Last gasp of a dying dolphin. Are we too late to save Māui? – Stuff.co.nz

It is an agonising death for an endearing, gentle creature.

When a dolphin swims into a fishing net, often invisible in murky waters or at night, they quickly become entangled.

Their lungs are small, roughly the same size as humans’. If they can’t surface to breathe within minutes, they begin to suffocate.

Desperate to avoid drowning, they thrash and struggle breaking teeth or fins. The nets cut deep into their flesh.

READ MORE:
* Māui’s dolphin found dead on a beach at Te Akau
* Miners given access to Māui dolphin sanctuary
* Three Hector’s dolphins killed in net off Canterbury coast
* Four endangered Hector’s dolphins caught in fishing trawls

With just 60 left, Māui dolphin are listed nationally and internationally as critically endangered.

University of Auckland

With just 60 left, Māui dolphin are listed nationally and internationally as critically endangered.

Last February, a fisherman aboard a trawler pulled up his nets, bursting with the usual catch – mullet, flatfish, trevally, tarakihi or moki – and discovered the carcasses of five nationally endangered Hector’s dolphins. It was the second time he’d caught Hector’s dolphin in his fishing gear.

Set nets (sometimes called gill nets) are the oldest form of industrial fishing. Anchored at both ends, about a metre high and permitted to stretch for three kilometres, they are sentencing one of New Zealand’s rarest dolphins to extinction.

Dolphins die a gruesome drowning death in set nets.

SUPPLIED

Dolphins die a gruesome drowning death in set nets.

The experience was so distressing, the fisherman gave up set netting and began to catch his quota on longlines (with baited hooks attached at intervals).

Screen captures from footage taken by the Ministry for Primary Industries show a Hector's dolphin caught in a commercial fishing net.

MPI

Screen captures from footage taken by the Ministry for Primary Industries show a Hector’s dolphin caught in a commercial fishing net.

The tragedy, off Banks Peninsula, horrified the public. Fisheries Minister Stuart Nash and Conservation Minister Eugenie Sage called a press conference. Sage floated the idea of a total ban on set nets, which also ensnare penguins and albatross.

Commercial set-netting has a reported catch of 8000 tonnes annually, about two per cent of New Zealand’s total. They are efficient, and often the only way to target certain species.

Dr Barbara Taylor, of the US National Oceanic and Atmospheric Administration, is an expert in endangered Hector's dolphin and vaquita porpoise.

Supplied

Dr Barbara Taylor, of the US National Oceanic and Atmospheric Administration, is an expert in endangered Hector’s dolphin and vaquita porpoise.

Critics say they are indiscriminate and environmentally destructive.

“They don’t kill just the target species, they kill everything. Which means economically, if you are a fisherman, that’s the way to go ,” said marine mammal expert Barbara Taylor, of the US Government’s National Oceanic and Atmospheric Administration.

“It is truly unsustainable fishing.”

A year on from the deaths, there is still no ban. And conservationists are mourning the killing of another seven Hector’s dolphins over summer . In December, three were pulled up in one net, near Canterbury’s Pegasus Bay.

Between 10-15,000 Hector’s dolphin remain, down from 29,000 in the last 45 years. Māui, a sub-species found off the West Coast of the North Island, are in a more parlous state. Only about 60 exist in a stretch over water between Maunganui Bluff and the Whanganui River mouth, although their natural range stretches much further.

They roam shallow coastal areas and forage in harbours and estuaries. Both are unique to New Zealand waters and have especially winsome looks.

“It is very small, it has got quite striking black and grey and white features, but the distinctive thing about them is they have a Mickey Mouse-type rounded fin,” said Amanda Leathers, a senior research and policy analyst at WWF New Zealand.

Hector's dolphin are a popular sight for tourists visiting Canterbury.

BLACK CAT CRUISES

Hector’s dolphin are a popular sight for tourists visiting Canterbury.

The Yangtze River dolphin or baiji was the first cetacean species to be driven to extinction by human activity.

New Zealand and Mexico are now in a race to be the next country to preside over the loss of another.

The Mexican government has taken audacious steps to save their vaquita porpoise.

A ban on the deadly nets that trap and drown the creatures was enforced with navy patrols. Fishermen were compensated for loss of earnings and the United States refused to import the catch.

It hasn’t worked: between six and 22 remain alive along with only a sliver of hope remaining for the species’ survival.

On the other side of the Pacific Ocean, Kiwi efforts to save Māui from extinction has, by comparison, been listless.

The vaquita, the world’s smallest cetacean, is found only in the Gulf of California, and is on the brink of extinction.

supplied

The vaquita, the world’s smallest cetacean, is found only in the Gulf of California, and is on the brink of extinction.

Hector’s and Māui have been in serious decline for almost half a century.

“What scientists estimate is that both Hector’s and Māui are far reduced from their pre-human impacted size,” said Leathers.

“They think that, since the 1970s, Hector’s dolphins have reduced more than 70 per cent. One of the biggest human threats to the dolphins is fishing nets, and in particular set and trawl nets.

“The fishers fish in the same area where the dolphins live and the dolphins can accidentally get trapped in the nets.”

WWF's Amanda Leathers says that in areas around Kaikōura, Banks Peninsula, and Timaru, bycatch rates are far higher than Hector's dolphins can sustain.

MONIQUE FORD / STUFF

WWF’s Amanda Leathers says that in areas around Kaikōura, Banks Peninsula, and Timaru, bycatch rates are far higher than Hector’s dolphins can sustain.

In 2007, fisheries and conservation officials developed a threat management plan to manage the risks from fishing, as well as tourism, pollution, climate change, and disease.

Four new sanctuaries were created with mining and acoustic seismic surveying restrictions and new fishing rules.

The fishing industry fought hard. It took two years to develop the plan, and over 2000 submissions were received.

Five years later, a dolphin died in a set net off Cape Egmont, Taranaki – although it is disputed whether it was a Māui or Hector’s. Seafood NZ, the industry body, says no Māui dolphin death due to commercial fishing has been reported since 2002.

The tragedy was compounded when a survey revealed there were likely only between 48-69 adult Māui dolphins remaining. A government risk assessment concluded “total human-induced mortality is higher than the population can sustain”.

But little changed. The threat management plan was to be reviewed in 2013, but is now six years late.

Campaigners are now pinning their hopes on a new threat management plan, to be unveiled by Sage and Nash within months.

“The previous threat management plans haven’t gone far enough to remove the threats to Māui and Hector’s dolphins,” Leathers said. “They haven’t removed the threat from the entire Māui dolphin habitat – and they haven’t dealt with risk of seismic surveying.

“The science says we need to start dealing with the human-caused death of the dolphins as quickly as possible

“We need to do it properly this time. It has got to be now. Our decision makers have to make strong, brave decisions to remove the threats. This is the threat management plan that has to save the dolphins.”

The draft plan will go out for public consultation, and environmental groups fear it will be diluted by powerful fishing interests, which have influential connections to New Zealand First. One seasoned campaigner called it “the Shane Jones effect”.

Seafood NZ says it is working with the Government. It points out there is 95 per cent government observer coverage in set net territory between New Plymouth and Hawera, and 90 per cent coverage in the trawl fishery between Kaipara Harbour to Hawera.

The industry, along with government officials, has developed its own protected species mitigation plan for vessels operating in Hector’s habitat.

Massey vet clinic pathologist Wendi Roe does a post mortem on an adult female Hector dolphin, found on a beach in Hokitika. Her daughter Kristi, 11 helps out.

LEILANI HATCH/ FAIRFAX NZ.

Massey vet clinic pathologist Wendi Roe does a post mortem on an adult female Hector dolphin, found on a beach in Hokitika. Her daughter Kristi, 11 helps out.

Dr Justin Cooke, a marine population assessment specialist at the Center for Ecosystem Management Studies in Emmendingen, Germany, is one of the independent experts working on the threat management plan.

He is a long-time member of the IUCN Species Survival Commission’s Cetacean Specialist Group and the Scientific Committee of the International Whaling Commission (IWC) and has also been involved in the fight to save the vaquita.

Cooke made a sophisticated Māui dolphin population model which shows threats to the dolphins must be reduced by 50-75 per cent within five years.

“I first presented an analysis to the working group for ministers in March 2018. I thought maybe there was still a chance to save the Māui dolphin,” he said.

“I am not convinced of that anymore.”

A Maui dolphin bow riding off the Manukau Harbour west coast in 2017.

Delwyn Dickey/Stuff

A Maui dolphin bow riding off the Manukau Harbour west coast in 2017.

That’s because Cooke’s data suggests fishing bycatch deaths alone don’t tell the full story of the dramatic population slide.

Scientists have a new suspect: cats. A 2013 Massey University study found a quarter of Hector’s and Māui dolphin that were beach cast over five years died of toxoplasmosis, a disease transmitted through cat faeces and washed into waterways.

Three of the dead dolphins were Māui.

Like drowning in a net, toxoplasmosis is a dreadful death.

Wendi Roe, deputy head of Massey’s School of Veterinary Science, said: “What we see in dolphins is the damage is worse in the liver, the lymph nodes and the lungs.

“Based on the amount of damage, they get sick and die fairly quickly, maybe a week or so. They would feel awful.”

It also causes behavioural changes, still births and reduces the dolphins’ already sluggish reproductive rate.

But so much is unknown about how great the threat is. Many warm-blooded animals carry the parasite, but it rarely causes sickness and death. It’s not clear if the pathway is domestic or feral cats, or if it is a particular strain that proves fatal to marine mammals.

“There is more information that we could gather that would be useful in helping us clarify or quantify the problem better. But my concern would be if we just waited until we got all the information,” Roe said.

“It might be too late, especially for a species like the Māui dolphin. It would be horrible to say in 10 or 20 years that we now know where it came from but it’s too late.

“I do believe you should never focus on obvious loud problems to the exclusion of others. We need actions on as many threats as we possibly can.”

Minister of Conservation Eugenie Sage says the Government will take a new scientific assessment approach to protecting Hector's dolphins.

STACY SQUIRES/STUFF

Minister of Conservation Eugenie Sage says the Government will take a new scientific assessment approach to protecting Hector’s dolphins.

When Roe’s study became public, the fishing industry seized on the results, claiming it has been unfairly targeted while disease and pollution from farming and industry were ignored.

But the study also found four of the dolphins were drowned in nets, and another died of an unknown blunt trauma.

Scientists estimate fishing is to blame for 95.5 per cent of human-caused deaths and most agree more fishing restrictions are necessary while disease is further investigated.

One controversial action is to capture dolphins, either to tag them for further study, or for a captive breeding programme, but that comes with unimaginable risk.

In 2017, in a last-ditch attempt to save the vaquita, conservationists attempted to capture a calf and an adult female in a sea pen. They reacted badly and both died.

The US imports 25-50 tonnes of New Zealand snapper every month. Sea Shepherd says they are caught using fishing gear known to ensnares Māui dolphins.

PETER DRURY/STUFF

The US imports 25-50 tonnes of New Zealand snapper every month. Sea Shepherd says they are caught using fishing gear known to ensnares Māui dolphins.

Barbara Taylor has worked on saving the vaquita and the New Zealand threat management plan. Hector’s dolphin are known to depredate, surfing waves around fishing vessels looking for an easy feed. But it’s not known if Māui exhibit the same behaviour.

“Quite frankly, we would not have got the action that we did get with the Mexican government if we hadn’t had a really intense monitoring programme,” she said.

“It takes a lot of evidence to get the governmental will and financial support to actually do the actions that are needed.There are two approaches you can take – you can either be super precautionary and say, ‘look we know they can go out to 10 nautical miles and so we are going to close all fisheries within 10 nautical miles.’

“Or, you figure out how the animals are using their habitat. It may be that if you put a tag on them and saw that they never interact with the trawl fishery… you could stop worrying about it. It is a learned behaviour so maybe the Māui just never learned to do that and they are fine. But it would be nice to know that.

“I know this will not be popular in New Zealand because it is invasive research of a critically endangered species. It is always a really hard thing as a conservation biologist to take a risk when you get down to low numbers. But if the alternative is not protecting them, then that is not a good alternative either.” 

Māui's dolphin or popoto is the world's rarest and smallest known subspecies of dolphin.

DELWYN DICKEY/STUFF

Māui’s dolphin or popoto is the world’s rarest and smallest known subspecies of dolphin.

Overseas conservationists and scientists are now agitating for action, frustrated at the Government’s inertia.

Sea Shepherd, the international marine conservation organisation, is petitioning the US government for a trade ban on snapper fished here. It will shortly file a case with the US Court of International Trade.

Legal director Brett Sommermeyer explained: “Recognising that the US is a major seaford importer, Congress, through the Marine Mammal Protection Act, chose to prohibit imports from foreign fisheries that fail to prevent bycatch of marine mammals in line with US standards.”

He said claims that the threat management plan provides adequate protection are “fanciful”.

“This TMP is not a new development. Rather, the TMP process has been characterised by chronic delays and ineffective management proposals …it is highly unlikely that the newest iteration of the TMP will include sufficient management measures.”

Sea Shepherd is calling for a complete ban on set nets and further restrictions on trawling, which is only prohibited in about five per cent of Māui habitat.

“Trawling within the 100 metre depth contour poses a potentially catastrophic risk to Māui dolphins. While expressly acknowledging this threat, the New Zealand government has failed to modify its regulations to prohibit trawling within this area,” he said.

Sage said the set net ban is under review but the new proposals will be a “significant improvement”.

“It is intended to be more specific on what Government wants to achieve…based on clear objectives for management of each of the populations. The approach taken in 2008 was more ad hoc…The risks from set netting, including around Banks Peninsula beyond the sanctuary, are being considered as part of the TMP review.”

Seafood NZ said the Sea Shepherd petition is based on “outdated or inappropriate information” and consideration should be deferred until the threat management plan is complete.

“The seafood industry is constantly working to reduce marine mammal deaths. We agree that there are some places that set netting should not happen. In Māui dolphin territory, over 6200 square kilometres of coastal waters are closed to set net fishing activity and 1702 square kilometres to trawl fishing activity.”

Source: https://www.stuff.co.nz/environment/112533375/last-gasp-of-a-dying-dolphin-are-we-too-late-to-save-mui

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