Bioaccumulation, contaminants, biological effects and benthic ecology

The following studies aimed to provide essential information for an integrated assessment of the health status of Cardigan Bay marine environment. During the cruise samples were collected to study the status of the seabed, presence of contaminants in sediments and biota, biological effects, species living in the habitat as indicators of the environmental quality and diversity.

Samples for bioaccumulation study (measurement of contaminants in vertebrates and invertebrates) were collected from the same trawls as samples for the fish disease and biomarker studies. Whole fish specimens (dab and plaice) were selected from the trawled samples collected at South-Inner Cardigan Bay area and Red Wharf Bay (station 1 and station 4 respectively). Invertebrates (whelks, hermit crabs, bivalves and shrimps) were also selected from the trawling samples collected at South-Inner Cardigan Bay, North Cardigan Bay and Red Wharf Bay (stations 1, 3 and 4). Fish and epifauna specimens were frozen for further analysis, and available bile from plaice was extracted to explore other methods to study bioaccumulation.

Sediment samples were collected to study the 1) contaminants content, 2) physical and chemical characteristics, 3) biological effects through screening bioassays. Sediment samples were collected at station 1 to 4, corresponding to the areas of trawling South-Inner Cardigan Bay, Inner Cardigan Bay, North Cardigan Bay and Red Wharf Bay. All sediment samples were frozen.

Benthic epifauna organisms were collected for examination and identification from the trawls at South-Inner Cardigan Bay, North Cardigan Bay and Red Wharf Bay (stations 1, 2, and 4). A preliminary assessment of the specimens collected carried out onboard did not revealed any signs or indication of abnormality. Reference samples for species identification was fixed in formalin.

Note: Weather conditions did not allow the sampling of macrofauna or sediment profile.