Female dolphin death ‘worstcase scenario’
THE Hector’s dolphin caught in a commercial fishing net off Dunedin’s coast was an adult female and could represent 10% of the local female breeding population.
University of Otago marine science emeritus professor Steve Dawson said the loss of a breeding female was enough to send the population of about 40 Hector’s dolphins that live off Otago Peninsula into decline.
Prof Dawson said because the dolphin was an adult female the incident was a ‘‘worstcase scenario’’ for the animals locally.
He went further and said the voluntary measures taken by the industry did not make sense.
‘‘Fishers have a social licence to catch fish. They don’t have a social licence to catch dolphins and it’s simply not acceptable,’’ Prof Dawson said.
‘‘These are sophisticated largebrained animals with complex social systems and fishermen simply don’t have a social licence to catch them.’’
Prof Dawson said the latest survey of the local population, in the summer of 2021, showed it numbered about 40 individuals.
Of those, half would be expected to be females, and half
A rare sight . . . One of a pod of Hector’s dolphins makes a spectacular leap while following a boat near the 1 Mile beacon off the Taiaroa Heads, at the entrance to Otago Harbour, in this file photo.
of those females would be sexually mature.
‘‘In this one event, we’ve lost 10% of the breeding females in this local area,’’ he said.
‘‘That’s enough to cause a decline.
‘‘It’s hard to say this, but it
matters less if it’s a male, and it matters most if it’s a breeding female.
‘‘And this was a breeding
female — it’s the worst case.’’
Earlier this month, Fisheries New Zealand said a Hector’s dolphin was reported caught in a fishing net off Otago Peninsula.
The fisher had been targeting school shark, a species commonly sold in fish and chip stores.
A fisheries observer was aboard the vessel and its skipper reported the catch to Fisheries New Zealand as required.
This week, Fisheries New Zealand fisheries management director Emma Taylor confirmed the dolphin caught was an adult female.
Ms Taylor said the fishing industry was implementing voluntary measures to protect Hector’s dolphins in the Otago area.
Local fishers had voluntarily agreed to closures across the area the dolphin was caught in, north of Otago Peninsula, for the remainder of the fishing year.
‘‘Fisheries New Zealand will be briefing the minister for oceans and fisheries who will decide if the voluntary measures go far enough or whether additional measures are needed,’’ she said.
Prof Dawson said protecting the area where the entanglement happened ‘‘really makes little sense to me’’.
‘‘There’s no reason why that particular place is special.
‘‘The dolphins are mobile and the fishers are mobile and protecting that one spot where an accident has happened in the past doesn’t seem to be so big a step forward and especially not so when avoidance by the fishers is ‘voluntary’.’’
The animals were more influenced by depth than anything else, and rules to protect the species should be based on
❛ In this one event, we’ve lost 10% of the breeding females in this local area
depth, he said.
What was necessary for the species was to prohibit entangling fishing methods, such as gillnetting and trawling in waters shallower than 100m, he said.
Minister for Oceans and Fisheries Rachel Brooking said the Government was serious about protecting Hector’s dolphins, and late last year introduced new measures to reduce the number accidentally killed as a result of commercial fishing.
‘‘On this particular incident, I am awaiting advice,’’ she said.