The overall aim of the project is to investigate the evolutionary effects and the potential for wild populations to adapt to anthropogenic contaminants (i.e. pollution). We aim, by combining genetic markers with physiological, morphological biomarkers and experiments, to identify populations adapted to the contaminants and if so we hope to be able to identify genes linked to phenotypic traits involved in this.

The Baltic Sea provide a good system for studying evolutionary effects of pollution as the Baltic Sea is not only a heavily polluted sea, but also evolutionary young and unique brackish environment. We will use to common and important Baltic Sea species, the blue mussel (Mytilus edulis x trossulus) and three-spined st ickleback (Gasterosteus aculeatus), as model systems.

Field sampling and experiments on Askö

The aim of the study that will be conducted during the summer of 2014 is to asses effects of sewage treatment plant disposal on three spine sticklebacks using different markers. In this study we aim to sample sticklebacks at outside 3-4 sewage treatment plants around Sörmland and Uppland, each plant will be paired with a clean reference site. At each site additional data such as temperature, pH, salinity, dissolved oxygen concentration, sediment samples and water samples will be collected for further analysis. The sampling is planned during April- May 2014. The sticklebacks will be sampled from the shore using a drop net. At each site we aim to collect around 30 individuals and the collected individuals will be brought back to Askö field station and put in aquarias in the experiment hall for further analysis and experiments. We plan to use the experiment hall for 20 days and the laboratory for 7 days. Individuals from the sewage treatment plants and reference sites will be used for the experiment. The fish will be divided into smaller tanks (buckets) and placed within the larger grey tanks. Each grey tank will contain experiment tanks and a control tank and to obtain a stable temperature free flowing deep sea water will surround the smaller tanks. This set up will be repeated in 4-5 large grey tanks. In each of the experiment tank an additional stressor (i.e. hormones, heat, freshwater) will be added. After approximately 20 days (depending on sampling succes) of exposure the experiment will be terminated and each individual fish be measured using a number of end points. Laboratory analysis at Askö field station for 7 days Mortality rate and overall condition for each tank will be recorded. Each individual will be measured, photographed and novel tank, shoaling and sctotaxis tests will be preformed. Fin clippings will be sampled for genetic analysis (stored in -80*C), muscle, gill and/or brain tissue will be sampled for gene expression analysis (stored in RNA later). Liver and gonads will be sampled for condition indices analysis (dried in 65°C for two days and the dry weight will be recorded) and histopathology analysis (stored in formaldehyde).

Researchers

Josefine Larsson (MSc), Mats Grahn (supervisor)
institution: School of Natural Science, Technology and Environmental Studies, Södertörn University