Issue 10
Monday, 03 July 2017
Charles Darwin University
E-news
The Prickly Dogfish (Oxynotus bruniensis) is found only around New Zealand and southern Australia, and eats nothing but the eggs of deep-sea egg-laying sharks and chimaeras. Photo: Brit Finucci
The Prickly Dogfish (Oxynotus bruniensis) is found only around New Zealand and southern Australia, and eats nothing but the eggs of deep-sea egg-laying sharks and chimaeras. Photo: Brit Finucci

Shark expert joins extinction risk study in NZ

By Leanne Miles

A Charles Darwin University shark expert has travelled to New Zealand to study some of the more unusual species found deep in the ocean to help assess their risk of extinction.

Research Institute for the Environment and Livelihoods Senior Research Fellow Dr Peter Kyne is teaming up with colleagues across the Tasman to find out more about the group known as the chondrichthyan fishes, which includes sharks, rays and chimaeras.

“New Zealand is home to close to 120 chondrichthyan species, a quarter of which are endemic, and many of which occur out of sight in the deep ocean,” Dr Kyne said.

“This project will assess the extinction risk status of species found in New Zealand and the Oceania region, using the world’s most comprehensive inventory of the global status of plant and animal species, the IUCN Red List of Threatened Species.”

He said that many shark species possessed biological traits, such as long lifespans and small litter sizes, which made them particularly susceptible to population depletion from overfishing.

“Some species are commercially important, while many others are often caught incidentally as ‘bycatch’ in fisheries targeting more productive or valuable bony fishes,” he said.

Dr Kyne will work with collaborators such as Brit Finucci from the Victoria University of Wellington, who has been studying some of the rare deep-sea species around New Zealand such as the Prickly Dogfish and the Pacific Spookfish.

“We have found that the Prickly Dogfish has a taste for the eggs of chimaeras, one of the few sharks to have such a specialised diet, and the only species known to feed solely on other chondrichthyans,” she said. “We’ve also found female spookfish are able to store sperm from males internally for later use.”

New Zealand has a long history of fisheries management, and the project aims to examine if this has resulted in lower extinction risk status of New Zealand species, compared with other locations where fishing management may be inadequate.

Dr Kyne said the project would include species assessments for wide-ranging deep-sea sharks that also occur in Australian waters and contribute to his research through the NESP Marine Biodiversity Hub.

“This information will feed into the NESP Marine Biodiversity Hub ‘Shark Action Plan’ project which aims to provide a conservation overview and management advice on Australia’s shark fauna.”

He said the research would contribute to the on-going global assessment of all chondrichthyan fishes and would help guide conservation and research efforts for this vulnerable group of fishes.