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Sea Turtle Recovery Action Plan for Barbados | |
| CEP Technical Report No. 12 1992 | All CEP Technical Reports |
Note: The designations employed and the presentation of the material in this document do not imply the expression of any opinion whatsoever on the part of UNEP concerning the legal status of any State, Territory, city or area, or its authorities, or concerning the delimitation of their frontiers or boundaries. The document contains the views expressed by the authors acting in their individual capacity and may not necessarily reflect the views of UNEP.
For bibliographic purposes the printed version of this document may be cited as:
Horrocks, Julia A. 1992. WIDECAST Sea Turtle Recovery Action Plan for Barbados (Karen L. Eckert, Editor). CEP Technical Report No. 12. UNEP Caribbean Environment Programme, Kingston, Jamaica. 61p.
Sea turtle stocks are declining throughout most of the Wider Caribbean region; in some areas the trends are dramatic and are likely to be irreversible during our lifetimes. According to the IUCN Conservation Monitoring Centre's Red Data Book, persistent over-exploitation, especially of adult females on the nesting beach, and the widespread collection of eggs are largely responsible for the Endangered status of five sea turtle species occurring in the region and the Vulnerable status of a sixth. In addition to direct harvest, sea turtles are accidentally captured in active or abandoned fishing gear, resulting in death to tens of thousands of turtles annually. Coral reef and sea grass degradation, oil spills, chemical waste, persistent plastic and other marine debris, high density coastal development, and an increase in ocean-based tourism have damaged or eliminated nesting beaches and feeding grounds. Population declines are complicated by the fact that causal factors are not always entirely indigenous. Because sea turtles are among the most migratory of all Caribbean fauna, what appears as a decline in a local population may be a direct consequence of the activities of peoples many hundreds of kilometers distant. Thus, while local conservation is crucial, action is also called for at the regional level.
In order to adequately protect migratory sea turtles and achieve the objectives of CEP's Regional Programme for Specially Protected Areas and Wildlife (SPAW), The Strategy for the Development of the Caribbean Environment Programme (1990-1995) calls for "the development of specific management plans for economically and ecologically important species", making particular reference to endangered, threatened, or vulnerable species of sea turtle. This is consistent with Article 10 of the Cartagena Convention (1983), which states that Contracting Parties shall "individually or jointly take all appropriate measures to protect ... the habitat of depleted, threatened or endangered species in the Convention area." Article 10 of the 1991 Protocol to the Cartagena Convention concerning Specially Protected Areas and Wildlife (SPAW Protocol) specifies that Parties "carry out recovery, management, planning and other measures to effect the survival of [endangered or threatened] species" and regulate or prohibit activities having "adverse effects on such species or their habitats". Article 11 of the SPAW Protocol declares that each Party "shall ensure total protection and recovery to the species of fauna listed in Annex II". All six species of Caribbean-occurring sea turtles were included in Annex II in 1991.
This CEP Technical Report is the second in a series of Sea Turtle Recovery Action Plans prepared by the Wider Caribbean Sea Turtle Recovery Team and Conservation Network (WIDECAST), an organization comprised of a regional team of sea turtle experts, local Country Co-ordinators, and an extensive network of interested citizens. The objective of the recovery action plan series is to assist Caribbean governments in the discharge of their obligations under the SPAW Protocol, and to promote a regional capability to implement scientifically sound sea turtle conservation programs by developing a technical understanding of sea turtle biology and management among local individuals and institutions. Each recovery action plan summarizes the known distribution of sea turtles, discusses major causes of mortality, evaluates the effectiveness of existing conservation laws, and prioritizes implementing measures for stock recovery. WIDECAST was founded in 1981 by Monitor International, in response to a recommendation by the IUCN/CCA Meeting of Non-Governmental Caribbean Organizations on Living Resources Conservation for Sustainable Development in the Wider Caribbean (Santo Domingo, 26-29 August 1981) that a "Wider Caribbean Sea Turtle Recovery Action Plan should be prepared ... consistent with the Action Plan for the Caribbean Environment Programme." WIDECAST is an autonomous NGO, partially supported by the Caribbean Environment Programme.
The Sea Turtle Recovery Action Plan for Barbados has benefited from the experience, advice and support of many people. In particular, I would like to thank Dr. Wayne Hunte and Dr. H. Oxenford (Bellairs Research Institute), Mr. Stephen Willoughby and Mr. P. McConney (Fisheries Division), Mr. Ken Atherley (Coastal Conservation Project Unit); Ms. Yvonne St. Hill (Environmental Consultancy Services); and the members of the Biodiversity Group (Environmental Unit; Ministry of Labour, Consumer Affairs and the Environment) for valuable input into earlier drafts. The assistance of the following persons in gathering data is gratefully acknowledged: members of the Barbados Environmental Association, employees of the National Conservation Commission, Ms. Lotus Vermeer, Ms. Purnima Govindarajulu and Ms. Honor Wiltshire (Bellairs Research Institute), and Mr. William Bertalan. Finally, I would like to thank the WIDECAST regional Sea Turtle Recovery Team 1/, most especially Dr. Karen Eckert, for their friendship and for giving this Recovery Action Plan the benefit of their extensive knowledge of sea turtle biology and conservation. The Recovery Action Plan is dedicated to the many Barbadians who want to ensure that sea turtles remain around Barbados to enrich the lives of future generations.
1/ The WIDECAST regional Recovery Team provided impetus for this document and critiqued earlier drafts. These persons are the following: Lic. Ana Cecilia Chaves (Costa Rica), Dr. Karen Eckert (USA), Jacques Fretey (France), John Fuller (Antigua), Molly Gaskin (Trinidad), Dr. Julia Horrocks (Barbados), Maria Teresa Koberg (Costa Rica), Dr. Peter Pritchard (USA), Dr. James Richardson (USA), and Dr. Georgita Ruiz (Mexico). The IUCN/SSC Marine Turtle Specialist Group (Dr. Karen Bjorndal, Chair) also provided useful comments on an earlier draft. Major financial support for the international WIDECAST project has come from Monitor International, The Chelonia Institute, the UNEP Caribbean Environment Programme, and the U.S. National Marine Fisheries Service.
PREFACE
ACKNOWLEDGEMENTS
ABSTRACT
I. INTRODUCTION
II. STATUS AND DISTRIBUTION OF SEA TURTLES IN BARBADOS
2.1 Caretta caretta, Loggerhead Sea Turtle
2.2 Chelonia mydas, Green Sea Turtle
2.3 Dermochelys coriacea, Leatherback Sea Turtle
2.4 Eretmochelys imbricata, Hawksbill Sea Turtle
2.5 Lepidochelys kempi, Kemp's Ridley Sea Turtle
2.6 Lepidochelys olivacea, Olive Ridley Sea Turtle
3.1 Destruction or Modification of Habitat
3.2 Disease or Predation
3.3 Over-utilisation
3.4 Inadequate Regulatory Mechanisms
3.5 Other Natural or Man-made Factors
4.1 Manage and Protect Habitat
4.11 Identify essential habitat
4.111 Survey foraging areas
4.112 Survey nesting habitat4.12 Develop area-specific management plans
4.121 Involve local coastal zone authorities
4.122 Develop regulatory guidelines
4.123 Provide for enforcement of guidelines
4.124 Develop educational materials
4.132 Lights
4.133 Beach stabilization structures
4.134 Beach cleaning equipment and vehicular use of beaches
4.135 Beach rebuilding projects4.14 Prevent or mitigate degradation of marine habitat
4.141 Dynamiting reefs
4.142 Bleaching reefs (by man)
4.143 Industrial discharges
4.144 At-sea dumping of garbage
4.145 Oil exploration, production, refining, transport
4.146 Agricultural runoff and sewage
4.147 Others4.2 Manage and Protect all Life Stages
4.21 Review existing local laws and regulations
4.22 Evaluate the effectiveness of law enforcement
4.23 Propose new regulations where needed
4.231 Eggs
4.232 Immature turtles
4.233 Nesting females
4.234 Unprotected species4.24 Augment existing law enforcement efforts
4.25 Make fines commensurate with product value
4.26 Investigate alternative livelihoods
4.27 Determine incidental catch and promote the use of TEDs
4.28 Supplement reduced populations using management techniques
4.29 Monitor stocks
4.291 Nests
4.292 Hatchlings
4.293 Immature and adult turtles4.3 Encourage and Support International Legislation
4.31 CITES
4.32 Regional cooperation
4.33 Subregional sea turtle management4.4 Develop Public Education
4.41 Residents
4.42 Fishermen
4.43 Tourists
4.44 Non-consumptive uses of sea turtles to generate revenue4.5 Increase Information Exchange
4.51 Marine Turtle Newsletter
4.52 Western Atlantic Turtle Symposium (WATS)
4.53 WIDECAST
4.54 IUCN/SSC Marine Turtle Specialist Group
4.55 Workshops on research and management
4.56 Exchange of information among local groups4.6 Summary Sectorial Recommendations
4.61 Government organisations
4.611 Coastal Conservation Project Unit (CCPU)
4.612 Town Planning Department (TPD)
4.613 National Conservation Commission (NCC)
4.614 Ministry of Agriculture, Food and Fisheries
4.615 Ministry of Trade, Industry and Commerce
4.616 Royal Barbados Police Force and the Coast Guard4.62 Non-government organisations
4.621 Architects and landscape architects
4.622 Bellairs Research Institute (BRI)
4.623 Barbados Environmental Association (BEA)
4.624 Barbados Wildlife Reserve
Monitoring of nesting activity:
Tagging of post-nesting females:
Movement of nests endangered by a significant threat:
Monitoring of hatching events:
Strandings and the care of sick/debilitated sea turtles:
Sea turtle database:
Increasing environmental awareness:
PROPOSED ACTIVITIES
RESULTS AND OUTPUTS
BUDGET
LIST OF MAPS AND FIGURES
MAP 1: Barbados is the most easterly island in the Lesser Antilles.
MAP 2: Locations of sea grass and offshore bank coral reefs around Barbados.
MAP 3: Locations of potential nesting beaches and actual nests for the leather- back sea turtle (Dermochelys coriacea) in Barbados, 1984-1991.
MAP 4: Locations of hawksbill sea turtle (Eretmochelys imbricata) nests re- ported by the public in 1990 (stars) and 1991 (dots) in Barbados.
MAP 5: The Barbados Marine Reserve includes 2.2 km along the west coast and extends 1000 m offshore.FIGURE 1: Four species of sea turtle are reported from Barbados. These species are, in decreasing order of abundance, the hawksbill (Eretmochelys imbricata), the green turtle (Chelonia mydas), the loggerhead (Caretta caretta), and the leatherback (Dermochelys coriacea).
FIGURE 2: The number of hawksbill sea turtle nests laid per month in Barbados, as reported by the general public, 1987-1991.
FIGURE 3: The number of hawksbill sea turtle nests laid per month in Barbados, as reported by the general public, 1989-1991.
Barbados is the most easterly island in the Lesser Antilles. Four species of sea turtle are recorded from the waters of Barbados: the hawksbill (Eretmochelys imbricata), leatherback (Dermochelys coriacea), green turtle (Chelonia mydas), and, rarely, the loggerhead (Caretta caretta). The primary nesting species is the hawksbill; leatherbacks nest only occasionally. Hawksbills nest in all months except February and March, but there is a marked peak in nesting between June and August. Leatherbacks are seasonal visitors, arriving to nest between April and June. Sea turtle nesting activity has been monitored over the past five years. The data suggest that not many more than 50 hawksbills and fewer than two leatherbacks nest each year. Juvenile green turtles are commonly seen feeding in nearshore sea grass and algal beds, particularly off the east coast. In contrast, hawksbills feed on coral reef-associated sponges. Subadult and adult loggerheads are sometimes captured in deep water; foraging has not been observed. Estimates of population size for non-nesting sea turtles (green turtles, hawksbills, loggerheads) around Barbados are not available. It is generally acknowledged by fishermen that sea turtles are less common today than in previous years. The primary stresses on sea turtles in Barbados are exploitation, nesting habitat deterioration, and, to a lesser extent, foraging habitat deterioration.
Hawksbill turtles are taken during nesting or in nets at sea for meat, eggs and shell. The shell is either fashioned into products sold locally or it is exported to Japan. Since Barbados is not yet a member of CITES, importation and exportation of shell is permitted with the appropriate documentation, although new policy requires that the Chief Fisheries Officer give his permission for export. Discussions on Barbados' accession to CITES are in progress. In addition to the harvest of hawksbills, juvenile green turtles are caught in nets set a few hundred yards from shore on the east coast, and adult greens and loggerheads are speared opportunistically by pelagic fishermen whilst they wait for gill nets to fill. The meat (rarely the shell) from green turtles and loggerheads is used; leatherbacks are not killed, only the eggs are taken. National legislation prohibits at all times the take of sea turtles or their eggs on the beach or within 100 yd (90 m) of shore, and the capture of turtles weighing less than 30 lbs (13.6 kg). The penalties are inadequate, however, and do not serve as an effective deterrent. Enforcement of legislation is problematic because of the lack of seriousness with which the offense is viewed, the difficulty of proving that a turtle was taken illegally, and because of manpower constraints within the enforcement agencies. Very few people depend on turtle exploitation for a living and redrafted legislation banning the harvest of all sizes and species of sea turtles, as well as the use of entangling nets, is presently being considered by Cabinet. If a national ban on harvest comes into effect, there will be even greater reason to accede to CITES in order to control the importation of shell.
Hawksbills prefer to nest on the west and south coasts of Barbados, often in beach vegetation. These same beaches have been altered, primarily by development for tourism. Buildings and walls constructed close to the high water mark, and the positioning of gabions and boulders on beaches to protect beach-front properties has reduced the amount of beach suitable for nesting. The loss of stabilizing vegetation which has accompanied extensive beach-front development is also implicated in beach loss. Ornamental and security lights deter females from emerging to lay eggs and cause hatchling disorientation and mortality. In 1990, hatchlings from 83% of monitored nests were disoriented by lighting. Heavy pedestrian use of beaches leads to compaction of the sand over nests, increasing mortality among eggs and hatchlings. The patchy spatial distribution of hawksbill nesting makes it difficult to identify and protect specific nesting areas. However, an estimated 15 different hawksbills nested on 1.5 km of the southwestern coast between 1989 and 1991, suggesting that this is an area within which any future development should be carefully managed. On other beaches, measures can be taken to reduce the impacts of development on turtle nesting; e.g., lighting problems can be minimised by keeping lights low to the ground, shielding them from shining directly onto the beach, and using low sodium vapor lamps in preference to full-spectrum white lights. Fortunately, the few leatherback nests recorded each year are made on the largely undeveloped high energy east and southeast coasts. Nesting habitat for leatherbacks appears unstressed at the present time.
In addition to the deterioration of nesting habitat, feeding grounds have also been affected. Hawksbills, ranging in size from small juveniles to adults, are known to forage on reef-associated sponges on the fringing and bank coral reefs around Barbados. Juvenile green turtles forage within sea grass and algal beds. Coral reefs and sea grass meadows are important to the survival of sea turtles in Barbados, yet coral cover and diversity on west and south coast fringing reefs has deteriorated over the past 30 years. Likewise, sea grass beds have diminished in size. Both types of habitats are impacted by land-based sources of pollution; e.g., sewage, household chemicals, agrochemicals, and sediment. Careless fishing practises, indiscriminate anchoring, and illegal fishing practises such as dynamiting, further contribute to the degradation of these habitats. One area of the west coast has been designated as a marine reserve, where fishing and boat use are restricted and where turtle harvest is illegal. Efforts to identify sources of pollution and implement measures to protect nearshore habitats along the entire west and south coasts are ongoing as part of a national coastal conservation project. Important sea turtle foraging habitats will benefit from these measures.
A project for improving the institutional effectiveness of coastal zone management in Barbados has recently been conducted. Enforcement of legislation pertaining to the coastal zone is one of the areas under review, and all aspects of coastal zone law enforcement may ultimately become the responsibility of one agency specifically trained in environmental legislation and its enforcement. Increasing environmental awareness among the public through educational materials and activities will assist enforcement agencies. The WIDECAST Sea Turtle Recovery Action Plan for Barbados strongly supports ongoing efforts at improving sea turtle conservation legislation, enhancing the effectiveness of law enforcement and coastal zone management, and allocating financial and personnel resources more efficiently by consolidating coastal zone responsibilities. The Plan also supports ongoing field research and public awareness campaigns and proposes several activities to enhance and expand sea turtle conservation in Barbados. In concert with national efforts, and recognizing that sea turtles are highly migratory (meaning that Barbados may share its sea turtles, particularly its hawksbills, with neighbouring islands), a tagging programme that includes at least St. Lucia, St. Vincent and the Grenadines, Grenada, and Barbados is suggested. The full recovery of shared populations will require regional cooperation. The Government of Barbados is encouraged to support multinational efforts aimed at the conservation and recovery of depleted marine species, such as sea turtles, by ratifying the Cartagena Convention Protocol concerning Specially Protected Areas and Wildlife (SPAW Protocol).
RESUMEN
La isla de Barbados es la más oriental de las Antillas Menores. En sus aguas, se encuentran cuatro especies de tortuga: la carey (Eretmochelys imbricata), la barriguda (Dermochelys coriacea), la tortuga verde (Chelonia mydas), y muy infrecuentemente, la tortuga de mar (Caretta caretta). La especie que más anida es la carey; la tortuga barriguda sólo anida de vez en cuando. La tortuga carey anida todos los meses con la excepción de febrero y marzo pero el anidamiento llega al tope entre junio y agosto. La barriguda es visitante estacional. Viene a anidar entre abril y junio. El anidamiento de la tortuga marina ha sido vigilado durante los últimos cinco años. Según los datos, poco más de 50 tortugas carey y menos de dos barrigudas anidan cada año. A menudo se ven tortugas verdes jóvenes alimentándose de la yerba marina cerca del litoral y lechos de algas, sobre todo afuera de la costa oriental. En contraste, las carey se alimentan de esponjas asociadas con los arrecifes coralinos. Las tortugas de mar maduras y quasimaduras son capturadas de vez en cuando en las aguas profundas; no se ha notado forraje. No hay cálculos del tamaño de la población de tortugas marinas alrededor de Barbados que no anidan (la tortuga verde, la barriguda, la tortuga de mar). Los pescadores por lo general reconocen que las tortugas marinas son menos frecuentes hoy que anteriormente. Las presiones primarias que experimentan las tortugas marinas en Barbados son la explotación, el deterioro del habitat donde anidan y a menor grado el deterioro del habitat de forraje.
Las tortugas carey son capturadas durante el anidamiento o pescadas del mar con redes por la carne, los huevos o el caparazón el cual o se elabora para la fabricación de productos que se venden localmente o se exporta al Japón. Dado que Barbados aún no es miembro de CITES, se le permite la importación y exportación del caparazón con el único requisito de que tenga la documentación apropiada, aunque la nueva política requiere que el Oficial encargado de la Pesca otorgue permiso para la exportación. Las discusiones con respecto a la adhesión de Barbados a CITES están encaminadas. Aparte de la cosecha de las tortugas carey, las tortugas verdes jóvenes están atrapadas en redes colocadas unas cientas de yardas costa afuera del litoral oriental y las tortugas verdes y las tortugas de mar adultas son pescadas con arpón por pescadores pelágicos oportunistas mientras esperan que se llenen las redes rastreras verticales. La carne (rara vez el caparazón) de las tortugas verdes y las tortugas barriguda son utilizadas; las tortugas de mar no son matadas, sólo se les quita los huevos. La legislación nacional prohibe de modo perenne la capturación de las tortugas marinas o sus huevos de la playa o dentro de un límite de 100 yardas (90 m) de litoral y la capturación de tortugas que pesan menos de 30 libras (13.6 Kilos). Sin embargo, las multas son inadecuadas y no sirven de freno afectivo. La ejecución de la legislación es problemática a causa de la falta de seriedad con que ven el delito, la dificultad de probar que una tortuga fue capturada de forma ilegal y las limitaciones de recursos humanos dentro de las agencias que ejecutan la legislación. Hay pocas personas que ganan la vida de la explotación de tortugas y el Gabinete está en el proceso de estudiar la legislación remodelada que prohibe la cosecha de todo tamaño y especie de tortuga marina asicomo el uso de redes rastreras verticales. Al aprobarse una ley nacional prohibiendo la cosecha, habrá aún más razón para integrarse a CITES para poder controlar la importación de caparazones.
La tortuga carey prefiere anidar en las costas occidentales y meridionales de Barbados, a menudo entre la vegetación de la playa. Estas mismas playas han sufrido cambios, primordialmente debidos al desarrollo turístico. La construcción de edificios y paredes próximos a la linea de la marca alta y la colocación de garriones y piedras grandes sobre las playas para proteger las propiedades con playa han reducido la extensión de playa que se presta idóneamente para el anidamiento. La pérdida de playa también incluye la pérdida de vegetación mínima de sustentación que ha acompañado el desarrollo extensivo de propiedades con playa. Las luces decorativas y de seguridad sirven de freno a las hembras que no salen a poner huevos y también conduce a la desorientación y la mortalidad de las recién nacidas. En 1990, las recién nacidas del 83% de nidos observados fueron desorientadas por las luces. El constante paseo de personas resulta en la compactación de la arena sobre los nidos, y el aumento de la mortalidad de huevos y recién nacidas. La configuración irregular del anidamiento de la tortuga carey dificulta la identificación y protección de áreas específicas de anidamiento. Sin embargo, alrededor de 15 tortugas carey anidaron sobre una extensión de 1.5 km de la costa sudoccidental entre 1989 y 1991, lo cual indica que ésta es una área donde habrá que vigilar todo tipo de desarrollo futuro. En las otras playas, se pueden introducir medidas para reducir el impacto del desarrollo sobre el anidamiento de la tortuga, por ejemplo, el problema de las luces se puede minimizar al mantenerlas bajas, juntas al suelo sin iluminar las playas directamente y utilizando lámparas de vapor de bajo volúmen de sodio. Afortunadamente, los pocos nidos de tortugas barrigudas que se registran cada año se encuentran en las costas por mayor parte no desarrolladas y altas en energía del lado oriental y sudeste de la isla. Por el momento, el habitat donde anidan de las tortugas barrigudas parece no ser presionado.
Aparte del deterioro del habitat de anidamiento, los terrenos de forraje también han sido afectados. La carey, jóven y adulta se alimentan de esponjas de los arrecifes coralinos que se encuentran en las bordes y las orillas de la isla. Las jóvenes tortugas verdes forrajean entre la yerba marina y los lechos de algas. Los arrecifes coralinos y los prados de yerba marina son importantes para la sobrevivencia de las tortugas marinas de Barbados a pesar de que la cobertura coralina y la diversidad de los arrecifes costeros al oeste y al sur de la isla se han deteriorado durante los últimos 30 años. Asimismo, los lechos de yerba marina se han achicado. Ambos tipos de habitat son afectados por fuentes terrestres de contaminación, por ejemplo, el alcantarillado, los productos químicos domésticos, las agroquímicas y la sedimentación. Las prácticas irresponsables pesqueras, el anclaje indiscriminado y actividades ilícitas pesqueras, por ejemplo, el uso de dinamita, contribuyen aún más a la degradación de estos habitats. Una área de la costa occidental ha sido designada como reserva marina, donde la pesca y el uso de barcos están controlados y donde la cosecha de tortugas es ilegal. Los esfuerzos para identificar las fuentes de contaminación y aplicar medidas para proteger los habitats litorales a lo largo de las costas occidentales y meridionales son continuos y forman parte de un proyecto nacional de conservación costera. Los habitats importantes de forraje de tortugas marinas se beneficiarán de estas medidas.
Recientemente, se ha llevado a cabo un proyecto para la mejora de la eficacia institucional en cuanto al manejo de la zona costera de Barbados. La aplicación de legislación relativa a la zona costera es una de las áreas bajo revisión y todos los aspectos de la aplicación de legislación relativa a la zona costera en última instancia devendrá la responsabilidad de una agencia específicamente adiestrada en la legislación ambiental y su aplicación. Mayor concientización ambiental entre el público por medio de materiales y actividades educacionales ayudará las agencias en la tarea de aplicación. El Plan de Acción de WIDECAST para la Recuperación de las Tortugas Marinas de Barbados apoya rotundamente los esfuerzos encaminados a la mejora de la legislación relativa a la conservación de la tortuga marina, la de la eficacia de la aplicación de la ley y el manejo de la zona costera asicomo la distribución más efectiva de los recursos financieros y de personal por medio de la consolidación de las responsabilidades por la zona costera. El Plan también apoya la investigación encaminada en el campo y las campañas de concientización del público y propone varias actividades para mejorar y expandir la conservación de la tortuga marina en Barbados. Junto con los esfuerzos nacionales y en reconocimiento del hecho de que las tortugas marinas son altamente migratorias (que significa que Barbados pueda compartir sus tortugas marinas, en particular la carey con las islas vecinas), un programa compartido que incluya por lo menos a Santa Lucia, San Vicente y las Grenadinas, Granada y Barbados ha sido recomendado. La recuperación de las poblaciones compartidas requerirá la cooperación regional o por lo menos subregional. Al Gobierno de Barbados se le anima apoyar los esfuerzos multi-nacionales dirigidos a la conservación y recuperación de las especies marinas decimadas tales como la tortuga marina, por medio de la ratificación del Protocolo relativo al Convenio de Cartagena del PNUMA tocante las Areas y Fauna y Flora Silvestres Especialmente Protegidas en la Región del Gran Caribe.
RESUME
L'île située le plus à l'est des petites Antilles est la Barbade. Quatre espèces de tortues de mer ont été observées dans les eaux entourant la Barbade: la tortue a écaille, (Eretmochelys imbricata), la tortue à cuir (Dermochelys coriacea), la tortue verte (Chelonia mydas), et une espèce plus rare, le caouan (Caretta caretta). Ce sont les tortues à écaille qui ont la fécondité la plus élevée. Les tortues à cuir ne niched qu'occasionnellement. Les tortues à écaille nichent pendant toute l'année sauf en février et en mars mais leur période de pointe s'étend du mois de juin jusqu'au mois d'août. Les tortues à cuir sont des visiteurs saisonniers qui arrivent uniquement pour nicher entre avril et juin. Les pratiques de nichage ont été observées pendant les cinq dernières années. Les informations recueillies montrent que pas plus de cinquante tortues a écaille et moins de dux tortues à cuir nichent tous les ans. D'ordinaire, les jeunes tortues vertes se nourissent d'herges marines situées dans les zones côtières et aussi dans lles chmaps d'algues qui se trouvent le plus souvent près de la côte est. Par contre les tortues à écaille se nourissent d'éponges associées aux ris de coraux. Les couans les plus jeunes et les vrais adultes sont souvent pris dans les eaux profondes mais aucune surveillance n'a été effectuée en ce qui concerne leurs habitudes d'alimentation. Les estimations relatives aux populations de tortues de mer, telles que les tortues vertes, les tortues à écaille et le couans, qui ne nichent jamais dans les eaux de la Barbade ne sont pas disponible. Les pêcheurs pensent généralement que les populations de tortues de mer diminuent aujourd'hui par rapport aux années passées. A la Barbade, les pressions que subissent les tortues de mer proviennent de l'exploitation, de la détérioration des habitats de nichage et, dans une moindre mesure, de la diminution des habitats d'alimentation.
On attrappe les tortues à écaille pendant les périodes de nichage ou bien dans la mer à l'aide de filets pour utiliser leur chair, leurs oeufs et leurs écailles. L'écaille ser à fabriquer des artiles vendues sur place ou bien elle est expotée au Japon. Puisque la Barbade ne fait pas encore partie de CITES, l'importation et exportation des écailles accompagnées des documents appropriés sont encore légales bien qu'une décision récente exige un permis d'exportation deliré par le Chief Officier de la Pêche. Des négociations sont en cours en ce qui concerne l'adhésion de la Barbade au CITES. Outre la pêche des tortues à écaille on attrappe les jeunes tortues vertes `a l'aide de filets placés à quelques centaines de yards de la côte orientale; et les tortues vertes adultes et les couans sont capturés par les pêcheurs pélagiques qui se servent de lances pendant qu'ils attendent que leurs filets à ailette se remplissent. Concernant les tortues vertes et les couans, c'est plutôt la chair (et rarement l'écaille) qu'utilise la population. On ne tue pas les tortues à cuir; on utilise uniquement leurs oeufs. La législation antionale interdit définitivement et strictement d'attrapper sur les plages les tortues de mer et leurs oeufs, et les prises ne doivent plus se faire à l'intérieur des 90 mètres (100 yards) de la côte. La législation interdit aussi la prise des tortues qui pèsent moins de 13, 6 kg (30 lbs). Cependant les amendes sont toujours insufficantes et par conséquent n'agissent pas comme une arme préventive efficace. La mise en vigueur de la législation crée des problèmes préventives efficace. La mise en vigueur de la législation crée des problèmes préventives efficace. La mise en vigueur de la législation crée des problèmes du fait que le délit n'est pas pris au sérieux et qu'il est difficile de prover qu'une tortue a été attrappée illégalement, et aussi en raison des contraintes de personnel au sein des organismes de contrôle. Très peu de personnes vivent de l'exploitation des tortues de mer et donc le Cabinet étudie actuellement la révision d'un législation interdisant les prises de tortues de mer de toute taille et de toute espèce ainsi que l'emploi de filets enchevêtrés. Si l'interiction des prises à l'échelon national était mise en vigueur, il constituerait une raison de plus en faveur d'une adhésion rapide au CITES afin de contrôler l'importation d'écailles.
Les tortues à écaille préfèrent nicher sur les côtes ouest et sud de la Barbade et souvent dans la vegétation du littoral. Ces plages à alimentation ont été altérées et ceci, à la suite surtout du développement du tourisme. Les édifices et les murs qui ont été construits près de la marque des eaux profondes, et les grosses pierres et les gabions qui ont été mis sur les plages pour protéger les résidences ont beaucoup réduit la superficie des zones de nichage. La perte de végétation stabilisatrice qui a accompagné le développement intensif des plages entraîne aussi la diminution de ces superficies. L'éclairage ornamental et celui de sécurité empêchent les femelles de sortir pour pondre leurs oeufs et causent la mort et la désorientation en matière de nichage. En 1990 les nouveux-nés sortis de 83% de nids surveillés étaient désorientés par l'éclairage. Une forte présence de promeneurs entraîne une certaine densitée de sable sur les nids et ceci donne lieu à une mortalité élevée, ce qui accroît la mortalité des oeufs et des nouveaux-nés. Le peu d'espace consacré au nichage des tortues à écaille rend difficiles l'identification et la protection des zones spécifiques de nichage. Cependant entre 1989 et 1991 environ 15 tortues à écaille différentes auraient niché sur un espace de 1,5 km sur la côte sud-ouest et ceci indique que c'est là une zone à l'intérieur de laquelle tout développement sur les champs de nichage des tortues; par exemple, les problèmes d'éclairage peuvent être minimisés, si on installe des lumières basses, c'est à dire, à fleur de terre, pour les empêcher d'éclairer directement les plages, et en se servant de lampes à vapeur et à faible contenu de soude plutôt que de lampes blanches à lumières forte. Heureusement, un petit nombre de nids des tortues à cuir observés chaque année se trouvent sur les côtes isolées de l'est et du sud-est bien eclairées. En fait, il n'y a aucune preuve de pression à l'intérieur des habitats de nichage dont se servent les tortues à cuir.
Outre la détérioration des habitats de nichage, les champs d'alimentation ont aussi été atteints. On sait que les tortues à écaille qui varient en grandeur jusqu'à l'âge adulte se nourissent d'éponges associées aux ris de coraux ou avoisinant les terrasses sous-marines autour de la Barbade. Les tortues vertes se nourissent d'herbes et d'algues marines. A la Barbade les ris de coraux et les champs d'herbes marines jouent un rôle important pour la survie des tortues de mer; et pourtant la superficie et la variété de coraux sur les ris des côtes ouest et sud se sont beaucoup détériorées pendant les trente dernières années. Egalement les champs d'herbes marines se sont rapetisées. Les deux types d'habitats se trouvent fortement atteints par la pollution dont l'origine se trouve à l'intérieur de la Barbade tel que les égouts, les produits chimiques ménagers, les produits agro-chimiques et les sédiments. Par ailleurs, les pratiques de pêche négligentes, le mouillage sans discrimination et les activités de pêche négligentes, le mouillage sans discrimination et les activités de pêche illégales telles que le dynamitage accentuent la dégradation de ces habitats. Une zone de la côte ouest a été désignée comme réserve marine et à l'intérieur de celle-ci, la pêche et l'utilisation des bâteaux sont controlées et la prise des tortues est illégale. On poursuit des initiatives visant à identifier les sources de pollution et à mettre en application les mesures propices à la protection des habitats tout le long des côtes ouest et sud dans le cadre d'un projet national de conservation des zones côtières. Les grands habitats d'alimentation des tortues de mer benificieront de pareilles mesures.
On a récemment entrepris un projet afin d'améliorer l'efficacité institutionelle de la gestion des zone côtières de la Barbade. La mise en vigueur de la législation en matière de zone côtière est un des domaines considérés et il est probable que tous les aspects relatifs à la mise en application de la loi régissant les zones côtières relèvent de la compétence d'une agence spécialisée en matière d'environnement et d'exécution. Une connaissance plus approfondie de la part du public concernant l'environnement grâce à un programme de sensibilisation aidera les agences d'exécution. Le projet appelé "WIDECAST Sea Turtle Recovery Action Plan" pour la Barbade appuie fortement les programmes en cours visant à améliorer la conservation des tortues de mer en augmentant l'efficacité de la loi et celle de la gestion des zones côtières et en consacrant des resources financières et humaines de façon plus éfficace grâce à la consolidation des compétences en ce qui concerne les zones côtières. En outre, le projet apporte son appui aux recherches sur le champ déjà effectuées et aux programmes de sensibilisation et il propose la mise en place de plusieurs programmes de sensibilisation et il propose la mise en place de plusieurs activités ayant pour bût d'améliorer et d'accroître la conservation de la tortue de mer à la Barbade. Parallèlement aux initiatives prises à l'échelon national et en reconnaissant que les tortues de mer sont de grands animaux migratoires (c'est à dire que la Barbade partagerait ses tortues, et surtout ses tortues à écaille avec les îles voisines) on propose de mettre en place un programme continue à la Barbade avec la participation des îles suivantes: Ste. Lucie, St. Vincent, les Grenadines et la Grenade. Un tel programme qui impliquera la participation de populations diverses peut être entrepris dans le cadre de la coopération régionale, ou sous-régionale. On recommande au gouvernement de la Barbade de s'efforcer d'appuyer les initiatives multi-latérales qui visent à conserver et à récupérer les espèces marines en voie de disparition, telles que les tortues de mer et ceci, en ratifiant le Protocole de la Convention de Cartagène conclue par la PNUE et relative aux zones spéciales protegées et à la flore et la faune de la région des Caraïbes.
Barbados (59°35'W, 13°10'N) is the most easterly island in the Lesser Antilles (Map 1). Historical evidence suggests that turtles may never have been particularly common around Barbados. Turtle bones, dating back to about 1000 AD, have been found at only one of five Amerindian sites excavated in the country. By contrast, the bones of turtles are commonly found at Amerindian sites of a similar period in Antigua, as well as in St. Vincent and the Grenadines. Ligon (1673), in an account of the society, economy, and natural history of Barbados recorded during a stay between 1647 and 1650, mentions an abundance of green turtles (Chelonia mydas) in the Leeward Islands of the Caribbean. A lover of turtle meat, he was disappointed that green turtles were so few around Barbados, and moreover that those present were neither "fat nor kindly". Perhaps the green turtles he encountered were immature, or perhaps he was misidentifying hawksbills as immature green turtles.
Fresh green turtle meat was widely eaten in the Caribbean, and calipee especially was considered a delicacy in the Leeward Islands, at the time Ligon was writing. Yet the only turtle meat that was available in Barbados was pickled turtle meat imported from the Leeward islands. Ligon (1673) postulated that the lack of green turtles reflected the fact that there were no sandy beaches for turtles to nest on in Barbados. This is somewhat surprising, since one of the primary attractions of Barbados as a present day tourist destination is its white sandy beaches. Nearly two centuries later, Schomburgk (1848) included three species of sea turtle in the vertebrate fauna of Barbados: the hawksbill, green, and loggerhead sea turtles, archaically known as Caretta imbricata, Caretta esculenta, and Caretta cephalo, respectively. He made no mention of the distribution or abundance of these species, nor whether they nested on the island.
Today, hawksbills and an occasional leatherback (Dermochelys coriacea) are the only species of sea turtle known to nest in Barbados. Hawksbills, loggerheads, and green turtles are all harvested (additional detail is provided in section 3.3). Hawksbills are primarily caught with the use of nets set between the outer edges of fringing reefs and the bank reef (1000 m offshore) off the west and south coasts. Juvenile green turtles are caught in similar nets set a few hundred yards from shore on the east coast. Adult greens and loggerheads are speared opportunistically by offshore pelagic fishermen whilst they wait for gill nets to fill. The meat, eggs, and shells of hawksbills are used, as well as (but more rarely) the meat and shells of green turtles, the meat of loggerheads, and the eggs of leatherbacks -- despite the fact that egg harvest is illegal at all times (section 4.21). Turtle shell articles such as jewelry and combs are on sale in numerous tourist-orientated shops. Although present legislation prohibits the possession of any turtle under 30 lbs (13.6 kg), preserved and mounted juvenile hawksbills (generally <30 cm carapace length and thus clearly under the 30 lbs limit) can be bought from a few wayside vendors.
Sea turtles of all species can be legally caught at a distance greater than 100 yd (90 m) offshore, providing that they are over 30 lbs in weight (section 4.21). Fishermen set nets for turtles during the hawksbill's breeding season (May-October), which is said to coincide with the dropping of manchineel tree (Hippomane mancinella) berries. Since fishing practises have developed to reflect the availability of resources, the seasonality of fishing may suggest that there are insufficient numbers of adult turtles around Barbados to make fishing for them profitable outside of the breeding season. Alternatively, adult turtles may be present all year but may be harder to catch because they are not approaching and departing from nesting beaches, nor are they mating at the water's surface. Thus, during the season when pelagic fish such as flying fish (Hirundichthys affinis) and dolphin fish (Coryphaena hippurus) become abundant, fishermen concentrate on this more profitable fishery rather than on sea turtles.
Very few fishermen, if any, are dependent on the turtle fishery for their primary livelihood. No reliable records of turtle landings at fish markets have ever been kept, again suggesting that the turtle fishery was never considered important. At the present time, the majority of turtles are probably captured illegally whilst laying eggs on the beach. Certainly a high proportion of hawksbills observed nesting by the public is killed annually (15-22%, section 2.4). Consistent with a lack of economic dependence of Barbadians on sea turtles, there is a general lack of superstitions or traditions associated with sea turtles when compared to other islands in the region. This lack of dependence, combined with the high literacy rate in Barbados, may make conservation of sea turtles in Barbados relatively easier than in some other parts of the region.
II. STATUS AND DISTRIBUTION OF SEA TURTLES IN BARBADOS
2.1 Caretta caretta, Loggerhead Sea Turtle
There are no indigenous common names applied to this species and the preferred name is loggerhead. The loggerhead turtle is recognized by its large head, thick, somewhat tapered carapace (=shell), brown and gold or reddish-brown colouration, and characteristically heavy encrustation of invertebrate epifauna (especially barnacles). There are typically five pairs of lateral scutes on the carapace (Figure 1). The large head and strong jaws, for which the species was named, are necessary adaptations to a diet of mollusks and hard-shelled crabs; tunicates, fishes, and plants are also eaten (Dodd, 1988). Adults attain a straight-line carapace length of 120 cm (nuchal notch to posterior tip) and weigh up to 200 kg (Pritchard et al., 1983).
The species has a wide oceanic distribution. In the Atlantic Ocean individuals have been sighted as far north as Newfoundland (Squires, 1954) and northern Europe (Brongersma, 1972) and as far south as Argentina (Frazier, 1984). Nesting grounds are often located in temperate latitudes, with the greatest numbers of nesting females recorded on the Atlantic coast of Florida (USA) and on the shores of Masirah Island, Oman. Nesting is also reported from various islands of the Greater and Lesser Antilles (although firm records are not always available), the Caribbean coasts of Mexico and Central America, and the Atlantic coast of South America from Venezuela to Brazil, as summarized by Dodd (1988).
Loggerheads are not known to nest in Barbados, but juveniles (one weighed 32 kg) and adults or near-adults (one measured 83 cm straight carapace length) are occasionally caught opportunistically offshore by pelagic fishermen. These turtles are usually speared by the fishermen as they wait for their gill nets to fill (see section I). The meat is eaten whenever available. Foraging grounds have not been identified. Neither spatial nor temporal patterns of distribution are known. Population estimates are not available. The species is considerably rarer than either the green turtle or the hawksbill.
2.2 Chelonia mydas, Green Sea Turtle
Local common names for this species include green turtle and green-back. Green turtles are recognized by a single pair of scales on the forehead between the eyes and a round, blunt beak serrated for clipping sea grasses. The carapace is smooth and the plates (=scutes) do not overlap one another (in contrast to the hawksbill turtle, see section 2.4). The carapace is characterized by four pairs of lateral scutes (Figure 1) and is generally free of barnacles. Adults at-tain weights of 230 kg and generally measure 95-120 cm straight-line carapace length (nuchal notch to posterior tip) (Pritchard et al., 1983). Individuals of varying sizes are present in the waters surrounding Barbados throughout the year.
Green turtles are herbivorous and in the Caribbean they feed primarily on the sea grass Thalassia testudinum (Bjorndal, 1982). Field studies indicate that individual turtles maintain feeding "scars" by returning to the same area of sea grass meadow to forage everyday (Bjorndal, 1980; Ogden et al., 1980, 1983). These scars, or grazing plots, are maintained by regular cropping for several months and the more digestible newer growth (higher in protein, lower in lignin) is preferred (Bjorndal, 1980). When the cropped grasses show signs of stress (blade thinning, increased inter-nodal distance), the turtle generally abandons the scar and moves on to form another. Sea grasses are relatively rare in Barbados. The best developed foraging areas are found on the south coast and in protected bays on the east coast (section 4.111) (Map 2).
There are no documented incidents of green turtles nesting in Barbados, although a single hatchling was found in 1990 on land at a site far from the sea. Where it came from and how it got there are unknown. Adults are occasionally caught opportunistically offshore (usually speared), but they are rarely seen in coastal waters. In contrast, juveniles (5-18 kg in weight) are relatively common in coastal waters, especially on the east coast. Some fishermen take them opportunistically and more rarely set nets for them, although those they catch are often below the 30 lbs (13.6 kg) legal size limit (see section 4.21). Green turtles are long-lived and require 25-35 years to reach sexual maturity in the Caribbean (Frazer and Ladner, 1986). Age structure of the population(s) feeding in the waters of Barbados has not been studied.
2.3 Dermochelys coriacea, Leatherback Sea Turtle
Leatherbacks are the largest of all the sea turtles (nesting females often weigh 300-500 kg) and they have the most extensive geographic range of any turtle. Aside from their great size, leatherbacks are easily distinguished because they lack a bony shell. The smooth, black skin is spotted with white. The carapace is strongly tapered, measures 130-165 cm in length (straight-line, nuchal notch to posterior tip), and is raised into seven prominent ridges (Figure 1). Powerful front flippers extend nearly the length of the body. Adults, at least adult females, are excellent divers, having been recorded at depths exceeding 1000 meters in Caribbean waters (Eckert et al., 1989). Leatherbacks feed predominately on jellyfish and other soft-bodied prey (Den Hartog and Van Nierop, 1984; Davenport and Balazs, 1991). Based on offshore studies of diving by gravid (=egg-bearing) females nesting in St. Croix, Eckert et al. (1989) proposed that inter-nesting dive behaviour may reflect nocturnal feeding on vertically migrating zooplankton, chiefly siphonophore and salp colonies.
Yalimapo-Les Hattes, French Guiana, is the largest nesting colony in the Western Atlantic and supports an estimated 14,700-15,300 females (Fretey and Girondot, 1989). In contrast, most Caribbean populations, particularly those associated with islands, are small (<150 females). This is the case in Barbados, where only a few nestings occur each year between April and June on the remote and high energy Atlantic beaches of the east and southeast coasts (Map 3). Eight nests were reported between 1984-1987 (Horrocks and Willoughby, 1987). Based on data collected elsewhere in the region, we assume that individual females return on 2-3+ year intervals and deposit an average of 5-6 clutches/yr, each clutch averaging 80-90 yolked eggs (a variable number of smaller yolkless eggs are also laid). Nests are made on 9-10 day intervals.
The evidence currently available from tag returns and strandings in the western Atlantic suggests that adults engage in routine migrations between temperate and tropical waters, presumably to optimize both foraging and nesting opportunities. This appears to be the case in Barbados, where the leatherback is not resident but occurs only during the egg-laying season. Leatherbacks are not fished or killed whilst nesting; they are considered rather unusual and not very edible. Only the eggs are taken (illegally, see section 4.21). Fishermen have towed large leatherbacks back to Barbados to show people before returning them to the water, and newspapers have published photographs of large nesting females. In a very unusual occurrence, an adult female (149 cm curved carapace length, 109 cm curved width) washed ashore headless and limbless in early December 1991, apparently butchered at sea. Young juveniles occasionally strand on the east coast (Horrocks, 1987).
2.4 Eretmochelys imbricata, Hawksbill Sea Turtle
The hawksbill is distinguished by a narrow, pointed beak with which it pries sponges and other soft-bodied organisms from the reef. The carapace is often posteriorly serrated and carapace scutes overlap, like shingles on a roof (Figure 1). Adults rarely exceed 80 kg and a carapace length of about 90 cm (straight-line, nuchal notch to posterior tip). Bright mottled colouration (brown, orange, gold) is common. Hawksbills have proven difficult animals to study and very little is known about Caribbean populations in general. Gravid females often nest on isolated beaches, including those flanked by exposed coral and rock, and routinely retreat into supralittoral vegetation such as the sea grape tree (Coccoloba uvifera) prior to egg-laying. As a result, there may be little evidence of the nest aside from a faint asymmetrical crawl (about 0.7 m wide) leading to and from the ocean.
An island-wide survey by the Barbados Environmental Association in 1987, as well as reports by the public up to the present, have shown that hawksbills nest primarily on the more sheltered, more steeply sloping west and south coast beaches (Horrocks and Scott, 1991) (Map 4). An area of relatively concentrated nesting occurs on 1.5 km of the south coast where 5-7 females nest per annum. There are records of hawksbills nesting during all months of the year, with the exception of February; peak nesting occurs during June-August (Figures 2, 3). Nest counts indicate that, on average, fewer than 50 females nest in Barbados each year (see sections 4.112, 4.291). Mean clutch size is 139 eggs (n=81 nests), which falls within the range reported for other Caribbean populations (120-200 eggs: Witzell, 1983; Corliss et al., 1989). At Pasture Bay, Antigua, inter-nesting intervals average 14-15 days (Corliss et al., 1989); preliminary data from Barbados indicate likewise.
Hawksbills are "spongivores" feeding on reef-associated sponges in the Caribbean region. Sponges contributed 95.3% of the total dry mass of all food items in digestive tract samples from 61 animals from seven Caribbean countries (Meylan, 1988). Specific feeding areas have not been identified in Barbados, but foraging is assumed to be more or less coincident with the distribution of coral reefs around the island (section 4.111). All size classes 23 cm straight-line carapace length and larger are seen in Barbados' nearshore waters. The turtle fishery concentrates its efforts within the nesting season (May-October). At this time, entangling nets (20-30 cm mesh) typically 2.5-3.5 m deep and 20-150 m long are set close to shore where females are likely to be approaching and leaving beaches. Nets set within 100 yds of shore are illegal, but enforcement is problematic (sections 4.21, 4.22).
The illegal killing of nesting hawksbills remains a problem, primarily because the penalty (Bds. $100) is insufficient and enforcement of the present legislation is difficult. In 1987, 22% of nestings reported by the general public resulted in the female being slaughtered. In addition, poaching of eggs occurred in approximately 15.2% of all reported nestings. In 1991, Bellairs Research Institute received information on nesting by a total of fewer than 50 different turtles, and eight of these animals (>16%) were slaughtered. The habit of nesting on the highly developed west and south coast beaches has meant that hawksbills are also adversely affected by coastal development and beach erosion (see section 3.1). Jewelry and other items made from hawksbill shell are widely available in tourist-oriented shops and there is some export of shell to Japan (section 3.3).
2.5 Lepidochelys kempi, Kemp's Ridley Sea Turtle
There are no records of Kemp's ridleys foraging or nesting in Barbados, nor would the species be expected to occur. With the exception of a single recapture from Caribbean Nicaragua of a "head-started" individual (Manzella et al., 1991), which may have displayed altered behavior due to having been held captive during its first year (Woody, 1991), Kemp's ridleys are confined to the Gulf of Mexico and temperate northern Atlantic. Unarguably the most endangered sea turtle in the world, the total adult population is thought to number no more than 900 females and an unknown number of males (Ross et al., 1989). Some 42,000 females were observed nesting in a single day at the primary rookery at Rancho Nuevo in 1947, whereas 200-400 females nest annually today (Richard Byles, U. S. Fish and Wildlife Service, pers. comm.). The species nests almost exclusively in the state of Tamaulipas, Mexico.
2.6 Lepidochelys olivacea, Olive Ridley Sea Turtle
There are no records of olive ridleys foraging or nesting in Barbados. However, occasional individuals may be expected in view of the occurrence of this species in Trinidad and Suriname. In the Western Atlantic, significant levels of nesting appear to occur only in Suriname, primarily at Eilanti Beach (Schulz, 1975). Olive ridleys nesting in Suriname have declined considerably in recent years, dropping from about 3,000 nests per year in the late 1960's to fewer than 500 nests per year today (Fretey, 1990). Diffuse nesting occurs in northwestern Guyana and in French Guiana (Reichart, 1989).
III. STRESSES ON SEA TURTLES IN BARBADOS
3.1 Destruction or Modification of Habitat
Beaches on the west and south coasts of Barbados are composed of coralline particles derived from the reefs offshore and are subject to seasonal erosion and accretion. Erosion generally occurs between January and March and accretion between April and September on west coast beaches; and erosion between March and September and accretion between October and February on south coast beaches. West coast beaches have diminished in size (presently they are about 15 m wide) at an average of 0.3 m/yr over the period 1954 to 1982. If this rate of erosion continues, some of these beaches may disappear by the year 2000. The south coast beaches, with a few notably bad exceptions, have remained fairly stable over this same period. Their stability may be due in part to the construction of groynes for sand entrapment. The east coast beaches have remained the most stable over this time period. The sand on these beaches is primarily siliceous and is derived from land-based sources, but they, too, are subject to erosion during the time when wave energy is at its highest on this coast (June-September). The erosion of beaches has serious implications for the future of tourism, and hence the economy of Barbados, apart from the effect on turtles nesting in Barbados.
The loss of beaches has been attributed in part to natural phenomena such as the rising sea-level, but a more immediate correlation with disappearing beaches is the extensive beach-front development and accompanying loss of stabilizing beach vegetation that has occurred over the past few decades. Seawalls and boulders are often used to protect sea-front properties. These structures may aggravate beach erosion by deflecting wave energy abruptly downwards, thereby increasing the scouring effect of waves. The construction of hotels and houses continues on the few remaining undeveloped beach front areas on the west and south coasts. Hotels modify nesting areas more seriously than private houses. Ornamental and security lighting, removal of beach vegetation, and heavy pedestrian use of beaches may discourage turtles from nesting, as well as increase hatchling mortality and aggravate erosion. Specific measures designed to mitigate the degradation of nesting beaches are discussed in sections 4.13 and 4.6.
As noted above, the lighting of beaches adjacent to houses and hotels may deter females from nesting (see also section 4.132). Moreover, several nesting females have been found on their backs in storm drains or wedged between boulders that have been placed to fortify the beach. There are now very few undeveloped beach front areas along the west and south coasts where females can emerge and nest in darkness. When nesting does occur adjacent to hotels and houses, hatchlings are invariably attracted to lights, and often not found until the next day or later. Mortality among disorientated hatchlings is high, and those that are found alive are often too exhausted to be released. Of 27 nests monitored in 1987-88, 14 (55.6%) were affected by beach lights at hatching, with up to 100% of hatchlings in affected nests orienting inland instead of toward the sea (section 4.132). In 1990, hatchlings from 83% of 35 monitored nests were disoriented by lighting. The problem may be worsening due to a generalised increase in security lighting.
The health of the west and south coast fringing reefs in terms of coral cover and diversity and fish abundance and diversity is generally acknowledged to have deteriorated over the past 30 years. In order to quantify and monitor the status of these reefs, an extensive data base has recently been obtained (section 4.11). Reef deterioration is likely to be attributable to poor nearshore water quality, over-fishing, poor fishing practises (e.g., careless deposition of traps and pots, illegal dynamiting for fish), and anchor damage. Since hawksbills appear to depend on sponges and other reef-associated invertebrates for food in the Caribbean, this species is likely to be adversely affected by the deterioration of coral reefs. In addition, it is the opinion of knowledgeable residents that sea grass beds, which provide important food for the herbivorous green turtle, have diminished in size over the past two decades. Degradation of sea grass beds may be attributable to increased inputs of sediment resulting in clouding of the water and a reduction in rates of photosynthesis, and increased inputs of herbicides and pesticides via land run-off (section 4.146).
Nesting and feeding areas on the less developed east coast are not affected as severely as those on the south and west coasts. Habitat stresses on leatherbacks, which nest primarily on the east coast and forage in the open ocean, are therefore minimised.
There are few data available to assess whether sea turtles are seriously stressed by disease or non-human predators in Barbados. In 1980-81, 5-10 juvenile green turtles were caught off the east coast with tumors over their eyes and on their flippers, indicative of a disease known as green turtle fibropapilloma. In 1990, 19 of 21 green turtles (weight range 5-18 kg) caught by two east coast fishermen were afflicted by this disease. The extent to which these tumors affect the survival of sea turtles in Barbados is not known, but to date the disease has been found only in green turtles caught on a small rocky outcrop surrounded by sea grasses off Barclays Park. Green turtles caught at other east coast sites 6-8 km away from this area were not affected (Gamache and Horrocks, 1991). Green turtle fibropapilloma has been documented extensively in Florida (Ehrhart, 1991) and has more recently been found in Curaçao (Jacobson, 1990), Venezuela (Guada et al., 1991), and Belize (Karen Eckert, WIDECAST, pers. comm.). The cause of this debilitating and often fatal disease is unknown.
In addition to disease, depredation is a factor impacting on sea turtle populations. During the incubation period, eggs attacked by insects in the nest can be subsequently infected with fungi and bacteria. Vertebrate predators, such as mongooses, are rarely seen on beaches, but on two occasions at one location mongooses were seen carrying eggs from nests. Both of these nests had been previously exposed, by poachers in one case and wave action in the other case. Dogs also sometimes consume turtle eggs (Horrocks and Willoughby, 1987). After hatching, ghost crabs (Ocypode quadrata) prey on hatchlings as they crawl across the beach and fishes consume the small turtles once they enter the sea. Since most nesting occurs on the west and south coasts where nearshore water quality and over-fishing have affected the abundance and size of potential predators, reef-associated predation of hatchlings may be less serious than that in the vicinity of healthier reefs elsewhere in the Caribbean. Two young juvenile leatherbacks (20-30 cm straight-line carapace length) have been found stranded in east coast rock pools since 1984. Each had a recently bitten-off front flipper, suggesting shark attack (Horrocks, 1987). An adult female with her right front flipper severed off in a manner again suggestive of shark attack stranded on the same beach (Cattlewash Beach) in February 1989 (Horrocks, 1989).
Dr. Wayne Hunte of the Bellairs Research Institute reported to the Western Atlantic Turtle Symposium (Hunte, 1984) that, since fishery catch statistics began to be compiled in the early 1960's, there had been no specific record-keeping for sea turtles. Turtles were included under "any other deep water species" on Fishery Division's Recording Forms, suggesting that their harvest was never a very large enterprise. It is not possible to ascertain what portion of turtles landed were brought to landing sites, nor what portion of those were recorded; however, landing data are likely to represent an acceptable subsample of the catch as a whole. Three points are noteworthy: (1) there was a continuous decline in turtle catch between 1963 (nearly 1300 lbs/landing site) and 1974 (<100 lbs/landing site), whereafter the catch leveled off until 1982 (the last year for which data were presented by Hunte) at 200 lbs/landing site, (2) during the 1950's the mean number of turtles caught per fishermen per month was in the order of 35, whereas at the time of Hunte's (1984) writing this had declined to two turtles, and (3) the average size of turtles caught may also have declined.
Sea turtles are turned whilst nesting, or captured at sea using entangling nets (20-30 cm mesh) typically 2.5-3.5 m deep and 20-150 m long. Nets are set both at the surface and at the bottom. Sometimes turtles are speared. Turtle fishing is conducted by only a few fishermen, and only as a supplement to their other fishing activities (Hunte, 1984). Today, as was true a decade ago, it is generally acknowledged by fishermen that turtles are less common than in previous years. The fishery continues to target adult females, and the removal of this age/sex class is likely to affect the viability of remaining populations most severely. A high percentage of hawksbills observed nesting by the public is killed annually (16-22%, section 2.4). The female is either killed prior to laying and the eggs are removed and sold, or the eggs are taken from the nest. Some turtle poachers will take the female but leave the eggs. This is viewed as a conservation measure to ensure that there will continue to be sufficient turtles in the future, but the fact is that harvesting adult turtles, regardless of whether or not the eggs are left behind, is extremely detrimental to sea turtle populations (see section 4.233).
There are several market points around the island for the handling and sale of turtle meat, eggs and shell. Because the sale of sea turtle is increasingly covert, the exact number of turtles sold each year is not known. Approximately half of a turtle's weight is considered to be meat, which sells at an average of Bds. $2.80 (US $1.40) per lb. An adult turtle also yields about 6-8 lbs of shell which sells at Bds. $15.00 per lb. Eggs sell at Bds. $2.00 per lb. An average adult hawksbill weighs approximately 160 lbs (average weight of breeding female; Olson, 1985). A turtle of this size is therefore worth Bds. $224.00 in meat and Bds. $105.00 in shell, making a total of Bds. $329.00 (Horrocks and Willoughby, 1987). Meat and eggs are sold and consumed domestically, as is some of the shell. Turtle shell (also known as 'tortoiseshell') articles are widely available in tourist-orientated shops. Until recently, when department stores were reminded of the laws protecting small turtles, whole stuffed juveniles were also offered for sale (Horrocks and Willoughby, 1987). Harvest is continuing, but restaurants have responded to ongoing public awareness campaigns and have voluntarily removed turtle meat from their menus (section 4.41).
Persons wishing to export turtle shells or shell products from Barbados require documentation from the Ministry of Trade, Industry, and Commerce (Barbados Export Promotion Corporation) and from the Ministry of Labour, Consumer Affairs and the Environment (Price Control Division). Permission from the Chief Fisheries Officer is also required. Present policy does not permit the exportation of turtle shells that originate in Barbados. Japanese Customs data indicate that 1,930 kg of "bekko" (hawksbill shell scutes) was imported from Barbados between 1970-1986 (Milliken and Tokunaga, 1987), and that a further 529 kg was imported in 1990 (Canin, 1991). It is unlikely that the population of hawksbills around Barbados could supply this amount of bekko and the data suggest that Barbados, a non-party to CITES [Convention on International Trade in Endangered Species], has been named as the port of export even though the shell did not actually originate from Barbados. This practise is not uncommon among dealers trying to evade CITES restrictions (Canin, 1991).
The lateral and vertebral scutes from the carapaces of two adult hawksbills caught in Barbados (82 cm and 95.5 cm curved carapace length) yielded an average of 1.4 kg bekko (J. Horrocks, unpubl. data). This agrees with the calculated average yield of 1.34 kg bekko per hawksbill imported into Japan from the Caribbean region (Milliken and Tokunaga, 1987). Based on the Japanese Customs statistics cited above and the average yield of bekko per hawksbill, we can estimate that 1,440 turtles were killed between 1970 and 1986, and nearly 400 more in 1990, in order to supply the bekko exported (or allegedly exported) from Barbados to Japan.
3.4 Inadequate Regulatory Mechanisms
It is illegal to take turtle eggs, to catch or attempt to catch turtles on the beach or within 100 yd (90 m) of the shore, or to buy, sell or possess any turtle of weight less than 30 lbs (13.6 kg) (section 4.21). If found guilty, offenders are punishable by confiscation of the turtle, eggs, and/or fishing gear and by a fine of Bds. $100 (US $50). The present legislation offers little deterrent since an "average" female is worth between Bds. $200-300 in meat alone (section 3.3). Confiscation of gear, such as boats, is a more serious deterrent, but since catching a female on the beach requires no gear that can be confiscated, the fine of Bds. $100 is totally insufficient to deter the widespread poaching of nesting females. Recognizing that present legislation is inadequate, new regulations are proposed in section 4.23. Improving local enforcement efforts is discussed in sections 4.22 and 4.616.
3.5 Other Natural or Man-made Factors
Four additional sources of mortality should be mentioned. First, the illegal practise of dynamiting coral reefs for fish (section 4.141) kills an unknown number of turtles each year. Second, there are increasing reports of turtles being struck by speed boats and jet skis in the waters off the west and south coasts. Third, compaction of sand over nests, caused by heavy pedestrian beach use, prevents the emergence of hatchlings, and has caused up to 100% mortality in some nests (Horrocks and Scott, 1991). Fourth, nest flooding by salt and freshwater is a serious threat to the successful hatching of eggs in some areas (Horrocks and Willoughby, 1987). All sea turtle embryos require oxygen during their development and will drown if submerged in water for an extended period of time.
IV. SOLUTIONS TO STRESSES ON SEA TURTLES IN BARBADOS
4.1 Manage and Protect Habitat
The protection of important foraging and nesting habitats is crucial to the survival of sea turtles in Barbados. As is true for many territories in the Caribbean, the decline in sea turtle stocks in Barbados has coincided with a decline in nearshore fishery resources in general, including lobster, conch, and sea eggs, and chronic deterioration of marine and coastal environments. Nearshore fisheries are both easily accessible, and so the first to be over-exploited, and are the most vulnerable to land-based sources of pollution (see sections 4.143, 4.146, 4.147). Where the pollution of nearshore waters negatively impacts on coral reef health, the effectiveness of reefs as dissipators of wave energy is diminished and beach erosion can follow. Therefore, nearshore habitat deterioration will ultimately affect more than just the livelihoods of fishermen. The island's economy is heavily dependent upon tourism, and the management and protection of natural resources is beginning to receive high priority (sections 4.611, 4.612). Sea turtles are fortunate in that they should also benefit from most management and protection plans designed to mitigate the many threats posed by pollution and general neglect of the marine environment.
In Barbados, coral reefs and sea grass beds are utilised by sea turtles for foraging and sandy beaches are utilised for nesting. Primary habitats are poorly known, although some survey work has been undertaken. There are no marine or terrestrial parks or reserves designated for the protection of sea turtles. However, turtles and other marine life are protected from pollution and harvest within the confines of the Barbados Marine Reserve, which extends 2.2 km along the west coast and 1000 m offshore (Map 5).
Limited resources dictate that the management and conservation of sea turtles focus first on those habitats most critical to their survival in Barbados; further study is sorely needed in order to identify these areas. The Coastal Conservation Study (1984) mapped the locations of sea grass beds and coral reefs around the west and south beaches of Barbados (Map 2). These areas all represent potential foraging habitats for green and hawksbill sea turtles. Loggerheads, which are rare in Barbados, would be expected to forage on crustaceans and mollusks in reef, rock and other hard bottom areas. Leatherbacks have not been observed to feed in the waters of Barbados, and apparently remain in deep waters between nestings. This species would be expected to consume jellyfish and related animals either at the surface or in the water column. Foraging has been cited as an impetus for deep diving by gravid females in the U. S. Virgin Islands (Eckert et al., 1989).
Sea grasses are much less extensive around Barbados than around most other Caribbean islands and their role in the coastal ecosystem of Barbados has not been studied. The largest grass bed areas are on the south coast from Oistins to Bridgetown, and there are smaller beds in protected bays on the east coast. Along the western coast, sea grasses are very sparse. Know-ledgeable residents report that sea grass beds have diminished in size over the past two decades. Increased inputs of sediment, resulting in clouding of the water and a reduction in rates of photosynthesis, and increased inputs of herbicides and pesticides via land runoff are implicated in sea grass decline. Sea grass beds and coral reefs are both important to green turtles, for whom they provide food and shelter, respectively. The relative scarcity of green turtles as compared to hawksbills may perhaps be explained by the lack of sea grass around Barbados.
Barbados is a coral island dotted by fringing reefs and a more or less continuous bank reef approximately 1 km offshore along the western and southern coasts (Map 2). A principal component of the diet of hawksbill turtles is reef-encrusting sponge; thus, for hawksbills, reefs are used not only for shelter but also for food. Over the past twenty years the health of fringing reefs has declined, due primarily to poor nearshore water quality (see also sections 4.143, 4.146, 4.147). Bellairs Research Institute, under contract from the Coastal Conservation Project Unit of the Ministry of Labour, Consumer Affairs and the Environment, conducted the first quantitative benthic survey of the fringing and bank reefs on the south and west coasts of the island (Oxenford et al., 1989). The survey provided baseline data on the present state of the reefs and will allow any future changes in reef health to be quantitatively assessed. The survey also quantified fish abundance and diversity, and coverage of hard coral, soft coral and algae.
Preliminary nearshore surveys (line transects) at water depths of 3-15 m along a northern section of the west coast of Barbados were conducted by Bellairs Research Institute in July-August 1991 as part of their sea turtle conservation activities. Juvenile turtles (greens and hawks-bills combined) were encountered at a rate of about 0.4 per km. No adults were observed. The only information available to date on foraging habitat used by sea turtles is qualitative, consisting of occasional sightings from the cliffs along the northeast coast and reports from SCUBA dive operators visiting the same areas repeatedly. A comprehensive long-term survey is needed in which dive operators, marine research scientists, and fishermen should all be encouraged to participate. The dive operators have already expressed a willingness to take part in small-scale surveying of nearshore foraging habitats. This cooperation will be very useful in assessing the relative importance of various coastal habitats.
The Coastal Conservation Project Unit (CCPU) is an agency within the Ministry of Labour, Consumer Affairs and the Environment. It was established in 1983 to advise on coastal erosion matters. Its routine activities include monitoring of beaches around the island and the review of applications made to the Town Planning Department (Ministry of Housing and Lands) for any proposed coastal development. The CCPU surveys 38 beaches at 3-month intervals, 20 at 2-week intervals, and 17 annually. The resulting profiles allow changes that have taken place over the past five years to be quantified, and strategies for subsequent beach stabilization measures to be developed. These data are also very useful for the long-term monitoring of sea turtle nesting habitat.
The first comprehensive attempt to survey beaches for sea turtle nesting activity was made in 1987 in preparation for WATS II, the Second Western Atlantic Turtle Symposium (Horrocks and Willoughby, 1987). It was estimated that from June to August (peak nesting period) there were about 44 km of suitable nesting beaches around Barbados; where a suitable beach was defined as one for which some sand remains exposed at even the highest tides. This figure exaggerates the number of beaches actually used by turtles for nesting, since it does not take into account the presence of housing developments nor the amount of vegetation on the beaches. However, because hawksbills do sometimes nest on highly public beaches, all beaches that were suitable as defined above were included in the assessment of the total amount of potential nesting beach available. On the west and south coasts, changes in beach width can be dramatic between nesting and hatching, although most nesting activity has ceased by the time the largest swells arrive.
Information on nesting activity in 1987 was collected by two methods. First, as part of a national information campaign, the public was asked to call a telephone number provided for the purpose of reporting observations (night or day) of turtle nesting or hatching activity. Second, volunteers from the Barbados Environmental Association conducted a series of early morning beach surveys during the peak breeding season (June-August) (section 4.291). Reports of hawksbill nesting came from most beaches along the west and south coasts of Barbados, as well as some sheltered east coast beaches (Map 4). Data combined from nesting reports and beach patrols indicated that 120-362 hawksbill nestings occurred (Horrocks et al., 1987; see also section 4.291). Gravid hawksbills in Antigua deposit up to six clutches of eggs per season (Corliss et al., 1989), but the modal (most common) number is five clutches (Jim Richardson, University of Georgia, pers. comm.). Based on an average of five nests per female, an estimated 24-72 hawksbills nested in Barbados in 1987.
Public awareness and participation in the monitoring of sea turtle nesting activity has increased substantially since 1987. In 1989, 1990, and 1991, the number of hawksbill nests reported by residents was 71, 60, and 91, respectively (Figure 3). Analysis of the timing and placement of these nests suggests that 37, 25, and 47 females nested in Barbados in 1989, 1990, and 1991, respectively (see also section 4.291). In addition to valuable input from residents, 1.5 km of beach on the south coast from the Barbados Hilton east to Ocean View, where it was claimed that turtles nested in high numbers, was surveyed each morning throughout three consecutive nesting seasons (1989-1991) by a volunteer as part of the sea turtle conservation activities of Bellairs Research Institute. The results of this survey indicated there were 5-7 hawksbills nesting annually on this stretch of beach. Assuming a remigration interval similar to Antigua (Corliss et al. 1990), an estimated total of only 15 individual females nested on this beach over the entire three year period. Although these numbers are small, in the context of the estimated size of the Barbados population, this area warrants protective measures.
It is important for beach surveys to continue in order to further define essential habitat in Barbados, to monitor trends in nesting numbers, and to minimise threats to nesting turtles and their eggs. Systematic surveys should be initiated at beaches where hawksbills are known to nest and where the illegal killing of turtles is reported to occur; e.g., Long Beach on the south coast, a strip of beach between Heywoods and Six Mens on the northwest coast, and Bath on the east coast. Early morning surveys could be conducted by volunteers, but this would require collaboration between several organisations, including Bellairs Research Institute, Barbados Environmental Association, Barbados National Trust, the secondary schools, etc. Bellairs Research Institute (Lead Organisation for WIDECAST in Barbados) or Barbados Environmental Association could co-ordinate activities and provide training for volunteers. Alternatively, interested persons could be employed to monitor specific beaches throughout the nesting season. Night surveys are preferred in order to deter poaching and to permit the systematic tagging of females.
Persons employed to monitor beaches at night and tag post-nesting turtles will require specific technical training. Hawksbills can be very easily deterred from nesting by activity on the beach, and it is vital that survey activities of preferred nesting beaches do not result in these habitats being avoided by turtles. Training sessions could be conducted by Bellairs Research Institute staff. [N.B. An introductory training course in sea turtle biology and management is available from the Caribbean Conservation Corporation, see section 4.55.] The important Hilton-to-Ocean View stretch of south coast beach described above is already monitored in the early morning, but nocturnal surveys would enable tagging to be initiated. Night surveys would require the assistance and support of enforcement agencies.
Presently, there are no specific management plans for sea turtles in Barbados. Although there are provisions in current legislation for establishing marine reserves and protected beach areas, the patchy spatial distribution of hawksbill nesting and the infrequency with which leatherbacks nest make it difficult to identify and protect the nesting areas of either species. However, the 1.5 km stretch of south coast beach described in section 4.112 (Barbados Hilton east to Ocean View) appears to warrant special consideration; a specific management plan is recommended. This beach is developed for most of its length, but buildings are set back and the beach remains relatively wide and dark compared to most other south coast beaches. The recent finding that a minimum of 15 hawksbills nested at this site during three consecutive years (1989-1991) makes this area important to protect from any future development that will negatively impact on sea turtle nesting. Hotels adjacent to the beach have already been cooperative in monitoring nesting activity and attempting to minimise disorientation of hatchlings from known nests by reducing the amount of light shining in the area of nests.
A disadvantage of designating particular areas for the protection of hawksbills is that this may be seen as an adequate measure of protection and result in the relaxation of regulations elsewhere on the island. In some cases, however, such as the site described above, specific protection is encouraged. In addition, it is likely to become necessary for a beach or section of beach to be reserved for nest reburial, perhaps through the Marine Areas (Preservation and Enhancement) Cap 392, 1976 legislation (see section 4.21). Ultimately, the most appropriate strategy for protecting nesting and feeding areas may lie in a coastal zone management plan applicable to the whole coast of Barbados. Atherley (1987) suggests an outline for comprehensive Coastal Zone Management legislation that would plug legal loopholes and give the responsibility for enforcement to one independent agency with skills in coastal zone management. A project for improving the institutional effectiveness of coastal zone management in Barbados was conducted in 1991 through the Coastal Conservation Project Unit. The challenge will be to integrate all the separate agencies into unified enforcement and policy implementation. Coastal zone management legislation is especially important for the management of the (as yet) largely undeveloped east coast.
The Coastal Conservation Project Unit (CCPU) is the agency responsible for research and monitoring of the coastal zone (including beaches and reefs) and acts as an advisory body to the Town Planning Department, the Minister of Housing and Lands, and the Ministry of Labour, Consumer Affairs and the Environment. The CCPU has been advised of the ways in which coastal development affects sea turtles. They have already contributed useful ideas in discussions about how conflicts between the needs of sea turtles and the economic and social development needs of Barbados might be resolved. For instance, they have suggested that endangered nests be relocated to safer beaches or to beach hatcheries, and that beach vegetation receive similar protection to that given to trees over a certain size under the Trees (Preservation) Act 1981.
At present the coastal zone is managed and legislation is enforced by several different agencies. The National Conservation Commission (NCC) is responsible for the maintenance of beaches, and also acts as an advisory body to the Minister of Housing and Lands for decisions pertaining to the construction of beach recreational facilities, and prevention of beach erosion. NCC personnel include rangers, wardens, life guards and beach cleaners. Rangers and wardens have powers to arrest persons committing certain offences under the National Conservation Cap. 393. Beginning in 1991, NCC personnel have been incorporated into the programme (sponsored by Bellairs Research Institute and the Fisheries Division of the Ministry of Agriculture, Food and Fisheries) that is presently monitoring sea turtle nesting activity (see also section 4.291). Agency-specific measures recommended in the area of sea turtle conservation are discussed in section 4.6.
The following actions are of fundamental importance to the sustained protection of sea turtle nesting and foraging areas: (1) amend and/or rewrite existing coastal zone laws pending suggestions arising from the institutional strengthening project, increase penalties to act as a more serious deterrent, and strengthen enforcement efforts.
In addition to these general improvements, more specific regulations will be needed to protect particularly important foraging or nesting areas. When areas are defined as especially critical to remaining sea turtle populations, regulatory guidelines will be essential in order to establish a framework within which appropriate land use and development (commercial, residential, recreational) can occur. For instance, development proximal to important nesting beaches should be required to design beach front lighting in such a way as to preclude or minimise the disorientation of hatchlings or nesting adults (section 4.132). Construction of solid jetties and beach walls, and activities such as sand mining (section 4.131) and dredging should be regulated in such a way as not to result in the erosion of nesting beach habitat. Similarly, boaters should be prevented from indiscriminate anchoring in reef or sea grass habitats (section 4.147) and from discarding refuse at sea (section 4.144). These are, in many cases, common sense measures which will not only defend important habitat for the benefit of endangered and declining sea turtle populations, but also ensure that sensitive areas are properly safeguarded for future generations of Barbadians.
Enforcement is the responsibility of the Royal Barbados Police Force, the Barbados Coast Guard, and to a lesser extent the National Conservation Commission (NCC). These agencies have recently been sensitized to the legislation pertaining to sea turtles. Enforcement of legislation protecting turtles and their nesting and feeding habitats should be shared between the police, Coast Guard and, ultimately, trained coastal zone rangers. The National Conservation Commission already employs personnel with limited powers of arrest for offences committed on beaches; e.g., selling goods or services on a beach without an appropriate license. Training NCC personnel to assist the Barbados Police Force to enforce legislation protecting nesting turtles and their eggs would be very valuable.
Since no specific area or zone for official protection has been designated to date, it is desirable that citizens throughout the country continue to be made aware of efforts to conserve turtles and be told what they can do to assist these efforts. A number of pamphlets, books, posters and car stickers are already in circulation in Barbados, and these are supplemented by radio and television broadcasts throughout the sea turtle breeding season (section 4.41). In the past, the Barbados Environmental Association has surveyed the beaches of the whole island once a month during the breeding season. They are planning to repeat these surveys and to encourage the public to participate. The Association is seeking funding to produce posters targeting tourists at the airport and sea port, advising them against buying turtle products (section 4.43). They are also planning to make a wildlife documentary of Barbados that will include a section on sea turtles.
4.13 Prevent or mitigate degradation of nesting beaches
The chronic removal of sand from nesting beaches accelerates erosion and degrades or destroys beach vegetation either by removal or by salt water inundation. In severe cases, saline ponds are formed in unsightly pits left by mining operations. With the loss of sandy beaches, the coast's potential to support recreation, wildlife (e.g., sea turtles), tourism, and commercial development is reduced. It is presently illegal to remove sand from the foreshore of Barbados, and specific areas adjoining the foreshore have been identified for protection against sand mining (section 4.21). Recently, however, the illegal removal of sand from beaches (e.g., Long Beach, which is reported to be an important hawksbill nesting area) has been observed. It is the recommendation of this Recovery Action Plan that the law banning the removal of sand from beaches be enforced diligently.
Beach front lighting is a serious cause of mortality among hawksbill hatchlings, and may also be a deterrent to nesting females. Sea turtle hatchlings orient to the sea using light; that is, using the brightness of the open seaward horizon as their primary cue. As many as 100% of the hatchlings emerging from nests exposed to beach front lighting have been found orienting away from the sea and toward the artificial light source (section 3.1). While there are presently no official regulations with regard to the lighting of beach front properties, several means to mitigate the problems caused by badly placed lights have been employed. These include the sending of a form letter to all hotels and restaurants along the west and south coasts early in the hawks-bill breeding season. The letter asks that unnecessary lights be turned off, and that lights which cannot be turned off for security and safety reasons be checked each morning at dawn for disorientated hatchlings. This letter has produced very encouraging results. Bellairs Research Institute staff collect disoriented hatchlings for release at a suitable beach the following night.
Another approach has been to talk directly with architects and their clients about lighting plans for new developments along the coast (see section 4.621). When alerted to the problems caused by beach illumination, developers have proved to be quite willing to cooperate even in the absence of legal requirements to do so. Lighting problems can be miminised by keeping lights low to the ground, shielding them from shining directly on the beach (this is accomplished using structural shields or attractive hedges of vegetation), and using low sodium vapor lamps which emit light in the range of 590 nm, which is known to be far less attractive to hatchlings than full-spectrum white lights (Raymond, 1984; Witherington, 1990). Although it would be beneficial, it is very unlikely that any lighting restrictions will be legislated in the foreseeable future. Thus, voluntary compliance with lighting alternatives and restrictions is seen as crucial to the reproductive success of sea turtles in Barbados.
Beach erosion is a serious problem on the west and south coasts of the island (section 3.1). Many properties built before legislation governing set-back limits were enforced have erected beach walls, or revetments such as rock-filled wire baskets (gabions) or boulders to minimize loss of their land to the sea. For much of the coastline, turtles are unable to climb very far above the normal high water mark due to these coastal protection structures. The annual loss in beach width of 0.3 m along the west coast means that there is likely to be an increasing need for coastal protection and armouring in the near future. This will decrease the amount of suitable nesting habitat left available to hawksbills if the structural solutions to coastal erosion outlined above (e.g., the placement of boulders) are implemented. Some hotels have also erected groynes in attempts to increase the width of their beaches. These groynes have altered sand movements along extensive stretches of the coast and have sometimes resulted in the complete loss of adjacent beaches at certain times of the year. On some beaches, sea turtle nesting may also have been adversely affected (see also section 4.135).
The conservation of beaches in Barbados, because of their social and economic importance as recreational areas, has recently been, and will continue to be, given high priority by Government. The Coastal Conservation Project Unit (an agency within the Ministry of Labour, Consumer Affairs and the Environment) has implemented remedial measures suggested by the Coastal Conservation Study (1984), including the removal of some private, destructive groynes and the erection of a few reconstructive groynes. It is the recommendation of this Recovery Action Plan that the use of set-backs (prohibiting the construction of buildings seaward of the primary dune line or zone of permanent woody vegetation) and native vegetation (to retain and stabilize beach sands) be considered favorable alternatives to armouring the beach. It is presently illegal to construct any building within 100 ft (30 m) of the high water mark (section 4.21).
Mechanized beach cleaning equipment can puncture or crush incubating sea turtle eggs and its use should be avoided. Rakes which reach deep into the sand and compaction resulting from tractors and trucks all diminish the hatching success of eggs incubating on the affected beach. Fortunately, mechanical cleaning of beaches in Barbados is rare, although it does occur adjacent to Sandy Lane Hotel and on the main Barbados Hilton beach, among others. The positions of any nests made on these beaches are reported to Bellairs Research Institute and nests are marked so that beach cleaning machinery does not run over them. The sandy beaches in front of most hotels are hand-raked by hotel personnel in the early morning. On some other beaches, cleaning is done by employees of the National Conservation Commission. All beaches in Barbados are public.
In recent years there has been increasing use of cars and jeeps on beaches. Driving vehicles on the beach compacts the sand, damages beach vegetation, and can cause or exacerbate coastal erosion. Erosion exposes eggs in situ to wave action and reduces the amount of beach available for sea turtles to nest on. Compaction adversely affects sea turtles by crushing eggs and killing hatchlings. After breaking free from their eggs, full-term hatchlings work together with their siblings to reach the surface of the beach and then remain just below the sand until night-fall. When the sun sets and the beach cools, they are cued by the change in temperature to emerge fully and crawl to the sea. If vehicles run over the unseen hatchlings waiting below the surface, they can be fatally crushed. In addition, tyre ruts left in the sand can trap hatchlings and prevent them from reaching the sea (Hosier et al., 1981). Vehicles can also strike and kill hatchlings crawling to the sea, or frighten females away from nesting.
Beach rebuilding projects are generally closely related to beach stabilization efforts in Barbados (see section 4.133). Beach rebuilding projects typically involve the redistribution and trapping of sand from existing beaches, and herein lies the problem. The existence of hotels more or less continuously along the south coast means that trying to rebuild beaches at one hotel may affect adjacent beaches and hotels. Solving such beach erosion problems has been the responsibility of the Coastal Conservation Project Unit (CCPU). For instance, the CCPU advised that the length of an already existing groyne at Sandhurst on the south coast be reduced after complaints had been made that the groyne was starving a beach on its down drift side. The CCPU also advised that a second breakwater be constructed off the Barbados Beach Village on the west coast, after the hotel became concerned about erosion. This caused considerable reaction from local residents who were worried about the erosion that had been caused in 1982-1983 by a poorly designed groyne that had been erected privately by the same hotel. The same beach that was affected in 1982-1983 is well known for hawksbill nesting activity. So far, there have been no adverse effects on this beach from the new breakwater.
As an alternative to the use of impermeable structures, the CCPU has been carrying out the revegetation (primarily using native "sea grape", Coccoloba uvifera) of selected beaches. The use of vegetation such as sea grape for beach stabilization will have an additional benefit for nesting hawksbills, since they often prefer to nest amidst vegetation (Mortimer, 1982). Adequate protection of supralittoral vegetation cover on beaches may require additional legislation (section 4.23). Another alternative which has been used to promote the accretion of beach sand is synthetic seaweed. Synthetic seaweed was installed at Rockley Beach on the south coast on an experimental basis in 1985. After some initial success and noticeable sand build up, the seaweed fronds started to sink under the weight of enmeshed sand and beach erosion resumed. There are no immediate plans to install any more synthetic seaweed in Barbados unless the weighting problem is resolved.
The reconstruction of beaches elsewhere in the region is sometimes accomplished by dumping sand dredged from offshore onto a beach or former beach. This causes several problems for sea turtles, aside from the danger that heavy equipment on the beach and/or in adjacent waters can obstruct or preclude nesting and the new over-burden can smother incubating eggs. The most serious concern is that physical and organic characteristics of offshore sediments generally lead to compaction on the beach. This is well documented in Florida (USA) and was recently observed in Belize when a "renourishment" effort on Caye Chapel resulted in a hard compacted sand beach unusable to sea turtles for nesting (Smith et al., 1992). If this expensive method of reconstruction occurs in Barbados, the new sand should reflect the original material (e.g., organic content, grain size) and rebuilding should not occur during the nesting season.
4.14 Prevent or mitigate degradation of marine habitat
Dynamiting for fish is illegal (section 4.21), but occurs quite regularly on both fringing and bank reefs on the west, south and southeast coasts. Dynamiting is an extremely destructive form of fishing. Many fish killed by dynamiting do not float to the surface and therefore are not collected. Moreover, the destruction wrought on slow-growing coral reef environments reduces the fish carrying capacity of the system. Localized reef blasting has been conducted to improve fishing boat navigation channels at several points along the east coast (Tent Bay, Foul Bay, Skeete's Bay and Conset Bay). The long term effects of these actions are not fully known, but it appears that the exposed coral and coral rubble created by the blast are very susceptible to erosion, the navigation channels are already quite undercut, and the beaches parallel to reef cut channels may be more prone to erosion.
Because healthy coral reef ecosystems are vital to sustainable fisheries and tourism (both economically important industries in Barbados), as well as to endangered sea turtles, it is the recommendation of this Recovery Action Plan that laws prohibiting the use of explosives for the purpose of fish extraction be rigorously enforced. In addition, blasting to improve access for marine vessels should be closely regulated, if not prohibited, and ongoing studies to evaluate the long-term effects of past blasting should be conducted. Penalties for fishing with explosives should be severe and include heavy fines, in addition to the confiscation of vessels and other equipment in use at the time of violation.
It is illegal to use bleach or other chemicals for the purpose of fishing in Barbados (section 4.21) and this practise is not known to occur. However, many houses and hotels on the west and south coasts have swimming pools with filter backwashes discharging into the coastal zone. Chlorine is extremely toxic to corals, and local deleterious effects on coral reefs have been documented. As part of the Coastal Conservation Project Phase II, the sources of near-shore pollutants, including chlorine from swimming pools, industrial and agricultural pollutants and sewage are being identified. Because healthy coral reef ecosystems are crucially important to sustainable fisheries and tourism (both economically important industries in Barbados), as well as to sea turtles (providing them with food and shelter), it is the recommendation of this Recovery Action Plan that deleterious discharges of chlorine into the sea be illegal at all times and under all circumstances. Penalties should be stiff enough to serve as a deterrent to the use or discharge of chlorine and other toxic chemicals in the marine environment.
Toxic effluents from the rum refinery and heated effluents from the power station pose serious pollution problems in the area where they are released (Brighton), with decreasing effect on reef quality with distance from the source (Tomascik and Sander, 1985). The rum refinery effluent contains yeast, methanol, higher alcohols, aldehydes, ketones and esters and has a high BOD [biological oxygen demand] loading (Coastal Conservation Project, 1984). The Coastal Conservation Project (1984) advised that a long term solution may be to link these sources of nearshore pollution to planned sewage systems. However, sewage systems are not generally designed to handle these chemicals and another method of disposal may be more effective. Solutions are sorely needed in this regard, and field studies are necessary to ascertain the extent to which effluents of other types are degrading the marine environment of Barbados.
The discharge of sewage, oil, garbage, plastic, toxic materials, discarded fishing gear, styrofoam and a myriad of other materials into the ocean is a serious regional and global problem (e.g., O'Hara et al., 1986; CEE, 1987; Laist, 1987). The beaches of the east and southeast coasts of Barbados are most affected by garbage, sometimes dumped from boats at sea and sometimes derived from land-based sources. Fishing boats, yachts, cruise-liners, and military vessels dump their refuse at sea; sometimes the country of origin can be identified by examining the refuse. The discharge of garbage into the sea is a particular problem for sea turtles; both ingestion of and entanglement in persistent debris can be fatal to sea turtles.
The Barbados Environmental Association monitors the amount and types of garbage found on beaches during sea turtle nesting beach surveys and clean-ups, and supplies this information to the Center for Marine Conservation, an organisation in Washington D. C. that is analyzing the occurrence of marine debris on a regional and global scale. Bellairs Research Institute has recently started monthly monitoring of garbage on two beaches as part of the marine debris monitoring programme of IOCARIBE/CEPPOL. Legislation prohibiting pollution of territorial waters already exists (section 4.21), but more effective enforcement is needed.
The National Petroleum Corporation of Barbados, through Exploration Consultants Ltd. (U. K.), as well as private companies who have bought exploratory concessions from the Government of Barbados, have conducted preliminary oil exploration off Barbados over the past few years. The results of seismic soundings and preliminary drilling suggest that there are large reserves of petroleum (crude oil) within 30 km of the west coast of Barbados. The water there is at least 1 km deep; thus, production from this reserve will be expensive. However, if oil prices rise sufficiently, it is expected that large-scale drilling will take place. Sea turtles are potentially very vulnerable to oil spills. Studies suggest that the turtles have a limited ability to avoid oil slicks. Physiological experiments indicate that the respiration, skin, some aspects of blood chemistry and composition, and salt gland function of 15-18 month old loggerheads are seriously affected by crude oil (Vargo et al., 1986). In both experimental and stranded oil-fouled turtles, Vargo et al. (1986) observed oil clinging to the nares (=nostrils) and eyes and in the upper portion of the esophagus; oil was also found in the feces.
Beach tar deposits have been monitored at selected sites around the island as part of the CARIPOL programme, the marine pollution research and monitoring programme of IOCARIBE [Intergovernmental Oceanographic Commission's Regional Sub-commission for the Caribbean and Adjacent Regions]. Owing to the current direction, east coast beaches are susceptible to any current-bourne pollutants. Most of the tar ball deposits on these beaches are thought to be derived from oil tankers washing out their holds between cargoes. Barbados is in a vulnerable position in that it lies in the path of tankers passing to the north and south of the island en route for Trinidad, South America, and the Gulf of Mexico. An additional source of beach tar may be derived from natural sea floor oil seeps off the east coast of the island.
Relatively small amounts of high grade oil are pumped from land-based wells to the southeast of Barbados. More refined hydrocarbons such as gasoline, diesel, and kerosene are pumped ashore from tankers moored off Oistins on the south coast and off Brighton on the west coast. Legislation exists to protect against fouling of territorial waters and beaches by oil (section 4.21). Nonetheless, every precaution should be taken to protect Barbados from the degradation and expense of a spill or accident. The vast expense of cleaning up oil spills could probably be met only through international cooperative agreements and sharing of costs, as encouraged by the Protocol to the Cartagena Convention [Convention on the Protection and Development of the Marine Environment of the Wider Caribbean Region] concerning Oil Spills. Barbados ratified the Cartagena Convention and the Oil Spill Protocol in May 1985 (section 4.32).
Run-off and soil erosion are serious problems in Barbados. Most agricultural land is still under sugar cane cultivation and field peripheries are lined with low hedges of khus khus grass (Vetiveria zizanioides). The khus khus serves to keep top soil on the field following cane harvest. With the increasing mechanization of cane harvest, khus khus hedges are being removed for vehicle access and soil erosion and run-off are worsening. Attempts to diversify agriculture away from cane cultivation and into vegetable production are underway. However, since vegetables cannot compete with weeds as well as the taller sugar cane can, farmers resort to large amounts of herbicides. The relative bareness of the soil under vegetable cultivation compared to that under cane cultivation means that more soil is eroded by wind and rain. In addition, the soil is heavily fertilized (nitrates and phosphates) to allow several vegetable crops to be grown on each field per season. The increasingly heavy use of herbicides, pesticides, and fertilizers increases the pollutant composition of run-off. Changing agricultural practises may also cause an increase in the suspended particulate matter (SPM) load, as well as the amount of nitrates and phosphates in coastal marine waters.
SPM stresses marine organisms in a number of ways, such as by decreasing light penetration and reducing the growth rate of corals, by physically smothering corals, and by impairing fish respiration. Sediment-covered surfaces restrict larval settlement, and large quantities of SPM settling and decomposing on a reef cause an increase in bacterial activity. In small quantities, nitrates and phosphates are important nutrients needed for the metabolic processes of living organisms. In excessive quantities, however, they cause phytoplankton blooms blocking light and decreasing the rate of coral growth. Sewage is another source of SPM, and of inorganic nutrients as well. With the exception of one major sewage treatment system in Bridgetown, sewage is disposed into septic tanks or pits. These are either 'soak-aways', or the contents are piped a short distance offshore and released. A sewage treatment system will be constructed to serve the needs of the south coast in the near future, and one is also planned for the west coast. One option is that lightly treated sewage will be deposited offshore beyond the bank reef and into currents which will carry the sewage away from the island. Such a system is preferable to heavy chemical treatment and deposition closer to shore. Some of the chemicals used in sewage treatment (e.g., chlorine) may be more lethal to corals than the sewage itself, and treatment to remove nitrates and phosphates is too costly.
The effects of pesticides and herbicides on nearshore marine communities in Barbados are unknown, but east coast fishermen partially attribute the decline in sea eggs (Tripnuestes ventricosus) to the effects of pesticides on nearshore sea grass communities. Attempts to investigate this problem quantitatively are currently underway. Since a variety of nearshore marine communities, most notably sea grass beds and coral reefs, are essential for the survival of depleted sea turtle stocks in Barbados, this information will also be useful in implementing a national recovery strategy for sea turtles.
Careless anchoring of boats on coral reefs and the dragging of anchors and anchor chains causes an unquantified amount of damage, particularly to coral reefs situated off the west coast. Mooring facilities are greatly needed, particularly on the west coast, to accommodate visitation to coral reef areas. The Barbados Marine Reserve is protected by legislation (section 4.21) that prohibits damaging anchoring and fishing practises within a small designated area of the west coast nearshore waters. Elsewhere, inexpensive and effective mooring technologies, such as those designed by Halas (1985), should be installed in Barbados as soon as possible. Land has recently been reclaimed and the sea floor dredged for the construction of fish markets at Oistins and in Bridgetown. The effects of these constructions on current movements are unknown, but a short-term effect has been a substantial lowering of the clarity of water in the area. Hotels and houses on the west and south coasts often dispose of kitchen waste water through short drainage pipes that discharge directly onto nearshore reefs. Kitchen waste water contains high concentrations of phosphates which are known to be detrimental to corals. Phosphate-free detergents are now sold in supermarkets and their use should be encouraged.
Table of Contents | Section IV
4.2 Manage and Protect all Life Stages
The Fisheries Regulation Act was passed in 1904 to consolidate the Acts of the island relating to Fisheries under one piece of legislation. The Fisheries Regulation Act presently encompasses turtle preservation, sea egg preservation, whaling, and the destruction of fish by explosiv