Outbreeding concerns outlined in Cayman green sea turtle study

A newly-published study shows ninety percent of Cayman’s green sea turtle nesting population shares DNA with turtles from the Cayman Turtle Centre.

Let’s flash back to 1968 when the private company that would later become the Cayman Turtle Centre started its captive breeding programme.

Through 1978, adult green sea turtles and eggs were imported from the nesting populations of Costa Rica, Suriname, Guyana, Ascension Island, Mexico, and from the foraging area of Nicaragua to establish the Cayman Turtle Centre’s founder stock.

In the study, scientists analysed the genetic diversity of 257 captive turtles and 57 wild green turtles nesting in the Cayman Islands, yielding some interesting findings.

“We are not seeing very low levels of genetic diversity, which would be quite concerning if we had inbreeding,” said DOE Research Officer Janice Blumenthal. “The levels of genetic diversity are currently similar to or higher than other wild populations, so we have not seen any negative impact in terms of very low hatch success.”

The report expressed some concern that the breath of diversity among the Cayman Turtle Centre’s original founding stock could one day impact the fitness and reproductive capacity of offspring through a phenomenon called outbreeding depression.

The report says further monitoring is essential to detect and prevent any negative impacts on natural populations of the Caribbean.