Most folks know that oysters were good for the Chesapeake Bay generations ago. They filtered the water better than anything man-made. Then pollution and a few oyster diseases culled their numbers.
But Roger Mann of the Virginia Institute of Marine Science adds another benefit--buffering the increasing acidity of water. It seems that ocean acidity has increased by 30 percent since the Industrial Revolution and that oyster reefs can act like a giant bottle of Tums. Their calcium carbonate content reduces the acidity by changing the pH.
Mann's study estimates that oysters were once responsible for 70 percent of all baywide buffering in 1870, but only about 3 percent today. So I'll continue to toss those oyster shells overboard and feel even better about it. Some spat may be able to attach to them and lead a happy life. That is until a waterman harvests them.
The Chesapeake Bay Foundation encourages restaurants to gather up their spent oyster shells and return them. Then they can be cleaned and returned to Bay waters. Click here to learn more about dropping off shells in three Virginia locations.