Turtle farm hopes for improved breeding season

| 05/08/2011

(CNS): Eleven of the Cayman Turtle Farm’s green turtles laid some 900 eggs in one evening on the facilities beach officials have revealed which they hope is an indication that the breeding rates are about to improve. As the nesting season gets underway Dr. Walter Mustin, Chief Research Officer at the Farm and an expert in hatchery management and aquaculture nutrition has high expectations for at least one of the female turtles which has been breeding for some 19 years. However he pointed out that four of them are making their first attempt at motherhood.

“Records show that one of these turtles has laid 88 nests over the past 19 years with 32% hatch success and we have high expectations for her eggs this year,” said Dr Mustin. “In contrast, these are the first eggs that have ever been laid by four of the females.  Others in this group have nested before with none of their eggs hatching.”

One of the reasons may be that these breeders are not quite old enough to lay viable eggs. Green sea turtles in the wild reach sexual maturity only when they are 20-30 years old.  Someof our females are laying eggs at the early age of eight years, which is a result of the ample food and protein provided them.

After Hurricane Michelle, over 300 relatively young turtles were placed in the breeder pond to replace the 75% of the breeder herd that was lost to the storm. 

“Now, these replacement breeders are 10-15 years old, young by biological standards. Eventually, I expect this younger population sector to come to maturity and produce more and more eggs that actually hatch,” Dr. Mustin explained. 

Meanwhile, research aimed at improving sea turtle hatch rates continues at the farm on multiple fronts the facility has revealed. A custom breeder diet is being formulated that more accurately reflects and mimics the nutritional composition of the green sea turtle’s wild diet which is turtle grass, liver sponge, and marine algae.

“The causes of infertility are being examined. All eggs that do not hatch are staged to determine the state of fertility and/or development.  New incubation techniques that reduce early hatching mortality are also being implemented,” Dr. Mustin added.

The ultimate goal of the Cayman Turtle Farm team is to be able to release more and more green sea turtles.

“As our hatch rates improve, so will our ability to release greater numbers to the wild,” the doctor stated. “We know from tagging studies on turtles released from the Cayman Turtle Farm that our released turtles are not only surviving and travelling throughout the Caribbean, but that turtles that we released in the 1980s are now sexually mature and returning to Cayman beaches to lay their own eggs.”

Of the 30-60 green sea turtles that the Department of Environment estimates visited our beaches last season to lay eggs, at least five of them were released as yearlings from the Cayman Turtle Farm some 25 years earlier.

Turtle Farm Managing Director Tim Adam said he was very pleased by the successful nesting, which showed how well the breeding programme was advancing.

“We are very excited with the activity we saw on this one night; and hope that it is indicative of future breeding successes,” he said.  “Our team of experts continue to develop and try new methods and conduct scientific research that will boost hatch rates as well…. The efforts of Dr. Mustin and his staff and their commitment to improving hatch rates will ensure that as our females reach breeding age they will be able to lay greater numbers of viable eggs. Their work is vital to our mission to promote conservation of the green sea turtle.”

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