Fish die offs happened in 2004 and many other times too.
- New Hypoxic 'Dead Zone' Found Off Oregon Coast ...
www.sciencedaily.com/releases/2004/.../040810091946.ht...
Science Daily
Aug 10, 2004 - For the second time in three years, a hypoxic "deadzone" has formed off the central Oregon Coast. It's killing fish, crabs and other marine life ...