The desperate plight of our seabirds

Commercial fishing crews and seabirds are on the water for the same reason – to feed their families. A joint effort by conservationists and the industry is warding off the threat of extinction from declining black petrels, the New Zealand species most at

This is prime real estate. Nestled in a forest, shaded by ancient rimu and kauri, with breathtaking views of dramatic surf beaches, and easy commuter access, this home is in hot demand. Burrow 69 is one of many black petrel (takoketai) nests that honeycomb the forest floor on Aotea/Great Barrier Island/Aotea’s Mt Hobson/Hirakimata.

It also comes with a special history: A breeding pair canoodling in the love nest features in the morning birdsong broadcast on Radio New Zealand’s Morning Report.

Tucked away on a ridge under the 627-metre summit, the burrow is only metres from ‘‘Launch Rock’’, a natural platform from which the birds launch into the skies in search of food for their chicks.

On summer nights, the forest comes alive with the distinctive male ‘‘clack clack’’ as they try to attract a mate, or the female aerial call as she returns from foraging for squid and fish.

With a metre-wide wingspan, you hear them swoop through the night sky before crashing into the dense canopy, like stocky Angry Birds (from the video game). By some miracle – likely an acute sense of smell – they land, unharmed, only a metre or two from their burrow.

Seabird ecologist Biz Bell lifts a wooden hatch covering the burrow and dips her hand into the earthy entrance. There’s a bird tucked inside, velvety black feathers with midnight blue eyes staring up at us.

‘‘It was empty when we were here [last],’’ she says, pulling on a pair of thick gloves. The bird bites, locking its beak around her finger, and she gently walks it up the narrow passage.

The stunned-looking bird has a distinctive white swoosh painted on its forehead.

‘‘He’s an interloper. He does not belong in this burrow,’’ she says. ‘‘We’ve handled [him] before because we’ve painted twink on his head. So we know he’s the same bird.

‘‘So we’ll be able to check his band number, look it up on our app and see where this bird has come from.’’

With a gentle but firm grip behind the bird’s head, Bell examines a tiny, metal band wrapped around its leg. ‘‘36354. He’s from Burrow 77 . . . about 20 metres away. He’s 14 years old.’’

She chides the unfortunate creature: ‘‘The owners of the burrow won’t like you being in here.’’

Bell, of Wildlife Management International, has monitored this colony for more than a quarter of a century, returning three times a year and amassing a treasure trove of data.

With each passing year, the statistics tell a bleak, but familiar, story.

Mt Hobson is the main breeding colony, with 900 to 1000 pairs over 35 hectares. There are an estimated 500 breeding pairs on uninhabited Little Barrier Island/Te Hauturu-o-Toi.

But they are a remnant population. Once, black petrels were recorded across the entire North Island and down to northwest Nelson. Now they number about 15,000, and are listed as ‘‘nationally vulnerable’’.

They were driven from their habitat, which was destroyed, burnt or farmed, and left to the mercy of predators like rats, cats, stoats and dogs. They are also the seabird most at risk from commercial fishing – caught in nets or on lines as they dive to retrieve baits.

Ornithologists love to call New Zealand the ‘‘seabird capital of the world’’. It’s a fair claim as there are 360 known species, and 86 breed in our corner of the planet. They include albatrosses, gannets, gulls, penguins, shags, shearwaters, skuas, terns – and petrels. Seabirds are that which gather most of their food offshore. The subtropical convergence – where warmer waters meet cooler subantarctic depths – stretches around the South Island and east to the Chatham Islands, meeting ocean floor landforms that create an upwelling of nutrients. These are a rich draw for marine life.

Black petrels spend much of their life alone at sea, and silent – rarely calling as they soar above the waves.

‘‘They are endemic to New Zealand, but they’re pretty much an international traveller,’’ Bell says. ‘‘Once they finish breeding season here, the parents and the chicks migrate to South American waters.

‘‘They only come to land in New Zealand, but they do visit pretty close to some of the Peruvian, Ecuadorian [and] Chilean coastline and around Gala´ pagos to feed on that amazing Humboldt current.

‘‘They just hang out at sea, sleep on the surface. Black petrels are not the most social birds . . . Generally they’re solo feeders.’’

The juveniles don’t return for three or four years. Bell calls it an extended ‘‘gap year’’ as they learn how to feed, often picking up scraps from around pods of whales and dolphins.

Once ready to breed, the males will return first, in October, to set up home, often digging out an old burrow.

‘‘They mostly come back to their natal area. They even come back and fight with their parents over their own burrow, where they were born, before they have to learn to dig their own.’’

The petrels excavate an almond-shaped tunnel directly under a tree trunk, with a ‘‘veranda’’ cleared of debris for romancing. ‘‘They do all the housework, dig it all out, tidy it up,’’ Bell says.

Then single males begin to court. Black petrels are monogamous, and paired-up birds will call for their mate.

‘‘They stand with their mouths wide open and go ‘clack clack clack clack’,’’ Bell says. ‘‘They’re saying: ‘We’re home, come back down.’ They mate for life, and they can live till about 40 or 50 years old. There are very rare cases of divorce.

‘‘When she comes down, the pair bond and canoodle in the burrow. And then they mate, and go back to sea.’’

Parents-to-be return in late November, and the female lays a single egg. They take turns incubating it, for seven to 10-day stretches. Once

‘‘I don’t know any fishermen that would willingly injure seabirds . . . They are there in our office, they come and talk to us during the day. They are your company for long voyages. ’’ Zak Olsen Fishing boat captain

the chick is born – a ball of grey fluff about the size of your palm – both parents keep it fed.

‘‘For the first month and a half they’re just getting big and fat and fed,’’ Bell says.

This is a key time for her. She spends three weeks at the colony in January and February, monitoring breeding success and survival, and fitting some with tracking devices.

‘‘We’re here to understand what their population is doing and how it’s going. At the moment, they’re a bit less stable to . . . declining,’’ she says.

One mystery is why less than one in 10 juveniles make it back.

‘‘Some birds will die, regardless. They’re in a poor body condition. They’re not heavy enough, they didn’t get fat enough through that chickraising period. But there seems to be a large number that shouldn’t be dying. We’re trying to work out why,’’ she says.

A collaboration with scientists in Peru and Ecuador revealed a significant number die in large wrecks – when emaciated seabirds wash up on shore, starved to death, after a catastrophic failure in their food supply, such as a huge storm. Climate change is making these events more common.

The work also revealed black petrels are being fished out of existence. In the waters off Ecuador and Peru it is the third-most-abundant bird observed around vessels.

But many are also caught in the waters off the northeast of New Zealand’s North Island, snared on baited long-line hooks that are set along the seabed for snapper, hapuka and kahawhai.

The birds dive down to eat the bait from hooks, get hooked and drown. Or they chase uneaten bait as lines are hauled in. They can also be caught in trawl nets.

It’s slightly before 2am when the RV Southern Cross casts off from Cross Street wharf into Tauranga harbour. As she slips past cargo ships, lights ablaze, deckhands Matthew ‘‘Matty’’ Anderson and Django Broeschart go below decks to grab two hours’ precious sleep in their bunks. Skipper Zak Olsen is at the helm. Underneath the shelter of the volcanic guardian Mauao [Mt Maunganui] the waters are

calm. But as the boat moves into the harbour mouth, the waves become steep as the incoming tide runs against the wind.

It’s going to be a rough night.

Olsen leaves in the dead of night so he can begin fishing while the sun is still below the horizon.

Snapper feeds on the change of light, so he aims to get his longline in the water before dawn. It is also a technique to avoid accidentally killing seabirds.

Many are active at dusk and dawn, and research has shown that sets that continue into twilight and daylight hours are often associated with high levels of bycatch.

‘‘The earlier we get our gear in the water, the less interaction we have with seabirds,’’ Olsen says.

‘‘I don’t know any fishermen that would willingly injure seabirds. They’re beautiful magnificent creatures.

‘‘They are there in our office, they come and talk to us during the day. They are your company for long voyages. They’re a staple at sea.’’

For two hours, Olsen speeds across whitecapped waves and into the inky black. He’s headed for a spot just east of Mo¯ tı¯tı¯ Island, more than 20 km northeast of Tauranga.

As he slows the boat, Anderson and Broeschart emerge, pulling on oilskins and lighting skinny rollies.

Broeschart takes the wheel, as Olsen and Anderson begin setting a backbone line that runs from a winch mounted in the centre of the boat.

A tori – or bird-scaring – line is towed from the roof over the area where they are deploying the baited hooks. Long pink streamers hang off the 120-metre line, every five metres, deterring seabirds from flying, swimming or diving as the hooks sink into the water.

The backbone line is strung with smaller lines of hooks baited with squid and pilchard, dangling at evenly spaced intervals.

Olsen feeds the backbone through one hand, using the other to attach the hooks woven around a wooden card. They were painstakingly hand-baited by Anderson and Broeschart before they slept.

Each card has 48 hooks, and for every 24 hooks, Anderson throws down a weight to ensure they sink faster. He can also monitor and adjust how deep and fast the lines are sinking.

Broeschart maintains a steady speed of five knots to reduce tension on the backbone, allowing for a more direct descent of hooks. At three-metre gaps, 5000 hooks will stretch out over 10 nautical miles, soaking for two hours before the line is brought in.

‘‘The aim of the game is to get your line into the water as quickly as possible,’’ Olsen explains.

‘‘It’s always more time, more money, normally less fish as well. Every time you do a little bit more for mitigation, you give up a little bit of your fishing. It’s not a major loss, but it is definitely noticeable.’’

The hauling station is sheltered with a roof to stop seabirds trying to dive for disused bait as the line is reeled in, gulls hovering under the bruised skies.

The trio work quickly off the starboard side. A nor’west swell meets west-south-west wind, turning the chop beneath into a washing machine.

As Olsen sets a course for home, Anderson and Broeschart pack snapper, sea perch and gurnard into bins lined with crushed ice, swaying to reggae tunes and puffing on cigarettes.

Olsen, a 31-year-old father of two from Whanga¯ rei, has been fishing from North Cape to East Cape since he was 16.

‘‘I’m lucky to have always worked on vessels where seabird mitigation was at the very forefront of our fishing practices. So, I’ve seen very little seabird bycatch, but I still have seen some, and we’re still working on ways to eliminate it completely, hopefully.’’

He works for Adam Clow, a Whitianga fisherman who has won awards for his conservation work. Since 2013, Clow has taken his crew to Mt Hobson/Hirakimata to help Bell and her team band black petrels.

‘‘It creates a really strong understanding of the birds with the crew. And it means that they’ll go that extra mile to make sure that we don’t catch them,’’ Olsen says.

Bell says collaboration between scientists and fisheries ‘‘is what’s getting us some development and really good measures’’.

Bycatch reached a peak in 2002 and then began to decrease, according to Stats NZ research. The Ministry for Primary Industries could not provide annual black petrel bycatch figures.

The Southern Cross crew is also trialling flashing lights on their lines to scare more birds – and regularly take Department of Conservation (DOC) staff out on research trips.

‘‘The whole long-line industry is doing what we’re doing. Everyone’s trying tori lines. People are setting at night, using lots of weight if they set during the day.

‘‘The bird killers – that reputation of the fishing industry is old. And the way that it operates now is not current with our reputation.’’

But the migratory nature of seabirds means it is impossible to completely protect them from fishing gear.

Graeme Taylor has been DOC’s leading seabird adviser for nearly three decades and says the risk to seabirds now comes from international fleets operating outside New Zealand’s exclusive economic zone – 200 nautical miles from our coasts.

‘‘The biggest concern we have is what’s going on in the high seas, where people are supposed to be using those methods, but there’s no-one there to make sure,’’ he says.

‘‘Unfortunately, there’s some parts of the world where the demand for protein and food is so high, the pressure is on to put more boats out there to find it and there is probably less concern or awareness.

‘‘That is going to continue to be a really big risk for our seabirds. If they just stayed within the New Zealand EEZ [exclusive economic zone], they’d probably be OK, but the fact is they spend a big part of their life outside the EEZ.’’