Mercury gets into the water when items such as deodorant, hand lotions and body washes/shampoos get washed off of humans and get into the water supply.

Has a small concentration of contaminants due to using contaminated water for photosynthesis.

Primary consumers have a higher concentration of contaminants because they consume more energy than producers and receive all of the contaminants from the producers they eat.

As the secondary consumers consume the primary consumers the concentration of toxins gets higher because of the larger amount of energy required for them to consume as well as them consuming the more toxic primary consumers.

The Apex predators have the highest concentration of toxins in the food web because they require the highest energy intake of all of the animals in the web and also consume animals with a high concentration of toxins.