Wind farms within inner shelf regions of the southern Mid-Atlantic Bight (DelMarVa region) will greatly increase the amount of structured habitat for coastal fishes. Installed wind turbines present permanent (decades) impervious structures, which can alter movement behaviors by fishes and the fisheries associated with impacted species. Fish concentrations surrounding oil rigs are but one example of how artificial structures can influence both fish and fisheries. We hypothesized that many coastal migratory fishes currently use southern Mid-Atlantic Bight shelf waters as a migration corridor, but that fields of wind turbines in this relatively “featureless” region could alter behaviors of migratory fishes causing them to dwell on high relief wind turbine structures.
The objective of this project was to measure seasonal transit and habitat occurrence of striped bass and Atlantic sturgeon in relation to depth, temperature, and other oceanographic and benthic variables in and adjacent to the Maryland Wind Energy Area (MD WEA). We used biotelemetry deployed in a beforeafter-gradient design centered in the Maryland Wind Energy Area to gather baseline measures of seasonal patterns of migration by Atlantic sturgeon and striped bass and model their incidence against gradients of depth, temperature, and other oceanographic variables. This study leverages recent and concurrent telemetry studies in NW Atlantic shelf regions and the availability of hundreds of acoustically-tagged striped bass and Atlantic sturgeon. Specific objectives included (1) two-year deployment of an extensive telemetry receiver array within the MD WEA and adjacent shelf reference regions; (2) analysis of patterns of incidence, transit, and depth; (3) development of predictive habitat models for the MD WEA shelf region; and (4) extensive data sharing through the Atlantic Cooperative Telemetry Network and the MidAtlantic Telemetry Observing System.
In triannual cruises beginning November 2016 and ending December 2018, we deployed, maintained, and retrieved 20 VEMCO VR2AR Acoustic-Release receivers in the test MD WEA array. We deployed additional receivers at two sites to test receiver detection distances for the period December 2017- December 2018 under different oceanographic conditions. To augment tagged coastal striped bass available for detection, 40 large striped bass were surgically implanted with depth-transponding transmitters. Environmental data for the array was compiled from receiver-logged bottom temperature and noise levels and from NOAA buoys, and remote sensing platforms. Patterns of seasonal species incidence and environmental dynamics were analyzed together with transit rates between the MD WEA and DE Wind Energy Area. Incidence data was transformed into relative density based on modelled detection probability across seasons and strata. Generalized Additive Mixed Models were developed to predict the relative density and weekly residence of striped bass and Atlantic sturgeon based on environmental features of the MD WEA.