Marine ecology-- Ocean ecology-- Sea ecology 117 Marine biology-- Biological oceanography, Marine Science 115 Marine ecology 71 History 65 Latin America 60 Literature 50 Marine pollution 50 Marine biology 39 Marine fishes 31 Marine pollution-- Pollution in Ocean 31 Famines 28 Marine phytoplankton 26 Zooplanktons-- marine invertebrates, marine zooplankton 26 Oceanography 25 Climatic changes 20 Biography 19 Ecology 19 Marine animals 19 Economics 18 Marine mammals 18 Marine resources 18 Dissertations, Academic (Ph.D) 17 Marine animals-- Marine zoology 17 Women 17 Fishes 16 History and criticism 16 Pathology 16 Latin literature 15 Law and legislation 15 Marine sediments 15