Environmental Engineering Reference
In-Depth Information
FIG
67.
Mark Winder, Head Warden for the National Trust, with the remains of a leatherback turtle found on the
Worms Head causeway in 1996. (Paul Llewellyn)
West Glamorgan Archive Service for Figures
Populationsofleatherbacksareinseriousdeclineduetoanumberoffactors,butthemainthreatshave
been a prolonged harvest of eggs and the incidental capture in oceanic fisheries. The international nature
ofthis problem means that the survival ofthe species will depend oncross-border collaborations, focused
notonlyonthetropicalnestingbeachesbutalsoonthemoretemperatefeedinggroundsthatliethousands
of kilometres away. Despite this, our knowledge of leatherbacks outside the breeding season remains al-
most nonexistent.
In April 2003 the Irish Sea Leatherback Project was established as a joint initiative between the
University of Wales Swansea and University College Cork. Key elements of the project include aerial
surveys of the Irish Sea, satellite-tracking leatherbacks from their tropical nesting grounds to identify the
routes they follow to get to high latitudes, shoreline jellyfish surveys, schools workshops and public sem-
inars. The project hopes to answer the issue of whether leather-backs are merely oceanic wanderers that
find themselves in British waters or whether they form an important part of our natural heritage.
All other turtles seen off Gower are likely to be juvenile or subadult loggerhead and Kemp's ridley
turtles.Theloggerheadturtleisanotherlargeseaturtle,withacarapaceuptoametreinlength.Itisacar-
nivorous species, feeding mainly on benthic invertebrates, especially molluscs and crustaceans, using its
very bulky jaw muscles to crush their shells. Adult Kemp's ridleys are normally bottom-feeders, foraging
in crab-rich shallow inshore waters. It is critically endangered and the total population of this species is
thought to number no more than 900 adult females and an unknown number of males and subadults. The
occurrence of these 'hard-shelled' species in the Bristol Channel is not a normal part of their life history;
they have been blown from warmer waters by unusual weather conditions such as prevailing southwest-
erlystorms.Theanimalsareusuallyinverypoorhealth,ashard-shelledturtlesarenotadaptedtothecool
