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The City of Portland, Oregon

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

MAILING ADDRESS: 1120 SW 5th Ave, Room 1000, Portland, OR 97204

More Contact Info

Columbia Slough Fish Advisory

Columbia Slough Fish Advisory 

Columbia Slough mapFish in the Columbia Slough contain polychorinated biphenyls (PCBs) and pesticides. These chemicals may affect human development, reproduction, and immune systems, and may increase your chance of getting cancer. 

Who is most at risk?

  • Unborn babies
  • Pregnant women
  • Nursing mothers
  • Women of childbearing age
  • Children
  • People with weakened immune systems, thyroid or liver problems
  • People eating slough fish often and for many years

People in these groups should avoid eating resident fish from the Columbia Slough and instead eat migratory fish like salmon and steelhead. 

Why are these chemicals a problem? 

Even though the concentrations of PCBs and pesticides in slough fish are fairly low, they still pose a health risk because:

  • Babies can be exposed to the chemicals before they are born and through breast milk.
  • These chemicals accumulate in the body and may cause health problems many years after eating the fish.

What are the health risks of eating slough fish? 

Eating fish regularly with these chemicals over time may:

  • Harm unborn children - disrupting their development and ability to learn
  • Harm reproductive and immune systems
  • Increase the risk of cancer

If you choose to eat Columbia Slough fish, you can reduce your health risks by: 

  • Eating no more than one meal a month. A meal is about the size and thickness
    of your hand.
  • Eating smaller, younger fish because they have less contaminants
  • Eating smaller portions
  • Never eating carp, bass and catfish.

Follow these steps:

  • Healthy fish preparation diagramCut off and throw away the head, skin, fatty parts, and guts. PCBs and pesticides build up in these areas.
  • Bake or broil the fish (without skin and fat) on a rack so the fat drips off. Drain the fat, do not eat the fat drippings.
  • When eating crayfish, eat only the tail and claws.
  • Do not eat head and guts of fish or crayfish. 

Click here to watch an eight-minute video about catching and eating fish from the Columbia Slough. 

Click here to watch a one minute video about the proper way to prepare fish for cooking. 

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Are there safer places to fish? 

Yes, there are many places to fish in Oregon that may be safer to harvest fish from. However, there are fish consumption advisories all over the state. Click here or call 1-877-290-6767 to see if the water you plan to fish has an advisory.

Other Fish Advisories

Harmful chemicals enter rivers and water bodies through storm water running off of roads, parking lots, houses, and lawns. Pollutants also come from business, industry, and farm fields.

Should I stop eating all fish? 

No. Fish are good for your heart and brain. Both are low in fat, high in protein, and rich in nutrients like omega-3 fatty acids. Omega-3's provide protection from heart disease and are an important brain food for you, your children, and your unborn child. 

Fish consumption guidelines are designed to help you gain these health benefits while protecting you and your family from contaminants found in fish. The key is to make smart choices, and choose fish that are low in mercury, PCBs, and other contaminants. In general, younger, smaller fish have fewer contaminants. 

For more ideas on healthy fish preparation, download the What A Catch! Cookbook. (PDF Document 611kb) 

For More Information

For health-related questions, contact the Oregon Public Health Division’s Office of Environmental Public Health at 1-877-290-6767. 

For Smith and Bybee Lake questions, contact Metro at 503-797-1700.

What is the City doing to stop pollution?

Portland’s Environmental Services is working with the Oregon Department of Environmental Quality (DEQ) to investigate and eliminate sources of fish contamination in the Columbia Slough. 

For several years, Environmental Services has studied contaminants in both the water and sediments of the Columbia Slough. In 2000, Environmental Services finished building the Columbia Slough Combined Sewer Overflow (CSO) projects, which eliminated CSOs to the slough. The city is working on many other projects to improve water quality and fish habitat in the slough. They include:

  • Working with businesses to prevent pollution from industrial and commercial facilities
  • Stopping unauthorized and illegal discharges to storm sewers
  • Installing filters in city storm sewers to remove pollutants
  • Stopping soil erosion
  • Encouraging homeowners to landscape with native plants and reduce pesticide use
  • Building wetlands to filter stormwater
  • Extending City sewers to neighborhoods served by septic systems
  • Planting native vegetation on the banks of the Columbia Slough to buffer the water from human activity
  • Environmental education and outreach to let residents of the Columbia Slough watershed know how they can help keep rivers and streams clean

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