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Project: Wadden Sea Ecosystem - Wadden Sea ecosystem data assimilation and integrated modelling

Project details

Acronym : Wadden Sea Ecosystem
Full project name : Wadden Sea ecosystem data assimilation and integrated modelling
Initiating organisation : NIOZ Royal Netherlands Institute for Sea Research, Texel
Project leader : A.G. Brinkman
Supporting organisation(s)NIOZ Royal Netherlands Institute for Sea Research, Texel
Financing : Unknown
Project number : 83908230
Start date : Jan 01, 2009
End date : Dec 31, 2013


Programme :ZKO - Carrying Capacity: Line 2 - National Programme Sea and Coastal Research (ZKO) - Carrying Capacity: Line 2 - Monitoring
Main project :-


Description :

During the last decades, large changes were observed in the Wadden Sea and the nearby coastal North Sea zone. Abundances of several benthic fauna and fish species decreased drastically, and some new species appeared in the area. Several bird species showed a steady decline.
Since the mid-eighties, nutrient inputs ?especially phosphate- decreased as a result of the de-eutrophication measures in the Rhine countries; an ongoing process since other countries still are implementing similar policies. Climate change effects, such as increasing water temperature, atmospheric carbon dioxide content and changing wind fields will also influence the system behaviour. Fishery activities also intervene or have intervened on several ecosystem levels, i.e. by fishing on predators of small fish or prey for birds or large fish, or by disturbing abiotic (sediment) and biotic (mussel beds) structures.
Bottom-up drivers like nutrients and light will largely affect the amount and type of algae in a ecosystem like the Wadden Sea, and thus influence the quality and amount of food available to filter feeders. The timing of algal blooms and shellfish larvae production is probably crucial for reproductive success. Mechanisms of top-down control like predation by birds, fish, and crabs on lower trophic levels will cause a lower abundance of prey species than theoretically possible. These mutual relationships are highly non-linear, as many feed-back mechanisms occur, and the system may show multiple-steady or meta-stable states.

Unravelling these interactions demands (1) detailed process studies at the different ecosystem levels, (2) optimal use of existing and newly acquired data, and (3) integration of knowledge into a tool amenable for extrapolation and management applications.

We will develop models that will serve serve a number of goals:
1- data assimilation. The monitoring projects acquire data that have either a fine temporal, or a fine spatial scale. Spatial and temporal extrapolations of monitoring data will be produced covering the whole Wadden Sea.
2- Improved process descriptions. In cooperation with line-3 projects
3- integration of sub-models. . This will allow evaluating the system-wide implications of improved process knowledge. Ecosystem relationships are in many cases highly non-linear, and exhibit many feed-back mechanisms. Ecosystem behaviour can only be described if specific processes are linked in a wider context, also enabling the computation of flows of matter between trophic compartments and across boundaries.
4- predictions. The ultimate goal of the NWO-ZKO-project is to produce a tool for a better management of the Wadden Sea ecosystem and other, similar tidal and or coastal areas. That implies the use of integrated models and separate sub-models for estimating direct or indirect effects of management measures .

Data assimilation offers the possibility to use the monitoring results that are localised in time or space, thus widening the scope from the results from other ZKO-projects. A fine-scale hydrodynamic model, linked with an elementary ecological description will be applied for this purpose. Data analysis and the development of improved process descriptions will be performed in close cooperation with the other sub-projects. This will form the basis for improvement of integrating models.

The final result will be a combination of already existing models, which are refined and extended, and of new models and algorithms to be developed.  Management measures may affect an ecosystem on several trophic levels, and evaluation of their effects will thus require the several types of models developed and improved within the proposed project.