23 May 2019

'It's not a quick fix to revive these ecosystems'

7:21 am on 23 May 2019

A petition to ban bottom trawling on underwater mountains has amassed 20,000 signatures in one week.

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Photo: Photo / 123RF

The petition was launched by environmental groups the Deep Sea Conservation Coalition, ECO, Forest and Bird, Greenpeace, LegaSea and WWF-New Zealand as well as recreational fishers.

It is calling for the government to ban the destructive practice on seamounts, or submarine mountains, and other ecologically sensitive areas.

A recent report from NIWA on the impact of bottom trawling, concluded that the benthic communities on the seamounts had low resilience to the effects of bottom trawling.

It said New Zealand's major deepwater fisheries occur on seamounts for a number of fish species, including orange roughy.

The study looked at six seamounts with a range of trawl histories, one with persistent levels of trawling, two with intermediate levels and two which were low or untrawled, and another which had been heavily trawled, but was closed to the practice in 2001.

It found the abundance, species richness and diversity of benthic communities were higher on the seamounts which had experienced low levels of trawling, than those that had been trawled.

It said in general communities on the closed off seamount remained similar to those on the persistently trawled seamount, showing little indication of steps toward recovery to its pre-disturbance state following its closure.

Greenpeace's oceans campaigner Jessica Desmond said seamounts are often covered in ancient coral forests which are habitat-forming and important ecosystems and might never recover from bottom trawlers, which she said destroy everything in their path.

"When we bulldoze them and get rid of that habitat, that has a really long lasting impact on the marine environment, it's not a quick fix to revive these ecosystems, once they're gone, they're really gone," she said.

The ban on the practice would happen through ammending the Fisheries Act, and the groups have also asked for the government to stop permitting New Zealand ships to bottom trawl outside of this country's waters in the South Pacific as well.

Ms Desmond said there had been a real groundswell of support, and 20,000 signatures in a week shows an enormous amount of public backing for the ban.