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Oregon Health Authority

Climate Change and Recreational Waters

Use the information below to help integrate climate considerations into your existing public health practice.

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Program Area: Recreational Waters

Climate-related events, like droughts and floods, can have an impact on Oregon's recreational waters.

Key messages

  • Climate change is creating conditions that are more favorable to harmful algal blooms (HABs).
  • Warmer air and water temperatures, more extreme precipitation events, flooding, droughts, and sea level rise can all affect the growth, survival, spread and toxicity of both fresh water and marine toxin-producing algae.
  • If affected water is swallowed, people may experience headaches, cramps, diarrhea, nausea, vomiting, numbness, dizziness, and fever. Children and pets are at increased risk of exposure because of their size and level of activity. People may confuse symptoms with food poisoning.
  • Marine algae can accumulate in shellfish commonly harvested on the Oregon coast. Shellfish harvesting closures are increasing and can have far-reaching economic impacts on coastal communities.
  • Although Oregon’s average annual precipitation is not projected to change, we will likely see rain fall in heavier, more extreme events. The first rainfall after a dry period can increase the levels of contamination in recreational waters, potentially making it unsafe to play or swim.

What can public health practitioners do?

  • Become familiar with water bodies in your jurisdiction that are popular recreational sites.
  • Review OHA’s advisory guidelines for issuing and lifting public health advisories.
  • Proactively communicate risks of HABs by posting educational posters near popular recreational waters.
  • Identify popular recreational areas located near outflows and post signs communicating risks.