Route masters

Many turtle species are endangered through a variety of human activities, from beach development, boating and shipping, and fishing. Awareness of the problems has mostly focused on protection of beaches used for breeding as individuals return to highly specific sites where they are particularly vulnerable. Apart from their breeding sites, much less is known about their long and complex movements around the oceans. Marine turtles typically migrate hundreds or thousands of kilometres between breeding sites and foraging areas. As such a small part of the life cycle is spent at the breeding site, conservation measures to protect these alone leaves the animals vulnerable for most of their lives. Recent efforts to tag and recapture turtles have revealed 'migratory corridors' through which the turtles move between breeding and feeding sites which highlight regions in which greater protection for turtles may prove beneficial. There has been rising awareness of the global threats posed to marine turtles through mortality as a result of fisheries by-catch for those species when in the open ocean. Long-line fisheries are estimated to catch hundreds of thousands of turtles per year, suggested as the cause of the dramatic decline of the leatherback turtle in the Pacific Ocean. Recent satellite tracking and tagging studies have revealed the enormous ranges of some turtles, in some cases at the scale of ocean basins raising questions about how conservation measures for such animals at sea could be improved. But a new study carried out over eight years in which individual female green and loggerhead turtles were given satellite transmitters after laying eggs on beaches in Cyprus has looked at individuals over different seasonal migrations and reveals the turtles each use almost identical migration pathways between Feature A new study reveals that turtles stick closely to previous tracks between breeding and foraging sites, offering new potential to protect these animals at sea. Nigel Williams reports. Route masters breeding and foraging grounds in the southern Mediterranean. No studies have systematically investigated whether marine turtles use the same migratory routes in different years and remain at the same foraging sites throughout the interbreeding interval. So a team led by Annette Broderick, at the University of Exeter Cornwall campus in the UK Spot on: Green turtles appear to repeat similar tracks between breeding and foraging grounds. (Picture: Photolibrary.)