Preservation of Wadden Sea area requires international measures

15-10-2011   Scientists from several different countries call for better international and integrated preservation measures for the Wadden Sea area. This is one of the conclusions of the international Wadden Sea Symposium, held on the island of Texel last week.

The Dutch trend is currently towards more regional policy decisions, which is at odds with the integrated ecological interests of the Wadden Sea and conflicts with the future sustainability of the Wadden Sea. At the Wadden Sea Symposium, scientists from various countries bordering the Wadden Sea called for a more unified, international approach to the preservation of the Wadden Sea.

At the Wadden Sea Symposium, scientists from various disciplines presented their latest results to one another, and the symposium thus helped to provide a clear and comprehensive view of the area. Approximately 150 scientists, including many young researchers, from the Netherlands, Germany and Denmark, presented their results in over 50 papers and a large number poster presentations on the ecology of the Wadden Sea area. The Wadden Sea Symposium was held at NIOZ on the island of Texel from 10 to 14 October and was organised by NIOZ, IMARES Wageningen UR and Deltares. The symposium was supported by the Wadden Academy and the Sea and Coastal Research Programme of NWO (Netherlands Organization for Scientific Research).

In addition to the call for international preservation measures, a number of other remarkable conclusions were presented. The importance of the shallow parts of the Wadden Sea was highlighted. The role played by sediment as the driving force of the system has long been underestimated, as organic material in sediment decomposes and is then released into the water as nutrients. Currents subsequently take these nutrients into and out of the Wadden Sea where they contribute to the cycle of growth and decay.

Another conclusion was that fears that the Pacific Oyster would supplant the mussels proved groundless. The Pacific Oyster has found its own niche in the ecosystem as a reef builder, and mussels can settle on these oyster beds and thus benefit from the oysters’ presence.

Further research is required into the invasion of the warty comb jelly in the Wadden Sea. This species arrived in the Wadden Sea via the ballast water of ships several years ago, and in some years vast numbers of this species can be found in the Wadden Sea in spring. The warty comb jelly eats shellfish larvae, and during springs when it occurs in massive numbers its presence may cause a markedly decreased spatfall of shellfish, which affects the produce of mussel hatcheries.   

The Wadden Sea is currently being monitored with cameras, sensors and transmitters 24 hours a day. This has revealed that oystercatchers eat at night.

The role of the shrimp in the Wadden Sea ecosystem turns out to be crucial. It seems the shrimp is an essential part of the system but further research should provide more detailed information on the role the shrimp plays. One of the conclusions of this symposium is then that further research into the shrimp should be high on the agenda.