James Perran Ross and David Carr
Caribbean Conservation Corporation, Gainesville, Florida 32602 USA
At Tortuguero, on the Caribbean coast of Costa Rica, is the largest nesting ground of green turtles in the Caribbean. Between about 5 and 50 thousand female green turtles nest at Tortuguero each year (Carr, Carr and Meylan 1978). The average nesting population is about 15 thousand. Since 1956 the Caribbean Conservation Corporation (CCC) has supported research and conservation activities at Tortuguero. This work and many of its results are familiar to all of you.
Turtles distribute from Tortuguero all over the Caribbean and the long term management and conservation of the species must include the maintenance of this, the only remaining large aggregation in the region. It is very difficult to discern the trends in this population. There is a substantial increase in number of turtles recorded this decade compared with the early 1960’s but variations in effort and wide interannual fluctuations make interpretation difficult. Several lines of evidence suggest that the population is still well below its carrying capacity and is probably still recovering from over-exploitation earlier this century. The density of nesting females is 6-44 Ikmlnight, 1-3 orders of magnitude less than unexploited populations in the Indian Ocean (Ross 1979) and Australia (Limpus 1981). The incidence of nest destruction by laying females is only 1-2% (Fowler 1979).
Analyses of survival between 1959 and 1972 (Bjorndal 1980) indicate that human predation away from the nesting beach continues to limit population recovery. There is still a legal harvest of 1600+ turtles a year in Costa Rica, and we know that at least 2.5% of neophytes tagged each year are caught by fishermen elsewhere. This population continues to merit our concern and require active conservation.
The CCC has been actively conserving this population, and trying, to react to the most immediate needs and threats. We now recognize that conserving the sea turtle population is part of the larger problem of maintaining the ecological and economic stability of the whol~s region iincluding the turtle beach, the adjacent village, and nearby ecosystems of forest and river estuary.
The pristine rainforest of the Caribbean lowlands is greatly threatened as a result of increasing numbers of people, improved access, and the demands of the human population for economic well-being. Short-term exploitation is destroying the resource base of the region. The CCC believes that short-term economic gain by direct exploitation of these fragile resources is both economically and ecologically disastrous.
Commodity use of sea turtles may be appropriate in some places, but we believe it would be counterproductive at Tortuguero.
A clutch of turtle eggs is worth about $8.00 retail in San Jose and perhaps 115 of that on the beach. In contrast, we estimate that the same clutch of eggs is worth 100-250 times that much if used as a focus of tourist activity. There is a clear desire of people at Tortuguero fo ‘cash in’ on the tourist boom, but the experience of these people is that economic booms are short-lived (e.g., lumber. turtle meat. bananas). It is necessary to develop the infrastructure to enable a long-term noii-consumptive use of these resources.
To meet this need, the CCC has embarked on a large scale management plan for the Tortuguero region in conjunction with the Costa Rican National Park Service. Fundacion National (Costa Rica) and the U.S. Agency for International Development. This plan includes:
– A regulatory plan for land use and land acquisition to preserve present values and quality
– An Environmental and Interpretation Center to provide information for visitors and training for local people. A first step is our information kiosk.
– Coordination with the Park Service for approved and ecologically sound visitor access.
– Improvement of facilities for visiting scientists and educational groups.
– Acquisition of a wildlife corridor to join the Park with the Barra del Colorado wildlife management area.
– Land management research, analysis and implementzition for the upper watershed involving protection of riparian zones and experimental agro-forestry. – Continuation of research on the turtle population to maintain and evaluate conservation action.
– Training for regional turtle managers.
These efforts are neither cheap nor fast. The CCC has invested > $1,000,000 and 30 years of effort at Tortuguero and we expect it will take even greater conimitments of energy and money to continue. We believe that a comprehensive program recognizing local needs for economic stability will ensure the preservation of the whole Tortuguero ecosystem including the turtle population. In addition to conserving this turtle population, we believe that the solutions we develop at Tortuguero will be transferable to many other locations.
Bjorndal K.A. 1980. Copeia 1980(3):525-530.
Carr A,, M.H. Carr, and A.B. Meylan. 1978. Bull. Amer. Mus. Nat. Hist. 162(1):1-46.
Fowler L.E. 1979. Ecology 60(5):946-955.
Limpus C.J. 1981. p.297-304, In: K.A. Bjorndal (ed.), Biology and Conservation of Sea Turtles. Smithsonian Institution press, Washington D.C.
Ross J.P. and M.A. Barwani. 1981. p.373-384, In: K.A. Bjorndal (ed.), Biology and Conservation of Sea Turtles (op. cit.:373-384.)
Paper presented at 9th International Symposium, 1993