Portland’s fish exchange is in trouble, and city officials have asked for help from fishermen to keep the municipally run auction house alive.

They are on the right track: The fish exchange is a vital cog in maintaining a local commercial fish industry, and its function of providing a way for fishermen to sell their catch directly to the highest bidder has been a boon for fishermen over the years and will be again if fish stocks rebound.

But city officials are looking for help in the wrong place. What’s left of Maine’s commercial fishing industry is fighting for survival, and boat owners can’t be expected to take further financial losses to support an institution now, no matter how important it might be to its long-term future. This is a case where the state should step in and play a bigger role.

There are financial disincentives that have driving boats away from Portland and to the fish auctions in Gloucester and Boston, Mass.

One is the Maine law that prohibits fishermen from landing the lobsters that are caught incidentally in their nets, known as “bycatch.” Massachusetts does not have such a law and its fishermen benefit.

Another is Gloucester’s location nearer the Georges Bank fishing grounds and to market. Fishermen spend less time at sea bringing their catch in.

An attempt to change Maine’s bycatch law proved to be a political nonstarter because it pitted the economically weak groundfishermen against the robust and politically powerful Maine lobster industry. And no policy maker can do anything to change the distance of Portland to the fishing grounds.

But there are things that can be done at the state level that would preserve this vital institution while waiting for fish stocks to rebound.

Massachusetts fishermen do not have to pay a fuel tax, which makes sense because their boats don’t add to wear and tear on roads or bridges. In Maine that tax is not waived, giving fishermen another reason to base themselves elsewhere.

Waiving the tax would be a small gesture by the state to give Maine fishermen one less reason to head to Gloucester.

The industry is clearly suffering. Catch limits designed to help threatened fish stocks to rebound are driving many out of business.

But it’s also important to preserve the industrial infrastructure so that Maine will reap some benefit from this sacrifice. The fishermen are already struggling, so it will take state help to save the fish exchange.