The North Sea is used intensively for a range of human activities: shipping, fishery, aquaculture, energy production, sand extraction and coastal protection.

A major challenge for management is to ensure that ecosystem services as well as the region’s intrinsic natural values are conserved in the near and far future, despite all the changes that the North Sea is facing as a result of climate change and ever increasing human activities.

It is clear that we lack the knowledge as well as the data in order to understand the effects of all these changes and the aim of the NIOZ North Sea activities is to fill this void wherever we can, in cooperation with our (inter)national partners and to take a leading role in this.

Coastal protection

The Netherlands and other countries neighbouring the North Sea are highly vulnerable to sea level rise. In order to defend the Netherlands against sea level rise, sand is extracted below the -20m line and used for shore and beach nourishment.

However, biodiversity recovery after sand nourishment may take a long time. Meanwhile food availability for higher trophic levels such as fish, birds and marine mammals might be limited. This could be one of the reasons for the low fish abundance in the coastal zone and Wadden Sea.

NIOZ, working with partners, is addressing questions like:

• How does shore and beach nourishment affect (recovery of) biodiversity?
• Are there more sustainable methods for coastal protection? Can we work with nature to create more sustainable coastal defence methods?

Fishing

Fishing activities have severely changed the North Sea sediment. Stones, brought by glaciers during the ice ages, were covered with animals such as serpulid keelworms, sea anemones, sponges and soft corals. These stones have been removed by fisheries and the North Sea benthos is now dominated by soft-bottoms species.

The intense fishing pressure has also caused large fish species to disappear. But new fishing gear has been developed which is thought to be less intrusive. Will this change the sediment composition and biodiversity, and hence the biogeochemical cycles and sediment-water exchange?

Moreover, hard-surface structures such as oil and gas exploration platforms, windmills and shipwrecks are creating new hard-substrate habitats. Will these act as stepping stones for a new hard-core ecosystem in the North Sea? Can they provide a connected network so that more sessile species can migrate successfully, as they might be forced to by climate change?

Ecological process measurements

The North Sea will clearly face changes in the near future as a result of all these human activities, on top of the effects caused by climate change. NIOZ want to contribute to a more complete knowledge about ecological processes in a spatial context.

For example, is the North Sea’s carrying capacity decreasing, and how is primary production developing in its different areas? Process measurements addressing biogeochemical processes in the sediment and pelagic, and the links between them, are urgently needed.

Along with research partners, we plan to set up long-term measurements with newly developed sensors, deployed in and outside marine-protected areas. We will address gaps in knowledge like the role of zooplankton and of non-commercial fish, and will look at how the region’s seabird ecology has changed.

With this knowledge we can also better evaluate the effect of blue-growth initiatives like large-scale aquaculture and horticulture initiatives.