Top Down Studies

What imposes limits to survival?

Top-down effects are those limits to salmon survival imposed by what eats, competes with, weakens or otherwise kills juvenile salmon and steelhead. Targeted studies evaluate predation (what eats salmon and steelhead) and other factors that may be contributing to mortality, including: disease, toxic chemicals, competition between hatchery and wild fish, harmful algae, and aquaculture impacts.

Our Current Top-Down Activities