Oregon Public Broadcasting

Oceanographers are witnessing some of the best survival conditions for sport fish ever recorded off the Pacific Northwest coast.  A strong and sustained upwelling of colder water gets the credit.  Correspondent Tom Banse reports.

Scientists don’t completely understand why the North Pacific basin oscillates between warm and cool phases, each lasting for years.  What we do know is that the cool cycle is more favorable for fish survival, especially for growing salmon. 

Oceanographer Bill Peterson of Newport says it’s become clear the cycle flipped last year.  Cold currents and upwelling are stimulating the food chain near our shores.

Bill Peterson: “That’s certainly been the case.  There’s been a lot of zooplankton and they feed a pretty concise stock of what is called forage fish -- things like anchovies, sardines, herring, and little smelts. Those fishes are the main prey for the salmon.”

Peterson can’t predict how long the favorable ocean conditions will last.  He says it usually takes one or two years after the ocean turns cold for bumper salmon runs to show up in our rivers.