Introduction of extra nutrients and toxins

There are two main issues:

1. Eutrophication caused by addition of nutrients, particularly phosphorus from domestic sewage, industry and agriculture.
2. Inputs of persistent pollutants such as heavy metals eg mercury and chlorinated pesticides and industrial chemicals such as PCBs & Dioxins

However, you should be aware that the symptoms of eutrophication were exacerbated by the impact of alien zooplanktivores such as the Alewife. This altered zooplankton composition which in turn altered the algal phytoplankton composition - favouring bluegreen algae. This in turn added to de-oxygenation of the bottom waters and sediments, enhancing nutrient release and adding a further twist to eutrophication

Please Note that the full contents for this page are still being prepared

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Page Author: Dr Rick T Leah, Univ of L'pool - Contents last reviewed 05/01/2007