What hidden substances are we are eating when we eat game fish?

Land predators, like people, mostly eat animals that are plant eaters. In the ocean it is a bit different. The little plant plankton are eaten by other tiny animal plankton, then larger animals are eaten in turn by larger fish and again by larger fish and so on to the high level predators, the sharks. There is no equivalent predator on the land.

Each time an animal is eaten by another you could almost say that the elements of that animal are condensed and concentrated inside the one that ate it. A toxic element, mercury for example, becomes increasingly concentrated in higher ocean predators like tuna, swordfish and sharks.

Take some time to research which government bodies are responsible for the quality of the stormwater run-off into the rivers, lakes and ocean. Is it the same organisation(s) for both the urban and rural areas?

• Locate the stormwater drain nearest to your school. Arrange a visit from a local WaterWatch or water monitoring group and ask them to demonstrate water testing at the drain outlet.
• Determine a regime for continued testing and a protocol for raising the alert if findings are considered outside of norms.
• Design a communication strategy to make relevant stakeholders (who are they?) aware of any problems or good news reports.
• Present your findings and recommendations to the class and write an article for the school news.