|The influence of windmill artificial reefs on the diurnal feeding pattern of cod Gadus morhua in the Belgian Part of the North Sea|
De Rijcke, M. (2011). The influence of windmill artificial reefs on the diurnal feeding pattern of cod Gadus morhua in the Belgian Part of the North Sea. MSc Thesis. Ghent University: Gent. 25 pp.
Artificial reefs; Offshore constructies; Voedingsgedrag; Wind farms; Windmills; Gadus morhua Linnaeus, 1758 [WoRMS]; Gadus morhua Linnaeus, 1758 [WoRMS]; ANE, België [Marine Regions]; Marien
Cod; Gadus morhua; diurnal; offshore windmills; windmill artificial reef; feeding behaviour; generalized additive models
Increasing demand for renewable energy sources drives a substantial expansion of offshore wind exploitation in the Belgian Part of the North Sea (BPNS). The constructed wind turbines will alter bottom habitats by adding large quantities of artificial hard substrate to a soft bottom surrounding. Windmill artificial reefs may potentially act similar to other artificial hard substrates e.g. shipwrecks that are known to concentrate and/or enhance local fish stocks by providing shelter, increase feeding or acting as nursery areas However, little is known of the impact that these artificial reefs leave on the stocks of economically valuable species such as cod, Gadus morhua. This study represents the first research in the BPNS on the influence of windmill artificial reef on the feeding behaviour of cod. Through a 24-hour sampling campaign samples were collected at the operational C-power offshore wind farm. Stomach content analyses by means of indices, generalized additive modelling, principle component analysis and multidimensional scaling provided no evidence that cod displays the same diurnal feeding pattern that has been described for the natural habitat. Instead, feeding appeared to be continuous at this site. Furthermore, the analyses revealed that stomach content was dominated by hard substrate species (i.e. Jassa herdmani and Pisidia longicornis), indicating that windmill artificial reefs act as a preferred feeding habitat for cod. This study could however not determine if artificial reefs only attract ichthyofauna or actually enhance the biomass production underpinning the importance of continued research into this matter.