Sea Creatures’ Response to Ocean Acidification Shocks Scientists
Have you ever heard those tales of how dumping toxic waste into water will cause the aquatic life to mutate into something out of science fiction? Well, apparently marine life as of late are going through some shocking changes, and while it may not be like something out of the twilight zone, it sure has baffled scientists.
Acidification of the ocean has been on the rise, thanks to increasing levels of CO2 in the atmosphere. The CO2 dissolves in the water, which makes the water more acidic. This decreases the number of carbonate ions in the ocean, which some marine life use to build their shells and skeletons. Scientists had thought this acidic increase would cause shells of sea creatures to become brittle, but it would seem the opposite has happened. Crabs, lobsters and other such animals have been building more shell when exposed to the acidification, rather than losing shell.
Past studies showed that the changing ocean chemistry was thinning the shells of some microscopic creatures. However, the latest study—published in the journal Geology—shows that 7 out of 18 creatures built more shell when exposed to the acidic changes. One theory comes from former WHOI (Woods Hole Oceanographic Institution) member, Justin B. Ries:
“Most likely the organisms that responded positively were somehow able to manipulate … dissolved inorganic carbon in the fluid from which they precipitated their skeleton in a way that was beneficial to them. They were somehow able to manipulate CO2 … to build their skeletons.”
Apparently the process also affects shell-less sea life, such as algae. A lot more research is needed into this discovery, however. Why does it only affect certain marine life in this way, and not all marine life? What about the impact acidification has on coral? Now that some of the animals have been adapting to higher levels of acidification, what will happen to them if the acidic levels should drop again?
A lot of questions definitely need to be answered, especially in regards to the way animals have responded to the acidic changes. According to study co-author and WHOI research specialist, Anne L. Cohen:
“We were surprised that some organisms didn’t behave in the way we expected under elevated CO2. What was really interesting was that some of the creatures, the coral, the hard clam and the lobster, for example, didn’t seem to care about CO2 until it was higher than about 1,000 parts per million [ppm. Current levels are at 380 ppm.]. I wouldn’t make any predictions based on these results. What these results indicate to us is that the organism response to elevated CO2 levels is complex and we now need to go back and study each organism in detail.”
Given the amount of sea creatures scientists already know about, and the possible amount they have yet to find, this study could take quite a while to complete. It is an interesting thing to see the creatures adapt in such a way, but is it really a good thing?
By Heidi Marshall