Maui's dolphin swimming in sea of trouble

By Geoff Cumming

New measures to protect Maui's dolphins suggest the Government is responding to international fears for the diminutive dolphin found only in New Zealand waters. But is it too little, too late?

The fishing boat, Compass Rose, at Port Taranaki in New Plymouth. Photo / Mark Mitchell
The fishing boat, Compass Rose, at Port Taranaki in New Plymouth. Photo / Mark Mitchell

If the world's most endangered dolphin has any awareness of its plight, it would do well to make itself known to the Taranaki fishing fleet right now. Since July, the five set-net fishing boats out of New Plymouth have been barred from fishing within two nautical miles of shore, where the rig and blue warehou they target are most abundant. To fish further out - between 2nm and 7nm - they must have observers on board who record in their log books every 15 minutes what they have seen.

So far they have covered 4540nm during 168 days at sea both inside and outside the restricted area - and the number of Maui's dolphin sightings remains a big, fat zero.

But marine scientists want fishing restrictions extended even further and Primary Industries Minister David Carter is about to decide whether to retain the interim measures or to err on the side of caution and ban gill net fishing out to 4nm - arguably triggering extinction for the local fishing industry. The fishers may also, from October next year, have to cover the cost of observers (up to $1000 a day) and the town's only remaining longline trawler will also have to carry an observer.

The options are outlined in a review of the Threat Management Plan for Hector's and Maui's dolphins, for which consultation closes on November 12.

Click here for full map of Maui Fishing Restrictions list.

If the fishermen are right and there are no Maui's dolphins off Taranaki, what will the measures achieve? It's not just a handful of fishermen, their crew and families whose livelihoods are at stake. New Plymouth has two fish processors employing a further 30 people. The impact of the interim restrictions on catches has already forced one to lay off staff.

Their jobs might be a small price to pay for saving an endemic (found only in New Zealand waters) dolphin, not least in sparing the blow to our clean, green image that extinction will bring. But if fishers, marine scientists and conservationists agree on one thing, it is that the latest measures will not save the dolphins.

Most scientists on a risk assessment panel that informed the review agreed the extent of the dolphins' range is Wanganui, and wanted fishing restrictions extended that far south. The Department of Conservation wanted the interim Taranaki ban to go out to 7nm, in line with restrictions introduced in 2008 off Auckland and Waikato (as far south as Pariokariwa Pt).

International agencies including the International Whaling Commission support a ban on set nets and trawlers to the 100m depth contour. But the Ministry of Primary Industries - in charge of the fishing options in the review - gives Carter the choice of sticking with the 2nm ban as far south as Hawera or extending it to 4nm.

The fishermen say any restrictions are pointless south of Pariokariwa Pt because the dolphins aren't there. Keith Mawson, of processor Egmont Seafoods, says for the past decade targeting fishing has been a soft option rather than funding research into the Maui's numbers, location and health.

"We should be able to fish our historical grounds until there's evidence that there are Maui's dolphins in this area.

"There are guys who've been fishing for 35 or 40 years and they've never seen one. Hopefully, having observers will show that what we've been saying is correct."

But the industry's stance was not helped in January, when fisherman Ian McDougall killed a dolphin while gill netting off Cape Egmont. We'll never know whether it was a Hector's or a Maui's - he threw it overboard, fearing prosecution under the Wildlife Act for having an endangered species in his possession. But he reported the bycatch and MPI concluded it was most likely a Maui's.

He now believes the dolphin was a Hector's, after a dolphin that washed ashore at Opunake in April was found to be a Hector's. The dolphins are identical, distinguishable only by DNA analysis.

"I kick my arse every time I think about it," McDougall told the Weekend Herald. "I feel responsible for triggering all this."

Found only in New Zealand waters, the threatened Hector's dolphin is the world's smallest, with its critically endangered sub-species, the Maui's, growing to no more than 1.7m. The Maui's evolution as a sub-species stems from its isolation from South Island Hector's populations off northwest Nelson, Banks Peninsula and the bottom of the South Island.

Playful around boats, they are undeniably cute with their blunt beak, rounded dorsal fin and black and white markings. Raglan surfers are among their fans.

They prefer coastal shallows, harbours and estuaries, finding their way in turbid inshore waters using ultrasound, but they have trouble picking up modern nylon gill nets. Their plight was highlighted in the early 1990s when Otago University researchers Liz Slooten and Steve Dawson found large numbers were dying in gill nets off Banks Peninsula. On West Auckland beaches there was grisly evidence of fishermen slitting open dead dolphins in the hope they would sink without trace. But it wasn't until 2003 that restrictions were first imposed on gill nets and trawling off the North Island west coast between Bayly's Beach, north of Dargaville, and Pariokariwa Pt. Trawlers are banned within 2km of shore.

The January incident was the first in a sequence of developments that prompted DoC to bring forward the review by one year. Most alarming was a research estimate that the adult Maui's population was around 55, with fewer than 20 females of breeding age. This was half the estimate from a previous survey, using different methodology, a decade ago.

The DoC-funded research by University of Auckland scientists over consecutive summers also challenged assumptions that the dolphins don't travel far, revealing one had moved 80km.

Then came confirmed sightings of Hector's dolphins in the area - two live and two washed ashore. Their presence has excited scientists by raising the prospect that the Hector's could provide a lifeline for the Maui's through interbreeding, though there is no certainty that they will.

Fishers say the Hector's are occasional strays and argue that any interbreeding would result in a hybrid, not a Maui's.

Though genetic sampling has confirmed the Maui's were once as far south as Kapiti and Wellington harbour, they are now thought largely confined to the coast between the Kaipara and Kawhia harbours and concentrated in a 40nm stretch from Manukau Harbour to south of Port Waikato.

The Prime Minister's Chief Science Adviser, Sir Peter Gluckman, is one scientist who has publicly wondered whether the dolphin is beyond the tipping point for species survival. Gluckman singled out the Maui's at an environmental seminar in August, when he queried the wisdom of focusing resources on "iconic" species instead of preserving whole ecosystems.

"It will be very hard, if not impossible to bring [Maui's dolphins] back without a cost. ... We have to get cleverer at looking at species before they reach their tipping points."

But cetacean experts on the risk assessment panel concluded the Maui's is not beyond salvation. They point to the recovery of southern right whales and Antarctic blue whales from quite low numbers once protections were in place.

"Saving Maui's is quite simple," Slooten says. "It simply consists of stopping an impact. There is no need to pour millions of dollars in. All we need to say is, if you want to fish in a critically endangered habitat please use dolphin-safe methods."

Even so, any recovery would be very slow - an average of 1.8 dolphins a year. The dolphins live to only around 20 years and are slow breeders. Females mature late, at around 7 years, and give birth to a single calf every two to four years.

Sightings of Hector's dolphins in the area have raised hopes. Environmental groups and some scientists want a "protection corridor" created between Taranaki and northwest Nelson to increase the chances that Hector's dolphins may move north successfully. "Fifty-five adults is really low," says Slooten. "They don't stand much chance unless many animals come in from the South Island. It's better to have a slightly weakened Maui's dolphin gene pool than to preside over the extinction of an entire population."

Other scientists agree interbreeding would not erase the genetic differences that make the Maui's distinct. In fact, increased genetic diversity is what the tiny population desperately needs.

Nor are the scientists fazed by the observer reports of no dolphin sightings in Taranaki and the fishers' anecdotal claims that they haven't been around for years. The dolphins' small size, inconspicuous surfacing and preference for murky inshore waters makes them very hard to see, especially at the extremes of the population range, says the risk assessment. They are more commonly seen close to shore over summer.

Slooten says there's international scientific backing to extend the restricted area to Wanganui. Catch data shows set netting and trawling is continuing illegally inside the protected area north of Pariokariwa Pt. Extending restrictions would ensure the dolphins can safely venture beyond their current core range.

Slooten says there isn't time to obtain the level of proof needed to quieten the fishers. "We've got to make a precautionary decision and this seems to be lost on MPI."

It comes as no surprise that the options now being considered amount to deckchair-rearrangement as the last Maui's dolphin slips from view. An Environmental Defence Society report in September highlighted the gaps in protection for New Zealand's marine mammals and DoC's waning influence as successive governments promoted "sustainable" fishing for economic gain.

That same month, New Zealand was the only country to oppose an International Union for the Conservation of Nature resolution calling for gill nets and trawling to be banned to the 100m depth contour in areas of Maui's and Hector's distribution.

DoC representatives at the meeting bowed to Ministry of Primary Industries advice that such an extension lacked scientific evidence.

MPI is in charge of the fisheries recommendations for the current review. DoC is left to evaluate non-fishing threats: it outlines options for thundercat racing, seismic surveying, mineral exploration, oil spills, pollution and surf lifesaving carnivals.

Though potentially important, these issues were currently responsible for less than 5 per cent of human-induced Maui's dolphin mortality, the scientific panel decided. Fishing was ranked as the likely cause of 95.5 per cent of human-induced mortalities.

Latest research may challenge that thinking. Massey University pathobiologist Dr Wendi Roe has established a parasite traced to cats as the prime cause of death in seven of 28 beached Hector's-type dolphins she autopsied, including two out of three Maui's dolphins.

The fishing industry has seized on the findings to back its argument that, instead of targeting fishing, urgent research is needed into the range, health and abundance of the dolphins so steps can be taken to rebuild the population.

Egmont Seafoods' Mawson blames DoC and other agencies for failing to adequately research the dolphins.

"They've known there was a problem since before 2000. DoC and others have [been] pointing the finger at the fishing industry, but we've been excluded from where the dolphins are for the last 10 years. Something else is going on."

Minister Carter says the Government recognises that more information is needed on human-induced threats and whether dolphins in the area are Hector's or Maui's.

But Conservation Minister Kate Wilkinson won't be drawn on whether she will seek more funding for research in next year's budget.

"The TMP review will address all known human-induced threats to the dolphins, how we can mitigate these threats, and future research priorities," she says.

"I look forward to its completion."


The cost to fishers

New Plymouth fisherman Rob Ansley borrowed heavily to set up fish processing company Ocean Pearl six years ago after struggling to make a living solely from fishing. The interim set net ban to protect Maui's dolphins has forced him to lay off more than half his 18 full and part-time staff and renegotiate with the bank.

"Unless we can get back inside the 2-mile limit we will be out of business. We can't go to other areas for warehou or rig - not for the volumes we need. If the Government wants us to go long-lining, they need to do something about the cost of snapper quota, otherwise we can't make money out of it. If we were killing these dolphins, fair enough. But it's just not happening ... you can't catch something if it isn't there."

Scientists and conservationists have suggested fishermen change methods or target other species but the fishers say there are no viable alternatives; nor can they simply switch to other species. Blue warehou won't be caught on a longline, says Ansley.

The fishermen say the Ministry of Primary Industries has badly underestimated the impacts of the restrictions on their incomes. The threat management consultation document estimates the set net ban out to 2 nautical miles will cost the fishers about 15 per cent of their catch by value, or $482,000 a year.

The fishers say the inshore area earns them close to 50 per cent of their income. "The catch estimates are miles out," says Ansley.

Taranaki Commercial Fishermen's Association president Ian McDougall expects a big drop in income from the coming rig season. "I will make it up with school shark and a percentage of rig but most of the rig is right on the beach." McDougall has spent $4500 fixing acoustic "pingers" to his nets to deter the dolphins, after a dolphin died in his gill net in January. He maintains it was a Hector's. "We've been telling them for years: we don't see [Maui's]. They have to listen to us - we've been called liars for too long."

Keith Mawson of export processor Egmont Seafoods says the New Plymouth industry will struggle on if, as expected, the interim measures are extended to 2015. If the set net ban is extended to 4 nautical miles, that would put most boats out of business and processors won't have enough fish to slice. An industry collapse would cost the Taranaki economy $15 million.

"Just about our entire fishery is being removed from us. [The MPI] forgets that sales dropped significantly when the first restrictions were imposed in 2003 and again in 2008 - it's a cumulative effect."

Arcane quota management and annual catch entitlement (ACE) rules mean fishers can't simply swap from one species to another, Mawson says. Primary Industries Minister David Carter has promised to ease rules so boats with an observer on board can return bycatch to the sea if it is likely to survive, without attracting ACE liability or cost.

New Plymouth environmentalist Anne Scott suggests fishers and processors should be compensated for loss of income. "The plight of this dolphin was well known 10 years ago but the MPI hasn't supported the industry to alter practices. They have let down the local industry; now they are taking these red light measures."

Scott chairs the Nga Motu Marine Reserve Society, which promoted the 1400ha Tapuae Marine Reserve, bordering New Plymouth. "The society would support a sanctuary down to Wanganui. International scientists are saying they can be saved and this is how we must do it - this is the last chance."


Have your say

Consultation on the Maui's dolphin threat management plan review closes on Nov 12.

Go to: fish.govt.nz/en-nz/Consultations/default.htm

- NZ Herald

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