Employing eDNA to Assess the Presence and Distribution of Winter Flounder in MA Embayments

Photo credit Jennifer Polinski

Winter flounder (Pseudopleuronectes americanus) spawn during winter and early spring months in New England embayments where dredging projects often occur that are vital to maintain and improve navigational waterways for the growth of coastal community economies throughout Massachusetts. To protect winter flounder spawning success, NOAA and MA DMF apply strict precautionary time of year (TOY) restrictions for dredging activities for up to six months of the year because turbidity and burial caused by dredging can lead to mortality in demersal eggs. However, detailed information regarding the timing and location of spawning within embayments is currently lacking, which may cause these regulations to be unduly restrictive for dredging activities. To address this, we are using eDNA technology, which measures genetic material shed by an organism into the surrounding water, as a simple and inexpensive approach to gain a detailed understanding of winter flounder spawning behavior in six Massachusetts coastal embayments. In a collaborative project with MA DMF, we are intensively sampling water from several sites within three embayments along Cape Cod Bay and three embayments off of Nantucket Sound over the period of a year and screening for the presence of winter flounder DNA.

Results will provide detailed information on winter flounder spawning habitat that can guide where and when time of year restrictions should be applied on dredging activities in Massachusetts embayments. Our goals are to better refine the timing of arrival to embayments for spawning (i.e., identifying appropriate start of TOY period) and the areas within embayments where spawning activity is concentrated (i.e., identifying appropriate embayment locations and habitats for TOY applications).