Sea turtles find protected cover
Sea turtles are using marine protected areas (MPAs) to protect themselves from the threats of fishing and to forage for food, a new international study shows. Presented in the journal Global Ecology and Biogeography, the findings show that more than a third of the world's green turtles are found within MPAs. This figure is much higher than what they anticipated because just a small number of shallow oceans are designated as MPAs.
Led by the University of Exeter in the United Kingdom, researchers from Australia, the Cayman Islands, Greece, Guadeloupe, Indonesia, Italy, La Reunion and the United Kingdom used data on the movements of 145 green turtles from 28 nesting sites. They used extensive satellite tracking to capture the data. According to the researchers, green turtles are able to travel for thousands of kilometres from their breeding sites to their feeding grounds. The team identified that 35% of the turtles foraged in MPAs. Overall, 21% were found in MPAs that are the most strictly protected and older MPAs were more likely to contain turtles.
'Notwithstanding limitations in the satellite tracking data currently available, results clearly show that foraging adult green turtles are found in association with MPAs far more often than expected by chance,' the authors write. 'We might reasonably expect MPAs to be in better health than other areas of coastal seas and thus a better/safer habitat for exploited species, especially if there is a positive feedback loop with these large consumers maintaining habitat quality.'
MPAs are areas in the ocean where marine activities are restricted. Governments and non-governmental organisations (NGOs) are responsible for regulating these areas. MPAs in the tropics are often rich in seagrass and algae, which in turn are used by turtles for food. It should be noted that foraging also helps maintain these habitats.
Several categories of MPAs exist, and the most strictly protected ones are managed solely for scientific purposes.
'Our global overview revealed that sea turtles appear in Marine Protected Areas far more than would be expected by chance,' says Professor Brendan Godley from the Centre for Ecology and Conservation at the University of Exeter. 'There has been debate over the value of MPAs, but this research provides compelling evidence that they may be effective in providing safe foraging habitats for large marine creatures, such as green turtles. The satellite tracking work that the University of Exeter has played such a lead role in developing allows us to assess the value of MPAs in a way that would never have previously been possible.'
Commenting on the results of the study, British Fisheries Minister Richard Benyon said: 'This study unlocks some of the secrets surrounding the life cycle of marine turtles, whose movements have long been a mystery. The results will mean we will better manage the oceans and protect turtle habitats which are key to helping them survive.'
Data Source Provider: University of Exeter
Document Reference: Scott, R., et al. 'Global analysis of satellite tracking data shows that adult green turtles are significantly aggregated in Marine Protected Areas', Global Ecology and Biogeography. doi:10.1111/j.1466-8238.2011.00757.x
Subject Index: Food; Scientific Research; Resources of the Sea, Fisheries