Why Didn’t Salmon Come Back?
By OB B
Salmon most likely didn’t come back, because of their habitat being destroyed. The creek is no longer suitable for a spawn which caused the most likely caused the salmon to find another place to spawn.

Aggresion Between Species
By OB O
Here is a video clip of a Mallard duck feeding on salmon eggs in a spawning pool. The salmon then proceeds to attack the duck, defending its young.