Loggerhead Turtle



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Loggerhead Turtle IUCN Status Category: Endangered

Caretta caretta (Linnaeus 1758) CITES Appendix: I

INTRODUCTION
The loggerhead turtle has a rusty coloured carapace which measures an average of 92cm long in the adult. These turtles carry more encrusting organisms such as barnacles on their carapaces than other marine turtles. An adult loggerhead weighs about 115kg.
This species is distinguished mainly by its large head and strong jaws. It is carnivorous throughout life, eating bottom dwelling molluscs (conches, clams), crabs, urchins and sponges, as well as free swimming jellyfish and seemingly impenetrable prey such as the queen conch.
The age of sexual maturity is uncertain; it has been estimated at between 10 and 30 years but studies from Australia indicate that it may be between 34.3.and 37.4 years. Nesting frequency is also uncertain. Females nest an average of three to five times per season, but they have been documented nesting up to six times in a season. Between 40 and 190 eggs (mean about 100) are laid per clutch. As with the other sea turtles, the loggerhead does not appear to nest every year: data from the USA suggests that nesting takes place about every two years.
Loggerheads are highly migratory, making the longest journeys known of all sea turtle species. The possibility that juvenile loggerheads cross the Pacific Ocean has been corroborated by studies showing Baja Californian loggerheads have a genetic affinity with those found in Japan, and recently the first trans-Pacific migration of a loggerhead was recorded with a satellite transmitter. It is thought that an ability to detect wave direction and the Earth's magnetic field enables this species to navigate across open oceans.

DISTRIBUTION
Loggerheads are widely distributed in coastal waters, mainly in subtropical and temperate regions and travel large distances following major warm currents like the Gulf Stream and California Current. Nesting beaches are distributed in more temperate latitudes than those of other sea turtles. The major Atlantic nesting grounds are in Florida and South Carolina. Loggerheads are the most common turtle in the Mediterranean, with nesting reported from many coasts, especially in Greece, Turkey, Cyprus and Libya. In the Indian Ocean, the coast of Northern Natal and Masirah Island, Oman are the main nesting sites. Nesting occurs throughout Southeast Asia to Australia, but rarely in the central and western Pacific islands.
Nesting Range States: Angola?, Australia, Bahamas, Bangladesh, Belize, Brazil, Cape Verde?, Cayman Islands, China, Colombia, Costa Rica, Cuba, Cyprus, Dominican Republic, Egypt, Greece, Grenada, Guadeloupe, Guatemala, Haiti, Honduras, India?, Indonesia, Israel, Italy, Jamaica, Japan, Libya, Madagascar, Mexico, Montserrat, Morocco, Mozambique, Myanmar?, Namibia, New Caledonia, Nicaragua, Oman, Panama, Papua New Guinea?, Philippines, Puerto Rico, Senegal, South Africa, Sri Lanka, St Lucia, Turkey, Turks and Caicos Islands, USA, Venezuela, Virgin Islands (British). [Atlantic (eastern central, northeast, northwest, southeast, southwest, western central), Mediterranean and Black Sea, Pacific (eastern central, northeast, northwest, southeast, southwest, western central)]

POPULATION
Worldwide numbers of sea turtles are almost impossible to calculate because of the wide range of these migratory animals. It is possible to estimate numbers of adult females on nesting beaches, however not all of these sites have been surveyed, and numbers may be confused due to uncertainty about how many times an individual nests in a season. A recent estimate of the numbers of nesting female loggerheads is 60,000 + (Euro Turtle 1999).
Studies on mitochondrial DNA of Atlantic and Mediterranean populations has revealed six demographically separate groups, corresponding to nesting beaches in (1) Carolina, Georgia, and northeastern Florida, USA, (2) southern Florida, USA, (3) northwestern Florida, USA (the Gulf of Mexico panhandle), (4) Quintana Roo, Mexico, (5) Bahia, Brazil, and (6) the Peloponnesus, Greece.
Major Breeding Population: Masirah Island, Oman appears to support the largest single nesting population, with a minimum of 30,000 females estimated to nest annually in the 1980s. The second most important region is southeast USA, where 5,000 to 15,000 females nest annually, mainly in Florida. Elsewhere, there are major nesting populations in Western Australia and Queensland, and low to moderate numbers nest at sites in the central and eastern Mediterranean, Japan, and many other sites in the warm temperate areas and the subtropics. Nesting is sparse in the Caribbean and most other tropical areas.

THREATS
Loggerheads are less likely to be hunted deliberately than other sea turtles: their meat is considered less desirable than that of the green turtle, and the shell is less prized than that of the hawksbill. However there is some direct exploitation in Cuba, and loggerheads’ eggs are collected and eaten in many parts of the world.
The main mortality is believed to be as fisheries by-catch. In 1987, some 32,000 were captured in the Atlantic and 10,500 in the Gulf of Mexico. Assuming 20 per cent mortality this was equivalent to 640t in a year, when the world fishery catch was recorded as being 238t. Shrimp trawlers operating in seas where the loggerheads feed and breed catch large numbers in their funnel-shaped nets. Many of these animals then drown. Before the introduction of Turtle Excluder Devices (TEDs) approximately 50,000 loggerheads were killed in shrimp nets in the Gulf of Mexico and the Atlantic Ocean, perhaps ten times as much mortality as all other fisheries (seines, gill nets, traps, and longlines) combined. Although the requirement for TEDs has been legally challenged, it remains in force, and the lessons learned may develop into a model for certifying turtle-safe shrimp.
Loggerheads also drown after taking baited hooks, or severely wounded after becoming entangled in longlines. In 1991 between 10 and 40 per cent of fishing trips in the Ionian Sea, Greece, snared between one to three loggerhead turtles in swordfish longlines. Although the use of drift nets on the high seas has declined worldwide since a 1992 United Nations ban, they have killed thousands of loggerheads which are particularly vulnerable given their migratory behaviour. Abandoned drift nets continue to drown loggerheads in unknown numbers.
Habitat loss, nest disturbance, beachfront lighting, pollution and disease are also serious threats to this species. Debilitating and disfiguring tumours have also been recorded in leatherback turtles.

WWF's CONSERVATION AND RESEARCH ACTIVITIES
Monitoring trade: TRAFFIC, the wildlife trade monitoring arm of WWF and IUCN, documents the extent of the illegal international trade and is working to bring violations of international treaties to the attention of government authorities. TRAFFIC is also working with governments to improve protection of species threatened by trade, even where that trade is largely internal and legal. TRAFFIC North America has just completed a review and legal analysis of the fisheries and primarily commercial trade in marine turtles in the Bahamas, Cuba, Dominican Republic, Haiti, Jamaica, Mexico, Puerto Rico, Turks and Caicos Islands, British Virgin Islands, and US Virgin Islands.
Mediterranean
In 1998, WWF published recommendations for a new approach to conserving the Mediterranean’s turtles. These described a number of urgent measures to reduce mortality of adult and sub-adult turtles, including: reduction of deliberate killing, especially in Egypt; reduction of bycatch in bottom trawls, longline fisheries and a variety of small coastal fisheries; and education aimed at reducing mortality of turtles accidentally caught by all kinds of fisheries.
WWF is working to establish a fully representative network of protected areas in the Mediterranean and is collaborating with governments and local conservation organizations to protect loggerhead nesting beaches in Turkey and Greece. In 1999, the Greek government declared a Marine National Park in Zakynthos, which hosts the Mediterranean’s highest density of nesting loggerheads. As part of its "Out of the Blue" programme, WWF has placed observers on Italian longline fishing fleets to monitor fish catches and document the extent of sea turtle and shark bycatch and mortality. The monitoring programme has been hampered by the unwillingness of many fishing captains to allow observers on board.
Indo-Pacific
In 1999, WWF together with a network of NGOs and governments participated in the 2nd Association of Southeast Asian Nations (ASEAN) sea turtle meeting in Sabah, Malaysia. Coordinating measures for sea turtle protection on a regional basis is a priority for sea turtle conservationists. Despite government and WWF efforts over the past 30 years, sea turtles are declining throughout the region, affected by coastal development, sand and coral reef mining, pollution, unsustainable egg-collection, and accidental killing by fisheries. In Malaysia alone, the numbers of four species of marine turtles have fallen dramatically in recent decades. The creation in 1996 of the Turtle Islands Heritage Protected Area, a group of nine islands shared by the Philippines and Sabah, Malaysia offers some hope for the future. WWF is also assisting research and monitoring of sea turtles in Con Dao National Park, Vietnam.
Western Indian Ocean
WWF is building capacity and strenghtening the network of turtle biologists in this region. WWF has sponsored regional scientists to attend international marine turtle meetings, and co-sponsored a workshop on TED technology for resource managers and fishermen from Kenya, Tanzania, Eritrea, Madagascar, and Mozambique.

WWF is involved in a number of marine protected areas on the east coast of Africa, including Mafia Island in Tanzania, the Kiunga Reserve in Kenya, and the Bazaruto Archipelago in Mozambique. A prime objective in all these areas is to ensure that marine resources are used sustainably by local communities and that critical habitats for coral fish, sea turtles, and dugongs are protected. In Madagascar, community-based conservation programmes are being started in the Fort Dauphin area where green, hawksbill and loggerhead turtles come to nest. In South Africa, the Tongaland Sea Turtle Project, which has been running for more than 30 years, continues to monitor long-term trends in loggerhead and leatherback turtle populations.



Central American Region and the Caribbean

In October 2000, WWF and its affiliates developed a Marine Turtle Action Plan for Latin America and the Caribbean. Much of WWF’s work in Latin America and the Caribbean is focussed on protecting breeding populations of olive ridley, Kemp’s ridley, green, leatherback, and hawksbill turtles. The loggerhead rarely nests in the region but is often observed feeding in shallow coastal waters. WWF is working to encourage local communities and fishermen to protect turtles through the use of TEDs. Other initiatives include campaigns to keep trash, such as plastic bags, and twine from banana plantations, out of rivers and oceans. A major effort to conserve marine turtles in the Central American region is being made through the Central American Environment Programme (Programa Ambiental Centroamericano -- PROARCA), which seeks to promote integrated coastal management and protected areas programmes. In 1999 WWF co-sponsored a meeting on Marine Turtle Conservation in the Wider Caribbean: a Dialogue for Regional Management. Its recommendations will be used to implement regional cooperation for marine turtle conservation.



Eastern Atlantic


Mauritania

The Banc D’Arguin National Park, an important nesting and feeding ground for green and loggerhead turtles, has been supported by WWF since 1976. It is hoped that WWF’s work on fisheries management will help reduce turtle bycatch in the offshore shark fisheries.




OTHER CONSERVATION ACTIVITIES
Turtle Excluder Devices (TEDs): After ten years of studying shrimp-fishing related turtle mortality in the Gulf of Mexico, the US National Marine Fisheries Services developed TEDs for use by commercial fishermen in an attempt to reduce bycatch mortality of sea turtles. TEDs are panels of large mesh webbing or metal grids inserted into the funnel shaped shrimp nets. As the nets are dragged along the bottom, shrimp and other small animals pass through the TED and into the narrow bag at the end of the funnel. Sea turtles, sharks, and fish too large to get through the panel are deflected out of an escape hatch (the TED), reducing bycatch by up to 97 per cent. There have been problems in enforcing their use, as it also allows a small loss of shrimp (about 6%) and many fishermen have illegally refused to use them or sewn them up at sea.
Turtle-Safe ™ Shrimp: A recent conservation measure aimed at assisting loggerheads and other turtles, is the introduction of a certification scheme, Turtle-Safe Shrimp. Although the use of TEDs is compulsory by law, the resistance to the introduction of TEDs will probably mean that there is a need for policing, at least in the short to medium term. Shrimp certification schemes attempt to try and encourage consumers to buy 'safe' products, so providing an increased market share, and economic incentive, for fisherman who stick to the rules. In two years, the programme has expanded to include 125 vessels that supply USA markets with 3 million pounds of certified shrimp annually. Three major retailers and several smaller stores in the USA have begun to promote the shrimp, using the certified Turtle-Safe logo to market the product. Dozens of top restaurants in the USA feature this shrimp on their menus (Shore 1999).
Nesting Beach Projects: Local efforts to conserve loggerheads are similar to those for other marine turtles, i.e. protection of nesting beaches from development, reduction or elimination of egg harvest, public education programmes, relocation of eggs laid in 'unsuitable' locations, lighting bans on the foreshore to prevent hatchlings from being disorientated away from the surf, legislation to protect adults from hunting etc. The success of these measures varies considerably from location to location.
Ecotourism: Turtles are so enigmatic that any species will always be a draw for tourists who enjoy watching nesting females or hatchlings running to the sea, or just the observe turtles underwater. The economic success of the tropical holiday industry is dependant in great measure on the welfare of this and many other species. One of the largest challenges facing conservationists is making the beneficiaries of such holidays (tour operators, local communities, and tourists themselves) fully aware of this fact.

LEGAL STATUS
As with most other sea turtles, the migratory life history of the loggerhead means that its conservation cannot be achieved without effective international agreements and conventions. International trade in turtle products was historically a major cause of population depletion. Since all species of marine turtles were listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the legal international trade involving Party states has largely ceased. However, hunting for international markets outside the CITES framework remains of concern, and use for local consumption continues. Appendix II species are subject to "strict regulation" and Appendix 1 "must only be authorised in exceptional circumstances". The loggerhead turtle was added to CITES in 1975 in Appendix II. In 1977 this was upgraded to Appendix 1. There have not been and currently are no reservations for this species.
Turtles are ideally matched to the aims expressed by the Convention on the Conservation of Migratory Species of Wild Animals (the Bonn Convention or CMS). The text of the CMS includes many of the concepts fundamental to regional conservation of migratory marine animals and their habitat. All species of sea turtles found in the western hemisphere are listed in both Appendix I and Appendix II of this convention.
In the USA, more local legislation has been applied to loggerheads than to most other turtle species, perhaps because the distribution of nesting grounds in densely populated parts such as Florida. There are laws to regulate activities such as beach driving and shore lighting, and, not surprisingly in an area whose economy is heavily dependent on tourism, these laws have often been highly controversial. However, loggerheads nesting in Florida, Carolina and Georgia constitute approximately 30-40 per cent of the world population.
The Inter-American Convention for the Protection and Conservation of Sea Turtles (IAC) is the major international treaty dedicated exclusively to sea turtles. Recently initiated (1998) the Co-operative Agreement for the Conservation of Sea Turtles of the Caribbean Coast of Costa Rica, Nicaragua and Panama has united the three countries in the recognition of the important migratory corridor for the green, leatherback, loggerhead and hawksbill turtles in these waters. This aims "To implement the international and national conventions and agreements of the Parties for the conservation of sea turtles through the execution of a Regional Management Plan".

Further Reading
Euro Turtle. 1999. Species outlines. Loggerhead sea turtle Caretta caretta. http://www.ex.ac.uk/telematics/EuroTurtle/logger.htm
Kemf, E, Groombridge, B, Abreu, A, and Wilson, A. 1999. Marine Turtles in the Wild. WWF Species Status Report. WWF International, 1196 Gland, Switzerland.
Chelonian Conservation and Biology. Journal of the IUCN/SSC Marine Turtle Specialist Group.
Marine Turtle Newsletter. The newsletter of the Marine Turtle Research group, University of Wales, Swansea. http://www.seaturtle.org/mtn


WCMC and WWF International. March 2001


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