Times of the Islands Summer 2015

green pages
green pages newsletter of the department of environment & maritime affairs
newsletter of the department of environment & maritime affairs
head office: church folly, grand turk, tel 649 946 2801 • fax 649 946 1895
• astwood street, south caicos, tel 649 946 3306 • fax 946 3710
• national environmental centre, lower bight road, providenciales
parks division, tel 649 941 5122 • fax 649 946 4793
fisheries division, tel 649 946 4017 • fax 649 946 4793
email environment@gov.tc or dema.tci@gmail.com • web www.environment.tc
HEIDI HERTLER
Turtles are commonly observed in the near shore reefs around the Turks & Caicos Islands.
MEGAN NASH
This intrepid turtle hatchling is making its way to the sea.
Keeping Tabs on Turtles
Beach profile monitoring for marine turtle nesting areas.
By Charlotte de Fontaubert, Heidi Hertler, Aaron Henderson, and Anela Akiona
Near shore coral reefs are extremely productive, supporting
most of the TCI economy, either through fisheries
or tourism, along with resident and transient marine turtles.
TCI waters support regionally significant foraging
aggregations of green (Chelonia mydas) and hawksbill
(Eretmochelys imbricata) turtles, and, to a lesser extent,
loggerhead (Caretta caretta) turtles, all species which
have been designated as endangered or critically endangered
by the International Union for the Conservation of
Nature (IUCN). They are also listed under Annex I of the
Convention on International Trade in Endangered Species
(CITES), and while this listing protects these species from
international trade between parties to CITES, they are still
harvested throughout the Caribbean, largely for domestic
consumption. Marine turtles utilize a variety of habitats
throughout their lives including sandy beaches, coral
reefs, seagrass beds, and other shallow nearshore foraging
areas.
Sea turtles are one of the most ancient groups of
animals. They are primarily found in warm and temperate
waters around the world. Many migrate over 1,000
miles from feeding grounds to nesting beaches, the same
beaches from where they were born. Female green turtles
mate every two to four years, usually in June through
September; while female hawksbills breed every two
years, usually in April through November. Sand temperature
determines the sex of the turtle, where below 30ºC is
predominantly male and above is predominately female.
Hatchlings emerge at night from buried nests to make
their way to the sea. Turtles feed on jellyfish, seaweed,
crustaceans (crabs and shrimp), sponges, and algae, all
of which are abundant around the Turks & Caicos Islands.
Whilst the full extent of the impacts of climate change
on marine and coastal ecosystems is hard to predict in
any significant detail, many of these impacts have already
been observed and felt, globally and in the Turks & Caicos.
For instance, sea-surface temperatures have increased,
sea-level has measurably risen, current pattern changes
have been documented, and even water pH balance has
changed as a result of ocean acidification. These impacts
are of great concern for the survival of marine turtles.
Temperature profoundly influences many aspects of
marine turtle life behavior and distribution, from adults’
distribution to sex ratios of hatchlings. Elevated sea
surface temperature and changes in precipitation affect
turtle growth rate, nesting periodicity and onset of nesting
season, incidence of disease, and change predator
distribution and prey abundance. Sea-level rise affects
beach erosion pattern and size, thus reducing nesting
site option and success. Altered strengths and locations
of sea-surface currents affect migration patterns and alter
distribution of juveniles.
The Turks & Caicos Islands (TCI) are an archipelago of about forty limestone islands. Most of the land
habitat is scrub lands. The mangrove forests, seagrass ecosystems, salt flats and coral reefs that line the
coast are among the most biologically productive coastal tropical systems, functioning as both nurseries
and refuge from predators. Scattered between these coastal ecosystems and limestone cliffs are white
sand, isolated beaches, proven to be ideal for turtle nesting.
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