Acronym NA
Category
Fisheries
Title A human-driven regime shift through the loss of ecosystem engineers: consequences for the trophic structure and recovery potential of the Wadden Sea ecosystem Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator B.D.H.K. Eriksson Coordinator email b.d.h.k.eriksson@rug.nl
Coordinator institution
RuG - University of Groningen (Netherlands)
Institutions involved
NA
Start year 2009 End year 2014 Funding (€) € NA Website https://www.nwo.nl/en/projects/83908310 Summary The great international importance of the Wadden Sea for conservation of biodiversity and the major associated economic revenues of the area?through gas extraction, fisheries and tourism? suggests that we have good predictive models and clear-cut insights into how this ecosystem functions; and that we understand how, e.g., hydrological engineering, surface subsidence and dredging for shellfish affect it. Unfortunately, that is far from true. Despite a long research tradition, our knowledge is very fragmented. Specific ecological, geomorphological or biochemical interactions have been studied, as has the ecology of particular species; but this knowledge has not been put together in a synthetic framework that focuses on the key interactions between the biotic and the abiotic components of the system. Unfortunately, we cannot easily apply existing knowledge from other marine systems such as the rocky intertidal or pelagic systems, and apply it to the soft-bottomed Wadden Sea, because the nature of the interactions among species and their environment is different. Dominant species in these other systems mostly respond to the main environmental factors of wave exposure, water depth, salinity and temperature. In contrast, the key environmental factors in the Wadden Sea including sediment texture, stability, aeration and topography are mostly determined by ecosystem engineers, i.e., mussels, cockles, seagrasses and polychaete worms. Intense human use of the Wadden Sea?through fishing and sediment disturbance?has affected these ecosystem engineers causing a reversal in the causality of the relationship between species and the environment. In other words, the engineering species no longer create the environment; rather the environment is dictating the species?their abundance and, most critically, their functional/foundational role. We hypothesize that the current trophic structure is the result of a drastic regime shift due to the loss or reduction of ecosystem engineers. Deposit feeders have replaced the filter feeders as the dominant consumers at the bottom of the food web. This means a radical alteration in the main energy flow through the food web involving mechanisms that may not be reversible. Even if physical environmental conditions could be restored, the biological components will not return to their original states. In this programme, we combine five projects that will test this hypothesis of altered ecosystem configuration and the inherent non-linear response that will result from it. In light of recent discussions regarding ?carrying capacity? of the Wadden Sea, this programme is especially important to developing a full understanding of the system?s recovery potential?including biodiversity and currently impaired ecosystem services. The programme proposes a novel synthetic view on the key interactions between biotic and abiotic processes that when fully explored, will have wide applicability in threatened soft-bottom tidal ecosystems worldwide.
Keywords
Physical disturbance;
Environmental impact;
Ecosystem approach;
Indicators;
Marine Region
5
Southern North Sea (27.IVc)
1
Marine Region Map
