When May 1 rolls around this year, commercial fishermen in New England will get something that they haven’t had in a long time: Good news.

Following one year of a new management program that divides the right to catch fish among cooperatives of fishing boats called sectors instead of limiting individual boats’ days at sea, the Department of Commerce is increasing the catch limits on 12 different groundfish stocks.

The new limits are evidence that after many years of overfishing followed by years of harsh regulation, the fish populations are rebounding. They also show that the new sector management program has been a success, and that what has been good for the fish is also good for the fishermen, offering hope to a beleaguered industry.

The new rules are not universally loved and are under challenge in court from two Massachusetts communities, New Bedford and Gloucester, which charge that the old system was fairer. While some parts of the industry may have done better under the old system, it’s also true that it was not successfully conserving the fish or offering a sustainable basis for the industry as a whole. Mainers interested in a sustainable fishery should encourage federal authorities to fight the lawsuits and protect the new system that is showing signs of progress.

Regulators under the days-at-sea system told fishermen what they could not do: It limited when they could go out, how much they could catch in a day and where they could set their nets.

Sector management lets fishermen decide when and how they fish, as long as their catch does not exceed proscribed amounts.

Fishermen have a share of a quota, which they can fill themselves or sell to another boat. When prices are low, they can stay home.

When the fish move out of their area, they can sell or trade part of their quota to a fisherman who could catch them. When they near their quota on one species, they can switch to another that is more plentiful.

This year under sector management, some fisherman made more money even though they caught fewer fish, because they could better time when they brought their catch to market.

Knowing how much they can expect to catch for the year, the fishermen can manage their share to their advantage. The lack of restriction on days at sea gives them the flexibility to experiment with different techniques that may be more efficient in the long run, but would never be tried when precious days at sea were the only currency that mattered.

Still, there are those who out of limited self interest are willing to toss out the system instead of trying to improve it, and want to return to the days-at-sea management style that was quickly putting Maine’s commercial fishery out of business. Few businesses could expect to operate successfully only 40 days a year, and that’s what local fishermen would be looking at if sector management were overturned.

And the wasteful techniques forced by the days-at-sea approach, like dumping excess catch overboard one day and going out to fish again the next day, were preventing the fish stocks from rebounding fast enough to help the fishing economy.

The goal can’t just be the short-term survival of a few elements in the industry. It should be a sustainable fishery that will continue to grow along with the fish stocks in the years to come.

The fishing communities of New England have already sacrificed too much for this science-based management program — which is already showing signs of working — to be abandoned.

This year’s increase in catch allotments is the evidence. It is the first good news in a long time, but it doesn’t have to be the last.

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