Offshore Wind Power Projects in the Great Lakes - Ministry of ...

Offshore wind power projects in the Great Lakes: Background and science considerations for fish and fish habitat
sediment dynamics, for example, might also be useful to aid predictions of local, far-field, and
potential long-term impacts from wind turbine installations. However, measurements conducted
in the field will still be necessary to ground-truth or confirm the results of predictive models.
Although supplemental studies can be undertaken to better quantify or predict the response of
fish species to the impacts of offshore wind power projects, it is always important to
acknowledge their respective limits and applicability.
Unfortunately, individual proponents are not likely to conduct independent studies beyond the
project-specific monitoring required of them through their licensing agreements. For this reason,
there is both a clear need and a unique opportunity for university or other government funded
institutions or groups (with potential industry collaboration) to undertake supplementary
laboratory or mesocosm-type studies to investigate species-specific responses to various wind
power project related stressors. As a starting point, basic laboratory studies to assess the
sensitivities, behavioural and physiological thresholds of Great Lakes fish species to stressors
like noise and electromagnetic fields have yet to be conducted on a large scale. These types of
studies are relatively straightforward, but the knowledge gleaned by conducting them can help to
guide environmental risk assessments for offshore wind projects, and steer appropriate mitigation
measures. Subsequently, mesocosm-type studies similar to those conducted for marine fish can
also enhance our understanding of and ability to predict the impact that these novel stressors
could have on representative Great Lakes fish species.
For example, many studies investigating the physiological effects of pile driving noise on marine
fish species have involved holding fish in enclosures at increasing distances from the sound
source and examining them after exposure. These types of in situ studies can improve our
understanding of the physiological effects that pile-driving noise has on different species of fish
at varying distances from the source, and under different site conditions including depth,
substrate type and wave or current strengths. In addition, similar experiments to those in which
caged fish were exposed to pile driving noise both with and without sound attenuation measures
employed can demonstrate the ability of different mitigation options to reduce harm to fish.
However, in order to avoid some of the problems identified with these earlier studies, it is critical
that sound pressure levels be recorded at each exposure distance, that fish are handled and
Aquatic Research and Development Section 93