Diving behaviour of wildlife impacted by an oil spill: A clean-up and rehabilitation success?

The value of rehabilitating oiled wildlife is an on-going global debate. On October 5, 2011, the cargo vessel C/V Rena grounded on Astrolabe Reef, New Zealand (NZ), spilling over 300 tonnes of heavy fuel oil. As part of the Rena oil spill response, 383 little blue penguins (LBP, Eudyptula minor) were captured, cleaned, rehabilitated and released back into a cleaned environment. This research investigates foraging behaviour changes due either to the oil spill or by the rehabilitation process by comparing the diving behaviour of rehabilitated (n = 8) and non-rehabilitated (n = 6) LBPs and with LBP populations throughout NZ. Stabile isotope analysis of feathers was also used to investigate diet. There were no foraging behaviour differences between rehabilitated and non-rehabilitated LBPs and the overall diving behaviour of these LBPs have similar, if not less energetic, foraging behaviour than other LBPs in NZ. This suggests the rehabilitation process and clean-up undertaken after the Rena appears effective and helps justify the rehabilitation of oiled wildlife across the world.