Freeing the Elwha: "Hatcheries - Saviors or Scourge for Wild Salmon?"
- Grade Level:
- Middle School: Sixth Grade through Eighth Grade
This activity helps students understand the history and roles that hatcheries serve in sustaining commercial fisheries, native fish populations, and saving endangered fish stocks. They will also do their own research on the pros and cons of hatcheries.
Hatcheries were historically a popular tool for propagating large numbers of fish for sustaining commercial fisheries, however, a series of problems have resulted in increasing controversies over their use. Some of the problems include the use of non-native stocks, the development of non-competitive behaviors, and over-stocking fish beyond the natural carrying capacity of the environment at the expense of wild native fish. However, as wild fish runs become threatened with extinction, hatcheries are also proving to be a valuable tool for saving these wild native runs.
- Hatchery: A facility used to rear juvenile fish for the purpose of stocking rivers or lakes, producing fish for commercial fishing activities, or restoring endangered fish populations.
- Carrying Capacity: The largest number of individuals an ecosystem can support, based on food availability, behaviors, and space limitations.
- Gene pool: The total number of genes of every individual in an interbreeding population. A large gene pool indicates high genetic diversity, increased chances of biological fitness, and survival. A small gene pool indicates low genetic diversity, reduced chances of acquiring biological fitness, and increased possibility of extinction.