Expert: Walter Hintz - 12/24/2005

Question
Hi Walter,  I live in the San Francisco Bay Area and within the last 15 years or so some of the local streams have been cleaned up to that there are reported small scale salmon runs in some of them.  My question is how can salmon runs start in a stream that hasn't had any in years since mature salmon only spawn in steams where they were born.  I have not heard of anyone planting salmon eggs or fry into these streams.  Any ideas?  Thanks very much.  

Answer
Hi Doug:
 I was unaware that salmon have been running in streams in that area.  My question is " Are they spawning in these streams"?   If so it would mean that the idea that they spawn only in streams where they were born is false.
Perhaps the fact that the streams drain a common watershed is a factor.  No one really knows how they get back to the stream where they hatched.