Colonisation of wave power foundations by mobile mega- and macrofauna – a 12 year study

Published source details Bender A., Langhamer O. & Sundberg J. (2020) Colonisation of wave power foundations by mobile mega- and macrofauna – a 12 year study. Marine Environmental Research, 161, 105053.
Share Tweet Email

Actions

This study is summarised as evidence for the following.

	Action	Category
	Create hole habitats (>50 mm) on subtidal artificial structures Action Link

Create hole habitats (>50 mm) on subtidal artificial structures

A replicated, controlled study in 2007–2019 on 21 subtidal wave buoy foundations in the North Sea, off the coast of Sweden (Bender et al. 2020) found that creating hole habitats on foundations did not increase the mobile invertebrate and fish species diversity, richness or overall abundance, but did alter their community composition and increase brown crab Cancer pagurus abundances. After 12 years, the mobile invertebrate and fish species diversity (data reported as Shannon and Evenness indices), richness and abundance were similar on and around foundations with holes (10 species/foundation, 51 individuals/foundation) and those without (9 species/foundation, 33 individuals/foundation). The community composition, however, differed (data reported as statistical model results). Three mobile invertebrate species recorded on and around foundations with holes were absent from those without. Brown crabs were more abundant on and around foundations with holes (11/foundation) than without (4/foundation), while the abundances of 47 other fish and mobile invertebrates were similar for both (see paper for results). Hole habitats were created in April 2007 by drilling into the vertical sides of concrete foundations (diameter: 3 m; height: 1 m). There were 26 evenly-spaced cuboidal holes/foundation (width: 120 mm; height: 150 mm; depth: 300 mm): 13 at seabed level and 13 at 0.5 m above the seabed. Eleven foundations with holes and 10 without were placed on sandy seabed at 25 m depth. Fishes and mobile invertebrates were counted on and around (<1 m radius) foundations over 12 years. Holes at seabed level had been buried by sediment and no longer provided habitats.

(Summarised by: Ally Evans)