Scientific tagging of aquatic animals may put them at risk

Tagging aquatic animals with trackers, cameras or other instruments can disrupt natural behavior and threaten their health, US and Canadian researchers say. Scientists have for the first time quantified the energy cost to aquatic animals when they carry such devices, the University of British Columbia reported Thursday. Studying fiberglass casts of sea turtles in a wind tunnel, the researchers found that while most commercially available tags increased drag by less than 5 percent for large adult animals, they increased drag by more than 100 percent on smaller or juvenile animals. "Many marine animals make yearlong breeding migrations crossing entire oceans, while others may rely on high speeds and acceleration -- enabling them to catch prey or to escape predators," said T. Todd Jones, a scientist with the National Oceanic and Atmospheric Administration's Pacific Islands Fisheries Science Center in Hawaii. Jones led the study while a doctoral fellow at the University of British Columbia. "If the drag costs from carrying tags disrupts their natural behavior, they may miss out on breeding and foraging seasons, be unable to catch enough food, or even end up becoming someone else's meal," he said. "In addition to the animal welfare and conservation implications, excessive drag may also impede the collection of research data in the wild," he said.