Oceanographic Effects of Offshore Wind Structures and Their Potential Impacts on the North Atlantic Right Whale and Their Prey

The Oceanographic Effects of Offshore Wind Structures and Their Potential Impacts on the North Atlantic Right Whale and Their Prey Report from the American Clean Power Association (ACP) presents a comprehensive and objective summary of the current state of knowledge on the effects of offshore wind structures on ocean circulation and stratification and their relationship to the distribution and density of copepods and the suitability of foraging habitat for the critically endangered North Atlantic right whale (NARW).

Some key takeaways include:

• The Western North Atlantic Ocean where the North Atlantic Right Whale (NARW) occurs is a highly dynamic physical environment consisting of three main oceanographic regions, each with a distinct oceanography: the Gulf of Maine, Mid- Atlantic Bight, and South Atlantic Bight.
• Recent shifts in NARW distribution and foraging habitat utilization within the Western North Atlantic have been observed and are believed to be associated with shifts in copepod prey distributions caused by warming sea surface temperatures related to climate change.
• Local or regional scale fragmentation of copepod aggregations has been observed and is projected to continue with subsequent declines in copepod abundance under future climate scenarios.
• Current foraging habitats may not support sufficient prey populations to allow growth of the NARW population based on the relatively low reproductive rate presently observed for NARW. As waters continue to warm due to climate change, current foraging areas may once again be abandoned as NARWs continue to shift their distribution in search of prey.
• Offshore wind farms can impact hydrodynamics in the surrounding ocean in two principal ways: 1) through an atmospheric wake effect that reduces wind speeds behind wind turbines that can reach the ocean surface, reducing surface wind stress and wind-induced currents, and 2) through subsurface mixing induced by the presence of the turbine substructure within the water column.
• Hydrodynamics and wind wake effects around offshore wind turbines are driven by physical ocean processes including tides, stratification, water depth, and wind-driven currents; and atmospheric processes such as turbulence and stability, all of which have significant natural variation.

Read the report to learn more.