Abstract Objective The range of American monkfish (the commercial name for Goosefish) Lophius americanus in northwest Atlantic Ocean waters extends from the Grand Banks and the northern Gulf of St. Lawrence to at least North Carolina and includes both shallow inshore and offshore waters. Its fishery in the USA has been assessed and managed as two distinct units since the inception of its fishery management plan in 1999, with the boundary between the two management units being Georges Bank. However, biological data supporting this division are largely lacking. Our objective in this study was to use a genetic approach, microsatellite DNA analysis, to determine if monkfish constitute a single or multiple genetic stocks over almost their entire coastwide distribution. Method American monkfish-specific microsatellite loci were identified and 11 loci were genotyped in 2,395 monkfish specimens from 19 different project strata collected in 2013 and 2019 from Atlantic Canada to North Carolina through the combined efforts of a network of commercial fisherman and dealers, governmental trawl surveys, and academic institutions. Results Moderate levels of allelic diversity were observed across all loci; however, we failed to find significant genetic differentiation among any of the collection areas or between combined collection areas north and south of the stock boundary line bisecting Georges Bank. Conclusions The most parsimonious interpretation of our microsatellite data is that American monkfish constitute a single genetic stock across their entire coastwide distribution. Therefore, our results do not support the current practice of managing monkfish as two distinct stocks, although it would be prudent to further investigate this question with an even more sensitive approach, single nucleotide polymorphism analysis.
Wirgin et al. (Sun,) studied this question.