Science: Quicklime v. Asteroidea

Greatest bane of Atlantic seaboard oystermen is not the four months without R but the family of Asteroidea—starfish. When a starfish wants an oyster, it wraps its arms around an oyster’s shell and pulls. The oyster resists, but its shell-closing muscle eventually tires and its shell gapes. The starfish then intrudes its stomach into the opening, absorbs the oyster. To reduce the numbers of starfish preying on their beds, oystermen frequently drag frayed ropes over the sea bottom. The spiny skins of the starfish become entangled in the ropes and they are hauled to the surface and destroyed.

Last week a more scientific way of dealing with starfish was reported by Science Service from the U. S. Fisheries Biological Laboratory at Milford, Conn. The method, successfully tested in Long Island Sound, is to drop a barrage of quicklime through the water on the oyster beds. Quicklime, which is cheap and corrosive, eats holes in starfishes’ skin, exposes their vitals, finally kills them. A quicklime bombardment of 480 lb. per acre of sea floor disposed of four starfish out of five. The chemical does no appreciable harm to the better-protected oysters, clams, crabs.