DETECT: DEVELOPING A TOOL FOR ASSESSING ECOLOGICAL REFERENCE CONDITIONS IN THE COASTAL ZONE OF THE BALTIC SEA (Korhola)
Academy of Finland www.aka.fi/bireme
Coastal marine eutrophication has become a significant and wide-spread problem in recent decades. The same trend can be observed in the Baltic Sea, where the nutrient load has strongly increased from its natural level. In developing a strategy for the sustainable use of coastal ecosystems it is important to understand how a system has varied through time, and, in particular, how far it has departed from baseline conditions. The new EU Water Framework Directive (WFD) requires all surface waters in Europe to fulfill the criterion of “good ecological status” by the end of 2015. This status is defined with reference to undisturbed conditions. However, the implementation of the WFD in coastal areas will be challenged by the difficulty of assessing these reference conditions, as in most cases the systems were already heavily impacted before the start of monitoring programmes.
In the absence of historical water chemistry data the paleolimnological record preserved in coastal sediments can be used to address long-term changes in the trophic status. By combining chemical and biological proxies it is possible to reconstruct changes in the ecological structure of ecosystems affected by eutrophication. The development of new numerical approaches that allow quantitative reconstruction of ecological changes on the basis of modern reference data has been a major recent advance in paleolimnology. These approaches have been successfully used in fresh water ecosystems with regard to surface water acidification, eutrophication, and climate change. Preliminary studies have demonstrated that the multi-proxy approach and organism-based transfer functions are also applicable to coastal environments and suggest that palaeolimnology can offer powerful tools for coastal management.
Fig.1. Location of the diatom-nutrient training set (outlined area). The 40 reference sites are indicated by circles and the six long core sites by stars .
Harri Helminen, Doc., Ph.D.
Högne Jungner, Ph.D.
Stephen Juggins, Ph.D.