Experts say a broadnose sevengill shark found on Lemon Bay beach in the Bay of Islands was probably caught by a recreational fisher. Photo / Gene Williamson
Experts say a broadnose sevengill shark found on Lemon Bay beach in the Bay of Islands was probably caught by a recreational fisher. Photo / Gene Williamson
A 2.2-metre shark that washed up on a beach at Lemon Bay, between Ōpua and Paihia, last week has been identified as a broadnose sevengill shark.
It is the same species of shark that attacked a young woman in Southland last year.
The shark was discovered midmorning on Wednesday by dive instructor Gene Williamson and its species has since been confirmed by Dr Karen Middlemiss, a science adviser in the conservation department’s protected fishes and reptiles, marine species team.
Middlemiss said the sharks were more commonly seen in the warmer months but usually in the South Island.
They were an inquisitive species, known to attack people, so were best left alone by anyone who encountered a live one.
A 21-year-old woman was reportedly attacked by one at Riverton, in Southland, last December.
Williamson said: “I’ve always had an interest in sharks and even though I’ve worked in the area as a dive instructor for the last two years I’ve never encountered a shark on a dive before.
“However, between seasons I work in the Caribbean on a scientific dive programme with high school kids where we educate them about sharks and marine life, including the dissection of a dogfish [also known as rig].
“I knew it [the shark at Lemon Bay] was a female from my experience studying them and couldn’t find any obvious signs of death.”
He had spoken with an associate at Paihia Dive who thought the shark had probably been accidentally caught on a fishing line and thrown back in – judging by the bruising marks at the base of its tail.
Williamson said: “I was surprised and saddened to find it as sharks almost never act aggressively to scuba divers, so seeing this one in the water would have been a real treat.”
Shown photographs Williamson took of the shark, Middlemiss confirmed it was a female broadnose sevengill shark (Notorynchus cepedianus). She agreed it was most likely been caught by a recreational fisher but she couldn’t be entirely sure from photographs alone.
The broad nose of a sevengill shark is obvious is this frontal view. Photo / Gene Williamson
The species could be commonly found around all New Zealand coastline, particularly in shallow waters, including murky estuaries in spring and summer, Middlemiss said.
“They swim along the seafloor a lot of the time and mostly forage at night on a generalist diet that includes everything from octopus and crustaceans to seals and dolphins.
“They grow up to a maximum of around 3.3 metres, live for about 30 years, and females are larger than males.”
Best avoided by humans, there had been a number of reported attacks by sevengill sharks in New Zealand. The reported attack in Riverton last year involved the woman being “bitten and badly injured in knee-deep estuary water at two in the morning”, Middlemiss said.
The year before, a 13-year-old girl was also hospitalised after reportedly being bitten by a sevengill shark in the water beneath a wharf in Ōamaru Harbour that she and other teens were jumping off.
Middlemiss said the species was easily recognisable by their seven gill slits, mottled grey and white body with small black spots, large head and mouth and single dorsal fin.
“If you are in the water and see one it would be a good idea to quietly exit and leave them to it,” Middlemiss said.
“They are not a protected species, but if you do see one, or any shark species, please call 0800 DOC HOT or email sharks@doc.govt.nz and let us know. This helps us to build our understanding of shark distribution around New Zealand.”
Sarah Curtis is a news reporter for the Northern Advocate focusing on a wide range of issues. She has nearly 20 years’ experience in journalism, much of which she spent court reporting. She is passionate about covering stories that make a difference.
