The beauty about New Zealand's quota management system for commercial fisheries was that it would be self-policing, in theory. Once fishing companies were allocated a quota that could be traded, they would have a financial interest in the future of the fishery.

Therefore, it would be in the interest of each owner of a quota to catch no more than it was allowed and thus ensure the resource could be sustained and the quota would hold its value. It was also in the interest if each of them to see that all obeyed the rules. So they jointly set up a company that is contracted to police their catch.

This system has come under severe criticism this year following academic research that estimates fishing companies are catching more than twice their quota of some species and dumping the excess at sea. Even dumping filmed by CCTV cameras on board boats had not resulted in prosecution of their skippers by the Ministry for Primary Industries.

The ministry commissioned an inquiry into its decision not to prosecute and the report by Michael Heron QC has found its procedure "confused" and the decision "flawed".


Unsurprisingly, many are saying the whole system is flawed, questioning the wisdom of giving the policing task to an industry-owned company ("putting a fox in charge of the chicken coop") and calling for a ministerial review or a commission of inquiry into the quota management system.

Those who have called for a rethink include the author of the dumping study, recreational fishing lobbyists, Greenpeace and opposition political parties. But not all of them want to dump the quota management system and none of them have offered an alternative.

The obvious alternative, of course, is to employ an army of inspectors and put one on every boat every time it is hauling up a net, and ensure the on-board cameras are in a position to film any discarding of fish. It would seem obvious too that any dumping should be prosecuted and the skippers fined. But would any of this make much difference to fishing practices or the conservation of the resource?

It would not solve the basic problem that commercial fishers cannot control how many fish swim into their net. None of them will have been deliberately pulling up far more fish than they are allowed to land and sell. They are not fishing for fun.

As the ministry's director of fisheries management said in an internal email turned up by the Heron inquiry, "If we found the golden bullet to stop discarding we would probably put half of the inshore fleet out of business overnight."

Decisions to prosecute should not lose sight of the purpose of the regulations. The goal is not primarily to stop dumping - recreational fishers know too well they catch a lot of throw-backs and not all survive - the goal is to maintain fish stocks.

Commercial fishing quotas reflect an assessment of the stock that is based largely on the catch. It is vital, therefore, that the whole catch is reported, including the numbers dumped. Those urging prosecution in every case should keep their eye on the prize. Co-operation better serves conservation.