CHALLENGES & POLLUTION

• Loss of floodplain, riparian habitat, and river complexity resulting from a range of agricultural and urban development over the decades. In addition to poor fish passage at dams on the tributaries, has resulted in a Threatened listing for Spring Chinook salmon under the Federal Endangered Species Act. 

• A variety of invasive plant and animal species that threaten wild flora and fauna.

• Water quality violations for temperature, bacteria, and mercury. Increases in pesticides, as well as emerging contaminants such as flame retardants.

• Continued permitted point-source pollution that can be problematic for water quality.

• Non point-source pollution or runoff from urban and rural areas.

• Large dams on the  major tributaries that significantly block fish passage, resulting in a Biological Opinion that is being slowly implemented at best to improve fish passage.

• Fish consumption advisories due to mercury and PCBs.

• Storm water overflows can increase bacteria levels. 

• In some areas, increased blue-green algae during the summer months.

• A massive Superfund site in Portland Harbor - with 10 miles of contaminated sediments polluted with historic chemicals such as PCBs, DDT, and oil-based pollutants.