Related by context. Frequent words. (Click for all words.) 63 oceans 59 Polar Regions 58 ocean 57 polar caps 56 terrestrial ecosystems 56 freshwater ecosystems 55 ocean ecosystems 55 intertidal 55 oceanic 55 biota 55 polar regions 55 kelp forests 54 geomorphology 54 river deltas 54 marine ecosystems 54 seamount 54 hydrological cycle 54 marine biodiversity 54 Weddell Sea 54 glaciers 54 biosphere 53 glacial melt 53 seagrasses 52 coral reefs 52 seamounts 52 landmasses 52 ocean acidity 52 Arctic Ocean 52 icecaps 52 ecosystems 52 landforms 52 marine reptiles 51 Antarctica 51 moon Europa 51 Coral reefs 51 biogeography 51 biodiversity 51 sea 51 melting permafrost 50 mountain glaciers 50 atmospheric chemistry 50 species extinctions 50 freshwater 50 admiral asks 50 tropics 50 polar 50 habitats 50 coastal ecosystems 49 marine sediments 49 ecologies 49 ocean currents 49 glaciers melt 49 Antarctic ice 49 reefs 49 continental shelf 49 aquatic ecosystems 49 aerosol particles 49 mammals 49 subtropical regions 49 polar ice 49 kelp beds 49 Antarctic Peninsula 49 landmass 48 mangrove forests 48 temperature salinity 48 megafauna 48 marine ecosystem 48 extremophiles 48 methane hydrate 48 marine organisms 48 marine invertebrates 48 continental crust 48 zooplankton 48 estuarine 48 glacial melting 48 organisms 48 AP Interview CG 48 corals 48 icecap 48 retreating glaciers 47 phytoplankton 47 aquatic habitats 47 Antarctic 47 Pacific Ocean 47 atmospheric circulation 47 Arctic tundra 47 dugongs 47 Phytoplankton 47 temperate zones 47 stratospheric ozone 47 habitable planet 47 marine ecology 47 sediment cores 47 ocean acidification 47 Tibetan Plateau 47 lithosphere 47 tropical forests 47 benthic 47 earths 47 Saturn moons 47 gas hydrates