Nature Notes: A Calcium Deficiency
Calcium. An element that we and billions and billions of organisms cannot live without. All vertebrates, with their vertebral columns and many other bones and teeth need calcium. All shelled mollusks and barnacles require calcium. You don’t find many barnacles, if any, in freshwater environments. Calcium is found in a host of other animals where it serves a variety of vital functions. Plants don’t metabolize calcium per se, but the calcium in lime or limestone neutralizes acid soils, which inhibits the growth of many plant species, including grasses, forbs, shrubs, and trees.
In the seas, calcium ions help keep marine waters basic with pHs above 7, the value that is neither alkaline nor acidic. Lately we are learning that the oceans are losing some of their alkalinity and even becoming somewhat acidic, especially in estuarine and coastal waters. We can’t survive without calcium, and neither can the oceans!
Think about all those marine fishes that live in the ocean and are harvested daily for food, fishmeal or, even, fertilizer. Think of all of those shellfish — the clams, mussels, sea scallops, oysters — that are gleaned from seawater daily to satisfy our palates. We don’t eat the calcium portions. We throw them away in the trash and they end up in landfills or are buried with other municipal garbage. Native Americans caught and ate a lot of shellfish, as well as bony fish and other vertebrates. Where did the hard parts end up? In kitchen middens, deposited in upland sites generally quite a ways from the nearest seawater.
We have two long-term trends running counter to each other. Carbon dioxide is increasing in the atmosphere, and thus more is dissolving each day in ocean waters than previously, so calcium is being removed from ocean waters on an ever-increasing basis. The waters are becoming alarmingly acidic. Calcium input from rivers and groundwater feeds is continuing, but diminishing, as many soils through which groundwater flows, such as those on much of Long Island, are already calcium-depleted. They don’t put crushed oyster shells on roads, trails, and marina parking lots the way the used to do. The only new source of calcium running into marine waters comes from salting roads with calcium salts mined from inland salt deposits, left over from a much earlier time when the seas covered much more of the land’s surface than they do today.
Calcium combines with carbon dioxide to create calcium carbonate, the substance of marine shells. The late John Wood, who grew up in East Hampton and served as a town trustee for many years overseeing the many shellfish waters owned by the trustees, once told me that the shells of clams seemed to be getting softer. He observed in the same breath that we should be putting empty clamshells back in the water rather than throwing them away in upland sites. He was neither a scientist nor a chemist, nevertheless, he was very perceptive and was prophesizing a looming calcium deficiency.
It is interesting that one of the four commissions appointed by Governor Cuomo to prepare for the next Superstorm Sandy suggested oyster beds as a kind of vertically growing natural dam on shoals and coastal flats. Such extensive oyster beds once thrived in the Chesapeake Bay and even in the Great South Bay when the bay was brackish and as salty as the adjacent seas. They were wide and high and the ambient water was rich in calcium gleaned from the older lifeless shells at the bottom of the heap. There is now a revived effort to rebuild those same Chesapeake oyster beds that were removed in the past by harvesting and dredging for navigation.
Likewise, here on Long Island there is a group of shellfish enthusiasts trying to start up oyster beds in Port Jefferson and Stony Brook harbors. The Southampton Town Trustees are also well ahead of the rest of the field here on the South Fork. They’ve been building oyster beds in Shinnecock Bay and elsewhere with the help of the Southampton citizenry. The next time you dig (or buy) clams locally, think about returning the empty shells to the sea, rather than taking them to the nearest recycling dropoff, where they won’t be recycled but shipped off of Long Island with the other non-recyclable garbage.Calcium. An element that we and billions and billions of organisms cannot live without. All vertebrates, with their vertebral columns and many other bones and teeth need calcium. All shelled mollusks and barnacles require calcium. You don’t find many barnacles, if any, in freshwater environments. Calcium is found in a host of other animals where it serves a variety of vital functions. Plants don’t metabolize calcium per se, but the calcium in lime or limestone neutralizes acid soils, which inhibits the growth of many plant species, including grasses, forbs, shrubs, and trees.
In the seas, calcium ions help keep marine waters basic with pHs above 7, the value that is neither alkaline nor acidic. Lately we are learning that the oceans are losing some of their alkalinity and even becoming somewhat acidic, especially in estuarine and coastal waters. We can’t survive without calcium, and neither can the oceans!
Think about all those marine fishes that live in the ocean and are harvested daily for food, fishmeal or, even, fertilizer. Think of all of those shellfish — the clams, mussels, sea scallops, oysters — that are gleaned from seawater daily to satisfy our palates. We don’t eat the calcium portions. We throw them away in the trash and they end up in landfills or are buried with other municipal garbage. Native Americans caught and ate a lot of shellfish, as well as bony fish and other vertebrates. Where did the hard parts end up? In kitchen middens, deposited in upland sites generally quite a ways from the nearest seawater.
We have two long-term trends running counter to each other. Carbon dioxide is increasing in the atmosphere, and thus more is dissolving each day in ocean waters than previously, so calcium is being removed from ocean waters on an ever-increasing basis. The waters are becoming alarmingly acidic. Calcium input from rivers and groundwater feeds is continuing, but diminishing, as many soils through which groundwater flows, such as those on much of Long Island, are already calcium-depleted. They don’t put crushed oyster shells on roads, trails, and marina parking lots the way the used to do. The only new source of calcium running into marine waters comes from salting roads with calcium salts mined from inland salt deposits, left over from a much earlier time when the seas covered much more of the land’s surface than they do today.
Calcium combines with carbon dioxide to create calcium carbonate, the substance of marine shells. The late John Wood, who grew up in East Hampton and served as a town trustee for many years overseeing the many shellfish waters owned by the trustees, once told me that the shells of clams seemed to be getting softer. He observed in the same breath that we should be putting empty clamshells back in the water rather than throwing them away in upland sites. He was neither a scientist nor a chemist, nevertheless, he was very perceptive and was prophesizing a looming calcium deficiency.
It is interesting that one of the four commissions appointed by Governor Cuomo to prepare for the next Superstorm Sandy suggested oyster beds as a kind of vertically growing natural dam on shoals and coastal flats. Such extensive oyster beds once thrived in the Chesapeake Bay and even in the Great South Bay when the bay was brackish and as salty as the adjacent seas. They were wide and high and the ambient water was rich in calcium gleaned from the older lifeless shells at the bottom of the heap. There is now a revived effort to rebuild those same Chesapeake oyster beds that were removed in the past by harvesting and dredging for navigation.
Likewise, here on Long Island there is a group of shellfish enthusiasts trying to start up oyster beds in Port Jefferson and Stony Brook harbors. The Southampton Town Trustees are also well ahead of the rest of the field here on the South Fork. They’ve been building oyster beds in Shinnecock Bay and elsewhere with the help of the Southampton citizenry. The next time you dig (or buy) clams locally, think about returning the empty shells to the sea, rather than taking them to the nearest recycling dropoff, where they won’t be recycled but shipped off of Long Island with the other non-recyclable garbage.