Reef effects of structures in the North Sea: Islands or connections? (RECON)

The aim of this study is to investigate and model the species distribution and inter-connectivity of reef communities on offshore structures in the North Sea using different techniques. First, it provides community data from taxonomic species inventories. Second, a cost efficient method for inventory of communities is developed using state-of-the-art DNA metabarcoding. Third, the genetic population structures of the mussel Mytilus edulis and crustacean Jassa Herdmani, abundant invertebrates with different dispersal strategies, are analysed. Ultimately, the data from this study and other available data are used to model the distribution of species on offshore structures and their inter-connectedness. The methodology is proposed to address three main questions:

1. What is the species composition of marine growth on offshore structures?
2. To what extent is this composition explained by abiotic factors (e.g. depth, temperature, location, platforms age, marine growth cleaning frequency, et cetera) and biotic factors (e.g. food availability, proximity to marine growth on other offshore structures, distance to coastal populations, et cetera)?
3. To what extent are the communities on the structures isolated from or connected to each other and how is this explained by the factors noted earlier?

In addition to analysing existing footage collected with remotely operated vehicles, we carry out fieldwork in a highly cost efficient manner, using fully equipped mobilized diving-vessels already present at offshore installations for regular inspection and maintenance work. GDF-SUEZ provides in-kind co-funding by allowing our certified offshore diver-marine biologists to access their dive support vessels. This approach was implemented frequently by IMARES in 2014 and is a highly successful, unique and cost-efficient method for field inventories of reef communities on offshore installations. Part of the work is financed with cooperation and co-funding from several companies.