the dominant species, tolerating food or other conditions less than ideal for it, in order
to obtain the predator avoidance benefits of large schools. This reduces its potential
for increase in one respect, protecting it in another. Mixed schools have been widely
observed. Schooling tendency can be strong enough that huge schools cannot act
effectively to search the habitat for food (they are “trapped”). Maybe. Bakun modifies
this as the school-mix feedback loop – dominant fish with inappropriate behavior (say
some genotype) can lead whole schools to destruction. Maybe.
(^) Optimal stability window (Ann Gargett) – another window. The general suggestion
has been taken from Gargett’s (e.g. 1997) notion that an intermediate level of
turbulence provides ideal biological conditions. Intermediate wind speeds, wave
activity and vertical mixing rates are likely to provide the best conditions for survival.
(^) In addition, a number of explanatory notions have been adopted in fisheries from
general ecological terminology; these are also attempts to generate conceptual
templates. A portfolio effect (coined by Frank Figge) has been claimed by Schindler et
al. (2010) for lake-spawning sockeye salmon. The variability of the overall stock
returning to Bristol Bay, Alaska, is much less that those of the individual runs to
different lakes. Like a stock-investment portfolio, diversification of subpopulation
behavior provides some stability to the overall system. Others are the “rivet
hypothesis” – loss or sharp decline in one or a few species (“rivets” in the ecosystem
structure) can cause general breakdown; and functional compensation – more than
one species provides each function in the habitat, and reduction of one can be
compensated by others, with redundancy providing stability (the opposite of the
popping rivet notion). Like physicists naming quarks, gluons, and charm, fisheries
ecologists will continue to coin suggestive (and cute) terminology.
Status of World Fisheries
(^) The United Nations Food and Agriculture Organization (FAO) is the world’s central
data-gathering authority for fisheries. Each year they produce the FAO Fisheries
Yearbook, an elaborate statistical summary including data from several years prior to
2 years before publication. The FAO has websites with the majority of their recent
graphs and charts. A current review of world fisheries can be found by searching
under fisheries at the following site: http://www.fao.org/.
(^) Basic recent capture fisheries data, as well as inland fisheries and aquaculture
production figures, can be found by following links at:
[http://www.fao.org/fishery/statistics/en (“en” for English, also available in French and](http://www.fao.org/fishery/statistics/en (“en” for English, also available in French and)
Spanish)
(^) Use of the data files may require downloading and installation of the FAO
“Fishstat” software. Some of the more general tables are also available on the