Deep sea life also needs protection

By STEVE O'SHEA*

When fishermen in the Ross Sea hauled up in April the second-ever intact specimen of what is being termed the "colossal squid", the world wanted to know more.

Larger, faster and a more aggressive predator than the giant squid, it was a deep-sea monster that inspired the imaginations of millions when images of its razor-sharp, 360-degree rotating hooks and eyes the size of dinner plates were beamed around the world.

Now that the furore has died down, it seems the future of the colossal squid and countless other species is far from certain. Yet this fact does not appear to be of much interest to the local or world media.

The activities of commercial fisheries in our waters and across the world are not only depleting fishing stocks but also destroying the habitat of a wide variety of species, from tiny microbial organisms to the majestic sperm whale.

Tragically, many are yet to be discovered and some are likely to become extinct even before they are known to science. Five species of squid and octopus endemic to New Zealand waters face imminent extinction - three of these five were discovered only as recently as 1999.

Sperm whales consume about 800 to 1000 squid a day, and if they were to move away from our waters to find new sources of food, the effects on tourism in places like Kaikoura, where whale-watching is a big part of the local economy, could be disastrous.

There are 18 marine reserves in New Zealand, representing 7 per cent of our territorial waters. The reserves protect local species and their habitat from human disturbance, with no commercial or recreational fishing allowed.

Yet the reserves are all coastal, and 99 per cent of their area is contained within two large reserves around the Kermadec and Auckland Islands. Considering that an estimated 70 per cent of ocean-dwelling species have yet to be discovered, the need for marine reserves that cover areas of open sea is pressing.

One of the richest habitats for marine life in the waters around New Zealand are the seamounts, around 800 undersea volcanoes that rise steeply from the ocean floor. When the Department of Conservation commissioned the National Institute of Water and Atmospheric Research to study their potential for protection in 1999, it was discovered that many of the undersea fauna were unique to particular seamounts.

It is because seamounts are so rich in sea life that they have become a target for extensive commercial fishing activity in our waters and around the world. Our seamounts support large populations of commercially valuable fish species, including orange roughy. The Niwa study found that when the fishery discovered a seamount, it was fished intensively until catches declined and adjacent seamounts were discovered and exploited.

Trawling is the most common method of seeking out these commercially valuable species, and is particularly damaging to seamounts. The trawls scrape along the sea floor, netting targeted species, and other sea life such as coral and sponges indiscriminately. Their conical shape means seamounts can be trawled from most directions. Many show the scars of repeated trawling, with only a tiny proportion of their area untouched.

In recognition of declining commercial fish stocks, the Ministry of Fisheries has temporarily banned fishing from 19 of the seamounts, but this is a band-aid solution aimed more at conserving commercial fish stocks than endangered macro-fauna such as centuries-old true reef-forming deep-sea corals, primitive finned octopus species and species of large squid.

What is needed is the setting aside of some of the seamounts as reserves in perpetuity. Only then will these threatened species be given a chance to survive.

It is not just the ecosystem of the seamounts that is under immense pressure from the fishery but also areas of deep-sea soft-sediment communities, which are made up from the remains of foraminifera, single-cell organisms that sink to the sea floor when they die and make up a rich feeding ground for scampi and other commercially valuable species.

As with the seamounts, it is the other species of macro-fauna, some as yet undescribed by science, that suffer when these areas are fished intensively.

The Department of Conservation must recognise the importance of soft-sediment communities, which have no protection, despite their dire predicament.

If the aim of conservation policy is to set aside representative areas of our marine environment for protection, why are we not paying any attention to such rich areas of indigenous biodiversity?

The Government appears to be partly aware of the urgency of the situation and is developing an oceans policy to address, among other issues, the threat of species extinction in our waters.

A group of ministers chaired by Pete Hodgson, and including Phil Goff, Parekura Horomia, Marian Hobbs and Chris Carter, is charged with overseeing the development of the policy.

Citing a need for the integration of the sometimes conflicting laws pertaining to our territorial waters, and the lack of a clear statement of what New Zealanders value about the sea and coastline, it plans to release a public discussion paper by the end of the month.

When we compare the millions of dollars worth of profit that is taken from the sea every year with the scant resourcing for conserving a natural environment that is equally as important as the biodiversity found on land, we see a huge disparity.

If the Government is serious about conserving the natural resources of the sea, it must act quickly before more of this country's indigenous marine habitat, and the life it supports, becomes extinct.

* Dr Steve O'Shea is a senior research fellow in the Auckland University of Technology's earth and oceanic sciences research centre.