van Roomen M.,Dutch Center for Field Ornithology |
Laursen K.,University of Aarhus |
van Turnhout C.,Dutch Center for Field Ornithology |
van Winden E.,Dutch Center for Field Ornithology |
And 9 more authors.
Ocean and Coastal Management | Year: 2012
The Wadden Sea, shared by Denmark, Germany and the Netherlands, is one of the world's largest intertidal wetlands. Waterbirds are an important element of the Wadden Sea ecosystem. By their migratory behaviour they connect the Wadden Sea with other sites, ranging from the arctic to the western seaboards of Europe and Africa, forming the East-Atlantic Flyway. The Joint Monitoring of Migratory Birds (JMMB) project of the Trilateral Monitoring and Assessment Program (TMAP) follows the changes in population size within the Wadden Sea. In this paper we describe and analyse population trends over the years 1991-2009 for 22 waterbird species using the Wadden Sea in internationally important numbers and depending on intertidal mudflats. Population declines predominated in this 18-year period. More populations decreased in Schleswig-Holstein and Niedersachsen than in The Netherlands and Denmark. This is the case particularly for species feeding on polychaetes. In contrast, waterbirds feeding on bivalves are in decline in all regions except Denmark. On the finer spatial scale of tidal basins, these patterns in trends are still apparent, although much variation in trend directions exists within the Dutch Wadden Sea, especially in bivalve specialists. For those species for which we could compare the trend in the Wadden Sea with the trend of their entire flyway population, we found that the former were more negative. This finding and the contrasting trends between regions and tidal basins within the Wadden Sea suggest that causes of the population changes are to be sought within the Wadden Sea itself. These causes, which may act in combination, could be related to factors operating within the Wadden Sea only or with factors operating on a larger scale but having an intensified or differentiated effect within the Wadden Sea. Interestingly, the Wadden Sea regions where negative trends of benthivorous waterbirds predominate are characterized by a large tidal amplitude, whereas areas where bird numbers have generally increased are characterized by a small tidal amplitude. An inventory of possible causes indicated climate change, eutrophication, shellfish fisheries, invasive species and increasing numbers of avian predators as the most important candidates to be investigated further to explain the observed trends. © 2012 Elsevier Ltd.
de Jong F.,Common Wadden Sea Secretariat
Environmental Science and Policy | Year: 2015
In an analysis of North Sea eutrophication science and policies, focusing on the period 1980-2005, it was investigated how scientific information was used in policy-making. The analysis focused on the central assumptions of the rational policy-making model, i.e. that scientific information can be used to formulate decisions, based upon objective scientific information (rational decision-making), and secondly, can support implementing these decisions (rational management). In general terms, the following was concluded:. •More knowledge has increased rather than reduced uncertainty;•In order to handle the problem of dealing with complexity and uncertainty at the political level, a simplification of facts has occurred, in this case focusing on nutrients as the main cause of the problem, at the same time excluding other possible causes;•Both the limited scientific view (i.e. the nutrient view) and the exaggeration of the seriousness of the problem (impacts, scope) have been used as an authoritative basis for the justification of political decisions. Both were not supported by the majority of the scientific community;•New scientific knowledge, not in support of existing policies, has been excluded from the policy process;•The science-policy interface, mainly consisting of "civil-servant scientists", that emerged and increased its influence over the period of investigation, has been the central element in the simplification and exclusion process. The main lesson learned is that work at the interface of science and policy must be subject to democratic principles, i.e. be transparent and involving all parties with a stake in the issue under consideration. © 2015 Elsevier Ltd.
Dittmann T.,Institute of Avian Research Vogelwarte Helgoland |
Becker P.H.,Institute of Avian Research Vogelwarte Helgoland |
Bakker J.,National Institute for Coastal and Marine Management RIKZ |
Bignert A.,Swedish Museum of Natural History |
And 7 more authors.
Environmental Science and Pollution Research | Year: 2012
To categorize the marine environmental health status, the Oslo and Paris commissions have recently formulated Ecological Quality Objectives (EcoQOs) for many ecological features including the contamination of coastal bird eggs with mercury and organochlorines. In this study, we describe spatial and temporal patterns of egg contamination around the North Sea and compared them to the EcoQOs. Concentrations of mercury, polychlorinated biphenyl (ΣPCB) congeners, dichlorodiphenyltrichloroethane (ΣDDT) and derivatives, hexachlorobenzene (HCB) and hexachlorocyclohexane (ΣHCH) isomers were analysed in two tern species (Sterna hirundo and Sterna paradisaea) and Oystercatcher (Haematopus ostralegus) eggs collected between 2008 and 2010 in a total of 21 sites in seven countries surrounding the North Sea. Hg, ΣPCB and HCB were highest in the southern sites, while ΣDDT and ΣHCH concentrations were greatest in eggs from the western North Sea and the Elbe estuary. There were rarely any consistent decreases over time for any compounds. In the terns, Hg, HCB and ΣHCH increased at most sites, ΣPCB and ΣDDT in Sweden and Norway. In the Oystercatcher, HCB and ΣHCH increased at more than the half of the sites, ΣPCB, ΣDDT and Hg at several German sites. In the terns, Hg, ΣPCB and ΣDDT exceeded the EcoQO in all, HCB in most years and sites. At most sites, ΣHCH fulfilled the EcoQO in some study years. In the Oystercatcher, Hg, ΣPCB and ΣDDT exceeded the EcoQO in all or most years and sites. HCB and ΣHCH fulfilled the EcoQO in some or all years at most sites. The EcoQO was exceeded most frequently in estuaries. We conclude that EcoQOs are suitable for drawing contamination patterns of the coastal North Sea in an easily understandable manner, offering the opportunity to harmonize the EcoQOs with coordinated environmental monitoring programmes. © 2012 Springer-Verlag.