SEA turtles and their fragile existence will be the focus of a lecture dedicated to children at the Bermuda Underwater Exploration Institute (BUEI) next Wednesday.

The topic continues in a more adult fashion the following evening with a look at some of the more technical methods employed in sea turtle conservation such as diving physiology, marine electronics, satellite-telemetry and oceanographic features.

The lectures are to be given by Drs. Karen and Scott Eckert. The husband and wife have devoted more than 20 years each to sea turtle research and international conservation policies.

Sea turtles are hatched on tropical and sub-tropical beaches after which they head immediately into the open ocean, according to Mrs. Eckert. After spending an estimated two to seven years in pelagic zones, most settle in coastal areas. The leatherback, however, remains pelagic throughout its life. Powerful swimmers, they are the deepest diving and most migratory of sea turtles.

"Scott's global analysis of strandings, captures and other rare sightings of young leatherbacks concludes that individuals up to about 100 centimetres in carapace length, remain in waters warmer than 26 degrees Centigrade. Once they mature beyond that size, they move into temperate and even sub-Arctic environments," said Mrs. Eckert. "Scott's satellite tracking studies demonstrate that individuals swim more than 15,000 kilometres per year among preferred foraging sites, and that they routinely traverse entire ocean basins.

"Each species of sea turtle fills a unique niche in oceanic habitats, and plays an important ecological role. For example, pelagic leatherbacks feed exclusively on jelly-bodied animals," she added.

"This places them atop a distinctive marine food chain based on nanoplankton responsible for more than half of the total primary production of pelagic waters. They are the largest of the sea turtles, averaging in excess of 350 kilogrammes as adults, and are facultative homeotherms capable of exploiting exceedingly cold and deep waters."

As executive director of the Wider Caribbean Sea Turtle Conservation Network, Mrs. Eckert's major task is to prevent the extinction of six species of endangered sea turtles in the Caribbean basin by emphasising science-based tools in national policy-making and community conservation initiatives.

As an organisation, the group assists government and non-government agencies in the design and implementation of research and management projects and has served as a model for multilateral marine resource management throughout the world.

Mr. Eckert is a senior research biologist for Hubbs-Sea World Research Institute in San Diego, California. For more than two decades he has been active in the field of pelagic marine vertebrate research and conservation, focusing largely on sea turtles and, more recently, whale sharks. He has published more than 100 scientific and general interest articles, served as a consultant to various government and private organisations around the world and is the first to have successfully used satellite telemetry to study the movements and behaviours of leatherback sea turtles and whale sharks.

"All species of sea turtle that occur in US waters are listed as threatened or endangered under the Endangered Species Act of 1973," Mrs. Eckert explained. "In addition to various levels of national protection, three Caribbean species - the leatherback, hawksbill and Kemp's Ridley - are classified as critically endangered by the global red list maintained by the World Conservation Union. Critically endangered species have experienced an 80 per cent reduction in numbers in ten years or three generations, while endangered species have experienced a 50 per cent reduction over the same period."

Sea turtles are protected by a variety of international instruments and conventions. "It's a fact which is especially important as, because they are strongly migratory, the survival of the sea turtle depends on international collaboration and co-operation," she added.

"This is all the more important since Caribbean species continue to be harvested as a source of food and income throughout their ranges. They are mainly killed for meat, shell, oil, skin and eggs and the direct harvest has either depleted or exterminated most nesting assemblages.

"The situation is exacerbated by the fact that sea turtles are accidentally captured in active or abandoned fishing gear, resulting in death to an estimated tens of thousands of them every year. Oil spills, chemical waste and persistent plastic debris, as well as the ongoing degradation of important nesting beaches and feeding grounds, also threaten the continued existence of these populations."

Mrs. Eckert's lecture for children and parents is to be held at the BUEI on Wednesday, July 17 at 7 p.m. Tickets are $5 for kids, $10 for adult members and $12.50 for adult non-members. The night's buffet, to include a special kids' menu, is $7.50 for kids 12 and under and $27.50 for adults. The cost of the following night's presentation by Mr. Eckert is $10 for members and $12.50 for non-members. The buffet price is $27.50. Those interested in attending either lecture may visit the admissions desk at the BUEI or call 297-7314.