Operation Green Turtle Revisited

Operation Green Turtle Revisited

Peter J. Eliazar, Karen A. Bjorndal, and Alan B. Bolten
Archie Carr Center for Sea Turtle Research, University of Florida, Gainesville, FL 3261

From 1959 through 1968. Archie Carr, with the assistance of the U.S. Navv. distributed over 130,000 green turtle hatchlings and eggs from Tortuguero, Costa Rica, to 17 countries throughout the Greater Caribbean. This massive relocation–called “Operation Green Turtle”–was undertaken in an attemot to reestablish extirpated green turtle nesting populations throughout the region. A major impetus for this effort was the excessive harvest of female green turtles at Tortuguero, the largest green turtle nesting c;olony in the Atlantic, and the bleak survival outlook of the population if the harvest continued. We have summarized the numbers of hatchlings released and the release sites during Operation Green Turtle because these data have never been presented and because of the current interest in genetic structure of sea turtle populations in the region.

During Operation Green Turtle, eggs were moved to a hatchery where they were screened and protected and the hatchllings could be easily collected. Before shipment, hatchlings were held in troughs under a thatched roof adjacent to the Tortuguero nesting beach. Sea water had to be carried daily from the ocean, usually by hand. Turtles were shipped in wooden boxes lined with plastic and with an absorbent mat to maintain moisture during shipment. Each box contained approximately 200 hatchlings. US Navy Grumman aircraft would land on the Tortuguero River to pick up hatchlings for transport to distant release sites.

Operation Green Turtle was discontinued after 1968 because of increasing demands on the military for the Vietnam War, the llow number of nests at Tortuguero in 1968, and the lack of evidence that any rookeries had been reestablished (remember, that then, biologists believed that green turtles reached sexual maturity in 6 years). Although there has been no known nesting resulting from Operation Green Turtle, the effort was a great success in raising awareness of the plight of sea turtles in the Caribbean and beyond.
Because these translocated green turtles may have contaminated the genetic composition of natural populations, studies on the genetic structure of green turtle populations in the Greater Caribbean have stimulated interest in the number, distribution, and survival potential of these hatchlings. We believe that the releases of hatchlings during Operation Green Turtle have probably had a minimal effect on genetic composition of green turtle populations. Current understanding of hatchling biology would suggest that the hatchlings would have had low potential for survival as a result of being held in water at Tortuguero past their swim frenzy period. Thus the hatchlings, when released, had depleted nutrient reserves and probably could not reach appropriate post-hatchling pelagic habitats. Looking back on the project in later years, Archie Carr realized, as he wrote in his epilogue to So Excellent a Fishe, that it would have been better to have transported eggs rather than hatchlings because of imprinting and the problems of holding hatchlings past the swim frenzy period. The 2,000 eggs that were distributed during Operation Green Turtle had low survivorship due to poor handling techniques. Those hatchlings held in captivity and released as yearlings in Florida, Bermuda, and Colombia, probably had better survivorship, but their migratory behavior may have been compromised with negative effects on reproduction. Those turtles that survived would now be approaching sexual maturity and would probably not have compromised recent genetic studie’s involving juvenile turtles.

Data used in this summary were gleaned from reports written by Archie Carr (annual reports of the Technical Director to the Caribbean Conservation Corporation and reports to the Office of Naval Research), correspondence between Dr. Carr and recipients of the turtles, and notes in regional publications (e.g., the West Indies’ Fisheries Bulletin published in Trinidad). We thank Marjorie Carr for housing the Archie Carr Archives at the University of Florida that allowed us access to these records.

Paper presented at 16th International Symposium, 1996