The future of marine turtles is grim…6 of the 7 species are Endangered or Critically Endangered. All 7 are listed on Appendix 1 of CITES making their trade internationally prohibited among the 166 CITES member nations. Even though the species are protected they still face multiple threats that are causing their numbers to decline at an alarming rate. This brief presentation aims to introduce you to these 6 species that may face extinction in the very near future if we, as co-inhabitants of this earth, do not share in the responsibility of their protection.
The KEMPS RIDLEY turtle is the most endangered species of marine turtle. It nests only on a small area of coastline in the Gulf of Mexico. They can weigh up to 40kg and have an average length of 69cm making them, along with the Olive Ridley turtle, the smallest species. The females are migratory, swimming vast distances to reach nesting grounds every 1-3 years. Females are able to reproduce at 12 years of age. Their carapace is olive grey and they have a white/yellow underbelly. Nesting occurs in broad daylight and only on one 20km stretch of beach on the Gulf on Mexico. Their survival hangs in the balance primarily due to over harvesting of their eggs and commercial fishing fleets. Even though some fishing fleets use turtle excluder devices their population has not been able to rebound. This species feeds mostly on invertebrates thereby playing an important role in open ocean and coastal ecosystems. There are only about 1,000 of these Critically Endangered breeding females left in the wild
Although the HAWKSBILL turtle is Critically Endangered and protected under CITES there is still an excessive amount of trade in products made with the shell of this turtle. This is thought to be the primary cause of their decreasing population trend. There shell is beautifully coloured with elaborate patterning. The scutes on the carapace are very unique with their hard, overlapping boney plates. This species is the only source of commercial tortoise shell ,often used to make jewellery and ornaments. There is a strong demand for these products in Japan as well as South and East Asia They weigh between 46-60kg and are usually less than 1m in length. Hawksbill turtles are primarily spongivorous. When they dislodge pieces from the coral it provides reef fish with food. They support healthy reefs by controlling sponges which would out –compete reef building coral for space. According to the IUCN there has been an 87% decline in the number of mature females nesting in the last 3 turtle generations. Other threats include excessive egg collection, slaughter for meat for human consumption and shark bait. Destruction of nesting and foraging habitat, hybridization of Hawksbill with other species of marine turtles when populations are very low, entanglement and ingestion of marine debris and oil pollution
The OLIVE RIDLEY turtle is the most abundant marine turtle and is listed as Endangered on the IUCN’s Red List and is protected under CITES. It nests on 5 beaches in Mexico, Costa Rica and North East India. On the beaches of Orissa in India it is estimated that 120,000 have been killed in the last 10 years. The genus of Ridley turtles (lepidochelys) split into 2 species - the Kemp’s Ridley and the Olive Ridley. They look quite similar except the Olive Ridley has a deeper body and the edges of its rusty coloured carapace are upturned. Average length is 75cm and weight is approximately 45kg. Primary threats include unsustainable egg harvest, illegal poaching of adult turtles, bycatch in fisheries (trawl, longlines, purse seines, gill net, hook and line) and habitat degredation. Fibropapilloma, a herpes infection found in many sea turtles but not believed to be prevalent in Olive Ridley’s, has been found in Costa Rica. It is thought that this herpes infection may be caused by run-off from land causing marine pollution and a weakening their immune systems
The LEATHERBACK turtle is listed as Critically Endangered and is protected under CITES. Based on information provided by the IUCN, global populations are in decline with the population in Costa Rica dropping from 1,646 nests to 500 nests on the main nesting beach on the Pacific Coast in just a little over a decade. Their main threats have been the prolonged unsustainable harvest of eggs and their capture by oceanic fisheries. In some areas harvesting of eggs and poaching of adults has removed more than 95% of the clutches. Longlines and driftnets as well as oceanic pollution by plastics are significant threats as well. Phthalates have been found in the yolks of Leatherback eggs. Leatherbacks eat jellyfish and often mistake plastic bags as this food source, ingestion results in a slow painful death due to their one way digestive system and inability to regurgitate. This causes them to starve To death. Populations may be as low as 34,000 nesting females
The GREEN turtle is listed as Endangered and is also protected under CITES. According to the IUCN the annual number of nesting females has declined by 48-57% over the last 3 turtle generations. They are harvested for meat in many tropical countries, it is thought that 100,000 are killed annually in the Indo-Australian archipelago and 30,000 in Baja California for this reason alone. In some areas they are suffering from potentially lethal tumours, this is thought to be due to increasing levels of oceanic pollution. These turtles get their name from the greenish color of their shell and the fat deposits around their internal organs. They are 80-150cm in length and can weigh up to 130kg. Green turtles are the only truly herbivorous marine turtle, feeding mostly on sea grasses and algae. The most detrimental human threat may be over harvesting of eggs and poaching of adults. Mortality associated with entanglement in fishing nets is the primary incidental threat. There are an estimated 203,000 left worldwide.
The LOGGERHEAD turtle is Endangered and protected under CITES. They are highly migratory and often get caught up in fishing nets and lines. Their shells are used to make paddle boats in Honduras. This species of turtle is one of the largest and carries more encrusting organisms on its carapace than any other marine turtle. Their shell is reddish brown and the underbelly is light yellow This turtle is carnivorous, feeding mainly on molluscs and impressively, also feeds on the almost impenetrable queen conch. There are thought to be more than 60,000 nesting females. Their main cause of mortality is thought to be the result of fishing bycatch, with abandoned driftnets continuing to drown these turtles every day. Before the introduction of turtle excluder devices, about 50,000 were killed in shrimp nets in the Gulf of Mexico and the Atlantic Ocean.
The mission of the Canadian Organization for Tropical Education and Rainforest conservation is to provide leadership in education, research, conservation, and the educated use of natural resources in the tropics.
Here is where the Cano Palma Biological Station is located
Marine Turtle and Monitoring Program <ul><li>On an unprotected stretch of beach, for the past 6 years, COTERC has been running a marine turtle program to aid in protecting and understanding the four species which come and lay their eggs there. </li></ul><ul><li>Photo credit: Jeff Tribe </li></ul>
Marine Turtle and Monitoring Program <ul><li>We invite you to join us in our endeavour! </li></ul><ul><li>Visit www.coterc.org and become a volunteer to help protect marine turtles. </li></ul><ul><li>Photo credit: Jeff Tribe </li></ul>