BOSTON — Gov. Deval Patrick is asking the federal government to raise the catch limit on a key fish stock.

In a letter today, Patrick asked U.S. Commerce Secretary Gary Locke to reset the catch limit on pollock “as high as possible while avoiding overfishing.”

Fishermen complain the pollock limit was set so low, they’ll quickly catch it and be forced out of the water for the rest of the year.

Pollock has become a key stock since tough new rules introduced strict catch limits for each Northeast groundfish species. If fishermen exceed their limit on one species, they must stop fishing for all species.

They’ve been pushing for an increase for months.

In his letter, Patrick cited preliminary results of a pollock study that indicate it’s not being overfished.