Abstract
The first offshore wind farm in North America, Block Island Wind Farm (BIWF), was built on a pilot scale (five 6 MW turbines) approximately 5 km southeast of Block Island, Rhode Island. Potential effects of the BIWF on dietary habits were examined for fish collected in a trawl survey conducted monthly over 7 years (October 2012 to September 2019). Stomach content analysis was conducted on 3457 flounder, gadids, and black sea bass collected near BIWF and in 2 reference areas during baseline, construction, and operation time periods. Other trophic metrics such as fish condition, stomach fullness, and % empty stomachs were examined for an effect of wind farm operation. Temporal variation in trophic metrics was more common than spatial differences, with no consistent indication of an effect of wind farm operation across metrics or species. Prey accumulation curves indicated that diets were adequately characterized with sample sizes of approximately 40 stomachs for most time period by area combinations. Diet composition of hakes and flounder in all areas included a greater proportion of mysids and amphipods during the wind farm operation time period. Summer flounder and winter flounder condition was lower during the operation time period in all areas. Inclusion of mussels and associated epifauna (mysids) in fish diets following turbine installation indicate fish forage on the colonized turbines. Although substantial changes to fish diets were not evident at BIWF, cumulative trophic effects of larger wind farms should be examined as the offshore wind industry expands on the northeastern US coastline.