- Futurity.org - http://www.futurity.org - Salmon boom and bust
in extra-long cycles Posted By Sandra Hines-UW On January 22,
2013 @ 12:52 pm In Earth & Environment | No Comments U.
WASHINGTON (US) — Scientists have known that salmon runs vary by
year and by decade, but new research reveals huge cycles in
stocks that last up to 200 years. On the smaller scale, there
are 30-year to 80-year booms and busts in salmon runs in Alaska
and on the West Coast that are driven by the climate pattern
known as the Pacific Decadal Oscillation. The new research shows
that those decadal cycles may overlay even more important,
centuries-long conditions, or regimes, that influence fish
productivity. The researchers found cycles lasting up to 200
years while examining 500-year records of salmon abundance in
Southwest Alaska. Natural variations in the abundance of
spawning salmon are as large as those due to human harvest.
“We’ve been able to reconstruct what salmon runs looked like
before the start of commercial fishing. But ra