Last Journey of the Sea Gypsies
By Dave Hansford - Last November, a baby Maui’s dolphin washed up dead on Sunset Beach, just south of the Waikato river mouth. Just a fortnight later, two dead females ? an adult and a youngster ? stranded further north, at Kariotahi Beach. Their demise meant the loss of some three percent of the total population of the world’s most critically endangered marine dolphin.
Maui’s, or popoto, lives only in New Zealand. There are perhaps110 left on earth, living in 11 small groups along the northwesterncoast of the North Island between Dargaville and New Plymouth. Andtheir future looks gloomy ? population models reveal we can’t afford tolose a single one from human impacts for another six years. That’s abreak we’re unlikely to give them.
Maui’s like to stay close toshore, particularly in summer, when they’ve been seen in the Kaiparaand Manukau Harbours. Typically, the visibility in such turbid,tide-swept waters is poor, so the dolphins get around by usingultrasound, taking a picture of their surrounds with high frequencyclicks and reading their reply.
But ultrasound, it seems, hastrouble spotting a monofilament gill net. Monofilament ? essentiallythe same green line you see on a fishing rod ? first appeared in gillnets in the seventies, set close inshore and around harbour entrancesfor dogfish, flounder and mullet ? directly in Maui’s path.
They died in droves.
Theircousin the Hector’s dolphin, found around South Island coasts, faredonly a little better; in 1970 they numbered 26,000. Today, just over7000 remain.
Kirsty Russell of Auckland University has studiedMaui’s dolphins since 1997. Taking skin samples, she read them for“genetic markers” ? each animal’s own DNA fingerprint. “It’s kind oflike a paternity test,” she explains.
From the results came anecho of disaster. “There’s definitely been a genetic bottleneck; thepopulation has suffered a massive decline at some stage and we’reassuming that’s due to the gill netting. We’ve lost a huge proportionof the population.”
That in turn raises concerns for thedolphins’ genetic richness; if it’s compromised, they may not bebreeding to capacity or could more readily fall victim to pathogenssuch as the Brucella bacteria that recently turned up in a sampledHector’s dolphin. Brucella can cause abortion and sterility, andfurther tests have shown that the dolphins are still carrying the wastewe threw away decades ago ? toxic levels of dioxins, PCBs, metals andeven the long-outlawed DDT ? in their blubber. Maui’s are our mostpolluted marine mammal.
Russell believes there are fewer than100 survivors. They range very widely in winter, she says, and while agroup might confine themselves loosely to an area one summer, they’llturn up somewhere completely different the next. “Two summers ago wehad a sighting off Waitara. They hadn’t been seen there for 15 years.They’re like gypsies.”
In late 2003, despite a legal challengefrom The Northern Inshore Fisheries Company, the Ministry of Fisheries(MFish) enforced a set net ban along the North Island west coast fromthe bottom of Ninety-Mile Beach almost to New Plymouth. It also imposeda ban on trawling within one nautical mile of the coast, butenvironment groups say that’s not enough.
In 2004 a coalition ofconservation groups put a formal challenge to the Government. Theydemanded that the Department of Conservation (DOC) and MFish complete along-overdue recovery plan to save Maui’s and Hector’s dolphins. “Wehad no confidence in their science or their vision,” says WWF’sconservation director Chris Howe, “so we came up with our own.”
Theygave the Government six months, but the deadline passed unanswered. Twoyears later, the plan still languishes as a draft in DOC in-trays.Shaun Cooper of DOC’s Marine Conservation Unit says the plan “is stillin the planning phase. We’re working on a timeline for consultationwith stakeholders.”
That glacial pace is unacceptable to Howe,who can’t understand why MFish and DOC “haven’t agreed or evenconsulted on simple management objectives for Maui’s and Hector’sdolphins. Surely, as an iconic species found only in New Zealand, thegovernment could agree to aim for some level of recovery?
“Instead,there’s talk of more research needed, and even though DOC has a draftplan, it’s been witheld under the Official Information Act.”
Lastsummer, 19 more Hector’s dolphins were found dead ? 11 of them fromentanglement in fishing gear ? prompting Fisheries Minister JimAnderton and Conservation Minister Chris Carter to propose interimprotection measures while DOC grapples with its management plan. Butthe move, now closed to consultation, came too late to save a furthersix Hector’s found dead since last September.
The measures couldmean commercial set net bans from Te Waewae Bay near Invercargill andalong parts of the Canterbury coast, or at least a requirement forfishers to stay with their nets while set.
In the North Island,Russell says no Maui’s have drowned in nets since the ban was enforced,which may be why the interim plan stops at “discussions with [PortWaikato and Taranaki] set netters to assess the extent to which theirfishing might represent a threat to dolphins”.
But OtagoUniversity marine biologist Liz Slooten has studied Maui’s and Hector’sdolphins for more than two decades, and says the absence of scarsdoesn’t exonerate set nets. She suspects too, that many more deaths gounreported. “We could stop gill net drownings tomorrow, she says. “It’svery readily preventable, simply by using other fishing methods. It’snot like we’re asking people not to fish here anymore ? all we’reasking is that if you’re going to go fishing in an area where there areHector’s dolphins, please don’t use gill nets. Surely that’s not toomuch to ask.
“We’ve dragged our feet for the last thirty years. How much longer are we going to have to wait? And will it be in time?”
Howe agrees; “Every day that goes by without decisive action … puts the species past the point of no return.”
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