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
detection of changes in local invertebrate and fish community assemblages in response to the
presence of wind turbine foundations.
The amount of time required for recently disturbed or newly developing ecological communities
to undergo succession and reach a state of biological equilibrium can be substantial, especially in
north temperate freshwater ecosystems. For example, based on long-term studies of succession at
artificial reefs in marine systems, it has been estimated that the time frame required to develop a
progressed community can be well over a decade, even in tropical ecosystems (Perkol-Finkel &
Benayahu 2005). Furthermore, the ability to detect changes in nearshore Great Lakes fish
abundance in response to anthropogenic disturbances usually requires many years of sampling
prior to and after an impact (Lester et al. 1996). Thus, while construction-phase effect
monitoring will require more focussed or continuous sampling efforts timed around specific
activities, operational phase monitoring, and the ability to detect long-term changes in the
distribution and abundance of fish or gradual changes to benthic habitat features or community
composition will require that investigators undertake ongoing sampling efforts over multiple
years post-construction. For example, in order to systematically test the benefit to fish
populations of potential no take areas for fisheries within wind power project areas, or owing to
the artificial reef effect that may arise from turbine foundations, it has been noted that monitoring
over longer time periods of 5-10 years will be required (Linley et al. 2007).
A minimum of three years of post-construction monitoring has been recommended or undertaken
for other offshore wind turbine installations (BSH 2007; Kjaer et al. 2006; MMS 2009).
However, the considerable uncertainty that exists as to effects of offshore wind power projects in
the Great Lakes would suggest that some form of monitoring should be maintained throughout
the operational lifetime of a project. The three year minimum adopted for wind power projects in
marine systems has been inadequate for documenting effects to fish distribution, population
dynamics and recruitment, and contributes to the considerable knowledge gaps that remain
despite the existence of offshore wind farms in Europe for over a decade. To address this
uncertainty, while at the same time recognizing that different effects will manifest over different
time scales (i.e. from days to decades), agencies could consider requiring intensive monitoring
seasonally for 3-5 years post-construction, but then follow-up by requiring less intensive
monitoring at intermittent periods (e.g. every 3-5 years thereafter) for the duration of the project.
Aquatic Research and Development Section 60