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Marine Turtle Newsletter 49:4-7, © 1990

Leatherback Turtles Disappearing from the BVI

Gillian Cambers and Halstead Lima
Conservation Office, Ministry of Natural Resources and Labour, Road Town, Tortola, British Virgin Islands, West Indies

Introduction

The leatherback sea turtle (Dermochelys coriacea) is a declining species in the British Virgin Islands (BVI). The leatherback, the largest and most pelagic of the sea turtles, typically weighs 300-500 kg. The species lacks a bony shell and cornified epidermal scales; the smooth, black skin is spotted with white. The carapace is strongly tapered, generally measures 130-165 cm in length (straightline, nuchal notch to posterior tip) and is raised into seven prominent ridges. Powerful front flippers extend nearly the length of the body. Leatherbacks, known locally as "Trunks", are seasonal visitors, migrating from temperate foraging grounds to nest on BVI beaches between March and July. Evidence suggests that historical nesting was higher than it is now (Eckert and Lettsome, 1988). Some BVI beaches were named after the turtle (e.g., Trunk Bay) and presumably the species once nested to some degree in these areas, but does not do so today. Regular surveys of known nesting beaches conducted in 1987, 1988 and 1989 suggest that the leatherback may be in imminent danger of disappearing from the beaches and waters of the BVI, if it has not already done so.

Historical Background

The following history of the leatherback turtle in the BVI is condensed from Eckert and Lettsome (1988). Historically, the leatherback fishery was never as important economically as the hawksbill/green turtle fishery because of its seasonal nature and the fact that there was not a large market for the primary product derived from the animal, which was oil. However, what the fishery lacked in economic importance, it made up for culturally. "Trunking" is deeply rooted in tradition and mysticism; some fishermen trace the roots of the fishery back to the days of slavery. There are several mystical aspects to the trunk fishery; the fishermen speak of music, unexplained movements in the vegetation, and maintain that they see turtle-shaped apparitions in the clouds that point to the beach where the female will lay her eggs.

Leatherbacks have traditionally been killed for meat and oil. The "Trunkers" or trunk fishermen (currently five in number and for the most part elderly) recount that 50-60 gallons of oil were rendered from a "big" leatherback and perhaps 35 from a "small" one. The exact amount is difficult to estimate because the oil is routinely poured into assorted household containers and the absolute volume rarely calculated. One source reported that 15 to 20 40-ounce bottles of oil were obtained from each turtle. Prices apparently range from US$ 20-40 per 40-ounce bottle. Drinking oil "makes you strong", and is sometimes reputed to have aphrodisiac qualities. The oil is most commonly used for medicinal purposes, generally in cases of respiratory congestion.

The Trunkers await the nesting females during the hours of high tide, believing that this is the most likely time of arrival; the full moon is preferred. When a turtle comes ashore, she is flipped over on her carapace, a machete is used to cut a hole in each front flipper, and her front flippers are tied over her plastron (belly). She is left until morning when the whole village community comes to share in the harvest. Women bring pans to carry chunks of meat home, and the men dismember the turtle and boil it in large cauldrons on the beach to render the oil. Some oil is shared with the community and the rest is sold locally. Sales have dropped in recent years and the lower demand (coupled with the sharp decline in turtles and rising economic opportunities in the business and tourist sectors) lessens the desire of the young men to perpetuate the fishery.

Current Status

The unique cultural ties to the turtle prompted initial efforts by the BVI Ministry of Natural Resources and Labour (MNRL) to study and protect the remaining BVI leatherbacks. The Turtles Ordinance (May 1959) was amended in May 1986 by the Turtles Protection Amendment Notice to include protection of the leatherback turtle (which previously had been excluded) and to extend the closed season from 1 April to 30 November, inclusive. Compliance with the new law has been quite good; one violation was reported to the Conservation Office as of September 1989. This involved a restaurant in Tortola selling turtle meat in June. This did not result in prosecution, although the MNRL did send a letter to the restaurant owner.

Beach surveys were conducted in 1987 by Mr. Bertrand Lettsome (then NMRL Conservation Officer) and Dr. Nicholas Clarke (then Director of the BVI National Parks Trust). Nests were confirmed at Long Bay Lambert, Josiahs Bay, Rogues Bay and Trunk Bay beaches on the island of Tortola; a total of nine leatherback nests were recorded between April and July 1987. The chronology of the nesting suggested 3-4 animals were responsible. The exact number cannot be verified with certainty due to interference from local fishermen who had erased some of the tracks. One animal was caught and killed illegally at Josiahs Bay and reports indicate that a second one may also have been captured (Lettsome, 1987; Eckert, 1987).

In 1988, regular beach surveys were again conducted by Lettsome with help from the Conservation Assistant, Mr. Halstead Lima. Surveys were conducted from mid-March to mid-June on the northeast coast of Tortola where most of the beaches suitable to leatherback nesting are located. One leatherback turtle nested once at Long Bay Lambert on 17 May 1988. In addition, one leatherback nested on the southwestern coast of Anegada, the northeasternmost of the British Virgin Islands (Lettsome, 1989). However, after nesting the Anegada turtle was attracted to a street lamp, became disoriented and dehydrated, and subsequently died. In April and May 1989, regular surveys (an average of once every 7.5 days, range 6-9 days) were conducted by boat of the north coasts of Tortola and Beef Island. More irregular surveys were conducted of Guana Island, Little Camanoe, Sandy Cay and Sandy Spit. A total of 14 beaches were surveyed, more than half of them on a weekly basis. The field survey was conducted by Mr. Halstead Lima with help from the Fisheries Assistant, Mr. Sam Davies. The beaches were surveyed at dawn and early morning (0530-0930 hrs). No evidence of nesting was observed. It is unlikely, given the longevity of the deep leatherback track, that tracks were weathered between surveys, but it is possible that fishermen or poachers may have obliterated tracks. It is interesting that the Fisheries Division reported sighting one leatherback turtle while on patrol, about 5 miles southeast of Virgin Gorda, around the beginning of 1989 (Mr. Laurens Blok, personal communication).

The 1987-1988 data represent a precipitous decline from reports of as many as six turtles nesting per night in the 1920's and 1930's (Eckert and Lettsome, 1988). The 1989 data serve only to confirm the trend observed in recent years that the leatherback turtle population in the BVI is fast diminishing, since the number of nests on the northeast coast of Tortola and Beef Island dropped from nine to zero between 1987 and 1989.

It would appear that this species has become, or is becoming, extinct from our beaches and waters. The impetus for this regrettable situation is undoubtedly multifarious, including a persistent subsistence harvest, habitat loss due to beach sand mining (particularly at Josiahs Bay which is extensively mined and used to be an important nesting beach), and dangers that the leatherbacks face at sea (plastic debris, pollution, and incidental catch). The Fisheries Division confirmed that two leatherbacks were accidentally hooked on longlines during the 1988 season; the fate of these animals is unknown since they were cut off the lines with the hooks still lodged in them (Lettsome, 1989).

It is relevant to note that the United States Virgin Islands has an indefinite moratorium on the harvest of marine turtles or their eggs, until their stocks recover. In this aspect of conservation the BVI is far behind some of its neighbors in the wider Caribbean. It appears that there are four major areas in which we must concentrate our future efforts:

1. Continue regular surveys of Tortola and Beef Island, and extend these surveys to other islands: Peter Island, Sandy Cay, Sandy Spit, Guana Island, Great and Little Camanoe and especially Virgin Gorda and Anegada;
2. Expand our awareness work with the public, the fishermen and the schools;
3. Strengthen enforcement capabilities to ensure that animals are not taken illegally;
4. Declare a five-year moratorium on leatherback turtle harvesting.

We have applied for a small grant from the World Wide Fund for Nature (U.K.) to hire two local persons to survey Anegada and Virgin Gorda; if we are successful in obtaining this grant, the 1990 survey should be more complete geographically and give us a better handle on the remaining leatherback "population".

The possible extinction of the leatherback turtle from Tortola and Beef Island is too high a price to pay. The economy of the BVI is dependent on tourism and fisheries; the necessary resource for both these industries is the natural, unspoilt, unpolluted marine environment. By degrading and destroying our marine environment, we are not only damaging our environment, for ourselves and our fellow species, but also our very livelihood.

Eckert, K. L. and Lettsome, B. B. 1988. WIDECAST Sea Turtle Recovery Action Plan for the British Virgin Islands. U. N. Environment Programme/Caribbean Environment Programme contract #CR/5102-86. 50p.

Eckert, K. L. 1987. British Virgin Islands National Report to the Western Atlantic Turtle Symposium II, 12 October 1987, Mayagüez, Puerto Rico.

Lettsome, B. B. 1987. British Virgin Islands Marine Turtle Survey Annual Report (1987). Ministry of Natural Resources and Labour, Government of the British Virgin Islands.

Lettsome, B. B. 1989. British Virgin Islands Marine Turtle Survey Annual Report (1988). Ministry of Natural Resources and Labour, Government of the British Virgin Islands.