Report 604
Feasibility study for meta-analysis of red-throated diver displacement
Coppack, T., Searle, K., Butler, A., Daunt, F., Dirksen, S., Petersen, I-K., Rehfisch, M. & Buisson, R.
The aim of this report is to assess the feasibility and levels of stakeholder interest in undertaking a meta-analysis of data on displacement of red-throated divers Gavia stellata by offshore wind farms.


Red-throated divers Gavia stellata winter around the North Sea, the Baltic Sea and the Irish Sea.  Many OWFs have been constructed in these areas and there is evidence of red-throated divers being displaced from such developments (including a buffer around them), being displaced by activities associated with such developments and being displaced by other human activities in the marine environment.  Evidence to quantify the extent of displacement and what causes this response to vary among wind farms is sparse.  The effects of these developments on red-throated diver distribution are usually only considered in isolation and comparisons between multiple developments have not been previously undertaken.  To produce a single consolidated assessment of the extent of displacement of red-throated divers at OWFs across Europe, ideally, all data from developments across the North Sea, Baltic Sea and Irish Sea would be combined in a single meta-analysis. 

There may be considerable obstacles to undertaking such a meta-analysis.  These include willingness to collaborate and share data, statistical difficulties regarding the type of meta-analysis and the feasibility of combining data from different sources as well as buy-in from relevant stakeholders including the use of the outputs.  These issues could pose a risk to the meta-analysis being undertaken successfully.  The work undertaken by APEM and collaborators, contracted by JNCC, sought to evaluate and quantify the extent to which that may be the case.

Questionnaire responses from stakeholders indicated strong support for a meta-analysis but a low response rate from data custodians implies data accessibility would be problematic.  The project concluded that access to raw data on diver densities, and how these change in response to construction of OWFs, varies by country but substantial amounts of raw data are not publicly available.  Whilst meta-analysis approaches exist that do not require access to raw data, the project found that an approach that did require raw data would be optimal in this context.  Combining data obtained using different survey methods also presents substantial statistical challenges.  Consequently, a recommendation was made that the meta-analysis does not proceed without the co-operation of data custodians. 



You will need the free Adobe Acrobat Reader to view this document.
Available free from JNCC
ISSN 0963-8901
Please cite as: Coppack, T., Searle, K., Butler, A., Daunt, F., Dirksen, S., Petersen, I-K., Rehfisch, M. & Buisson, R., (2017), Feasibility study for meta-analysis of red-throated diver displacement, JNCC Report 604, ISSN 0963-8901