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.