Spatial variation in habitat associations for monkfish (Lophius americanus V.) in the northwest Atlantic

The monkfish, Lophius americanus V., is an important commercial species in the Northwest Atlantic which is broadly distributed across the continental shelf and slope from Cape Hatteras, North Carolina to the Grand Banks of Newfoundland. We investigated habitat associations for monkfish based on data collected during annual spring and autumn bottom trawl surveys conducted by the NOAA Northeast Fisheries Science Center (NEFSC) from 1968-2008. Cumulative distribution functions (CDFs) were used to characterize and compare available and occupied thermal habitat for monkfish in the Gulf of Maine (GOM) and Southern Mid-Atlantic Bight (S-MAB). Distributions for available and occupied bottom temperature and depth were also compared for two time periods, 1968-1978 and 1998-2008, to investigate changes in habitat association's overtime. Monkfish in the GOM occupied similar temperature and depth distributions for both spring and autumn surveys and the two time periods. In the S-MAB, monkfish occupied cooler temperatures in autumn and warmer temperatures in spring than those available within the habitat during the surveys and two time periods. Available habitat in the GOM may reflect the preferred ranges of temperature and depth for monkfish. Variation in the distribution of available habitat in the S-MAB may trigger interannual changes in the habitat associations of monkfish.