The short-term risk from the capture and tagging of three Hectors dolphins earlier this year appeared to be low. Further assessments in the trial will take place next year but it appears that long-term risks are also low. Holes were drilled in their dorsal fins, and tags were attached with pins and nuts. They are designed to corrode within three months. The tags send data through satellite on the dolphinâs movements. Auckland DoC head Rob McCallum said satellite tagging revealed more about the dolphinâs behaviour than had been learned in the past 20 years. But Otago University marine biologist Dr Liz Slooten, who has studied the dolphins since 1984, said that the initial satellite date revealed nothing new. Hectors Dolphins are endangered and numbers range from 3000 to 4000.