PhD defence

North Sea Reefs. Benthic biodiversity of artificial and rocky reefs in the southern North Sea

PhD candidate dr. JWP (Joop) Coolen
Promotor prof.dr. HJ (Han) Lindeboom
Co-promotor prof. dr. S. Degraer
Organisation Wageningen University, Aquatic Ecology and Water Quality Management

Wed 15 March 2017 13:30 to 15:00

Venue Aula, gebouwnummer 362


Benthic biodiversity on temperate reefs can be very high. Approximately 30,000 artificial reefs including oil and gas platforms, wind farms and shipwrecks are present in the North Sea. These may have similar species communities as natural reefs. The aim of this PhD thesis was to understand the patterns of benthic biodiversity on artificial North Sea reefs and their effect on species distribution.

Results show that similarity between species communities on natural and artificial reefs depends mostly on depth and structure type. Deep rocky artificial structures are most similar to natural reefs whereas shallow steel structures are not. When rocky reefs are present on a sandy bottom, local biodiversity is doubled. The results strongly suggest that species with a pelagic larval stage utilise offshore artificial structures as stepping stones to colonise habitat out of their natural range. This may have implications for indigenous and exotic species. It could be suggested to leave parts of artificial reefs such as platforms and wind farms in place.