Wadden Sea Ecosystem No. 18 - 2004.
Recent Spatial and Temporal Trends. Seabirds at Risk? Effects of Environmental Chemicals on Reproductive Success and Mass Growth of Seabirds Breeding at the Wadden Sea in the Mid 1990s
Citation: Essink, K., Dettmann, C., Farke, H., Laursen, K., Lüerßen, G., Marencic, H. and Wiersinga, W. (Eds.), 2005. Wadden Sea Quality Status Report 2004. Wadden Sea Ecosystem No. 19. Trilateral Monitoring and Assessment Group, Common Wadden Sea Secretariat, Wilhelmshaven, Germany.
Birds play a prominent role as bioindicators: They are conspicuous, one of the best studied groups of organisms, relatively easy to observe and in the focus of public interest and care. As top predators, raptors and seabirds accumulate persistent chemicals, which affect their physiology, reproduction and even survival. This can cause population declines, which have frequently been an indicator of environmental change.
This value of birds was also recognized for the Wadden Sea by the Trilateral Monitoring and Assessment Group (TMAG 1997), which has an outstanding importance for the life cycle of millions of bird individuals each year. Consequently, among the parameters of the Trilateral Monitoring and Assessment Program (TMAP) selected to assess the ecological state of the Wadden Sea, five refer to birds: “Numbers and Distribution of Breeding Birds”, “Monitoring of Migratory Birds”, “Beached Bird Surveys (BBS)” and “Contaminants in Bird Eggs” are implemented; the fifth parameter “Breeding Success” was proposed, tested successfully in a pilot study (Thyen et al. 1998), but to date has still not been implemented trilaterally. [Read further]