New Zealand’s marine environments offer excellent research opportunities, and we have some world-leading ocean scientists helping to inform evidence-based fisheries management.
Professor Wendi Roe leads Massey University’s marine mammal pathology team in Palmerston North. This isn’t an office job – Dr Roe can usually be found in the university’s icy-cold labs undertaking a necropsy to determine the cause of a dolphin or other marine mammal’s death.
She is supportive of the decision in May 2022 by the Department of Conservation (DoC) to allow commercial fishers to bring any dead dolphins back to shore, for DoC to assess and transfer to the university.
Until now, it’s been illegal for a fisher to hold a dead dolphin on their boat – if they find one dead in the water, on shore or accidently catch one.
With Māui and Hector’s dolphins being New Zealand’s most endangered dolphins, more information is needed about their demographics, physiology, diet, genetics structure and to what diseases they are susceptible. Given the impact toxoplasmosis is known to have on the dolphins, more information on the incidence will help understand the nature and extent of that threat to the dolphins.
DOC’s researchers and scientists currently rely on beach-cast animals for much of that information, however, many of those beach-cast bodies are in various stages of decomposition and are not suitable for in-depth research.
In the five months between November 2021 and May 2022, 15 Hector’s dolphins were found dead on South Island coastlines, showing no evidence of having been caught in fishing nets and with eight calves among them. Only some of the dolphins were in good enough condition to be able to be sent to Massey for a necropsy however.
“Although it is always tragic when a dolphin is caught, at least we will now have the opportunity to gain vital information from bodies that come to necropsy. There is a lot we have yet to learn about these iconic dolphins, and this new guidance will help us to fill critical knowledge gaps about their health and their biology,” says Dr Roe.
DoC Aquatic Director Elizabeth Heeg says that the assistance of inshore fishers (approximately 125) is valuable.
“We don’t expect to obtain many Hector’s or Māui dolphins in this manner due to extensive protection measures, but it is important we make the most of these opportunities to examine any of these taonga species. Having the fishing industry supporting us in this way will benefit our study and protection of these dolphins,” she says.