A fish-heavy diet can help curb human depression,
but what if I told you those fish might have
been raised in a depression-prone sadness
farm?
Yep, a new study published in Royal Society
Open Science argues that growth-stunted, anorexic
"drop-out" fish that float listlessly at the
surface of their overcrowded tanks are suffering
from severe depression. After all, we're not
talking about a ritzy aquarium or a stocked
pond, here. These drop outs swim about in
cramped, unnatural, stressful aquaculture
environments that have more in common with
cattle feed lots, overstuffed prisons or those
human battery towers in "The Matrix." Now
I know what you're thinking: Even fish pain
remains something of a contentious issue,
so how do we get to the idea of depressed
fish? According to lead study author Marco
Vindas, the doomed drop-out fish express behavior
and brain chemistry in line with depression
in other organisms -- namely, high levels
of the stress-response hormone cortisol. They
found that drop-out salmon’s serotonergic
systems, which regulate cortisol, were overactive,
overstimulated and defunct. The fish were
so stressed that they didn’t respond to
further stress. Human/fish ethics aside, growth-stunted
drop-out fish are a common and costly occurrence
in salmon aquaculture, so farmers have more
to gain than a "Sadness-free fish" sticker
in tackling the problem. And they don't necessarily
have to improve tank conditions if they can
improve the fish through research into stress-coping
genetic markers and selective breeding. Hey, then you don't have to change a thing.
Though,
the paper also indicates that several common
aquaculture practices may play a role, including
the employment of stressful vaccinations soon
after smoltification, the naturally-stressful
physiological adaptation of juvenile salmon
from fresh water to sea water. Vindas, a marine
biologist at the University of Gothenburg,
also believes these findings could eventually
aid in the medical prevention of human stress-based
pathologies -- as well as the depression you
might feel about the source of your fish sticks.
How does that sit with you? Let us know and
if you crave more weird science wonders, be
sure to visit now.howstuffworks.com each and
every day.
