Air Pollution Deposits
Four major groups of air pollutants affect water quality. They are:
- 1. Organic chemicals, which stay in the environment for long periods of times, bioaccumulate (the uptake, retention, and concentration of environmental substances by an organism) from low concentrations in water to high concentrations in animal tissue, and are highly toxic at low levels
- 2. Mercury, which is found in air, water, soils, and sediments, is transformed into a very toxic compound for fish, wildlife, and humans, known as monomethyl mercury
- 3. Nutrients which are carried through the air into bodies of water and can accelerate eutrophication (a process by which pollutants increase organic and mineral nutrients in a body of water and affect it adversely)
- 4. Deposits of heavy metals and other contaminants from processing ore
These pollutants along with others, travel long distances rapidly, and may either be deposited on land or water, dry or wet. They may interact with each other, form new even more complex pollutants, be highly bioaccumulative going from low levels of concentration in the water to high levels of concentration in animal tissue, be highly toxic at very low doses, and persist for long periods of time. They may interact with the environment, stick to surfaces to become available at later dates, or re-volatilize into the air and start the process all over again. Typically, pollutants are evaluated individually; however, they are usually present in various combinations and therefore the results of their presence and the potential damage they do may be hard to predict.
Best Practices for Air Pollution (See Chapter 2, “Air Quality (Outdoor [Ambient] and Indoor)”) Alteration of Habitats
The alteration and destruction of habitat for fish and other marine life may occur from new techniques of fishing including bottom trawling; the cruise ship industry; coastal development; and hydromodification.
There are four major causes of habitat alteration:
- 1. Bottom trawling uses large bag-shaped nets which are pulled along the seafloor and dig into natural habitats, destroying the ecosystem for the targeted as well as non-targeted marine life.
- 2. The cruise ship industry destroys habitat through accidental groundings of ships, but most frequently by the dragging of anchors, sometimes weighing as much as 5 tons, along with the chains, through coral reefs, sea grass beds, and sea floors.
- 3. Coastal development, since 60% of the world's population lives within 60 miles of a coast, has threatened the oceans and the land in the event of storms by destroying or changing the coastal marshes and estuaries (a shallow body of water where a river meets the ocean and fresh water and ocean water mix).
- 4. Hydromodification (physical modification of water systems) occurs when there is a channeling of water, building of dams, and use of techniques to prevent erosion of stream banks and shorelines of lakes and oceans. This can alter the habitat of marine life, change the pattern of water temperature, produce different types of sediments than that which is normally found, and increase the amount and speed at which non-point source pollutants move from the upper portions of the watershed into coastal waters.