Employing eDNA to Characterize Winter Flounder Spawning Habitat and Inform Dredging Activities in Massachusetts

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.

As a marine organism interacts with its environment, DNA is shed into the surrounding seawater leaving a temporary, local signature of its presence. This environmental DNA (eDNA) can be isolated directly from seawater samples to determine which organisms are currently, or were recently present. The application of eDNA technology to the marine environment provides tremendous promise for monitoring species distribution and abundance with greater spatial and temporal coverage than is possible through traditional approaches. Improvement and advances in this technology will help to refine, automate, and extract more information from eDNA data for applications in marine resource monitoring and biodiversity assessment.

As a marine organism interacts with its environment, DNA is shed into the surrounding seawater leaving a temporary, local signature of its presence. This environmental DNA (eDNA) can be isolated directly from seawater samples to determine which organisms are currently, or were recently present. The application of eDNA technology to the marine environment provides tremendous promise for monitoring species distribution and abundance with greater spatial and temporal coverage than is possible through traditional approaches. Improvement and advances in this technology will help to refine, automate, and extract more information from eDNA data for applications in marine resource monitoring and biodiversity assessment.

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.

Result 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).

GMGI is developing eDNA technologies to assess overall biodiversity and to detect target fish and shellfish species in seawater samples from a variety of marine environments.