A Rainbow Trout caught in Crater Lake.
Crater Lake contains kokanee salmon and rainbow trout
- the introduction of these fish is the greatest human impact on Crater Lake
- Kokanee exhibit a boom and bust cycle in abundance over about a ten year
- when the kokanee are abundant certain zooplankton become scarce due to predation
- the kokanee "eat themselves out of house and home"
- kokanee vary widely in size and maturity during the boom/bust cycles
- when the zooplankton prey is scarce size is reduced and fewer reach maturity