Your article on plastic pollution in our oceans (ENVIRONMENT, June 2) brought back memories of fishing on the Chesapeake Bay with my father and watching him go out of his way to clear the waters of debris left by fellow fishermen. Man has used his planet as a giant dump, and even now as other creatures are choking on refuse, man chooses to fill the world with more perils. If we cannot stop ourselves from throwing a beer can overboard, how can we effectively manage nuclear weapons, atomic energy and gene splitting. My hope is that we can; my fear is that we cannot. James R. Vernon Fort Worth The picture of the herring gull sitting proudly but snarled by the plastic mesh of a six-pack haunts me and makes me terribly sad. Richard N. Sorensen Lincoln, Neb.