Nature restoration in our North Sea

From above, our North Sea looks like a uniform body of water. Below the water's surface, however, there is a great diversity of fauna and flora present in different habitats. This biodiversity is currently under severe pressure from human disturbance and climate change. How can we restore nature in our North Sea?


©Saskia Van Gaever - Marine Environment Department  
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​Valuable nature in our North Sea

Despite its small size, the Belgian part of the North Sea is home to a rich biodiversity consisting of more than 2,000 species! There are different habitats, each of which is home to a whole range of species. This diversity is due to, among other things, the numerous sandbanks found in the area, the pronounced currents and tides, the variation in food gradient (the concentration of nutrients in the water) under the influence of the Scheldt, and the large variations in sediment type found on the bottom.

However, these habitats are currently under severe pressure from disturbance due to human activities and climate change. Rising temperatures, seawater acidification, pollution and seafloor disturbance are just a few examples of threats to the marine environment.

The biologically most valuable habitats currently remaining in our North Sea are the gravel beds (areas of coarse rock) and the aggregations of the sand mason worm (Lanice conchilega). Both habitats provide a form of stability within the otherwise turbulent conditions of the North Sea, providing shelter for a great many different species. However, pressure on these habitats has caused them to be in a highly degraded and/or impoverished state. In the past, our North Sea also contained banks of the European flat oyster (Ostrea edulis), which were real hotspots for biodiversity. These disappeared completely in the early 20th century due to disease and overfishing.

Why do nature restoration in the Belgian part of the North Sea?


Several  EU directives, conventions and strategies such as the Marine Strategy Framework Directive, the Habitats Directive, OSPAR and UNCLOS insist on the importance of restoring and protecting healthy marine ecosystems. A coherent network of marine protected areas is essential to achieve this. Given the impoverished state of nature in our North Sea, protecting the present nature is not always sufficient. Sometimes it is necessary to make additional efforts and cooperate with neighboring countries, to restore nature.  This in order to counteract the effects of years of human disturbance and the associated loss of biodiversity. So the precious habitats that are now struggling will get a boost. It is not only essential for the species found in these habitats but healthy and well-developed ecosystems also act as buffers against climate change and can provide benefits for fisheries, coastal tourism and water quality.  
 
Nature restoration focuses on repairing the damage that human activities have caused to natural ecosystems. These ecosystems seek to return to a previous state, from before these activities took place, or a state closely akin to a current one without human activities. Nature restoration can include both passive strategies (the cessation of local pernicious activities with the goal of regaining a balanced ecosystem) and active strategies (recovery of a minus value or the creation of an added value for at least one ecosystem service without a minus value for other ecosystem services).

Priorities for nature restoration: 3 habitats

 There is a lack of clarity about what nature restoration exactly means and which actions around nature restoration should be given priority in order to have the most positive effect on the ecosystem. Therefore, the Marine Environment Service of the FPS Public Health has developed the following vision on nature restoration in the Belgian part of the North Sea:

"The Marine Environment Department aims to preserve and restore ecosystems in the Belgian part of the North Sea, taking into account that these ecosystems are transboundary. Thus, efforts in the Belgian part of the North Sea, together with those made in neighboring countries, must contribute to a self-sustaining, strong, resilient ecosystem that provides numerous ecosystem services to humans."



In preparation for this vision creation we conducted an exploratory analysis to find out which nature restoration initiatives were already taking place in our North Sea and surrounding waters. We also examined the opportunities and challenges in the field of nature restoration and the vision and future plans of our neighboring countries. Based on this, we selected 3 priority forms of nature restoration:

  1. Restoration of gravel beds;
  2. Restoration of oyster banks;
  3. Enhancement of other reefs such as Lanice conchilega aggregations and Sabellaria reefs.

For each of these forms of natural restoration, a main objective was defined and concrete priority actions were required to achieve four intermediate objectives:
1) Reduce the pressure on the system;
2) Increase knowledge about the system and possible restoration actions;
3) Implement restoration actions;
4) Raise awareness among stakeholders and the general public.

To strengthen this last objective, the Marine Environment Department organized a  kick-off event about nature restoration in our North Sea over on 31 May 2022.