【明報專訊】◆Where do green turtles live?

Green turtles live in tropical and subtropical waters around the globe. They are the only species of sea turtle that lays eggs in Hong Kong, mainly on the beach of Sham Wan, Lamma Island. These endangered animals are precious local marine lives.

◆Why don't green turtles look green?

The shell of a green turtle is olive and brown. The species got their name from the green fat inside their body, but not their appearance. Young green turtles feed on small fish, shrimps and sea jellies. As they grow up, they become vegetarian and eat so much algae that their fat turns green!

◆How do green turtles breed ?

It takes 20 to 30 years before green turtles are mature enough to breed. The females go to beaches during their breeding season. These are not just random beaches, but their own birthplace. In other words, green turtles are born in the same place as their mothers and grandmothers. The females have to migrate between feeding grounds and the beaches — some may travel as far as 4,800 km across the ocean! At night, the female green turtles would dig a hole and lay more than 100 eggs inside, then return to the sea.

The eggs are incubated by sand and the gender of the babies depends on the sand temperature. Warmer sand gives more females and cooler sand produces more males. When the baby turtles hatch, they will immediately find their way to the ocean. During this time, predators like seabirds or big fish would prey on the baby turtles. Therefore, only a small proportion of them can survive and grow.

◆Why are green turtles endangered?

Green turtles are under threat due to human activities, such as overharvesting of turtles and their eggs, pollution, and coastal development destroying their nesting and feeding sites. Green turtles are harmed by marine litter, especially plastic items. In the ocean, they may mistake the plastic for food or get entangled. On land, the litter can become obstacles to baby turtles.

◆Conservation of green turtles

To protect the nesting site of green turtles in Hong Kong, Sham Wan has become a Site of Special Scientific Interest (具特殊科學價值地點). Access to this area is restricted during the breeding season from June to October. The aquarists and veterinarians of Ocean Park provide care for rescued or confiscated (充公) wildlife. Since 2000, over 60 sea turtles have recovered and returned to the sea.

(Text and photos: Ocean Park Hong Kong)

■Glossary

breed (v) 繁殖

incubate (v) 孵化

obstacle (n) 障礙

aquarist (n) 水族員

[Smarties' Power English 第203期]