Fishers in the Northeast grudgingly celebrated a victory yesterday when federal regulators and environmental groups agreed to put a nine-month freeze on new regulations that will dramatically limit fishing when enacted. The National Marine Fisheries Service has been hearing it from all sides — fishers have argued that any tougher rules will devastate their industry, while environmentalists have said that fishing limits up till now have not helped replenish depleted stocks. Fishers gained some ammunition when the NMFS admitted recently that some of its research gear had been faulty in the last two years. Last week, however, the agency said that the gear problems should not cause doubt on its conclusion that fish populations were plummeting. Enviros hope the nine-month cool-off period will give the two sides adequate time to agree on the science, but fishers had been pushing for a two-year delay in the regulations.