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

Offshore wind power projects in the Great Lakes: Background information and science considerations for fish and fish habitat
Table 4. Summary of the types of scientific investigation that can be undertaken to elucidate the effects of offshore wind power projects
on Great Lakes fish and fish habitat, highlighting the usefulness and limitations of each approach. Options are presented in an order of
increasing cost and effort, reflecting a subsequent increase in the amount and value of information that can be acquired.
Type of investigation What can be learned
Desk-top study (literature
review, review of
relevant fisheries survey
data)
Modelling studies
• Identification of potential impacts and/or benefits of offshore
wind power projects to fish and fish habitat; areas requiring
further investigation
• Population status and trends of Great Lakes fish species of
economic or ecological importance; general information on
distribution or habitat use; sensitivities of representative
Great Lakes taxa to certain impacts
• Noise attenuation/transmission loss through water under
different conditions; projections of area/extent of
hydroacoustic impact for different sound sources (i.e. pile
driving)
• Electrical engineering models can accurately predict EMF
strength and attenuation with distance from the source
• Changes in current strength, sediment dynamics and scour
processes resulting from the presence of submerged structures
under different conditions can be modelled in coastal
engineering studies
Limitations
• Studies of impacts currently limited to marine
systems and organisms; predictions of likelihood
or significance of potential effects suffer from a
high level of uncertainty
• Cannot replace site-specific field monitoring of
fish communities and habitat assessments,
especially to identify the presence/absence of
critical or regulated habitat or species at risk;
information on general ecology and habitat
requirements of many species still lacking
• Measurements of sound source levels in the field
required for model input; projections useful for
risk assessments but physical noise monitoring
still necessary for impact assessments
• Difficult to predict potential additive effect or
interaction of EMFs from multiple closely
arrayed cables; depth of cable burial (and
strength of emitted fields at sediment surface)
could vary along proposed route and with time
• Requires baseline studies of natural physical
processes within the proposed project area under
various seasonal/weather conditions; difficult to
predict far-field and cumulative impacts
Aquatic Research and Development Section 96