A new set of fishing rules promises to use the best available science to determine how many pounds of fish from each species can be caught allowing the populations to rebuild.

It also creates a new method of sharing the catch that gives fishermen the flexibility they need to maximize their earnings by controlling when and how they fish.

The biggest threat to the new system, however, is not biology or economics. It’s politics.

Pressure to increase the amount of fish that can be caught or to cut back on the monitoring necessary to make the system work will mean that this effort, like those in the past, is doomed.

These new rules, which went into effect Saturday, have a chance to work, but they will need time and resources. Fishermen, environmentalists, regulators and people who care about saving a traditional industry in coastal Maine all have an interest in this effort’s success.

OLD SYSTEM FAILED

One thing that is clear is that the previous regimen, which limited a vessel’s days at sea, did not work. Not for the fisherman or for the fish.

While some species are making a comeback, most are still declining after decades of intensive management. And nothing is disappearing as fast the fishermen themselves. While there were 350 boats in Maine 20 years ago, there are only about 65 now.

With the loss of active fishing vessels go jobs — on the boats and on the shore in businesses that serviced them. Further decline would wipe out that infrastructure, meaning that there would be no local industry to benefit when the fish stocks rebuild.

The old rules created the wrong incentives for fishermen. Limiting the catch by limiting days at sea and daily catch encourages wasteful practices, like discarding thousands of pounds of fish one day, and then going out for more the next. It also pushes fishermen to steam long distances, fish when the price is low or when conditions are unsafe just so they don’t miss their opportunity.

The new rules encourage fishermen to organize themselves in sectors, or co-operatives, where they would be given a catch allocation for each species based on their record in previous years. It’s up to the sectors to manage those allotments, and they can focus efforts to maximize fishing time when prices are high.

The key to the program is monitoring by federal officials, who will go out with different boats in the fleet and get the best data about fish stocks that will not only track progress in conservation but will give fishermen information they can use to be efficient.

Flexibility will also take some time pressure off fishermen and allow them to experiment with different gear and techniques that may help them find practices that use resources more efficiently. It will also give them the opportunity to go after healthier stocks at times when they have filled their quota of weak ones.

EXPERIENCE ELSEWHERE

Experiences in other fisheries indicate that this will take some time to work. The initial catch limits are low, based on the current health of the stocks, and fishermen will have to figure out how to use them efficiently. Boosting the quotas for political reasons would just slow down the rebound and threaten both fish and fishermen.

There is also a real risk that the fishermen who do not opt into sectors will continue to overfish and slow the progress.

Tight limits on catch and careful monitoring of fish populations are what’s needed to bring the fishery back to health. Along with time, they are the ingredients of success.