Feature

The state of our oceans

Trawl catch

A trawl catch.

Credit: Mike Gerner/AFMA

Scallop dredge

A scallop dredge after being dragged along the bottom of the sea floor.

Credit: Mike Gerner/AFMA

Tuna in tow

A school of Southern bluefin tuna swim in a tuna fishery tow cage.

Credit: Getty images

Japan Tuna Market

Fishmongers check the quality of meat on frozen tuna fish before trading at Tokyo's Tsukiji fish market.

Credit: Getty Images

Hammerhead killed in net

A hammerhead shark is fatally caught in a gill net.

Credit: Getty Images

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The Aussie industry

"Australia probably has one of the best management systems in the world and, in many cases, our fish stocks are in good shape,'' says Hunt. "One of the reasons for that is that we have institutions in place to manage the fisheries. But managing a fish stock sustainably is one of the hardest things in the world to do.''

In Australia, the state and Northern Territory governments are responsible for managing fisheries up to three nautical miles off the coast. Beyond there and out to 200 nautical miles, the federal government takes responsibility.

In terms of what we catch, in 2009 fisheries in Australia produced 173,000 tonnes of wild fish, crustaceans (crabs, prawns) and molluscs (abalone, squid, scallops).

The top three states for the commercial wild-caught fishing industry in 2009 were South Australia (38,205 tonnes), Western Australia (25,311) and Queensland (24,891) with Commonwealth fisheries contributing another 51, 416 tonnes to the haul.

The most abundant of Australia's wild fish catch is surprisingly the humble sardine. Some 31,500 tonnes of them were caught last year, accounting for about 13 per cent of all the seafood caught in Australian waters, but almost all are either exported or used as food in fish farms.

In 2008/09, some 193,000 tonnes of seafood was imported with three quarters coming from China, New Zealand, Thailand and Vietnam. Australia also exported almost 47,000 tonnes of seafood with more than half going to Japan and China.

Even though Australia's fisheries are acknowledged as being managed to ecological principles, a review of reports from federal and state managers still reveals problems. To assess the sustainability of a fishery, researchers look at the population number of each species in the water - known as the biomass - and then compare this to catch rates.

If the species is being fished too quickly for it to recover, it's considered to be subject to overfishing.
Overfished means the stock itself is already over-exploited or "the biomass is inadequate to sustain the stock in the long term".

Fish stocks managed by the Australian Government are placed into six classifications: overfished, not
overfished, uncertain if overfished, subject to overfishing, not subject to overfishing, uncertain if subject
to overfishing.

Of the 101 different types of fish assessed, 15 are overfished and a lack of information means the government is uncertain about a further 30. There are also 10 fish stocks that are currently subject to overfishing with uncertainty surrounding another 18.

States and territories also produce summary reports of their fisheries and how they're managed but comparisons are difficult because they don't all report in the same way and classifications differ.

Wildlife casualties

Fishing boats scouring the oceans for food have an array of ingenious methods to lure and catch the seafood that makes it onto our plate. Sophisticated nets and gears are deployed with many fishing boats equipped with sonar and GPS technology and accompanying helicopters to help them locate seafood. Mobile gears, such as trawlers, drag nets along the sea bottom to chase the fish. Static nets hang in the ocean at different depths and long-lines can stretch several kilometres with hundreds of hooks attached. Then there are the various pots used to catch lobsters and crabs.

"With all forms of fishing there's always going to be incidental catches and that is termed bycatch,'' explains Peter Horvat of the Commonwealth Government Fisheries Research and Development Corporation (FRDC). "Anything which is brought up but wasn't targeted is classified as bycatch." The term bycatch can apply to any fish that the boat isn't licensed to catch on a particular day, including undersized species, other fish and animals such as dolphins, seabirds, dugongs, turtles, sharks and even crocodiles.

CSIRO fisheries scientist Tony Smith says that it is unfair to conclude that one method of catch is any better or worse than another. "There are of course some methods we don't allow in Australia, such as dynamite fishing or poisoning that do occur in some parts of the world. But you have to look at what's happening on a case-by-case basis - just because it's caught by a certain method that does not mean consumers should automatically disregard it. Some people will say that anything caught by a trawl net is unsustainable, but I
wouldn't agree.''

Greenpeace oceans campaigner Genevieve Quirk counters: "Bottom trawling can destroy the ecosystem on which fish depend. A fishery with a future does not bottom trawl. Marine reserves are urgently needed to protect biodiversity decimated by trawling and to replenish overfished stocks."

An example that shows just what is at stake is that of the Australian sea-lion. An endangered species according to the International Union for the Conservation of Nature (IUCN) and listed as threatened by the Australian Government, the sea-lion has been particularly affected by gillnet fishing. Sea-lions like to forage for food on the ocean floor, sharing that space with commercial gillnets that are placed to catch shark and other species.

A report to the FRDC earlier this year estimated some 374 Australian sea-lions are killed by gillnets in each 18-month breeding cycle. Sea-lions also drown, the report explained, after getting their heads stuck in lobster pots, although experiments with different designs can reduce the death toll. "These results,'' the report said, "indicate that the majority of Australian sea-lion subpopulations in South Australia are presently exposed to unsustainable levels of bycatch mortality. If current levels and distribution of fishing effort are not modified, further population declines, subpopulation extinctions and reductions in range are likely to occur."

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