The rise of atmospheric CO2 concentration has raised a
myriad of environmental concerns. Environmental chemists are perturbed about methane release from
increased melting of polar ice, climatologists predict the weather to continue
to become more extreme, and biologists and biochemists have shown increased
levels of CO2 can have a detrimental effect on certain species.
Fish failing to adapt to rising carbon dioxide
levels in the ocean, a journal article
published on The Guardian, summarizes a peer-reviewed article called Effects of CO2 on fish behavior
undiminished by transgenerational acclimation. These articles explore
the effect of rising CO2 levels in the ocean on the spiny
damselfish.
The article in The
Guardian explains the general methodology of the spiny damselfish study. The fish were kept in either a control group,
with normal CO2 concentration (446 uatm), a variable group with
moderate CO2 concentration (656 uatm), or a variable group with high
CO2 concentration (912 uatm). The results revealed that when
higher concentrations of CO2 are exposed to the young offspring from
parents both in the control group and the variable groups, they lose their
ability to detect danger from predators (chemical alarm cue) and have a
diminished sense of smell. These findings demonstrated little to no
transgenerational acclimation within the spiny damselfish, which could result in a decline
in their population due to affected brain functions until genetic mutation
allows for adaptation.
The journal article in
The Guardian did a very good job of summarizing the peer-reviewed article.
It provided the methodology of the research study, explained the results, and discussed
the significance of the findings as they relate to the survivability of various
fish species. It
provides enough scientific information for readers to understand the issue, while
not potentially overwhelming those who do not have a scientific background.
Journal Article: http://www.theguardian.com/environment/2014/oct/06/fish-failing-to-adapt-to-rising-carbon-dioxide-levels-in-ocean
I know the article references this briefly, saying the neuronal transmitters are affected, but it would be interesting to see the exact mechanism occuring in the fish that links the causation between high CO2 and decreased ability of defense. It seems to me that it would be something more than just the fish being "increasingly wary," and I would be interested to see if it affected defense mechanisms in the fish, like their lateral line system, for instance.
ReplyDeleteI may be wrong, but I believe the mechanism for this decreased brain functioning is similar to that of humans at dangerous CO2 levels. When higher levels of CO2 are in the air/water, more CO2 enters the lungs/gills, thus allowing more of it to diffuse into the blood. CO2 in the blood can react with water to form bicarbonate (HCO3-), which decreases the binding affinity of oxygen to hemoglobin in our red blood cells. This lower binding affinity causes a lower concentration of oxygen in our blood and lower concentrations of oxygen diffusing into the brain. Lack of oxygen in the brain greatly affects brain functioning.
DeleteI'm glad to see articles that add to the discussion of ocean acidification which include physiological affects on species of marine life. There are many sources on the reduction of photosynthesis in marine plants, but this adds another key factor to the argument to reduce CO2 in the air/water.
ReplyDelete