Scientists from NIWA and Te Herenga Waka-Victoria University of Wellington, who are studying broadnose sevengill sharks in Fiordland in an effort to better understand the effects of climate change, returned to the southern fiords last month (May).

In their week-long stay they attached transmitters to the 11 sharks as well as installing 29 acoustic receivers on the seafloor.

The project, funded by the Save Our Seas Foundation, began in May 2023 when scientists deployed baited underwater video cameras in Breaksea Sound.

NIWA fisheries scientist Dr Brit Finucci said that sharks, as apex predators, played a crucial role in the ecosystem and could be indicators of the health of an environment.

"Fiordland National Park is an incredibly unique ecosystem. We know very little about the sharks that live in this area, but we do know that the Fiordland environment is at risk from climate change."

"Now is an opportune time to study how sharks may be impacted by a changing environment in the future."

The broadnose sevengill is commonly observed in Fiordland, reaching over 2.5m in length, but is globally threatened - with fishing activity reducing shark numbers in some locations.

Little is known about the impacts of climate change on their health and population.

"The sharks that we tagged were calm and relaxed, and it was amazing to see them so close when usually we only get glimpses of them whilst diving."

"The tags will transmit data for up to the next 10 years and the receivers we put on the seafloor will collect data every time a shark swims near it," Finucci said.

Project lead Dr Alice Rogers, a Senior Lecturer in fisheries science at Victoria University, said it is an exciting project to be working on.

"The team on the boat were great and it’s one of the most beautiful environments I’ve ever worked in, so I feel privileged to be doing this research."

"I also love this species - its ancestors date back to the Jurassic period, so they’re almost like dinosaurs."

"It’ll be great to see how resilient they are to the effects of climate change and warming seas," Rogers said.

The team will return to Fiordland every six months to gather the data from the receivers.

They will monitor the short- and long-term information on their movements to understand the sharks’ behaviour and how this may be changing.

While in the area, the scientists also use their time to work on other Southern Fiordland Initiative projects including studying the iconic Fiordland black coral, Antipathella fiordensis, and monitoring environmental conditions and deep-water communities at three long-term monitoring sites.