Any destructive or potentially destructive material that is introduced into the environment. For example, paint and solvents poured down the drain and fertilizers washed down rivers into oceans. The EPA has identified at least 67 toxic pollutants in urban runoff which accounts for 84 percent of coastal pollution. Plastic, rubber and foam are sometimes mistaken for food and ingested by animals killing them as a result. Some drown from entaglement, others are choked by plastic rings.
Metals usually contain poisonous materials,including the soldering from tin cans.
Some forms of algae thrive in areas where sewage is dumped. The algae flourish and multiply at such a rate that they can deplete the oxygen supply of surrounding waters. This condition chokes the other inhabitants of the area. Today, many coastal ecosystems and resources have been altered or destroyed by human activity, including pollution, development, dredging, landfill and neglect. The San Fransisco Bay estuary is the largest wetland complex in California, accounting for nearly 90 percent of the our salt marsh acreage.