Marine ecology-- Ocean ecology-- Sea ecology 117 Marine biology-- Biological oceanography, Marine Science 115 Marine ecology 71 Oceanography 54 Marine pollution 50 Marine biology 39 Marine fishes 31 Marine pollution-- Pollution in Ocean 31 Ecology 26 Fisheries 26 Fishes 26 Marine phytoplankton 26 Zooplanktons-- marine invertebrates, marine zooplankton 26 Fishery management 19 Marine animals 19 Literature 18 Marine mammals 18 Marine resources 18 Marine animals-- Marine zoology 17 Marine sediments 15 Climatic changes 14 Marine Resource- economics 14 Marine insurance 13 Biotechnology 12 Marine chemistry-- Aquatic chemistry 12 Marine environment 12 Marine resources conservation 12 Merchant marine 12 Population studies (Demography) 12 Tourism 12