WATER POLLUTION TERMS
Biological Magnification – The increasing concentration of a harmful, and
usually toxic, substance as it moves up the food chain. The toxins tend to
be stored in the fatty tissues of the animal.
Ex. DDT was 400x more concentrated in top carnivores (eagles, ospreys)
than in the producers. Other pollutants that tend to biomagnify include mercury, lead, and PCBs.
Eutrophication – The process where bodies of water are overloaded with
nutrients. It is often the result of human activities (artificial eutrophication).
Examples include fertilizer runoff, detergents, and leaking sewage.
It can lead to the rapid growth of algae in aquatic ecosystems that ultimately depletes the oxygen levels in the water and reduces water quality. Dissolved oxygen levels drop as excess algae die and decomposers consume the D.O.
Oligotrophic – Refers to a lake that is characterized by low nutrient levels
and plant life. They tend to have high dissolved oxygen levels.
Point Source Pollution – Pollution that is discharged from one location
(often in a concentrated manner). It is easier to regulate because the
source can be traced, identified, and monitored.
Ex. Discharge pipe from a sewage treatment plant, underground storage tanks,
Landfills, septic tanks, storage lagoons.
Non-Point Source Pollution – Pollution that comes from numerous, widespread locations. It can be difficult to pinpoint the sources of the pollution and even harder to regulate the pollution. The EPA estimates that 96% of polluted
bodies of water came from nonpoint sources.
Ex. Pesticide and fertilizer runoff from farms and lawns, oil spills in driveways,
salt applied to roads and sidewalks for ice, storm-water runoff,
chemicals poured down the sink, animal feces.
Limiting Factor - A condition that restricts a population’s growth.
Ex. space, food availability, lack of particular nutrient, pH, oxygen.