Fishers to assist Department of Conservation in dolphin research

Marine mammal pathologist Dr Wendi Roe undertaking a dolphin necropsy (animal autopsy) at Massey University. Photo supplied by Massey University.

4 May 2022

Commercial fishers can now support the Department of Conservation’s (DOC) ongoing research into Hector’s and Māui dolphins under new guidance to retain any deceased specimens caught or found floating in the sea.

Hector’s and Māui dolphins are unique to New Zealand. Although the Hector’s dolphins number an estimated 15,700, the Māui is the smallest and rarest dolphin in the world, with a recent survey finding there are only about 54.

Laws Lawson, Executive Chair of Fisheries Inshore New Zealand, says fishers have a useful role to play in supporting research and protection of the dolphins. Through new approvals provided by the Department of Conservation (DOC), fishers can now deliver any deceased Hector’s or Māui dolphin brought onto a vessel to DOC.

“Although the retention of any part of a protected species is forbidden under the Marine Mammals Protection Act, representatives from the fishing industry, DOC, and Ministry for Primary Industries believe there is greater research value in having a dead dolphin body on a pathology lab table rather than a dead body in the sea,” said Laws.

“With a very low rate or either accidentally capturing, or finding deceased dolphins floating, we don’t expect many dolphins to be recovered from our fishers, but we are very pleased to help this research initiative in any way, so our country can know more about our dolphins.”

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 beachcast animals for much of that information, however, many of those beachcast bodies are in various stages of decomposition and are not suitable for in-depth research. 

Under DOC authorisation, fishers will be able to place any dead Hector’s or Māui dolphins found in specific packaging provided by DOC and transfer the dead dolphins to DOC staff when their fishing vessel docks. DOC will then transport any recovered dolphins to Massey University for a necropsy, from which valuable information can be obtained. In coming weeks, DOC staff will be contacting 125 inshore trawlers and set netters operating in areas frequented by Hector’s and Māui dolphins to arrange delivery of packaging and instructions. 

“I see helping DOC research and increase their knowledge of the dolphins can only provide benefits for the future of the dolphins,” said Tony Threadwell, a fisher from Lyttelton.

“Not learning what we can from a dead dolphin is a lost opportunity that we can’t replace.”

Professor Wendi Roe, who heads the Massey University team undertaking the dolphin necropsies said ”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”.

“The assistance of the fishing industry in facilitating this research on Aotearoa’s smallest marine mammal species is welcomed,” said Department of Conservation Aquatic Director Elizabeth Heeg.

“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.”