Lottia digitalis Point on the California coast, "L. digitalis" coexists with the similar species, "Lottia scabra", but each occupies a slightly different habitat. "L. digitalis" tends to occupy vertical rock faces or overhangs and certain horizontal ones clothed by algae and barnacles. "L. digitalis" clump together more often, prefer wave-exposed areas, occupy sites further up the shore and are seldom found in rock pools. Both species move about freely when the tide is up but "L. digitalis" settles in a different location at each low tide whereas "L. scabra" tends to home to the same spot. "L. scabra" has a more rugged
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