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Saturday, February 16, 2008

A Tribute to Sea Turtles and Turtle Eggs

For hundreds of years Foochows from China love sea food nothing but sea food because they are coastal people and they go to sea for fishing.

I remember relatives buying many turtle eggs from Kuching, Labuan and Sabah and giving them as beloved gifts whenver they came home from travelling. Furthermore, I also saw many shops selling freshly boiled turtle eggs for their customers in the early days of Sibu. But today, turtle eggs are protected commodities and no one is allowed to sell them in the market.

Sea turtles are so endangered!!

But taking a look at the sea turtles of Malaysia one can see how rich Malaysians can be in terms of food from just this group of marine life.

Because so many turtle eggs have been consumed by Malaysians, we should now start conserving sea turtles for very obvious reasons.

Seven turtle species have been recognised living in the world's oceans, which are grouped into six genera. Out of this number, four species can be found nesting on Malaysian shores: the olive-ridley turtle (Lepidochelys olivacea), the hawksbill turtle (Eretmochelys imbricata), the green turtle (Chelonia mydas) and the leatherback turtle (Dermochelys coriacea). Unfortunately, these species are currently being listed on the IUCN Red List as endangered.

1. Olive-ridley turtle. Local name Penyu Lipas

The olive-ridley is a small turtle species. Its average clutch size is over 110 eggs, which requires a 52 to 58 day incubation period. This species inhabits tropical and subtropical coastal bays and estuaries. In Malaysia, the nesting status of olive-ridley turtle is fragmentary, with records available only for the states of Terengganu, Kelantan and Penang. Nesting has been recorded in Sabah and Sarawak but the numbers are probably insignificant compared to the major sites.

2. Hawksbill turtle. Local name Penyu Sisik, Penyu Karah

The hawksbill turtle is also one of the smaller sea turtles. Their shells are beautiful, which largely contributes to their endangered status. Humans kill them to get their shells, which are used to make jewellery and other products. Hawksbill turtles nest every three or more years. An average of two to four egg clutches are laid approximately fifteen days apart during nesting season. Each clutch contains an average of 160 eggs, which requires an approximately 60 day incubation period. This species inhabits near coral reefs in tropical oceans. In Malaysia, their nesting sites cover the shores of Terengganu, Johor, Melaka and Sabah, as well as Sarawak, and perhaps Pahang, Kedah and Kelantan.

3. Green turtle. Local name Penyu Agar, Penyu Pulau

The green turtle is the largest of the Cheloniidae family and are easily distinguished from other sea turtles because they have a single pair of scales in front of their eyes rather than two pairs as the other species. Diets of green turtles change significantly during its life. At less than eight inches long, green turtles eat worms, young crustaceans, aquatic insects, grasses and algae. Once green turtles reach eight to ten inches in length, they eat mostly sea grass and algae; the only sea turtle species that is strictly herbivorous as an adult.

Green turtles nest every three or more years. An average of three to five egg clutches are laid approximately twelve days between each nesting. Each clutch contains an average of 115 eggs, which requires an approximately 60 day incubation period. The green turtle can be found on tropical coasts and islands, and is the most widely distributed sea turtle species in Malaysia. In Peninsular Malaysia, major nesting sites include Perhentian and Redang Islands off Terengganu, and mainland beaches of Terengganu at Penarik, Kemaman and Kertih. They can also be found nesting in the states of Pahang (Chendor and Cherating) and Perak (Pantai Remis). In East Malaysia, the green turtle nesting sites are on the shores of Sarawak Turtle Islands, the Turtle Islands in Sabah and Sipadan Island.

4. Leatherback turtle. Local name Penyu Belimbing

The leatherback is the champion of sea turtles. It grows the largest, dives the deepest, and travels the farthest of all sea turtles. The leatherback turtle is the most unusual and distinctive of all sea turtles, as it is the only turtle that lacks a hard shell. Instead, this species has a large, elongate shell which is composed of a layer of thin, tough, rubbery skin, strengthened by thousands of tiny bone plates. Seven narrow ridges run down the length of the carapace, and the lower shell is whitish to black, and marked by five ridges. The body of a leatherback is barrel shaped, tapering at the posterior to a blunt point.

With this streamlined body shape and the powerful front flippers, a leatherback can swim thousands of miles across the open ocean and against fast currents. Leatherback turtles nest at intervals of two to three years. An average of six to nine egg clutches are laid approximately ten days between each nesting. Each clutch contains an average of 80 fertilized eggs the size of billiard balls and 30 smaller unfertilized eggs, which requires an approximately 65 days incubation period. The leatherback turtle can be found in tropical oceans, but they migrate to temperate waters to feed. In Malaysia, this species nest largely on the mainland beaches of Terengganu; especially along a 15 km stretch of beach centered at Rantau Abang.

Why are sea turtles declining?

Sea turtles have long played a vital role in the folklore of many world cultures, but this has not stopped them from being exploited by humans for food and income. The earliest known sea turtle fossils are about 150 million years old. However, in the past 100 years increased demand for turtle meat, eggs, skin and shells has lead to a rapid decline in their populations.

Sea turtles are practically exposed to threats at all stages in their life-cycle. In nature, sea turtles nests are predated by monitor lizards, crabs and ants. Once they emerge, hatchlings make bite-sized meals for birds, crabs and a host of predators in the ocean. After reaching adulthood, sea turtles are relatively immune to predation, except for the occasional shark attack. However, it is the pressure of human activities that is threatening the survival of sea turtle around the world. Moreover, the impact of these threats is multiplied by their slow growth and long maturation period.

Artificial lighting

Turtles typically seek dark and undisturbed beaches for nesting. Nesting turtles often avoid lighted areas; therefore strong light and noise from beachfront structures and coastal residents as well as uncontrolled use of torchlight and flash photography by beach visitors can disrupt nesting activity. This too may disturb other nearby turtles from landing or nesting successfully. Also, artificial light can disorientate hatchlings during their seaward crawl and may lead them to wander inland, where they often die of dehydration and predation.

Coastal development

Beachfront development and construction of recreational facilities, walkways and barriers to prevent beach erosion can hinder nesting. Structures such as sea walls and sandbags that are installed in an attempt to protect beachfront property from erosion may block female turtles from reaching suitable nesting habitat. Besides that, removal or replacing of sand or local vegetation cover can alter beach condition that is suitable for nesting. Also, if this activity persists during nesting season, nests may be buried far under the surface or run over by heavy machineries.

Turtle egg harvest

In their lifetime, an adult female turtle can produce thousands of eggs. Each female lays hundreds of egg per nesting season and return to nest only after three to four years. Therefore, the high number of eggs laid per clutch per season is to make up for the high levels of hatchling and juvenile mortalities before reaching adulthood. In Malaysia, turtle eggs are still harvested commercially. This practise of collecting turtle eggs for sale and consumption can seriously threaten turtle populations. Turtle eggs can be ten times more expensive than chicken eggs although their nutritional properties are comparable. Any medicinal property claimed in turtle eggs has never been scientifically confirmed.

Ingestion of debris and plastic

Upon emergence, hatchlings frantically swim to offshore waters, launching their pelagic life searching for edible floating debris or whatever food they can find that accumulate along drift lines. Unfortunately, these drift lines also accumulate non-degradable human litter that is often dumped into the sea. Thousands of sea turtles die from eating or becoming entangled in this debris each year, including packing strip, balloons, pellets, bottles, vinyl films, and styrofoam. Trash, particularly plastic bags thrown overboard from boats or dumped near beaches and swept out to sea, is eaten by turtles and becomes a deadly meal. For example, leatherback turtles feed primarily on jellyfish and their inability to distinguish between a floating plastic bag and a swimming jellyfish in seawater has lead to deaths of many leatherbacks turtles. Therefore, it is important that garbage is disposed of properly and not thrown into the sea or littered on the beach, as tide will carry the rubbish out to sea.

Pollution

Pollution can have serious impacts on both sea turtles and particularly on the food they eat. Turtle disease such as Fibropapillomas may be linked to pollution in the oceans and in nearshore waters. When pollution kills aquatic plant and animal life, it also removes food for sea turtles to eat. Oil spills, urban runoff of chemicals, fertilizers and petroleum all contribute to water pollution. Besides that, weathered oil slicks form tarballs, which may float on the sea surface for months or years, and are often mistaken by sea turtles for food.

Commercial fishing

The waters of South China Sea are a major habitat for turtles, but are also the main fishing grounds in Malaysia. Each year, during sea turtle migration across the open ocean between their feeding and nesting grounds, many become entangled in fishing nets and drown. Sea turtles are vulnerable to incidental capture in fishing gears. Globally, shrimp trawling probably responsible for the incidental death of more juvenile and adult sea turtles than any other source.

Case study: The leatherback turtle crisis in Rantau Abang.

The beaches of Rantau Abang, located in the state of Terengganu on the east coast of Peninsular Malaysia, are famed for being the landing sites of the Pacific Giant leatherback turtles. For decades, these marine reptiles come to the Rantau Abang shores biannually to lay eggs between the months of April and September. However, the leatherback turtles are in danger of being forever lost from Rantau Abang due to a significant fall in their population. According to the Department of Fisheries statistics the leatherback population nesting on Malaysian shores has declined to merely 2% of the actual number that arrived 50 years ago.

One primary factor that contributes to this devastating fact is the presence of humans at their nesting sites. Every landing season, large crowds consist of locals as well as tourists gather at Rantau Abang to witness this unique event. As these beaches are open to the public, it is often difficult to control the number of people present during leatherback nesting. Despite efforts by the government and the mass media to educate the public on turtle landings, there are still groups of people that camp in the area and build bonfires, which disturb the nesting process. Growth of the tourism industry in Rantau Abang also contributes to the decline, as bright lights and loud noises near the beachfront resulting in turtles to shy away.

Besides that, turtle landings in Rantau Abang also catch the attention of many egg poachers. Even with efforts to forbid the collecting of turtle eggs, they are still harvested commercially in some parts of Malaysia and often can be found for sale in local markets. To overcome this threat, an increasing number of turtle sanctuaries are currently being established along the Rantau Abang shores. Turtle eggs laid on the beach are located and replanted by scientists in incubator centres to prevent them from being stolen and eaten. These artificial hatcheries also provide controlled conditions which may help to overcome the problem of uneven sex ratio in the leatherback population, and consequently bring about the recovery of this species in Rantau Abang.

Conservation actions in Malaysia.

The urgent need to save our sea turtles has been realised long ago. In Malaysia, turtle conservation measures were introduced as early as 1927 by the British North Borneo Company in Sabah to protect the Hawksbill turtle species. Current turtle sanctuaries in Malaysia include:

The Turtle Islands

Located about 40 km off Sandakan, the Turtle Islands Park in Sabah is one of the premier green turtle and hawksbill turtle nesting sites in Malaysia. This sanctuary consists of three main nesting islands - Pulau Selingaan, Pulau Bakkungan Kechil and Pulau Gulisaan, covering an area of 1,740 hectares. In August 1966, the state government funded the establishment of the first turtle hatchery on the largest island, Pulau Selingaan. By 1977, all three islands were successfully converted into a marine park by the state government. Current management of the Turtle Islands is overseen by the Department of Fisheries in Sabah.

Ma' Daerah

Located in Terengganu, this turtle and terrapin sanctuary was established in June 1999. This project was undertaken through a partnership between the Department of Fisheries, BP Amoco and WWF Malaysia. Ma' Daerah stations as a turtle hatchery as well as turtle nesting research and management centre. Current conservation projects also include further education of the local communities on sea turtle crisis in Terengganu. Current management of Ma' Daerah is overseen by the Department of Fisheries Malaysia.


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