Anthropogenic inputs of copper into the marine environment have increased in recent decades due to a ban on tributyl tin as an antifoulant and its subsequent replacement by copper. Dose-response experiments were conducted to assess the impact of copper on environmentally relevant biota: phytoplankton, brown alga, mussels, and amphipods. Both alga and amphipods assimilated dose-dependent copper concentrations, while mussels did not. Effects of copper exposure included reduced growth of algae, increased superoxide dismutase activity (SOD; an indicator of stress) in mussels and increased mortality in amphipods. Reduced carbon and nitrogen assimilation and a change in diversity were measured in phytoplankton. Environmental surveys were employed to assess the dispersal of copper into water, sediment and biota from fish farm nets. Alga and mussels transplanted to waters adjacent to fish farms were employed to assess copper uptake and impact. A zone of increased copper concentration was found around farms with concentrations decreasing over distance. Within the contaminated zone, or footprint, decreased growth in algae and increased stress in mussels were recorded. By incorporating different trophic levels into an ecotoxicological study this project provided a more detailed view of copper in the coastal ecosystem than those based on one species. Of the methods employed, algae were the most consistent in showing a farm based impact. The different methods and species used together showed the complexity of fish farm copper in the coastal environment. Copper interacts with other farm outputs such as organic matter, which results in an impact over a limited distance from the cages.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:542655 |
| Date | January 2011 |
| Creators | Rodgers, Karen |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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