switching of the fishery to the more available alternative. We clearly must wait and
observe(!) through at least one more cycling from anchovy to sardines in all of these
regions to more fully understand the control mechanisms. More long-term climate
variation, including anthropogenic warming, may cause such cycles to shift in
duration and in their relationships to atmospheric events.
(^) Regime shifts have major economic and cultural consequences for entire regions
along the coast. There was a dramatic regime shift affecting salmon over the past
three decades. About 1976 there was a fairly sudden warming across the entire
northern reach of the Pacific, at least a 0.5°C increase in mean surface temperatures.
This was beneficial to salmon at the northern end of their range, so that catches in the
northern Gulf of Alaska and eastern Bering Sea climbed to unheard-of heights.
Meanwhile, with warming and probably reduced lower-trophic-level production, the
ocean survival of salmon plummeted off Washington and Oregon, USA. Most stocks
became inadequate to support commercial fishing. Not only was it hard to catch fish
in the Pacific Northwest in the 1980s and early 1990s, but prices were depressed by
abundant, and therefore cheap, salmon from Alaska. Boats were sold, processing
plants closed and port waterfronts were converted to tourist restaurants. In Alaska, in
contrast, boats were purchased, processors expanded, college students got summer
jobs cutting fish, and fishers and others made a good living. In about 1999 there was
another shift, at least off the Oregon and Washington coasts. Ocean survival,
particularly of coho salmon, rebounded, and in 2001 the number of salmon returning
to the Columbia River hatcheries set a record (perhaps partly because ocean fishing
had not yet rebounded in response). Returns have increased and decreased on a year-
to-year basis since. With some one-year exceptions, Alaska catches have remained
high.
Terminology Notes
(^) An elaborate, often cute, terminology has developed around regime shifts, recruitment
variation, and their relationships to fish biology and behavior. Andrew Bakun (2010),
who has coined some of these terms, considers them to represent hypotheses that have
recurring application in understanding stock changes and species interactions in
marine fisheries ecology. For example, we have defined wasp-waisted ecosystems
sufficiently above. Bakun calls these terms “conceptual templates” and “schematic
constructs” (which turn out to be the same thing), basically a tool kit of hypotheses
that may (or may not) be adjusted to fit a specific situation. Here are some more that
are in current use.
(^) Match–mismatch (David Cushing) refers to the necessity for strong recruitment that
spawning of a stock and development of its larval feeding requirements match the