Matt Stanelle
Hour 3 11/19/01
Fish Contamination in the Great Lakes
Defining Problem / Research Question
There are many chemicals in the water but only at a very low concentration. Some of these chemicals can bioaccumulate in aquatic organisms and can become very concentrated with chemicals such as: toxaphene and PCBs. Small fish and zooplankton eat large quantities of phytoplankton. Any of the chemicals accumulated in the phytoplankton become even more concentrated in that animals that eat them. This is the same for every step in the food chain. Fish like lake trout and lake salmon can have contamination levels millions of times higher than that of the water they live in. In fact, all foods, including fish, contain environmental contaminants.
State and provincial governments provide information to consumers regarding consumption of sport-caught fish. This involves interpretation of studies of health effects from exposure to contaminants. Some effects may include numbness of fingertips, dizziness, and the sensory loss that might occur from toxic exposure to methyl mercury. It is important that people are aware of contaminants in fish and the actions that can be taken to reduce exposure, particularly those people who are at the greatest risk from overexposure to contaminants found in fish. Precise levels that can strongly affect a person may vary depending on his/her age, sex, genetics, current physical condition, and previous exposure. People are high risks are those who eat a lot of great lake fish, regularly eat large predator fish, eat fish from highly contaminated waters, or eat a large amount of fish over a short period of time. Young children and fetus' are at the greatest risk.
Hour 3 11/19/01
Fish Contamination in the Great Lakes
Defining Problem / Research Question
There are many chemicals in the water but only at a very low concentration. Some of these chemicals can bioaccumulate in aquatic organisms and can become very concentrated with chemicals such as: toxaphene and PCBs. Small fish and zooplankton eat large quantities of phytoplankton. Any of the chemicals accumulated in the phytoplankton become even more concentrated in that animals that eat them. This is the same for every step in the food chain. Fish like lake trout and lake salmon can have contamination levels millions of times higher than that of the water they live in. In fact, all foods, including fish, contain environmental contaminants.
State and provincial governments provide information to consumers regarding consumption of sport-caught fish. This involves interpretation of studies of health effects from exposure to contaminants. Some effects may include numbness of fingertips, dizziness, and the sensory loss that might occur from toxic exposure to methyl mercury. It is important that people are aware of contaminants in fish and the actions that can be taken to reduce exposure, particularly those people who are at the greatest risk from overexposure to contaminants found in fish. Precise levels that can strongly affect a person may vary depending on his/her age, sex, genetics, current physical condition, and previous exposure. People are high risks are those who eat a lot of great lake fish, regularly eat large predator fish, eat fish from highly contaminated waters, or eat a large amount of fish over a short period of time. Young children and fetus' are at the greatest risk.
