The effluents are rejected into the natural environment, directly into coastal waters, thus adding a large amount of organic matter to the ecosystem. For a small farm with an area of 35 ha and a density of about 35 shrimp per m2, the daily volume of waste is about 70,000 m3.
It goes without saying that these wastes represent a disturbance of the natural environment, similar to physico-chemical pollution. For the time being, New Caledonia’s farms are small in scale and the only remarkable effects have been a hypersedimentation of fine particulate matter and the silting up of specific waste disposal zones. In contrast, in Indonesia, where over 16,000 ha of aquatic basins function on former mangrove zones, eutrophication has been observed (Guelorget et al., 1996). Such disturbed ecosystems are extremely simple, reduced to a procaryotic fauna, all the benthic macrofauna having disappeared.
Changes in the coastal zone in areas where aquaculture is practiced should thus be monitored and a coastal management plan should be defined so as not to reach critical levels of effluent concentration in certain zones. Good water quality is essential for coastal zones because this water is pumped into the basins. In addition, these farms are often installed in calm, shallow bays, behind mangroves, where water renewal is relatively slow; this runs the risk of worsening the process of hyper-enrichment of the environment.
Since 1993, an accord between the Northern Province, the Southern Province and IFREMER on the theme of "aquaculture and the environment" led to a program to study the impact of aquaculture wastes on the environment. IRD participated in this research at the case study site located in the Chambeyron Bay at Ouano, which has been monitored since the beginning of the operation in April 1995 (Garrigue and Bour, 1997).
Most of the islands of the Pacific have construction material supply constraints, especially concerning sand. Their terrestrial fossil sand deposits are exhausted and the crushing of river stones involves a high cost which has consequences for the entire construction industry. Thus, it is tempting to search for replacement materials by dredging sand and gravel from lagoon beds. Sand extraction is practiced either by scraping the bottom or by vacuum extraction. Besides totally destroying the flora and fauna of the extraction zone, these techniques greatly disturb the lagoons by stirring up fine particles and destabilising the sedimentation equilibrium. The fine particles, carried along by currents, cloud the water, reducing plankton production levels and settling on sessile organisms (corals, gorgonians, etc.), causing them to suffocate to death.
In New Caledonia, a proposal to mine lagoon sands, with an annual extraction of 106 m3, in the area around Ténia Islet (Southwest Lagoon), was submitted to the Maritime Affairs Office in 1993. A brief impact study, conducted by IRD, demonstrated that such an operation would have risks for the coral environment and the project was abandoned (Chevillon et al., 1993). The main potential effects revealed by this study were:
A review of the literature, carried out during the course of this study, demonstrates that all lagoon sand extractions in coral environments have produced the same effects with occasional genuine ecological catastrophes which go far beyond the zone and the period of extraction. The extraction of mineral aggregates for the construction of buildings or roads has led to severe degradation of reefs, seagrass beds and mangroves, from excessive sedimentation (Salvat, 1987; Rogers, 1990). The high levels of particulate matter in suspension alter the functioning of the ecosystem, with effects on organisms’ metabolism, growth and recruitment. The natural rate of sedimentation tolerated by the reefs is on the order of 1 to 10 mg/cm2/day or 10 mg/l (Rogers, 1990).
In the Johnston Atoll, coral sand extractions have caused the death of approximately 440 ha of reef and the stirring up of particles has caused the disturbance of a total area of 2,640 ha (Brock et al., 1966). The consequences of this activity can sometimes even lead to the decline of certain fisheries (Rogers, 1985). Its influence on the species diversity of fishes has been demonstrated for the Caribbean (Galzin, 1981).
In the Maldives, where reefs exploited 20 years ago are only just beginning to be recolonised (Brown and Dunne, 1988), attempts are being made to rehabilitate the sites by transplanting corals (Clarck and Edwards, 1995).
Most authors insist upon the necessity of carrying out an impact study before any work in coral areas. Extractions of living or dead corals or of mineral aggregates inevitably disturb the ecosystems so that plans for sustainable development activities must include the costs of these disturbances in their profit estimations.
The coastal zone of the Nouméa peninsula is under the regulatory control of the Nouméa municipality. Thus, the Mayor alone makes decisions concerning coastal development, and he does not always demonstrate concern for the environment. For example, decisions have been made, with no prior impact study, to dig up the fringing reef of the "White Coast", east of the Nouméa peninsula, to create a small port for jet-skis; or to fill in another zone to establish a sailing club. There is even talk of filling in an area of fringing reef at Anse Vata so as to play beach volleyball there! This strategy of placing environmental quality after recreational activities is not very responsible.
Most of the pollution generated by humans is directly linked to population density. It involves either urban wastes or industrial wastes such as chemical products (hydrocarbons) or hot water, or effluents full of agricultural products (pesticides).
Around urban areas, organic wastes cause local eutrophication of lagoon waters and heavily disturb benthic populations. Fishing and sailing activities cause the destruction of coral formations and result in overexploitation of certain species of fish and shellfish. To a lesser degree, the concentration of recreational sailboats, which dump their sewage in the bays, represent a localised source of pollution.
Maritime regulations require high tonnage cargo ships, such as oil tankers, to enter the lagoon by the Boulari Pass in order to limit their risks of running aground. However, small oil tankers (under 8,000 tons), which supply Nouméa and Vanuatu, navigate through the Southwestern Lagoon by taking Woodin Canal and Havannah Pass. On the 23rd of January, 1997, one of these small oil tankers, the "Konému", which was transporting diesel fuel, ran aground on the Morouéti Reef following a navigation error. About a hundred tons of diesel fuel spread throughout the lagoon and the oil slick, pushed by a southeasterly trade wind, reached the islets of Charron and Bailly, and then the coast of Mont Dore. Although techniques (sealing of the breach, floating barricade, absorbent polystyrene foam) were rapidly deployed (Polmar Plan), they proved to be insufficient and three days after the accident the rest of the fuel, non-evaporated and non-absorbed, reached the Boulari mangrove.
On the 28th of January, an observer mission, organised by the Southern Province Fisheries Office, visited Bailly Islet, classified as a "Special Reserve", to evaluate the impact of this pollution on the beaches. The southern coast of this islet had traces of oil, and large numbers of certain intertidal burrowing organisms such as sipunculids had perished. In some places, such as mangrove zones where wave action is less strong, all the benthic macrofauna had been destroyed along several hundred meters of coast: crustaceans Uca, Ocypode, Sesarma, Emerita; holothurians Halodeima, Stichopus; mollusks Littorina, Natica, bivalves and chitons), sipunculids and polychaetes. No study has been envisaged in order to estimate the total area of impact nor to monitor the fate of these populations.
Such oil tanker pollution affects only a small geographical area. However, it draws attention to the potential risk from chemical pollution which will increase with population growth, and to the insufficiency of the available means for fighting it.
In New Caledonia, two thirds of the population (about 120,000 inhabitants) are concentrated around the Nouméa peninsula (60% of the Territory’s population is located on about 1% of its area). Therefore, this is practically the only area within the Territory where large-scale disturbances linked to the urban impact on the coastal environment can be observed. These involve either the dumping of waste linked to human activities, urban or industrial effluents, or modifications to the coastline due to the construction of hotels, roads, or ports.
Since 1986, Nouméa has conducted studies for the creation of a regional sanitation program. A contract between the central government and the city for the carrying out of these public works included a budget of 10 billion French francs over a period of 20 years. The sanitation networks are managed by the Caledonian Waters Company (SCE). The topography of the Nouméa peninsula is particularly hilly, which complicates the treatment system’s design and construction. For the municipal area of 4,851 ha, between 70 and 85 watersheds have been counted (Roux, unpublished). This peninsula’s perimeter is indented with many bays, and its total coastline of about 147 km requires the construction of several sewage treatment stations. Although over the last few years great efforts have been devoted to improving the sewer networks which flow into the lagoon, by 1995 only 20% of residences were linked up, which means that 80% of domestic wastes are dumped more or less directly into coastal waters.
This pollution is characterized by organic and mineral materials, dissolved and in solution, mineral salts (ammonium, nitrate, phosphate) and bacteria. About 60% of the drainage system is a single pipe system ("everything goes into the sewer", which in this case means everything goes into the ocean) and for the entire system there are 312 outlets of which 205 open directly into coastal waters (SCE data).
A few studies of the water quality of the swimming areas of Nouméa’s beaches, carried out by the city’s Municipal Hygiene Office (which monitors 23 swimming spots per week), demonstrate that these beaches are often polluted and have high levels of coliform and streptococcus. Between February and June 1994, Anse Vata’s beach had coliform levels of above 20,000/ml (Gabrie, 1995).
Certain zones such as St. Mary’s Bay are very polluted and display characteristic signs of eutrophication: green algae growth (Ulva, Enteromorpha) and a nauseating odor, as well as the silting up of coastal waters. This bay has especially suffered from a poor management plan: filling in of the seabed, thus preventing normal water circulation and destroying coastal ecosystems (mangroves); road construction, construction of new housing developments since 1985 with no sewage system or treatment station. The watersheds connected to this bay are: Magenta (1,214 ha), Vallée des Colons (914 ha), Faubourg Blanchot (651 ha) and Ouémo (332 ha) and they flow into the bay through 49 outlets.
Nouméa’s domestic sewage treatment problems are practically impossible to resolve through collective sewage treatment due to the relief and the very rapid growth of the urban area. A few sewage treatment plants have already been rendered inadequate by population growth, and function poorly (Koutio, Magenta, Yahoué). Nonetheless, certain critical situations could be improved. For instance, purification of the canal that flows into St. Mary’s Bay would undoubtedly get rid of the intense manifestations of eutrophication (green tides). The ideal situation would be to restore the mangrove on the bay’s muddy seabed.
Urban pollution is chronic, due to the daily dumping of sewage, which is a function of the residential population. The degradation of coastal ecosystems is thus slow and gradual. Accidental pollution sometimes occurs, linked to fluctuations in rainfall. The sudden arrival of heavy rains after a dry spell can cause a massive increase in pollution levels and the asphyxiation of coastal ecosystems.
The country’s only large-scale industry is that of nickel. The refinery, located at Doniambo, on the peninsula of Nouméa, transforms raw garnieritic ore into ferro-nickel matte which is then exported for finishing in France. This matte is a nickel sulfate (Ni3S2) containing a small amount of iron and cobalt. The raw materials necessary for ferro-nickel manufacture are: coal, 140,000 tons/year, imported from Australia; anthracite, 80,000 tons/year; 5,000 tons/year of sulfur, imported from North America; 12,000 tons/year of silica and 3,200 tons/year of carbonate.
The possible sources of pollution are located either in the effluents from the refinery, which uses seawater as coolant, or in the dust sent out into the atmosphere. In 1993, 55,000 tons of nickel were produced, creating about 15 x 105 tons of slag which often serves to fill in coastal zones.
Small-scale metal treatment and plastic manufacturing plants, concentrated on the Ducos peninsula, similarly release pollution into the environment; neither the quantity nor the quality of these pollutants are monitored.
Certain fishing methods have devastating effects on the reef environment. These mainly involve explosives which break up coral, or chemical substances which kill it. These fishing techniques are, nonetheless, rarely practiced in New Caledonia.
On average, coral reef fisheries harvest 8 tons/km2/year. Counting all the world’s reefs, this represents about 6 x 106 tons/year (Smith, 1978). These fisheries involve very sensitive zones with the world’s greatest diversity of fish species.
Considering New Caledonia’s low population levels and the current abundance of resources, this fishing pressure has not yet caused major problems.
Coral materials have always been extracted from New Caledonia’s beaches. There are also isolated cases, especially on islets, of extractions linked to coastal development. However, following a study of the stock, and the design of harvesting management techniques, measures have been imposed to organise and limit these harvests.
Reef dredging is not practiced in New Caledonia.
Finally, the general attitude of shell collectors is very harmful to many of the world’s species and especially in New Caledonia. The most destructive effect is the destruction of biotopes through the turning over of large rocks.
Species introductions can be accidental or deliberate. Numerous examples exist of proliferations of exotic species in terrestrial island environments due to deliberate introductions (rabbits in Australia, Achatina in New Caledonia, etc.).
An introduced species always disturbs its new ecosystem because it must carve out a place for itself. It has not been moulded by time and co-evolution with the other species of this new environment, and thus causes an imbalance which often involves a period of proliferation. The exotic species enters into competition with the native species for space and trophic resources. In addition, there is a potential danger that the introduction of a species will also lead to the introduction of the parasites and diseases associated with it, or simply epibionts.
These introductions, sometimes called "biological pollution", are irreversible actions and, on the planetary scale, are one of the greatest causes of the long-term reduction of biodiversity by the homogenisation of the species populations (banalisation).
Deliberate introductions are generally associated with plans to develop new resources and are most often based on economic criteria with a short-term vision and no evaluation of the potential environmental risks.
Certain vegetative species of Pacific mangrove ecosystems were intentionally introduced (Ellison, 1995).
Aquaculture has become a source of accidentally introduced species and potentially represents a threat to the environment since, despite the precautions taken, the species can establish themselves in the natural environment and can enter into competition with local species (this was the case with crayfish).
Outside the tropics, a few examples of species introductions have been well documented.
The starfish Asterias amurensis is native to the coasts of Japan and Russia where it predates upon mollusk farms. Accidentally introduced in Tasmania, at the port of Hobart, probably in ballast waters of boats from the northern hemisphere, this species began to proliferate at an alarming rate. The first collection of this species in Tasmanian waters occurred in October 1986 but it was not correctly identified until March 1992, which gave it time to invade the area around Hobart. The authorities did not begin to react and to take action to limit this invasion until July 1993. The problems posed by this invasion include an ecological impact on the coastal fauna and an economic impact on aquaculture farms. In November 1993, the known range of this introduced species stretched along approximately 200 km of coastline. Attempts were made to gather it while diving, which allowed the destruction of several tens of thousands of individuals (Anonymous, 1994b; Johnson, 1994).
The immersed parts of ship hulls are quickly covered (after several months) with attached animals (tubiculous polychaetes, ascidians, seaweed, cirripeds, hydranths, bryozoans, porifera, etc.) which constitute what sailors call dirt or fouling and which they get rid of through periodic streamlining and by using toxic "anti-fouling" paints (Monniot et al., 1991).
These anti-fouling paints include components, such as tributyltin oxide (TBTO), which are now prohibited in Europe although their use persists in New Caledonia. In Fiji, in the Suva Lagoon, very high levels of TBT were discovered in the sediments and an ecotoxological study is being conducted to monitor the absorption of this chemical by filtering mollusks of the Anadara genus which are consumed by local populations (Newell, pers. comm.).
This attached fauna also includes a vagile fauna composed of mollusks, crustaceans and polychaetes. Current maritime activity in the Pacific is much less than during the 19th century when ships sailed the seas as part of colonial activities, whale hunting or trade (gold in California, tea in China, precious hardwoods in the Southwest Pacific, etc.) (Carlton, 1997).
Accidental introductions increased considerably in the 20th century with societies’ technological development. In the marine environment, these introduced species threatened to homogenise coastal faunal communities by reducing, and perhaps ultimately wiping out, indigenous species (Carlton, 1996). Carlton and Geller (1993) demonstrate that nearly complete sets of planktonic fauna are transported in ballast waters and that the mixture of species is thus already largely accomplished in these waters. Hundreds of species (367 species in the boats travelling between Japan and North America) belonging to all trophic levels are involved. The main groups found in ballast waters are, in order of decreasing frequency: crustaceans, polychaetes, turbellaria, cnidarians and mollusks. This phenomenon’s intensity is such that the authors believe that the coastal areas of bays and estuaries are among the planet’s most threatened ecosystems.
Carlton (1987) describes the 14 main ways in which marine species are dispersed in the Pacific by maritime traffic. For the most part, these species originate from Asian coasts. The evaluation of the impact of a species introduction, whether it be natural or human-caused, requires basic knowledge of the indigenous species (endemic or autochthonous). As this is far from being the case in the Indo-Pacific, the number of introduced species and their impacts on the ecosystems are certainly underestimated.
Despite the variety of cases and the lack of information, it is clear that the dispersal of species by humans has certain characteristics: the transportation vector is linked to boats, either by fouling or in the ballast waters; the places where these species become established are thus located near ports; after several centuries of accidental introductions, there develops a basic set of species common to all areas; depending on ecological conditions, certain regions tend more to be givers and other to be receivers (Carlton, 1987).
The excuses given for intentional introductions include the use of biological means to combat a "pest" organism (ex. mosquitofish to eat mosquito larvae), the raising of decorative species in aquariums, or the creation of stocks (live bait) for industrial or even sport fishing! Accidental introductions result generally from negligence, often committed by incompetent official organisations.
Although the impact of species introductions in the marine environment is much less well documented than for fresh water or terrestrial environments, it is a phenomenon not to be ignored and, in the long run, doubtlessly disturbs ecosystems more than chemical pollution. Pollard and Hutchings (1990b) suggest that the establishment of introduced species in polluted port areas may accelerate the transfer of pollutants such as heavy metals into trophic networks, where they even affect carnivorous species with commercial value (ex. the case of the Tanaidacea Tanais dulongi from Europe, introduced in Australia in 1978).
For a long time, it was generally believed that only the introduction of pathogenic species posed a danger and most intentional introductions would in fact "improve" the use of living resources. However, time has shown that all introductions disturb ecosystems, sometimes seriously, and that the benefits for human societies are weak or debatable. Legislation is starting to be introduced in order to regulate intentional introductions for farming, but it appears to be very difficult to control accidental introductions.
Intentional introductions for economic or recreational reasons raise an ethical question that government officials and administrations do not ask themselves: Do humans have the right to modify ecosystems by replacing indigenous species with others that suit them better, in the short term, without having truly evaluated the consequences?
Coral environments are located in warm seas, in sunny climates, and have one of the planet’s greatest concentrations of biological diversity. They are therefore a favorite tourist destination for residents of temperate areas that are overpopulated, polluted, and have dreary climates. In the collective unconscious, a tropical island coral reef is associated with paradise, and travel agents never miss an opportunity to refer to such clichés. For many small Indo-Pacific states, tourism is one of their main economic resources, sometimes the only one, and they make every effort to increase the influx of tourists. All the same, once the profits become significant or this flood of people is poorly supervised, tourism becomes harmful and may damage local ecosystems and biodiversity. There is thus a negative feed-back loop because a degraded coral environment no longer attracts tourists. Curiously, the same decision-makers who make efforts to develop tourism based on a healthy environment, often advocate the eminently destructive extraction of lagoon resources. In New Caledonia, the impact of tourism is not yet very directly worrisome, because it is still low (about 90,000 tourists in 1996).
Since tourism is one of the main sources of revenues for small island states, it generates significant coastal development (roads, hotel infrastructure, etc.) and certain reef-based activities (yachting, water sports, etc.).
On Grande Terre and the Loyalty Islands, several hotels have been built during recent years.
Nouméa’s Méridien Hotel: this prestigious building was constructed in 1994-95 on the Nouméa peninsula at the Magnin Point site. The coastline was modified to create a "coral" sand beach. A rocky islet was transformed into a helicopter platform, linked to the shore by a strip of sand. The coastal modification work also included destroying the fringing reef and covering this zone with sand, thereby destroying all benthic life along about 100 m of shoreline. The modification of the shape of the coast changed the water circulation, causing the accumulation of vegetation debris on the windward side and a depression dug by a whirlpool on the leeward side. After a period during which the faunal and flora populations stabilised, it is not certain that the situation is an improvement for tourism. The white sand beach, little used because of its exposure to the wind, is now nauseating and the coastal fauna of interest to tourists has disappeared.
Malabu Hotel at Koumac: this large-scale hotel complex, constructed in 1992, is located at the extreme north of Grande Terre. It is composed of a series of small bungalows which blend into the landscape relatively well. In contrast, the modification of the coastline, designed to create a space for water sports, was done in a manner contrary to good sense. The creation of an artificial islet, designed to break waves, created a settling area where seagrass debris and fine particulate matter accumulate. This recreation area has ended up full of mud and foul-smelling.
In the two examples above, a serious impact study would certainly have allowed for a less environmentally disturbing solution which would have better achieved the goal of promoting tourism.
A hotel was built on Casy Islet located in Prony Bay in a zone where the vegetation is over 80% endemic; a new project is in the works in Port-Boisé Bay, in an area of nearly total endemism.
A new hotel is currently in operation on the edge of the Oro Bay, on the Isle of Pines, in an exceptional site that was classified for its heritage and ecotourism value in 1954 and then declassified in 1980. Despite strong protests from NGOs and the intervention of the Administrative Tribunal which cancelled the building permit, the construction took place. In 2001, there is a proliferation of micro-algae which point to an excess of organic matter and nitrogen in the water.
About 50 ocean liners stop in Nouméa each year; during their voyage through New Caledonia’s waters, the passengers get off at the Isle of Pines, the Loyalty Islands or the small Amédée Islet. These sudden arrivals of thousands of individuals in small areas pose environmental problems.
On Ricaudy Reef, a vast fringing reef, the closest one to the Nouméa urban area (about 80,000 inhabitants), each low tide with a tidal coefficient less than 0.3 brings with it the arrival of about 100 people who turn over the rocks in search of collectable shells (cowries, cones) or who dig the sand to extract clams and octopuses (Baron, 1992a). Many of these gatherers behave in ways that are incompatible with the sustainable maintenance of a healthy reef: in essence, the fauna attached to the rocks is destroyed, and the branching corals are trampled and broken. These shallows, which already suffered greatly from road development in the late 70s, are rapidly being degraded by human pressures. The area was recently classified as a faunal and floral reserve although this has not in the least reduced the numbers of people who harvest its resources.
The groups most gathered by tourists for exportation are shellfish (gasteropods and giant clams) and corals (branching and Fungia). In 1996, DAFE delivered 708 export permits to tourists, of which 308 were for coral. In 1997, over a thousand permits were requested (Le Noel, pers. comm.).
In heavily visited lagoon and reef zones, the destructive effects of yacht anchorage is significant. The boat’s anchor breaks coral on its way to the bottom, leaving a long-lasting impact, and the anchor chain drags along the bottom when the boat swings at anchor, sometimes destroying large areas of fragile branching or table corals (this is equally true, to a lesser extent, for seagrass beds). To reduce this problem, due to tourists’ attraction to coral environments, various solutions have been proposed: prohibitions on anchoring in certain zones, setting up fixed anchorage points with a buoy to which small boats can attach themselves, etc. None of these solutions is fully satisfactory. Prohibitions on sailing or anchoring deprive the public, sensitive to nature’s charms, of a chance to better understand their environment, and the placement of fixed anchorage points disturbs the surroundings. These are generally very voluminous moorings to which a chain or rope is attached. The best solution is a set of regulations limiting visitor density and education so that reef enthusiasts themselves become aware of the necessity of protecting reefs by not anchoring just anywhere. Might it perhaps be a good idea to include environmental awareness as part of the training for navigational licenses?
Yacht anchors on Caledonian corals have a truly destructive impact in many places (Prony Bay, Maître Islet). The Southern Province authorities, aware of this problem, have since 1994 begun to mark reserve boundaries, set up fixed anchorage points for small boats, and distribute information brochures. It is still too early to judge the effectiveness of these measures.
Over 10,000 yachts are currently registered in the Territory of New Caledonia, with about 6,000 in the Nouméa area. Most of these measure less than 6 m in length and require no navigation license (Nguyen-Khoa, 1993).
In New Caledonia, a pontoon has been permanently fixed to the barrier reef since 1993. Besides the work done to ensure its anchorage, the main source of environmental disturbance is linked to the regular fish feedings which disturb trophic networks. A study conducted in French Polynesia on the impact of bungalows built on stilts on Moorea Island demonstrates that the fish population structure has been modified by such feedings, and especially that the species richness and fish biomass have increased (Planes and Doherty, 1995).
Similarly, shark feedings organised for tourists in the Boulari Pass result in imbalances in fish populations.
In Australia, a study of the impact of dive tourism on coral reefs showed that the places visited were often highly disturbed and that numerous corals were accidentally broken. Most of the destruction was attributable to divers and especially to inexperienced photographers.