Fibropapillomatosis

Sea Turtle Conservation Bonaire (STCB) was initiated in the early 1990s to protect the island’s marine turtle populations. Our current research and monitoring efforts, which were standardized more than a decade ago, include monitoring important nesting beaches around Bonaire, conducting intensive in-water netting and snorkel surveys (capture-markrecapture), and tracking post-breeding turtle migration using satellite telemetry. These techniques provide us with a better understanding of Bonaire sea turtles’ breeding success, abundance, health, residency duration, habitat quality, growth rates, migratory paths, distant feeding grounds, and threats.
During the 2013 season, we observed 77 nests at our index beach on Klein Bonaire. Total hawksbill (54) and loggerhead (23) nests documented there were similar to numbers observed during recent years. Across Bonaire and Klein Bonaire, we observed four species crawling 231 times, including 126 confirmed or suspected nests. Because our coverage of the island was not complete and weather conditions can quickly obscure crawls, these nation-wide figures represent the minimum number of crawls and nests that occurred on Bonaire and Klein Bonaire during 2013. As in previous years, nesting activities peaked during June through August. Thirty-four green turtle nests and a single leatherback nest were recorded in northeastern Bonaire, whereas hawksbills and loggerheads primarily nested on Klein Bonaire and beaches of southern Bonaire.
We observed green turtles and hawksbills along the west coast of Bonaire, around Klein Bonaire, and adjacent to Lac during snorkel surveys. Green turtle sightings were particularly high near Lac, and netting surveys also suggested large aggregations of green turtles in shallow, sea grass foraging sites of Lac. Green turtles documented there were larger than individuals reported elsewhere in Bonaire.
Five green turtles tagged in 2003 and 2006 were reported in Nicaragua’s sea turtle harvest, valuable data about sea turtle movements which complement our satellite tracking program. Unfortunately, incidences of fibropapillomatosis among green turtles were more widespread in 2013 than recent seasons.
In 2013, we tracked a post-nesting female hawksbill turtle using satellite telemetry from Bonaire to Honduras over a period of 85 days. The turtle passed through six national territorial waters, swimming over 5,000 km (3,000 mi) to reach a general area proven to be important foraging grounds for Bonaire breeding turtles.
We also outfitted a hawksbill with a datalogger to gather information on hawksbill habitat use and behaviors. The device, which collects GPS locations and depth information, was retrieved in July, 2013. Preliminary results are consistent with previously deployed dataloggers, indicating regular movements in and out of Lac Bay.
Sadly, we recorded 18 turtles stranded during 2013, 12 of which were found dead or had to be euthanized.
We will be undertaking several new research initiatives in the year ahead, including using our tagging data to estimate the total population of sea turtles using Bonaire’s waters (which will help to inform management policy) and to estimate the tremendous growth rates of green turtles in Lac, as well as reviewing our monitoring program to ensure that protocols are as efficient as possible.

Fibropapillomatosis is a disease that is affecting sea turtles all around the world. Turtles that are most at risk are those that live in near-shore waters and lagoons, especially areas next to large human populations with poor sewage treatment facilities. In this research project the main focus is fibropapillomatosis (FP) and green sea turtles captured by netting in Lac Bay, Bonaire. The research goal was to see how turtles living in Bonaire are affected by the disease. The two main research questions were: “What is the true rate of fibropapillomatosis affecting green sea turtles in Lac Bay?” and “What is the difference between healthy turtles and infected turtles that are caught by netting?”
To determine the true rate of FP, the percentage of diseased turtles is calculated as the percentage of captured turtles with FP compared to the whole amount captured during netting conducted from 2006 until 2014. In 2006 rates of FP were 20 percent, the infection rates then decreased dramatically, even reaching zero percent in 2010. FP rates started increasing again after 2012, and in 2014 the rates of FP now stand at 34 percent (n=89). It is still uncertain what causes FP to increase. To determine the difference between healthy turtles and diseased turtles, the length, weight, and overall growth rates have been assessed. Recapture rates were also assessed, to determine if diseased turtles were captured more, because of their limitations. There was a significant difference (p < 0.001) found between recapture rates of healthy and diseased turtles indicating that healthy turtles are recaptured more often than diseased turtles. Assessed length and weight of diseased turtles are not significantly different than from healthy turtles (p < 0.001). The growth rate in this research was not significantly different between healthy and diseased turtles. Overall there was no significant difference found between healthy turtles and diseased turtles living in Lac Bay, not in length, weight or in growth rates. The implications of this research suggest that the overall survival rate of turtles with FP on Bonaire is relatively high in comparison to other areas of the Caribbean. This could be due to the tumors not restricting the turtles to such a degree that they are unable to forage or flee.
 
Retrieved from http://www.bonaireturtles.org on April 13, 2015