Ocean dumping : hearing before the Subcommittee on Fisheries and Wildlife Conservation and the Environment and the Subcommittee on Oceanography of the Committee on Merchant Marine and Fisheries, House of Representatives, Ninety-third Congress, first session, on H.R. 5450, a bill to amend the Marine Protection, Research, and Sanctuaries Act of 1972, in order to implement the provisions of the convention on the prevention of marine pollution by dumping of wastes and other matter, and for other purposes, June 5, 1973.