Hauraki Gulf marine life has fallen by more than half since 1925, report finds

Thursday, 1 March 2018

The Hauraki Gulf - which lies between Auckland, the Coromandel peninsula and Great Barrier Island - is threatened by overfishing, climate change and a population boom. (Video first published in March 2018)

More than half the marine life in the Hauraki Gulf has vanished in the past 93 years, a new report says.

Snapper and crayfish populations have fallen fivefold since 1945, and there are 'serious concerns' about the area's critically endangered seabirds, including fairy terns and storm petrels.

The findings were published in the State of Our Gulf 2017 report, released by the Hauraki Gulf Forum on Friday.

The forum – made up of representatives from councils, government agencies, and tangata whenua – is now asking government ministers to carry out a 'fundamental review' of fisheries legislation.

* Plundered Waiheke Island coastline needs protection, scientist says

* Failure to report seabird and fish death 'commonplace' in industry, fishing company boss says**

Hauraki Gulf Forum member John Meeuwsen said more marine reserves were needed.

The report said the gulf, which lies between Auckland, the Coromandel peninsula, and Great Barrier Island, is New Zealand's most intensively recreationally fished area.

Of the top 15 finfish species caught there, only four were at or above their target levels for sustainable fishing: kahawai, albacore tuna, barracouta and gurnard.

The population of snapper in the gulf is about 20 per cent what it was in 1945.

Trevally numbers have reduced by 86%, snapper by 83%, and sharks, a key part of the ecosystem, by 86%.

The report said the snapper fishery was not at risk of collapse in the short term, but catches would probably need to be reduced to stop numbers 'declining towards collapse' in the medium to long term.

Fairy terns are New Zealand's most endangered species, with only about 40 of the seabirds remaining.

The loss of snapper and crayfish meant kina were thriving without predators and eating the kelp forest, reducing reef productivity, it said.

A recently-discovered large scallop bed had collapsed after about four years of fishing.

Over-fishing, marine farms, marinas and pollution pose threats to the Hauraki Gulf.

The report called on the government to focus on restoring fish habitats and increasing their abundance, rather than maximising yields for fisheries.

Forum member John Meeuwsen said it was a wake-up call to protect at least 20 per cent of the gulf with no-take marine reserves.

Currently, only 0.3 per cent is protected by reserves.

Meeuwsen is a member of the Waiheke Local Board, which has proposed a network of up to 12 marine reserves.

They would cover 127sqkm – just over 10 per cent of the board's area.

'We need to protect areas of the gulf that have a variety of environments and habitats to help the gulf rejuvenate itself and make it more viable for all the parties that want to benefit from it,' Meeuwsen said.

'The state of the water is definitely still going backwards.'

The Sea Change marine spatial plan and Friends of Motuketekete Reef have also proposed marine protected areas in the gulf.

Forest and Bird is calling for the government to take action on the Sea Change plan, released in 2016 by the Hauraki Gulf Forum, mana whenua, central and local government, and interest groups.

'If implemented, Sea Change would be transformative for the Hauraki Gulf - but without political commitment it will continue to deteriorate.

'There will be more toxic beaches, fewer fish, and continued ecosystem destruction,' said Forest and Bird's Hauraki Gulf advocate Alicia Bullock.

The State of Our Gulf report urges the government to take action on creating marine reserves and on encroachment into the gulf by aquaculture, marinas and ports.

Over the past three years, 505 hectares of marine farming have been approved, along with three new marinas and a dozen jetties and boat ramps.

The most pronounced recent change to pressures facing the gulf was the change to Auckland's population, the report said. It increased by 18 per cent – about 250,000 people – between 2006 and 2016.

Auckland Council has blacklisted 16 spots as unsafe for swimming because of long term water pollution.

The pollution of waterways was one of the 'unmet costs' of rural and urban development, and some of the environmental damage was permanent, the report said.

There was 'uncertainty about the ability of the sea to assimilate current nitrogen loads' in the Firth of Thames, adjacent to dairy farming areas, it said.

Climate change was also adding to pressures on the gulf, with seas expected to become warmer, more acidic and more vulnerable to invasive species from warmer regions. Rising sea levels and increasing numbers of storms were increasing flooding, erosion and sediment loads in the ocean.

The report noted some positives: the voluntary adoption of lower shipping speeds had reduced ship strikes on rare Bryde's whales, with only one whale hit in the past four years.

However, a 300 hectare zone for fish farming has been established in an area used by the whales.

Bottom trawling had reduced by about 23 per cent, and scallop dredging by about 40 per cent, in the past three years.

Predator eradication on gulf islands had helped some seabirds to recover their numbers.

However, 'serious concerns' remained about the survival of fairy terns, storm petrels, black petrels and flesh-footed shearwaters, with long-line snapper fishing reducing populations of two of these seabirds, the report said.