27 Years and Counting: Leatherback Turtles, Dermochelys coriacea, at Parque Marino Nacional Las Baulas in Costa Rica- Down but not Out!

PILAR SANTIDRIÁN TOMILLO; ROTNEY PIEDRA; TERA DORNFELD; PAMELA PLOTKIN; FRANK V. PALADINO; JAMES R. SPOTILA; NATHAN ROBINSON; VINCENT S. SABA; JENNIFER SWINGS; ANTHONY STEYERMARK ; GABRIELA S. BLANCO; BRYAN P. WALLACE; JULIANNE KOVAL; RICHARD REINA

New Orleans

Congreso; Joint Annual Meeting Icthyologists and Herpetologists, New Orleans, CA; 2016

We have been measuring the size of the leatherback turtle population at Parque Marino Nacional Las Baulas in Costa Rica since 1988. During that time we have marked 1993 nesting females and produced about 1,132,000 hatchlings from the beach and a hatchery. In 1988 the population was 1504 nesting females. In 2015-2016 the population was 25. That decline was predicted in a population model that we published in 2000. At that time we predicted that there would be about 25 turtles nesting in 2015 even with beach protection, an end to egg poaching and a hatchery. While the park has been partially consolidated and construction of homes and hotels stopped, the population has still declined. The decline still appears to be due to mortality at sea due to fishing activities such as gill nets and longlines along the South American coast. Mortality rates remainabout 22%% per year on nesting females and are probably the same on subadultanimals. Unless these activities change the population will not survive. The adult population nesting at Las Baulas and Northwest Costa Rica is about 120 nesting females and the East Pacific nesting leatherback population is about 300. While these numbers are very disappointing from a conservation perspective, it is important to note that the population can still recover. Protection of nesting turtles and their beaches provides a continuing supply of hatchlings to the population. If protection can be improved at sea the population can rebound.