Chapter 21: Water Pollution3. This article deals with a global issue.
4. Studies have shown that in the Hudson River, fish have developed a gene that makes them immune to the toxic effects of PCBs. This allows the fish to survive even in polluted waters, these fish are very fast evolving fish. For example one of these fish is called the Atlantic Tomcod. PCBs are mainly used for industrial purposes like electrical insulators. PCBs were banned in around 1979, 50 years after they were introduced. Although PCBs were banned the effects of them were still present. A 200-mile stretch along the Hudson River is the nations largest Superfund site. Scientists were fascinated that the Atlantic Tomcod were able to survive even in the contaminated area, so they began to study these fish and found a specific protein that regulates the toxic effects.
5. I think it is great the fish were able to adapt to their environment when it changed but I think it is bad that they had to adapt because of human mistakes. If we didn't use the PCBs the fish wouldn't have a problem. This is one species that was able to adapt but I am sure that there were others that were not able to survive under the harsh contamination and may have declined in population or even became extinct. I think we need to be more careful with the chemicals and toxins we use and how and where we dispose of them because we don't know the effect they will have on other species. Some species may adapt like the Atlantic Tomcod but others may be negatively effected.
6. Dredging- to clear out with a dredge; remove sand, silt, mud, etc., from the bottom of.
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