Research shows shortcomings in protection of underwater nature Wadden Sea

Using the results of this study, maps of ecological hotspots in the Wadden Sea—areas that house high biodiversity or fulfil important ecological functions—have been produced for the first time. These hotspots include both locations with rich species composition and areas that are particularly sensitive to benthic disturbance. The areas, which are permanently underwater, house lugworms, shellfish, starfish, sponges, shrimp, and crabs. These species form the foundation of the food chain in the Wadden Sea and provide insight into the stress resistance and recovery capacity of nature.

In addition to the biodiversity inventory, all conservation measures and threats were mapped for the first time in the submerged part of the tidal flats. This map was then compared with that of the ecological hotspots, providing insight into the current state of protection of our underwater nature. It reveals that this protection is entirely inadequate. For example, the areas most valuable for nature—those with the highest biodiversity—are, in practice, either poorly protected or not protected at all.

The study shows that human and economic activities are limited to only 10 per cent of the underwater part of the mudflats, while only 2 per cent can be classified as completely free from disturbance. Because disturbance-free areas are extremely rare, we do not know the full potential of the Wadden Sea. Moreover, most of these areas have only recently been closed.

Rich nature reserve

What we do know, is that the Wadden Sea is the most important natural area in the Netherlands. Its richness is most evident in the millions of migratory birds that visit every year. However, the importance of nature in the parts that are permanently underwater is less well-known. These areas are home to fish, shellfish, and shrimp, as well as mammals such as seals and porpoises. The shallow coastal sea also has an important function as a nursery for many fish species. A richly variegated mudflat bottom, with a diversity of bottom species, is essential for the Wadden Sea’s food web and all the species that depend on it. This important role of the Wadden Sea is partly the reason for its protected status as a Natura2000 area and designation as a Unesco World Heritage Site. Unfortunately, this does not mean that the current protection measures are sufficient to safeguard these values.

A patchwork of protection measures

Previous studies have shown that many natural riches in the Wadden Sea have disappeared due to human activities. It is therefore no surprise that numerous attempts have been made to protect underwater nature. However, due to competing interests, this has resulted in a patchwork of protection measures. Comparing these measures with current use and all exceptions, only a marginal area remains (10 per cent) that qualifies as a marine protected area by international standards. The Netherlands is not unique in this regard. Recent research indicates that across Europe, the protection of marine nature is often insufficient.

It has been agreed at the European level that nature in the Wadden Sea may not deteriorate any further. Nature organizations, governments, scientists, and interest groups have therefore made agreements on how to achieve a thriving Wadden Sea, where nature can recover and fully perform its essential role for migratory birds and as a breeding ground for fish stocks. The results presented here confirm that we are still inadequately protecting the most valuable Wadden Sea habitats.

More information

• The study was conducted through a collaboration between the Rijksuniversiteit Groningen, GELIFES, Royal Netherlands Institute for Sea Research (NIOZ) and Natuurmonumenten.
• The results were published in the scientific journal People & Nature on 27 November 2024. 

Text:Royal Netherlands Institute for Sea Research (NIOZ)
Photos: Oscar Franken; Kasper Meijer