Sea Turtle Recovery Action Plan for Barbados - WIDECAST

Barbados Sea Turtles …
years. In order to quantify and monitor the status of these reefs, an extensive data base has
recently been obtained (section 4.11). Reef deterioration is likely to be attributable to poor
nearshore water quality, over-fishing, poor fishing practises (e.g., careless deposition of traps and
pots, illegal dynamiting for fish), and anchor damage. Since hawksbills appear to depend on
sponges and other reef-associated invertebrates for food in the Caribbean, this species is likely to
be adversely affected by the deterioration of coral reefs. In addition, it is the opinion of
knowledgeable residents that sea grass beds, which provide important food for the herbivorous
green turtle, have diminished in size over the past two decades. Degradation of sea grass beds
may be attributable to increased inputs of sediment resulting in clouding of the water and a
reduction in rates of photosynthesis, and increased inputs of herbicides and pesticides via land
run-off (section 4.146).
Nesting and feeding areas on the less developed east coast are not affected as severely as
those on the south and west coasts. Habitat stresses on leatherbacks, which nest primarily on the
east coast and forage in the open ocean, are therefore minimised.
3.2 Disease or Predation
There are few data available to assess whether sea turtles are seriously stressed by disease
or non-human predators in Barbados. In 1980-81, 5-10 juvenile green turtles were caught off the
east coast with tumors over their eyes and on their flippers, indicative of a disease known as
green turtle fibropapilloma. In 1990, 19 of 21 green turtles (weight range 5-18 kg) caught by
two east coast fishermen were afflicted by this disease. The extent to which these tumors affect
the survival of sea turtles in Barbados is not known, but to date the disease has been found only
in green turtles caught on a small rocky outcrop surrounded by sea grasses off Barclays Park.
Green turtles caught at other east coast sites 6-8 km away from this area were not affected
(Gamache and Horrocks, 1991). Green turtle fibropapilloma has been documented extensively
in Florida (Ehrhart, 1991) and has more recently been found in Curaçao (Jacobson, 1990),
Venezuela (Guada et al., 1991), and Belize (Karen Eckert, WIDECAST, pers. comm.). The
cause of this debilitating and often fatal disease is unknown.
In addition to disease, depredation is a factor impacting on sea turtle populations. During
the incubation period, eggs attacked by insects in the nest can be subsequently infected with
fungi and bacteria. Vertebrate predators, such as mongooses, are rarely seen on beaches, but on
two occasions at one location mongooses were seen carrying eggs from nests. Both of these
nests had been previously exposed, by poachers in one case and wave action in the other case.
Dogs also sometimes consume turtle eggs (Horrocks and Willoughby, 1987). After hatching,
ghost crabs (Ocypode quadrata) prey on hatchlings as they crawl across the beach and fishes
consume the small turtles once they enter the sea. Since most nesting occurs on the west and
south coasts where nearshore water quality and over-fishing have affected the abundance and
size of potential predators, reef-associated predation of hatchlings may be less serious than that
in the vicinity of healthier reefs elsewhere in the Caribbean. Two young juvenile leatherbacks
(20-30 cm straight-line carapace length) have been found stranded in east coast rock pools since
1984. Each had a recently bitten-off front flipper, suggesting shark attack (Horrocks, 1987). An
adult female with her right front flipper severed off in a manner again suggestive of shark attack
stranded on the same beach (Cattlewash Beach) in February 1989 (Horrocks, 1989).
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