Under the sea, fish are growing abnormally large ear bones - and it's all our fault.
According to a study published Friday in the prestigious journal Science, boffins at the Scripps Institution of Oceanography at San Diego's University of California have discovered that rising carbon dioxide concentrations in the world's oceans are causing sea bass to grow oversized otoliths - that's boffinspeak for ear bones.
And what causes rising carbon dioxide levels? You guessed it: we humans.
A Scripps statement blames "human activities, particularly fossil fuel burning" for causing "both increased ocean CO2 and ocean acidification."
For the aforementioned bass, big ear bones may be no laughing matter. "Otoliths serve a vital function in fish," says Scripps, "by helping them sense orientation and acceleration."
David Checkley, a Scripps professor and lead author of the study, admits that "At this point one doesn't know what the effects are in terms of anything damaging to the behavior or the survival of the fish with larger otoliths." He adds, however, that "The assumption is that anything that departs significantly from normality is an abnormality and abnormalities at least have the potential for having deleterious effects."
The seafaring researchers plan further studies to determine if the same deformities are occurring in fish other than the sea bass and whether being otolithically big-boned affects a fish's survival and behavior.
"If fish can do just fine or better with larger otoliths then there's no great concern," says Checkley. "But fish have evolved to have their bodies the way they are. The assumption is that if you tweak them in a certain way it's going to change the dynamics of how the otolith helps the fish stay upright, navigate and survive."
We can only hope that the ocean's finned folk never learn of our complicity in their predicament. The briny deep is already a dangerous enough place without it being stocked with billions of enraged - if clumsy - smelt, scrod, grunts, and grunions. ®