The family car may not look much like salmon habitat, but there is an intimate connection between the way we use our automobiles and the safety of the rivers as a highway for fish. Oil is a major environmental pollutant. One quart of motor oil is enough to contaminate 250,000 gallons of water, yet Americans annually dump a third of a billion gallons of used motor oil into the environment. Additionally, millions of pounds of lead and other heavy metals, oil, and rubber deposited on the roads gets washed down storm drains and into our streams. Given that toxins in the water can affect the reproductive health, growth and survival of fish, the link between the road and the river is all too strong.
Roads can also have a direct impact on salmon.
Road building and maintenance can result in the removal of streamside vegetation that provides necessary shade and nutrients for fish. Herbicides used to kill roadside weeds can also harm fish if they get into nearby waterways. Excess sediment in the creeks can clog the gravel beds where salmon spawn, impeding the flow of oxygenated water that eggs need to survive. The best way to keep oil and fuel residues out of the environment is to reduce vehicle use in the first place. The next best step is to use vehicles with maximum efficiency.