WP 3.1 Microbial loop

Effects of mobile bottom-contact fishing on the North Sea ecosystem at the microbial level

While it is evident that fishing methods such as mobile bottom-contact fishing severely disturb the sea bottom, little is known about the effects of these disturbances on the ecosystem at the microbial level. As the microbes that inhabit marine sediments fulfill the essential functions at the lowest trophic levels (e.g., in decomposition and nutrient cycling), they are the basis of the ecosystem. Moreover, multicellular organisms fulfilling important ecosystem functions –including those targeted by mobile bottom-contact fishing– are colonized by microbial communities themselves, which may directly affect their health and development.

To draw the full picture of how mobile bottom-contact fishing affects the North Sea ecosystems and if these systems could recover, understanding how microbial communities in the sediment and associated to important species are shaped by few or regular disturbance events is fundamental. The primary aim of this project is to study how microbial communities in the sediment and those associated to common ecosystem members such as hermit crabs and starfish respond to the enforcement of marine protected areas (i.e., without fishing disturbance). To this end we have begun monitoring sediment and organism associated microbiota from hard and soft bottom localities from within and nearby three MPAs in the North Sea. This enables us to identify future changes associated with the implementation of no fishing zones.