The food-web in Crater Lake


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


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?