Strong protective measures are required to protect critically endangered North Atlantic right whales and other marine wildlife during offshore wind survey activities.
We need offshore wind, and we need to do it right. Offshore wind will help eliminate dangerous greenhouse gas emissions, promising healthier air as well as thousands of well-paying clean energy jobs. But as we fight climate change, we can and must avoid, minimize and mitigate threats that offshore wind development also poses to vulnerable ocean life.
Protection for our valuable marine wildlife is important at every stage of offshore wind development – from site assessment and characterization through construction and operations to decommissioning.
Overlap Between Geophysical Surveys and Marine Mammal Frequencies
A lot of attention is given to offshore wind construction, but site assessment and characterization activities can have serious impacts as well. Before offshore wind turbines can be placed, developers need to map the seabed using a geophysical survey. Geophysical surveys involve the collection of data using sonar to create a map of the seafloor and geological layers beneath. Surveys help determine the characteristics of a specific area, such as water depth, sediment types, presence of archaeological sites and potential hazards such as shipwrecks or other obtrusions. The resulting maps help offshore wind developers determine available options for cable routes, pile driving locations, mooring conditions, foundation type and turbine layout.
Some of the soundwaves used in geophysical surveys overlap with frequencies for marine mammal hearing, meaning they can be detected by these animals. Noise exposure from geophysical surveys has the potential to damage the hearing and sensory abilities of some species if they are close to the source of the sound when it occurs. Disturbance from noise can also cause stress and negative health effects, and drive animals from preferred feeding and breeding areas or known migratory paths. Survey vessels travelling at fast speeds also pose a lethal risk of collision, particularly for large whales. Vessel collisions are one of the primary factors driving the North Atlantic right whale to extinction.
Source: NRDC (Natural Resources Defense Council), United States