Sea turtles throughout the world are severely reduced from historic levels. According to the World Conservation Union (IUCN) Red List of Threatened Species, persistent over-exploitation, especially of adult females on nesting beaches, fatal fisheries interactions, and the widespread collection of eggs are largely responsible for the depleted status of all six Caribbean sea turtle species.
Green and Loggerhead sea turtles are classified by IUCN as “Endangered”, meaning that these species meet a specific series of “listing criteria”, including “an observed, estimated, inferred or suspected reduction of at least 50% over the last 10 years or three generations, whichever is the longer.” Leatherback and Olive Ridley sea turtles are classified as “Vulnerable” at a global scale, but the Northwest Atlantic subpopulation of the Leatherback (which includes the Wider Caribbean Region) is classified as “Endangered” and declining.
Hawksbill and Kemp’s Ridley sea turtles are classified by IUCN as “Critically Endangered”, a crisis category reserved for species that, among other things, are characterized by having sustained “an observed, estimated, inferred or suspected reduction of at least 80% over the last 10 years or three generations, whichever is the longer.”
The comprehensive process used by the global scientific community to assess the status of species is complex, and it’s the responsibility of the Marine Turtle Specialist Group (MTSG), one of more than 100 Specialist Groups and Task Forces that make up the IUCN Species Survival Commission, to undertake regular regional and global evaluations to determine the conservation status of sea turtle species. Visit the MTSG’s Red List page for updated information and links to specific assessment documents.
Why is this information important?
All aspects of human culture and economy rely on natural resources, many of them nonrenewable. Biodiversity provides humanity with food and fiber, shelter materials, medicine, essential ecological services, and inspiration for everything from engineered flight to nanotechnology to music and poetry. Biodiversity loss is one of the world’s most pressing crises. Experts estimate that the current rate of species extinction is 1,000 to 10,000 times higher than normal, and survival is further complicated by a changing climate.
If we are to reverse the trend toward extinction, governments and civil society need access to organized data. The IUCN “Red List” is the world’s most comprehensive inventory of the global conservation status of plant and animal species. The overall aim of the Red List is to convey the urgency and scale of conservation problems to policy makers and the public, and to motivate the global community to reduce causal threats. In characterizing sea turtles as endangered, IUCN draws attention to the conservation needs of sea turtle populations around the world.
Caribbean sea turtle status
Caribbean populations of sea turtles were described by historical accounts as “inexhaustible”. Seventeenth and eighteenth century mariner records document flotillas of turtles so dense and vast that net fishing was impossible, even the movement of ships was curtailed. Christopher Columbus described the sea turtles he encountered off the coast of Cuba as being “in such vast numbers that they covered the sea”.
Today some of the largest breeding populations the world has ever known have vanished, or nearly so. An example is the once famous green turtle colony of the Cayman Islands, considered to have been the largest nesting population in the greater Caribbean basin. Sea turtles were an easily attainable resource and they attracted people to the islands, which were first colonized in the mid-1600s. By the early 1800s, Caymanian turtle fishermen had exhausted the local nesting populations and were sailing to Cuba, then to the Miskito Cays (Nicaragua) to catch turtles.
In addition to harvest that has spanned a millennium, Caribbean sea turtles face complex modern-era threats, including accidental capture in active or abandoned fishing gear which results in death to uncounted thousands of turtles every year. Coral reef and seagrass degradation (from anchoring, dredging, blasting and pollution), agro-industrial waste and effluent, persistent plastic and other marine debris, an increase in coast- and ocean-based tourism, and a once-flourishing global trade in tortoiseshell have all contributed to the degradation or loss of populations and the habitats upon which they rely.
In some places, population recovery is hindered by a regulated but largely unmanaged harvest of large juveniles and breeding age adults, which are replenished at a very slow natural rate. The situation is exacerbated by the small size of many remnant populations, especially in the insular Caribbean, where the persistent take of only a few gravid females each year may represent a significant proportion of the remaining breeding stock.
Because threats accumulate over long periods of time and can occur anywhere in a population’s range, local declines often result from a combination of factors, both domestic and foreign. Sea turtles are migratory throughout their long lives, and what appears as a decline in a local population may, in fact, be a direct consequence of the activities of people many hundreds or thousands of kilometers away. Therefore, while local sea turtle management and conservation actions are crucial, cooperative action is also called for at the Caribbean regional level.
The Wider Caribbean Sea Turtle Conservation Network (WIDECAST) is uniquely designed to address conservation challenges at both local and regional levels, and is committed to ensuring that sea turtles survive in the Caribbean Sea at levels sufficient to enable them to fulfill their ecological roles.