Plundered Waiheke Island coastline needs protection, says scientist

Monday, 6 November 2017

Over fishing has degraded the marine environment around Waiheke Island, says marine ecologist Tim Haggitt.

Marine reserves are needed to restore the ocean environment around Waiheke Island, which has been degraded by over-fishing, says marine ecologist Tim Haggitt.

A report has just been released after Haggitt and his colleagues from eCoast spent several days making an underwater survey of the coast from Matiatia to Enclosure Bay on Waiheke Island in December 2016.

Big snapper are scarce around Waiheke island, says marine ecologist Tim Haggitt.

Despite 'rigorous searches' for spiny rock lobsters on Waiheke's north western coastline, which has ideal habitat for lobsters, the scientists did not find any.

Kina barrens from Enclosure Bay to Thompsons Point are another sign of over fishing, Haggitt said.

* MPI to launch $8m review of snapper numbers off east coast

* Marine scientists warn of seas at risk as fish stocks fall in Hauraki Gulf**

He supports the creation of some of the 12 marine reserves that were proposed by the previous Waiheke Local Board in March 2016.

'Fishing pressure is pretty high.

'We need fishing - everyone likes to go and catch fish - but we need to balance that up with a network of marine reserves ' Haggitt said.

Research shows adult fish in marine reserves produce larvae that drifts outside the reserve, restoring fish stocks within and beyond reserves.

Habitats that have potential to become marine reserves with flourishing biodiversity were found right around the north-western coast of Waiheke.

'Across the whole coastline we surveyed, there are patches of biodiversity that would be good to have protection.

'There is complex rocky reef habitat and high biodiversity areas, with scallops and horse mussels, but there are also pretty big urchin barrens around Enclosure Bay that are signs of over fishing and of the reduction of snapper and lobster that predate on those urchins.

'The island is next to a productive fisheries area, so you could probably get an increase in snapper and lobster if areas were protected and enforced and everyone got behind it,' Haggitt said.

Ideally, the proposed reserves need to be bigger to offer enough protection for marine biodiversity to recover, he said.

Reserves generally need to include about five kilometres of coastline and extend two kilometres offshore.

Haggitt said a marine reserve proposed by the local board from the southern headland at Matiatia to the western headland before Oneroa beach would be 'adequate'. However, the reserve would have more value if it was extended to include important habitats near a marine reserve planned around the Noises islands.

Proposed reserves at Little Oneroa from Puriri Road to Fisherman's Rock and from Fisherman's Rock to the western end of Palm Beach would be more effective if they were extended to Thompsons Point and went further offshore. This would provide greater protection for larger mobile fish species and sponge habitat.

Extensive kina barrens would be likely to persist from Enclosure Bay to Thompsons Point unless the reserves were increased in size enough to allow large snapper and lobsters to return.

Kelp forests are disappearing because predators of kina, such as big snapper and crayfish, have been plundered so heavily that kina numbers are now exploding.

'In the whole inner Hauraki Gulf, lobsters are functionally extinct.

'They have been fished so heavily they don't play a role in the ecosystem any more like they used to,' Haggitt said.

Keep Our Beaches has opposed marine reserves on Waiheke's northern coast, but Haggitt said people see the 'real benefits' of marine reserves that have been established at Leigh, Tawharanui and Hahei.

'Why do you have to drive to Leigh to see huge snapper and crayfish?

'There is always going to be 'not in my backyard', but what are you going to do for future generations?'

Haggitt said it was too easy for people to point the finger at commercial or recreational fishing, when realistic bag limits need to be put on all fishers to protect breeding stock.

'The current recreational take for lobster is six per person per day, which is unrealistic.'

Sedimentation of the marine environment on Waiheke's coast was 'relatively minor' at the time of the survey, but could be worse in wetter months, he said.

Proposed marine reserves on the southern coastline of Waiheke also have merit and could be assessed further, Haggitt said.

These include a reserve proposed from Te Whau peninsula to the eastern headland past Whakanewha Regional Park, and at Anzac Bay from the end of Wharf Road to the eastern end of Okoka Bay.

A report on eCoast's research was prepared for Waiheke Local Board and Hauraki Gulf Conservation Trust in April, but was only publicly released at the local board's meeting on October 26.