Issues of Concern and Associated Evidence Needs Table 2. High-level evidence needs and questions relating to marine birds (seabirds, divers and seaduck) and offshore wind farms, collated from and agreed by delegates at the 2nd IGF workshop. Evidence needs identified for other taxa are not listed here. related to offshore wind energy To answer this we would need a better of... Evidence need: More information is required on... What are impacts from offshore wind farms (OWF)? Numbers of birds using different sea areas at different times of year and consistency in distributions across years – defining populations at a regional scale as basis for assessment of cumulative effects More up to date information on bird distributions and numbers covering large sea areas – monitoring at scale of individual wind farm developments is too small to quantify cumulative trans-boundary impacts. Better quantification of impacts of offshore wind farms on birds (see below). Large-scale seasonal movements of birds and drivers of those movements (e.g. prey availability, weather conditions). Movements of birds, e.g. tagging studies, stable isotope analysis, etc. but with studies carried out in a coordinated strategic manner across multiple locations. Concurrent information on potential covariates, e.g. sea surface temperature, prey, etc. dynamics, Large scale tagging and ringing studies
e.g. natal dispersal, inter-annual movements between colonies of breeding birds. at multiple locations concurrently, e.g. (Meta) population sizes of relevant bird species, as well as estimates of (meta) population parameters such as success, mortality, life expectancy, etc. As complete as possible data on demographic parameters of the relevant species for the populations frequenting the North Sea What are impacts? of cumulative impacts across all industries which may directly or indirectly limit marine bird populations. Information on direct mortality (e.g. net entanglement) or indirect mortality (e.g. displacement from shipping, changes to discards, etc) and ability to quantify the magnitude of these impacts, relative to offshore wind energy industry impacts. What are the impacts of OWF relative to other causes of change, e.g. climate change? of climate change and an of mechanism, e.g. change in prey availability reduces Baseline information on population size, demographic rates and information on how these change with variables such as SST and prey. How many die from collisions Rate of collisions or an estimate from Year-round species-specific empirical data across multiple productivity
with OWF? collision risk models. sites and species for parameters that are used in collision risk modelling, especially those parameters that models are most sensitive to. Improved and tested technology to directly measure species-specific collisions as a proportion of birds using the area and to validate collision risk model estimates. The ability to assign collision mortalities to the appropriate relevant population exposed to collision risk. Do and barrier effects occur (not known for all species) and, where it is known to occur, what are the level of Does occur and if yes, does it bring incidental benefits, e.g. increased prey rates, models to quantify energetics of and impacts at population level. Better quality year-round information across multiple sites and species on displacement rates plus studies to quantify habituation. Studies dedicated especially to establishing possible changes in seabird inside and outside wind farm areas for species still considered to avoid wind farms