Marine mammal amendments : hearings before the Subcommittee on Fisheries and Wildlife Conservation and the Environment of the Committee on Merchant Marine and Fisheries, House of Representatives, Ninety-fourth Congress, second session, on Save the great whales, H.J. Res. 923 ... April 30, 1976, Killer whales, H.R. 12460, H.R. 12646, S. 3130 ... May 4, 1976, Tuna-porpoise amendments, H.R. 13865, H.R. 13883 ... May 20, 21, 24, 1976