Shell Museum: Shells & Bad Weather

“Shells and Bad Water: Ocean Acidification and its Effects on Mollusks”
By José H. Leal, Ph.D., Interim Director & Curator, Bailey-Matthews National Shell Museum

The presenter will discuss the some of the most recent finds and facts about the influence of ocean acidification on mollusks. Mollusks are small, slow-moving, slimy creatures that are barely noticed by most people. But there is much more to them than just a trail of slime or pretty empty shells. Mollusks are the second most diverse group of animals on Earth. There are at least 75,000 known species of mollusks, of which around 60% are marine. They are present in virtually all of Earth’s natural environments and ecosystems, including deserts, cold mountain springs, rainforests, and the deepest ocean trenches. They are important links in the oceans’ food webs. And, given the close association between accelerated increases in dissolved carbon dioxide (ocean acidification) and the chemical processes involved in shell growth, mollusks are probably the earliest to be affected by that human-induced phenomenon.

Ocean acidification is caused by the increased uptake of atmospheric carbon dioxide by sea water. More acidic sea water affects the shells of planktonic (open-water) mollusks, thinning and opening holes in those delicate structures. Acidification is already a tangible threat to several species of planktonic mollusks, including sea butterflies (pteropods), which are key links in open-ocean food webs, serving as food for many species of fish, which in turn feed larger animals such as sea birds, whales, and even polar bears. Recent research also shows, for instance, that the small, delicate larval shells of larger species are adversely affected. Minute increases in the oceans’ acidity going forward will certainly prove to be harmful to large numbers of species of molluscan species.

To celebrate its current “H2O Art Exhibition,” on display at the Bailey-Matthews National Shell Museum from February 9 through April 30, 2021, the Museum is presenting a free three-lecture series on the life-giving liquid, which will be available virtually via Zoom. Visit ShellMuseum.org for link to Zoom invite.