Thursday, June 5, 2008

The Bermuda Turtle Project


Today we are posting an update from Mark Outerbridge about the Bermuda Turtle Project - an affiliated project not under the BREAM umbrella, but also happening at the Bermuda Zoological Society and the Bermuda Aquarum (BAMZ).

You can learn much more about this 39 year conservation project at the web address for the Bermuda Turtle Project - which is: http://www.cccturtle.org/bermuda

The Bermuda Turtle Project continued in its thirty-ninth year and is still very committed to the goal of promoting the conservation of marine turtles through research and education. Project activities during 2007 included field and laboratory research, training of international and local students, participation in the Annual Symposium on Sea Turtle Conservation and Biology, and public education via presentations, classroom activities, local media, and the Bermuda Turtle Project webpage. The following as a brief summary of the major findings in 2007:

  • A total of 200 green turtle (Chelonia mydas) captures were made over a 10 day period at 13 sites around the island. All were immature and ranged in size from 24.7 - 68.1 cm straight carapace length. 31% of these net-captured turtles were recaptures from previous years. This compares with 41% in 2006 and 25% in 2005.
  • A total of 11 hawksbills (Eretmochelys imbricata) were sampled for genetic analyses (8 were strandings and 3 were live captures made by recreational divers).
  • The BAMZ sea turtle rehabilitation center also received 20 stranded greens, as well as 4 loggerheads (Caretta caretta).
  • 14 international tag returns of green turtles tagged in Bermuda were logged; 12 turtles were recaptured in Nicaragua, one in Cuba, and one in Colombia.
  • For the first time in Bermuda a sea turtle (green) was discovered with a disease known as fibropapillomatosis. Turtles affected by this disease are typically covered with multiple skin tumors which can often seriously compromise the health of the individuals affected.
  • Analyses of the long-term dataset on sex ratios of nearly 2500 green turtles in Bermuda revealed the surprising result that sex ratios appear to have become increasingly female-biased since the late 1980s. Possible explanations for this trend include global warming (which may have caused more female-biased sex ratios to be produced at the nesting beaches where Bermuda turtles originate), changes in the proportional contribution of source nesting beaches, and endocrine disruptors present in the environment that can affect hormone production.
  • The International Course on the Biology and Conservation of Sea Turtles was offered for the twelfth time on 5 – 17 August 2007. Ten participants were drawn from Argentina, Bermuda, Portugal, Saint Kitts, Saint Maarten, Saint Vincent, the United States, Uruguay and Venezuela. The participants came from a number of backgrounds, including universities and natural resource agencies in the Caribbean region. Three were PhD students and three were Master’s students. Funding came from ChevronTexaco International, the Caribbean Conservation Corporation, and the Friends of the Bermuda Aquarium.
  • Tissue samples for genetic analyses were collected from all sea turtles encountered in 2007 as part of our continuing efforts to understand where Bermuda’s resident sea turtles originate from, which provides critical information on the role that Bermuda plays as a developmental habitat for juvenile sea turtles. For example we know that many of the green turtles in Bermuda originate from Costa Rica and Florida, however, others have also come from Aves Island (Venezuela), Guinea Bissau, and Cuba and/or Mexico.