Lottia digitalis lobed and irregular. The shell characteristics are very variable. The color is usually brown or dark olive with white patches. The range of "L. digitalis" extends from northern Alaska to northern Mexico. It is a common species and is found among acorn barnacles on vertical rock faces in high to mid-intertidal zones, on both exposed and sheltered coasts. In California, young limpets, up to ten millimetres in diameter, often live on the opercular plates of gooseneck barnacles, "Pollicipes polymerus" and on mussel shells. In both cases, the colouring varies from that of the rock-based form and provides camouflage. At Mission
Drug pollution Drug pollution Drug pollution or pharmaceutical pollution is pollution of the environment with pharmaceutical drugs and their metabolites, which reach the aquatic environment (groundwater, rivers, lakes, and oceans) through wastewater. Drug pollution is therefore mainly a form of water pollution. "Pharmaceutical pollution is now detected in waters throughout the world," said a scientist at the Cary Institute of Ecosystem Studies in Millbrook, New York. "Causes include aging infrastructure, sewage overflows and agricultural runoff. Even when wastewater makes it to sewage treatment facilities, they aren't equipped to remove pharmaceuticals." Most such pollution comes simply from the drugs having been cleared and