The Northeast’s top fishing regulator says he’ll allow fishermen to boost next year’s catch by transferring over a portion of what they don’t catch this year. John Bullard said Thursday that fishermen can transfer up to 10 percent of their uncaught quota for bottom-dwelling groundfish species. The only exception is cod in the Gulf of Maine. Bullard said fishermen can transfer just 2 percent of unused quota on that species, since allowing more could cause overfishing on the species. The overall catch has been down this year, and fishermen are projected to catch well short of their allotments on several species when the current fishing year ends April 30. Bullard says this year’s poor catch proves fish populations are struggling. But some fishermen say the down year is just part of the natural cycle.