Learn & Explore/Habitats/Streams/Protection

Protection

Protecting native species and keeping Hawai‘i’s streams thriving.

Decline of Native Stream Species

  • Hawai‘i’s streams were once full of native freshwater species like ‘o‘opu and ‘ōpae.
  • Today, many streams are altered, and native species are much less abundant.
  • Main reasons for decline:
    • Population growth: Early 1900s ~150,000 people; today over 1.3 million.
    • Agriculture & ranching: Streams diverted for irrigation.
    • Urbanization & development: Channelization, damming, dumping, and restricted flows.
    • Environmental changes: Higher water temperatures and increase of alien species.

Reasons For Optimism

  • Many streams on neighbor islands still have healthy native populations.
  • Even altered streams can still provide habitat for native species.
  • Positive steps can be taken to restore and improve habitats.

Foundations For Healthy Streams

1.Maintain mauka-makai (mountain-to-sea) lifeline:

  • Ensures native animals can migrate between streams and the ocean.
  • Continuous flow into the ocean is critical for life cycles.

2.Protect riparian (streamside) vegetation:

  • Prevents erosion and reduces sediment/nutrient load.
  • Provides shade and cooler water preferred by native animals.
  • Channelization removes vegetation, increases water temperature, favors alien species, and removes rocks/boulders needed for shelter.

3. Prevent new alien species introductions:

  • Alien species compete with native animals for food and habitat.
  • They prey on native species and can carry harmful parasites and diseases.

How We Can Help Protect Hawai‘i’s Streams

Keep Streams Clean

  • Participate in clean-up programs like the Adopt-A-Stream Program.
  • Dispose of litter properly — wind and rain can carry trash into streams.

Do Not Release Alien Species

  • Returning unwanted pets to pet stores or animal shelters is safer and legal.
  • Alien species compete with native animals, prey on them, and spread parasites/diseases.
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Minimize Pollution

  • Reduce activities that send chemicals or sediment into streams (e.g., car washing, yard watering with fertilizers/pesticides).
  • Treat streets and driveways like “tributaries” — keep them free of oil, chemicals, and other pollutants.
  • Apply fertilizers and pesticides only as prescribed and when dry weather allows.

Learn More About Stream Ecosystems

  • Participate in educational programs from organizations like:
    • Hawai‘i Nature Center
    • Moanalua Gardens Foundation
    • Honolulu Board of Water Supply
    • Local school programs

Attend and Participate in Neighborhood Activities

  • Join board or community events, especially those focused on protecting local streams.