Fisheries Minister Joe Ludwig and Environment Minister Tony Burke are seeking advice on whether to allow the Abel Tasman super trawler to act as a factory ship. Seafish Tasmania aims to skirt the fishing ban on the super trawler by contracting smaller Australian-licensed trawlers to bring the small pelagic fish, caught under quota, to it for processing.

Before a decision is made on whether or not to allow transhipment at sea in the Small Pelagic Fishery, the fisheries management authority is seeking comment from interested stakeholders.

While there is some dispute over the sustainability of the quota in the Small Pelagic Fishery, the quota was approved by scientists. The real issue that led to disallowing the Abel Tasman from fishing was the death of protected Australian fur seals (Arctocephalus pusillus doriferus) in the trawler’s nets.

Seals are attracted to an easy feed: trawler nets provide this. While seal exclusion devices (SEDs) are fitted to nets, some seals inevitably fail to escape and drown.

However, the small trawlers will likely kill more seals – for the same tonnage of small pelagics – than the large Abel Tasman would have. While the super trawler’s net would have trapped seals, it would have been more effective at reducing seal deaths because of design improvements made to it compared with the devices fitted on the smaller trawlers.

Underwater cameras have shown that more seals meet their demise in mid-water trawl nets of the small trawlers than was previously thought. This is because the dead ones roll out of the net unseen during hauling. There is considerable scope to further refine the orientation, size and scope of seal exclusion devices. But crucial trials to find optimum devices have not taken place, due to lack of funding.

Bycatch is not a plausible reason for selectively banning the Abel Tasman. The Commonwealth’s South East Trawl Sector, with many more vessels, is already far more destructive than the Small Pelagic Fishery.

The South East Trawl Fishery interacts strongly with – that is, kills – the protected Australian fur seal and, to a lesser extent, the Australian sea lion (Neophoca cinera). This species is listed as vulnerable under the EPBC Act.

Between 1993 and 2000, the Scientific Monitoring Program suggested that an average of 720 fur seals are caught incidentally by the small trawl vessels in the South East Trawl Fishery each year. (The Abel Tasman, had it been allowed to fish, would have had its activity suspended any time it caught three fur seals.)

Compared with large vessel operators, who are well resourced, the operators of the smaller vessels or “wet-boats”, are constrained in applying mitigation methods such as seal exclusion devices. Recent trials of a flexible SED design have been relatively successful, but reliably estimating and reducing the level of interactions between seals and wet-boats remains an issue.

Conservation groups have been slow to grasp the South East Trawl nettle. Perhaps they are worried about the consumer backlash if flathead supplies to Sydney and Melbourne were diminished. There was no such risk in calling for a ban on the super trawler catching sardines for export.

The factory ship operation will be economically efficient in allowing the small feeder vessels to continuously fish. Moreover, it will be sustainable in the sense that the quota is very conservative, compared with other Commonwealth fisheries, representing only a small fraction of the biomass of the small pelagics.

If the factory ship is banned, consistency demands a moratorium in mid-water trawling elsewhere.

If there is no ban then there will be seal deaths. But this would be more acceptable if it was accompanied by the announcement of a major effort by the Commonwealth to seriously address the issue of bycatch in its trawl fisheries.