New findings suggest that the Northern Europe's Wadden Sea has experienced environmental decline for up to 1000 years longer than previously thought.

By analyzing and synthesizing both archaeological and historical data on social and ecological changes in the Wadden Sea, researchers from the History of Marine Animal Populations (HMAP) project of the Census of Marine Life have built a timeline of human induced environmental decline in this portion of the North Sea. Bordering Denmark, Germany, and the Netherlands, the Wadden Sea has historically been an important source of seafood products, transportation, and other services to the local population. Not surprisingly, environmental and ecological change has been a consequence of this human use. While it is not surprising that environmental and ecological decline has occurred, new finding suggest that degradation has been taking place for much longer than scientists formerly thought.

In an attempt to set a baseline for the Wadden Sea's "natural" state, researchers examined the historical record to see how long humans have been exploiting this body of water. Such a baseline could be used to indicate the extent of degradation in the ecosystem and would prove to be a valuable tool for the management of this heavily used coastal area. Through the course of this analysis, researchers were surprised to find record of overexploitation of marine resources going back at least 500 years rather than the commonly accepted figure of 150 years. Additionally, records show that human driven environmental change extended back to at least 1000 years ago when coastal populations began building dikes and reclaiming the sea. Eutrophication and nutrient pollution extends back about 100 years.

The result of these findings is that the baseline for a natural Wadden Sea has shifted backwards in time from previous projections to about 1000 years ago. Alarmingly, this baseline is outside the scope of current monitoring programs and management strategies. These current programs have been comparing changes in the environment against a false baseline because the ecosystem had already been substantially altered by human pressure. The implications of this for ecosystem-based management efforts are not clear. However, as monitoring and management efforts continue into the future, scientists and policy makers now have a more complete picture of the extent of anthropogenic influence on the Wadden Sea environment. Researchers suggest that these data may help managers develop new restoration and recovery targets that take into account the full transformation that this ecosystem has endured through time.

Research Location: The Wadden Sea, a portion of the North Atlantic Ocean that borders Denmark, Germany, and the Netherlands.

• What: Research suggests that human induced decline in the Wadden Sea environment extends back further in history than originally thought.
• Who: HMAP Scientists --> H.K. Lotze, K. Reise, B. Worm, J.E.E. van Beusekom, M. Busch, A. Ehlers, D. Henrich, R.C. Hoffman, P. Holm, C. Jensen, O.S. Knotternerus, N. Langhanki, W. Prummel, and W.J. Wolff
• When: 2004
• Where: The Wadden Sea/Southern North Sea, off the coasts of Denmark, Germany, and the Netherlands
• How: Analysis of Historical data and documents
• References: Lotze, H.K., K. Reise, B. Worm, J.E.E. van Beusekom, M. Busch, A. Ehlers, D. Henrich, R.C. Hoffman, P. Holm, C. Jensen, O.S. Knotternerus, N. Langhanki, W. Prummel, and W.J. Wolff. 2005. Human transformations of the Wadden Sea ecosystem through time: a synthesis. Helgoland Marine Research 59: 84-95.