• Wizard Island

    Crater Lake

    National Park Oregon

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  • 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 »

  • Lost Creek Campground CLOSED Nights of 9/19 and 9/26

    Lost Creek Campground will be CLOSED from 3:00 PM Friday, 9/19 until 5:00 PM Saturday, 9/20 because of the temporary road closure to vehicles on East Rim Drive. It will also be CLOSED from 3:00 PM Friday, 9/26 until 5:00 PM Saturday, 9/27.

  • 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 »

How are crayfish affecting Mazama Newts?

The Mazama Newt likely inhabited the entire lake shoreline since they colonized the lake as early as 6,000 years ago.

  • The figure below shows that the Mazama Newt only occupies 50% of the habitat with crayfish inhabiting the other 50%.
  • There are very few sites with both crayfish and newts.
  • Crayfish were introduced to the lake by humans in 1914 for fish food.
  • Studies with newts and crayfish in tanks show that crayfish will kill newts and/or force then to flee to other areas.

 
Locations of newts and crayfish in Crater Lake.
Locations of Mazama Newts and crayfish in Crater Lake.
NPS
 
food availability with and without crayfish
Experiments show that where crayfish are located in Crater Lake the number of aquatic insects is reduced.  The left (blue) bar shows the number of insects with no crayfish.  The right (red) bar shows insect numbers with crayfish present.  Both crayfish and newts depend upon insects for food.
NPS

Did You Know?

Junior Ranger activity booklet and badge

Kids can earn their Junior Ranger badge year round. Stop in the Steel Visitor Center to pick up the activity booklet and more information.