Tools for investigating spatio-temporal variability of contaminant concentrations in Baltic Sea biota – mercury as a case study

Our aim is to develop new methods for investigating drivers of spatio-temporal contaminant variability in Baltic Sea biota with mercury (Hg) as a test case.

The Baltic Sea is of great regional social and economical value and the surrounding countries have an interest in understanding contaminant exposure in the sea. For some Baltic Sea contaminants, such as Hg, no direct link is seen between input loads and biota concentration.

Recent studies therefore emphasize the importance of relating contaminant variability to physio-chemical changes and ecosystem structure and functioning.

In this project, we will develop novel statistical approaches that allow us to combine long term monitoring data from sub-programs within the Swedish National Environmental Monitoring Program (NEMP) to create a set of spatio-temporal predictive models for Hg in Baltic Sea biota.

Our aim is not only to find the drivers of the temporal trend at one location as has been the focus of previous studies, but also to understand the variability across geographical distances.

The NEMP data are sampled at different locations and development of tools for data interpolation are required to create a uniform dataset for analysis. Developed methods will be translatable to other contaminants and biota groups.

We believe the project will set a new standard for the use of NEMP data in informing governing bodies on the importance of input loads versus other ecosystem changes on the biota contaminant concentration.