What are the four H’s?
The four H’s are the four broad categories used by biologists to define human impacts on wild salmon and their environment. Specifically they are Harvest, Habitat, Hydro and Hatcheries.
Together these four have contributed to the decline of wild salmon and steelhead throughout their native range and any effort to recover wild fish must address all four in a comprehensive fashion.
While the specific details vary widely, the bottom line is: wherever there is overharvest, habitat degradation, hydroelectric dams and the widespread use of production hatcheries, populations of wild fish suffer.