The imminent arrival of one of the world’s largest fishing trawlers in Australian waters has set off howls of protest from conservation groups — but they may only have themselves to blame.

The supertrawler Margiris, at 140 metres the largest fishing vessel ever to work in Australian waters, is expected to arrive in Tasmania within weeks. Opponents warn the factory ship will deplete fish stocks, damage the environment and squeeze out smaller fishing operators (including recreational fishermen).

The public has every right to be concerned that this factory ship will drag an unimaginably huge net across the seafloor, possibly catching and drowning seals and dolphins, while perhaps dumping tonnes of fish for which there is no quota. It’s a type of vessel more suitable for trips of months in remote waters when there is no access to shore-based processing — not for coastal fishing.

But the supertrawler’s arrival is the logical and direct result of 20 years of fisheries reform that has been heartily backed by many of the green groups now protesting so loudly.

Authorities used to conserve fish stocks by “boat management” — restrictions on gear used, and the areas and seasons in which people could fish. The system has been reformed towards “catch management” (also called “quota management”), where total allowable catch is capped and transferable, with operators free to accumulate quotas and fill their quotas however they like. This has encouraged large operators to buy up quotas and dominate the market — and led to one massive supertrawler wending its way towards Tasmanian fish stocks.

The writing was on the wall for smaller fishing operators once this policy reform process was put in place. Economists might like it, and see the dominance of big players and big vessels as more efficient, but it has wreaked significant damage on the industry.

Gerry Geen, the director of SeaFish Tasmania, was a fisheries economist who played a key role in the introduction of quota management in Australian fisheries and is now part of the industry he helped establish. His company is bringing the Margiris to Devonport, Tasmania, in a joint venture with the ship’s Dutch owners, to fish for redbait and jack mackerel.

Setting fishing quotas and strictly limiting catches to prevent overfishing was sold to the Australian public and conservationists by scientists, economists and bureaucrats. For scientists it promised a massive increase in research dollars for a huge variety of species. The management bureaucracy expanded too, with all costs recovered from the industry and passed through to the price of fish.

Recreational fisheries have also been identified for future quota management. Now the recreational fishing sector is leading the protests against trawler.

Improving the economic efficiency in fisheries, replacing small so-called “inefficient” owner-operators with corporate owners and large boats, has been the aim from the outset. But was the small-fry nature of the industry ever really a problem?

Just one trawler can land 5% of the total allocated catch for a given species, but that it is apparently sustainable in the view of SeaFish Tasmania, the Australian Fisheries Management Authority, and marine scientists who have the job of estimating how many fish are in the sea — estimates we “should have faith in” according to Geen.

Extraordinarily, the implementation of quota management does not include habitat associated with the marine environment.

And in a bizarre twist, as the amount of fish caught declines under quota, the actual value of fish increases by more than that decline — making local fish very expensive to the public while also limiting their choice.

The underlying issue for the public, however, is the massive loss of jobs that fisheries reform has caused. It was not long ago that there was a multimillion dollar buyout of hundreds of licences, itself representing many hundreds of jobs lost. But the total quota was not reduced.

Fisheries economists only value the landed catch, not the jobs in crewing, building and maintaining boats or transporting, processing and retailing fish. Then there is the additional value of local fresh-caught fish in retail, so obvious in Hobart. The economic impact and job losses from Australian fisheries management reform has been grossly underestimated.

We the public, especially marine green groups, surely must share some of the blame. We have been quick to demonise the small-boat trawl industry for its apparent unsustainability, while lauding fish farming. Yet the environmental cost of the modification of seabed to make trawl grounds for small boats should be compared to that of factory farming. Even organic farming needs all the native vegetation cleared, while conventional farming uses a wide range of agricultural chemicals and fertilisers — pollutants at sea.

The arrival of this trawler perhaps highlights too the state of Australian fisheries management. Fishermen can neither land nor confess to dumping perfectly good fish, even when dead, that they have no quota for, for fear of being fined, losing their licence or even having their fishery closed.