Rock Fish

[dos ballenas]

Taken from science magazine:

http://www.sciencemag.org/content/327/5963/263.full.pdf

The Secret Lives of Ocean Fish

It’s easy to monitor the health of stocks of salmon because salmon spawn
in small, discrete, and accessible freshwater bodies. Tracking fish in the
ocean is a little tougher. But many scientists argue that ocean fish such as
cod segregate themselves into distinct environments, as salmon do—and
thrive or struggle for the same reasons.
For cod, population health depends on both human fishing and ecological
factors. The 6 billion or so kilograms of cod living off Newfoundland
and Labrador in Canada in the 1940s has dropped to hundreds of
thousands of kilograms today, partly due to overfishing, says George
Rose, a professor of fisheries conservation at Memorial University of
Newfoundland in St. John’s. “People thought little stocks [of cod] weren’t
important, and they got wiped out,” he says. When large stocks faltered
too, nothing could replace them.
But Rose’s research reveals tremendous variation in the way cod stocks
responded to the collapse. “Groups … very close geographically in fact
are subject to very different ecological conditions,” he says. As a result,
“even in the worst possible times, in the 1990s, we had a couple of groups
that were actually doing beautifully.”
Work in biocomplexity—the physical diversity of fish habitats—
explains why. To terrestrial animals (such as humans), oceans look
homogenous—cold, deep, and empty—says Larry Crowder, a marine biologist
at Duke University in Durham, North Carolina. However, oceans have
currents, canyons, mountains, reefs, and forests of plants, which alter a
habitat from top to bottom. Submerged vegetation supports prey at the
expense of predators, given that prey can slip away in tangles of weeds. Fish
rely on submarine currents to transport eggs and larvae from nests to feeding
grounds. Climate change or fishing can alter habitats, and depending
on how a stock’s habitat responds, its population contracts or expands.
To thrive overall, species need to hedge themselves, by finding a balanced
array of habitats to supply more or fewer fish as need be. “I guess it’s
like an orchestra,” Rose says. “You have the horns playing for a bit, then the

strings come in.” –S.K.






Everything is cyclical. There are lots of opinions out there. I think we still don't really know much about most ocean fish. Just do what you feel is right for you.