Marine Turtle Population Continues To Be Threatened: Legal Harvest Alone Tops 42,000 Each Year
Marine Turtles or sea turtles inhabit most of the world's oceans and all seven marine turtle species are currently listed on the IUCN Red List of Threatened Species. Forty-two countries around the world allow for legal harvest of turtles, which defines the number of turtles that can be taken within the law. Blue Ventures Conservation and staff at the University of Exeter's Center for Ecology and Conservation, recently conducted a study to review the number of turtles that were currently taken by law and compared this to other potential threats that the turtles face, according to a press release Thursday.
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"This is the first study to comprehensively review the legal take of turtles in recent years, and allows us to assess the relative fisheries threats to this group of species. Despite increased national and international protection of marine turtles, direct legal take remains a major source of mortality. However, it is likely that a fraction of current marine turtle mortality take is legal, with greater threats from illegal fisheries and by catch," said Frances Humber, a PhD student at the University of Exeter, who led the research.
Bermuda, in 1620, was the first country to legalize marine turtle harvesting. The law prohibited taking any turtle "under eighteen inches in the breadth or diameter." But large scale commercial hunting of turtles continued worldwide for many centuries and in the late 1960s global capture exceeded 17,000 tonnes. For example, during the peak of Mexico's sea turtle exploitation in 1968 it is estimated that the national take was over 380,000 turtles.
But recently efforts of protectionists and conservationists has led to greater protection of marine turtles. Currently, 178 countries are signed up with the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which restricts the international trade of turtle products. But inspite of conservation awareness turtle population is under threat.
The direct take of turtles, especially by traditional coastal communities and small scale fisheries, across many regions and countries, continues legally. The fisheries capture turtles and supply the local markets with meat and also shell. They are an important source of finance, protein, and cultural identity. However since there are so many of these fisheries it is difficult to keep track of the number of turtles being taken by them, making them one of the major threats to turtle conservation.
The researchers collated data for all seven species of marine turtles from over 500 publications and 150 in-country experts. They estimate that currently more than 42,000 marine turtles are caught each year legally, of which over 80% are green turtles. Legal fisheries are concentrated in the wider Caribbean region, including several of the UKs Overseas Territories, and the Indo-Pacific region, with Papua New Guinea, Nicaragua and Australia together accounting for almost three quarters of the total. The data indicates that since the 1980s more than 2 million turtles have been caught, although current levels are less than 60% of those in the 1980s.
But the greatest threat to marine turtles is when they are caught as bycatch, which are the unwanted fish and other marine creatures trapped by commercial fishing nets during fishing for a different species. Hundreds and thousands of turtles are caught each year as bycatch by trawl nets or gillnets.
Also, illegal fishing continues to be a major threat to the turtle population, with the researchers estimating a minimum of 65,000 turtles taken from Mexico alone since the year 2000. These numbers could also be severely underreported as it is difficult to collect accurate information on such an activity.
Dr. Annette Broderick, of the Center for Ecology and Conservation at the University of Exeter's Penryn Campus in Cornwall said, "We were surprised to find that there are 42 countries with no legislation in place that prohibits the harvest of marine turtles, although for many of these countries these harvests provide important sources of protein or income. It is however important to ensure that these fisheries are operating at a sustainable level."
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