WP4.1 Histopathological investigation: We will perform pathological investigations on biobanked and sampled tissues in order to investigate the health from key ecological and commercial upper-trophic level Baltic marine species prioritised in WP2. The health status will be evaluated from post mortem examinations including histopathology, immunocytochemistry, microbiology and parasitology. Tissues of the main organ systems, i.e. respiratory and gastrointestinal tract, reproductive, immune and endocrine systems are routinely preserved in formalin for histopathology, and fresh or frozen samples prepared for further microbiological, virologic, toxicological and parasitological investigations. In addition, skull pathology and morphology of seal species will be investigated using state-of-the-art DXA and CT scanning methods will be employed. The findings will be interpreted in relation to energetic stress (WP2), the exposure to AHSs (WP2), infectious diseases (WP5), and their spatiotemporal dynamics, and the output will feed into WP6.
WP4.2 Development of new biomarkers: A variety of established biomarkers will be used to non-destructively assess how the health of several protected species is impacted by energetic stress (WP2), the exposure to AHSs (WP2), infectious diseases (WP5), and their spatiotemporal dynamics. We will use live peripheral mononuclear cells to quantify AHS-facilitated endocrine impacts, using lymphocyte proliferation and natural killer cell activity. In addition, freshly sampled blood samples will be run for clinical-chemical parameters, in order to perform organ profiling, to study blood cell differentiation, and to identify hemo-parasites. Immune health will be further investigated using general gene transcriptomics and AhR (aryl hydrocarbon receptor) expression. Furthermore, new biomarkers from minimally-invasive biopsy samples will be developed for endocrine, energy metabolism and immune health (e.g. TRα, Leptin, ER1, RARα). The output of WP4.2 will feed into WP6.
WP4.3 In vitro toxicological methods: We will develop new and innovative exposure and effect scenarios on cell lines or collected live lymphocytes from Baltic upper-trophic level wildlife. Known dose-effect relationships from previous conducted experimental semi-field and laboratory studies will be linked to different predicted levels of contaminants. This approach provides the unique opportunity to explore species-specific responses to AHS exposure and disease prevalence, and will complement on-going efforts on Baltic and European Arctic top predators, and will feed into WP4.3 and 6.
WP4.4 Genetic adaptation: This WP will evaluate long-term genetic adaptation in Baltic top predators as a response to AHS exposure. We will employ the output from WP4.3 as well as to be generated data on genomic diversity in different seal species. Data on genomic diversity will be determined by analysis of a large panel of SNPs (10,000s), obtained through genotyping-by-sequencing, and will feed into WP6.
