Related by context. Frequent words. (Click for all words.) 62 reefs 62 coral reefs 61 seamounts 60 seagrasses 59 seabeds 58 subtropical regions 57 freshwater ecosystems 57 corals 57 intertidal 57 kelp beds 56 marine invertebrates 56 terrestrial ecosystems 56 marine organisms 56 Polar Regions 56 marine ecosystems 55 ecosystems 55 Coral reefs 55 seamount 55 coastal estuaries 55 biota 55 aquatic habitats 54 coral 54 lichens 54 oceans 54 river deltas 54 marine sediments 54 glaciers 54 baleen whales 54 coral reef 53 organisms 53 estuaries 53 Weddell Sea 53 oceanic crust 53 seagrass beds 53 habitats 53 Sperm whales 53 species 53 freshwater 53 marine habitats 53 microscopic algae 52 benthic 52 biodiversity hotspots 52 kelp forests 52 boreal forests 52 coral species 52 temperate zones 52 geomorphology 52 basking sharks 52 reef 52 retreating glaciers 52 freshwater lakes 52 aquatic ecosystems 52 freshwater mussels 52 zooplankton 52 aquatic species 52 landmasses 52 aquatic organisms 52 headwater streams 52 marine ecosystem 51 gobies 51 sediment cores 51 petrels 51 tropics 51 microscopic organisms 51 coastal ecosystems 51 marine biodiversity 51 ocean ecosystems 51 molluscs 51 mountain glaciers 51 hydrothermal vents 51 icecaps 51 leatherback turtles 51 vertebrate species 51 waterbirds 51 lake sediments 51 amphibian populations 50 barrier reef 50 filter feeders 50 ocean 50 Volcanic eruptions 50 mammals 50 seabed 50 geological formations 50 sea creatures 50 shorelines 50 biodiversity 50 krill 50 Antarctic Peninsula 50 marine reptiles 50 coral reef ecosystems 50 beaked whales 50 marine mammals 50 extremophiles 50 lichen 50 biosphere 50 leatherbacks 50 Whale sharks 50 harmful algal blooms 50 Humpback whales 50 species extinctions 50 tropical forests