Phosphorus: the large algal blooms from phosphorus can cloud the water and block out sunlight for other plants. When algae dies, they sink to the bottom of the lake and begin to decompose. Bacteria feed on this decomposing algae and consume the oxygen in the water, depleting dissolved oxygen for other plant and animal life.
Bacteria: the presence of fecal coliform bacteria, most commonly E. coli, indicates that there are feces from a warm-blooded animal contaminating the water. Contact with outside strains can lead to infection and serious illness. The more closely related the animal is to humans, the greater the chances are for infection to occur if humans come in contact with the bacteria either through drinking contaminated water or while swimming. Ingestion of other organisms who may have accumulated the bacteria in their system may also result in infection.
High Concentration of Heavy Metals: the heavy metals found can kill fish and aquatic plant life and create human health concerns. In Lake Whatcom, smallmouth bass and yellow perch have been found with high mercury concentrations.
Hydrocarbons: some of the hydrocarbon pollutants, such as PAHs, can result in negative health impacts to humans and wildlife.
Pesticides: they threaten aquatic life and can impact our drinking water quality. All pesticides are toxic at some level, but each type varies in its toxicity. While some pesticides may not be harmful to humans, they may be fatal for fish and aquatic invertebrates. Runoff carrying pesticides into our storm drains or directly into lakes and streams may result in serious impacts to fish and wildlife.
Aquatic Invasive Species: they impact the economy and the environment. They can displace and out-compete native species, disrupt entire food webs and decrease native biodiversity, bio-accumulate environmental contaminants and spread toxic algal blooms, attach themselves and damage infrastructure, water conveyance structures, and boats, clog intake structures and impede the flow of water to municipal water supplies, irrigation operations, and power plants, and cause long-term taste and odor problems in drinking water.