Sea Turtle Recovery Action Plan for Barbados - WIDECAST

CEP Technical Report No. 12
III. STRESSES ON SEA TURTLES IN BARBADOS
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3.1 Destruction or Modification of Habitat
Beaches on the west and south coasts of Barbados are composed of coralline particles
derived from the reefs offshore and are subject to seasonal erosion and accretion. Erosion
generally occurs between January and March and accretion between April and September on
west coast beaches; and erosion between March and September and accretion between October
and February on south coast beaches. West coast beaches have diminished in size (presently
they are about 15 m wide) at an average of 0.3 m/yr over the period 1954 to 1982. If this rate of
erosion continues, some of these beaches may disappear by the year 2000. The south coast
beaches, with a few notably bad exceptions, have remained fairly stable over this same period.
Their stability may be due in part to the construction of groynes for sand entrapment. The east
coast beaches have remained the most stable over this time period. The sand on these beaches is
primarily siliceous and is derived from land-based sources, but they, too, are subject to erosion
during the time when wave energy is at its highest on this coast (June-September). The erosion
of beaches has serious implications for the future of tourism, and hence the economy of
Barbados, apart from the effect on turtles nesting in Barbados.
The loss of beaches has been attributed in part to natural phenomena such as the rising
sea-level, but a more immediate correlation with disappearing beaches is the extensive beachfront
development and accompanying loss of stabilizing beach vegetation that has occurred over
the past few decades. Seawalls and boulders are often used to protect sea-front properties.
These structures may aggravate beach erosion by deflecting wave energy abruptly downwards,
thereby increasing the scouring effect of waves. The construction of hotels and houses continues
on the few remaining undeveloped beach front areas on the west and south coasts. Hotels
modify nesting areas more seriously than private houses. Ornamental and security lighting,
removal of beach vegetation, and heavy pedestrian use of beaches may discourage turtles from
nesting, as well as increase hatchling mortality and aggravate erosion. Specific measures
designed to mitigate the degradation of nesting beaches are discussed in sections 4.13 and 4.6.
As noted above, the lighting of beaches adjacent to houses and hotels may deter females
from nesting (see also section 4.132). Moreover, several nesting females have been found on
their backs in storm drains or wedged between boulders that have been placed to fortify the
beach. There are now very few undeveloped beach front areas along the west and south coasts
where females can emerge and nest in darkness. When nesting does occur adjacent to hotels and
houses, hatchlings are invariably attracted to lights, and often not found until the next day or
later. Mortality among disorientated hatchlings is high, and those that are found alive are often
too exhausted to be released. Of 27 nests monitored in 1987-88, 14 (55.6%) were affected by
beach lights at hatching, with up to 100% of hatchlings in affected nests orienting inland instead
of toward the sea (section 4.132). In 1990, hatchlings from 83% of 35 monitored nests were
disoriented by lighting. The problem may be worsening due to a generalized increase in security
lighting.
The health of the west and south coast fringing reefs in terms of coral cover and diversity
and fish abundance and diversity is generally acknowledged to have deteriorated over the past 30