Sea Turtle Recovery Action Plan for Barbados - WIDECAST

2.2 Chelonia mydas, Green Sea Turtle
Barbados Sea Turtles …
Local common names for this species include green turtle and green-back. Green turtles
are recognized by a single pair of scales on the forehead between the eyes and a round, blunt
beak serrated for clipping sea grasses. The carapace is smooth and the plates (=scutes) do not
overlap one another (in contrast to the hawksbill turtle, see section 2.4). The carapace is
characterized by four pairs of lateral scutes (Figure 1) and is generally free of barnacles. Adults
attain weights of 230 kg and generally measure 95-120 cm straight-line carapace length (nuchal
notch to posterior tip) (Pritchard et al., 1983). Individuals of varying sizes are present in the
waters surrounding Barbados throughout the year.
Green turtles are herbivorous and in the Caribbean they feed primarily on the sea grass
Thalassia testudinum (Bjorndal, 1982). Field studies indicate that individual turtles maintain
feeding "scars" by returning to the same area of sea grass meadow to forage everyday (Bjorndal,
1980; Ogden et al., 1980, 1983). These scars, or grazing plots, are maintained by regular
cropping for several months and the more digestible newer growth (higher in protein, lower in
lignin) is preferred (Bjorndal, 1980). When the cropped grasses show signs of stress (blade
thinning, increased inter-nodal distance), the turtle generally abandons the scar and moves on to
form another. Sea grasses are relatively rare in Barbados. The best developed foraging areas are
found on the south coast and in protected bays on the east coast (section 4.111) (Map 2).
There are no documented incidents of green turtles nesting in Barbados, although a single
hatchling was found in 1990 on land at a site far from the sea. Where it came from and how it
got there are unknown. Adults are occasionally caught opportunistically offshore (usually
speared), but they are rarely seen in coastal waters. In contrast, juveniles (5-18 kg in weight) are
relatively common in coastal waters, especially on the east coast. Some fishermen take them
opportunistically and more rarely set nets for them, although those they catch are often below the
30 lbs (13.6 kg) legal size limit (see section 4.21). Green turtles are long-lived and require 25-35
years to reach sexual maturity in the Caribbean (Frazer and Ladner, 1986). Age structure of the
population(s) feeding in the waters of Barbados has not been studied.
2.3 Dermochelys coriacea, Leatherback Sea Turtle
Leatherbacks are the largest of all the sea turtles (nesting females often weigh 300-500
kg) and they have the most extensive geographic range of any turtle. Aside from their great size,
leatherbacks are easily distinguished because they lack a bony shell. The smooth, black skin is
spotted with white. The carapace is strongly tapered, measures 130-165 cm in length
(straight-line, nuchal notch to posterior tip), and is raised into seven prominent ridges (Figure 1).
Powerful front flippers extend nearly the length of the body. Adults, at least adult females, are
excellent divers, having been recorded at depths exceeding 1000 meters in Caribbean waters
(Eckert et al., 1989). Leatherbacks feed predominately on jellyfish and other soft-bodied prey
(Den Hartog and Van Nierop, 1984; Davenport and Balazs, 1991). Based on offshore studies of
diving by gravid (=egg-bearing) females nesting in St. Croix, Eckert et al. (1989) proposed that
inter-nesting dive behaviour may reflect nocturnal feeding on vertically migrating zooplankton,
chiefly siphonophore and salp colonies.
Page 3