THE Mamanuca Environment Society commended the action of the Department of Fisheries and the Fiji Police Force for rescuing three female green turtles in Tailevu on September 6.
And the suspicion by the Department of Fisheries technical officer Aporosa Rabo that some villagers had been illegally catching turtle for some time is both appalling and sad as we are approaching the nesting season which is October to April.
Sea turtles are highly migratory and judging from their size, they were on their way to their nesting beaches when they were caught.
From our Mamanuca Turtle Conservation Project funded by Global Environment Fund Small Grants Project, we found that there are ten nesting beaches in the Mamanucas which is why we are very concern that turtles are still harvested in some villages in Viti Levu.
Sea Turtles are a keystone species and demonstrate the ultimate lesson of ecology – that everything is connected.
They are vital part of the beaches and marine systems. If sea turtles become extinct, both the marine and beach ecosystems will weaken.
Turtles start life on a beach as a hatchling, measuring no more than the length of a ring finger.
During the night in what is known as the “hatchling frenzy”, the individuals clamber over each other to reach the surface of their nest and rush toward the sea using the horizon’s light as a cue.
At this point they encounter one of the many challenges to their survival, natural predators like crabs, ants and birds. Another encounter is the confusion from artificial lights emanating from roads or buildings which they mistake for the horizon and the water’s edge.
Hatchlings that make it to the surf line keep crawling until an undertow sweeps them out into deeper water where they then set a course for the open ocean for a 96 hour non swim. Once they are in the open ocean young marine turtles then depend on ocean currents to freely drift and feed until they are a size of dinner plate at which time they tend to settle at inshore feeding grounds.
Marine turtles grow slowly and take between 30 to 45 years to reach sexual maturity. They live for years in the one place before they are ready to make the long breeding migration of up to 3000 kilometres from the feeding grounds to nesting beaches.
When breeding, nesting females return to the same area thought to be in the region of their birth. As hatchlings they become imprinted to the earth’s magnetic field and possibly the smell of the waters adjacent to the nesting beach which allow them to successfully complete their migration.
Courtship and mating take place in shallow waters near the nesting beach. Females often mate with more than one male. After mating the males return to the feeding grounds.
Between nesting efforts, female turtles gather adjacent to the nesting beaches. They return to the same beach to lay consecutive clutches. A female green turtle usually lays six clutches of eggs at two weekly intervals, with each clutch containing about 100 white, spherical, “ping-pong” ball sized eggs.
After laying its eggs, the turtle then fills the egg chamber with sand using the hind flippers and then fills the body pit using all four flippers before crawling back to sea. And then it is another wait before the next generation of hatchlings run down to the beachfront for another whole new cycle of life.
