Genetic Evaluation of Population Structure in Tautog

Abstract

Tautog Tautoga onitis supports both recreational and growing commercial fisheries from Virginia to Massachusetts. Tautogs, which aggregate around structured habitats (wrecks, rocks, bridge pilings, etc.), are slow to mature and have a low reproductive rate relative to other teleosts. Slow growth and easy catchability result in Tautogs being extremely vulnerable to overexploitation, and their populations are slow to rebuild. At present, Tautogs are managed by the Atlantic States Marine Fisheries Commission as four separate regions: Massachusetts–Rhode Island, Long Island Sound, New Jersey–New York Bight, and Delaware–Maryland–Virginia, despite a lack of genetic information to support this management scenario. The objective of the current study was to investigate the genetic connectivity of Tautogs throughout their management zone and provide stock structure information in support of fisheries management. We developed and used 18 variable microsatellite loci to evaluate the genetic structure of 789 Tautogs sampled across their effective U.S. East Coast range from Massachusetts to North Carolina. We also amplified and sequenced a 1,267 base pair portion of the mitochondrial DNA control region from Tautogs sampled from Massachusetts and Virginia. Comparison of pairwise FST values among samples collected from locations south of Cape Cod, Massachusetts, were low and nonsignificant, suggesting that gene flow is sufficient to prevent the accumulation of genetic differences. The collection from Cape Cod Bay, Massachusetts, was genetically distinct from all other samples (FST = 0.021 to 0.046), indicating that Cape Cod is a significant barrier to dispersal for Tautogs and suggesting that Tautogs north and south of Cape Cod should be managed as separate stocks.