• Wizard Island

    Crater Lake

    National Park Oregon

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  • Stage 1 Fire Restrictions in Effect

    To ensure public safety and to provide the highest degree of protection to park resources, restrictions on campfires, smoking, and fireworks are in effect. More »

  • Vehicle-Free Days on East Rim Drive

    The park will host two vehicle-free days on East Rim Drive, September 20 and 27, 2014. Although East Rim Drive will be closed for these events, all other roads through the park will remain open to vehicular traffic. More »

The food-web in Crater Lake

Figure showing the results of chemical tests on Crater Lake plants and animal showing the crayfish and newts eat similar foods.

Figure shows results of chemical tests on Crater Lake plants and animals indicating that crayfish and newts eat similar foods.

NPS

Researchers have studied the food web of Crater Lake using special chemical tests (stable isotopes of carbon and nitrogen).

  • Kokanee salmon feed on animals found in the middle part of the lake,
  • Rainbow trout feed closer to shore,
  • Introduced crayfish eat similar foods as the Mazama Newt.

Why are these food-web studies important?

  • Food is scarce in Crater Lake,
  • Crayfish are aggressive, they chase and eat newts, and compete for limited food resources,
  • As a result, crayfish may have reduced newt distribution by 50%,
  • Crayfish could eliminate newts from Crater Lake.

Did You Know?

Visitors viewing Crater Lake from the Sinnott Memorial.

An average of 482,000 people visit Crater Lake National Park each year. Open year-round, less than 100,000 people visit the park during the non-summer months.