While forensic scientists ponder the source of a barnacle-encrusted aeroplane wing thought to come from missing airline flight MH370, a PhD student is pioneering new research that could enable barnacles to reveal migration paths through the ocean.
Ecological Society of Australia’s 2015 Jill Landsberg Applied Conservation Scholarship winner, Ryan Pearson, from Griffith University in Queensland is looking to find out if the shell chemistry of barnacles can reveal the migratory origin of endangered loggerhead turtles.
“To conserve Loggerhead turtles, we need to know which parts of the ocean they use and when they use them. Scientists have tried to do this by measuring the chemical composition of the turtles, but this doesn’t always work.”
“Not all turtles within a group eat the same things in the same places, so sampling skin tissues from a few doesn’t always tell us the big picture.”
Enter barnacles. “Because barnacles are filter feeders, they all eat the same things in the same places, so their chemical composition will more accurately reflect where they’ve been in the ocean compared with the turtles.”
Pearson’s project aims to circumvent the diet-based concerns of using turtle tissues by analysing the stable isotope signals within shell layers of barnacles who go along for the ride on migrating south Pacific Loggerhead turtles.
“These shell layers offer chemical information about the area of the ocean in which the turtle has been swimming and, therefore, could allow us to identify the migratory origin of nesting turtles,” Pearson said.
Professor Angela Moles, vice president of the Ecological Society of Australia (ESA), points out that, “if successful, this method has the exciting potential to be applied not just to loggerheads but to any other migrating marine species that has commensal barnacles. This will provide critical information for their conservation that has been missing until now.”
“Ultimately there is also the potential to track the source of other objects that wash up on our shores, perhaps even components of missing aircraft or ships.”
Pearson will receive his award and AUD 6000 research grant at the ESA’s annual conference in Adelaide in December 2015, and will present his research findings at ESA16 in Fremantle.
Loggerhead turtles are listed as endangered worldwide by the International Union for the Conservation of Nature (IUCN). A recent United Nations Environment Program (UNEP) action plan listed a better understanding of the use of foraging habitat as an “essential” priority for the conservation of the south Pacific loggerhead population.
Edited by Peter Needham