Study

Infertility, embryonic mortality and nest-site selection in leatherback and green sea turtles in Suriname

  • Published source details Whitmore C.P. & Dutton P.H. (1985) Infertility, embryonic mortality and nest-site selection in leatherback and green sea turtles in Suriname. Biological Conservation, 34, 251-272.

Actions

This study is summarised as evidence for the following.

Action Category

Relocate nests/eggs to a nearby natural setting (not including hatcheries): Sea turtles

Action Link
Reptile Conservation

Relocate nests/eggs for artificial incubation: Sea turtles

Action Link
Reptile Conservation
  1. Relocate nests/eggs to a nearby natural setting (not including hatcheries): Sea turtles

    A replicated, controlled study in 1982 on a sandy beach in Suriname (Whitmore & Dutton 1985; same experimental set-up as Dutton et al. 1985) found that leatherback turtle Dermochelys coriacea nests reburied above the tide line had similar hatching success but lower predation rates than natural nests not washed over by sea swells. Results were not statistically tested. Average hatching success of leatherback turtle eggs reburied above the tide line was 69% compared to 33% in natural nests washed over by sea swells and 62% in natural nests not washed over by sea swells. Embryonic mortality in reburied nests was 23% compared to 35% and 13% in natural nests washed over and not washed over by swells respectively. Predation rates were 6% in reburied nests compared to 27% and 17% in natural nests washed over and not washed over respectively. Nesting turtles were surveyed <once/week in March–August 1982 on a 12 km long beach. Nests laid below the spring high tide line were relocated the next day to further up the beach above the spring high tide line (13 leatherback clutches, 50 eggs/clutch reburied together in 60 cm deep cavities 1 m apart). Relocated and natural nests (10–12 nests occasionally washed over by sea swells, 13–16 not washed over by sea swells) were excavated after emergence to evaluate hatching success.

    (Summarised by: Katie Sainsbury)

  2. Relocate nests/eggs for artificial incubation: Sea turtles

    A replicated, controlled study in 1982 on a sandy beach in Suriname (Whitmore & Dutton 1985) found that leatherback Dermochelys coriacea and green Chelonia mydas turtle nests incubated in Styrofoam boxes had comparable hatching success to natural nests not washed over by sea swells, but greater incidences of embryonic mortality and deformity than natural nests. Average hatching success of turtle clutches relocated to Styrofoam boxes was 60–73% compared to 33–67% in natural nests washed by sea swells, and 62–82% in natural nests not washed by sea swells (results were not statistically tested). Embryonic mortality and deformity occurred more often in eggs incubated in Styrofoam boxes (mortality: 26–33% of eggs, deformity occurred in 50–88% of clutches) than natural nests (mortality: 8–21% of eggs, deformity: 10–20% of clutches). No eggs incubated in Styrofoam boxes were predated whereas in natural nests 17–27% of leatherback and 11–12% of green turtle eggs were predated. Some leatherback turtle nests were reburied further up the nesting beach for comparison (see original paper, or “Relocate eggs/nests away from threats”). Nesting turtles were surveyed at least once/week in March – August 1982 on a 12 km long beach. Nests laid below the spring high tide line were relocated the next day to a hatchery for incubation above ground in Styrofoam boxes (11 leatherback clutches, 45 eggs/box; 8 green turtle clutches, 88 eggs/box). Relocated and natural nests (~35 green turtle and ~30 leatherback nests) were excavated after emergence to evaluate hatching success.

    (Summarised by: Katie Sainsbury)

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