-Small animals at the bottom of food chain absorb the chemicals as part of their food. These small animals are then eaten by larger animals that again increases the concentration of chemicals. Animals at the top of hierarchy of food chain have contamination levels millions times higher than the water in which they live. ("ConserveEnergyFuture)
-The biggest source of pollution in the ocean is directly from land based sources, such as oil, dirt, septic tanks, farms, ranches, motor vehicles, among larger sources. Thousands of tons of waste and trash are dumped into the ocean on a daily basis. ("ConserveEnergyFuture)