• 11 Natural history
• 11 Physical geography
• 10 Marine ecology
• 9 Animals
• 8 Ecology
• 8 Marine biology
• 8 Oceanography
• 7 Marine biodiversity
• 7 Ocean
• 2 Coral reefs and islands
• 2 Forests and forestry
• 2 Marine animals
• 2 Ocean waves
• 1 Biotic communities
• 1 Caves
• 1 Climatic changes
• 1 Coasts
• 1 Desert ecology
• 1 Deserts
• 1 Forest ecology
• 1 Fresh water
• 1 Grasslands
• 1 Habitat (Ecology)
• 1 Hydrologic cycle
• 1 Jungles

• 19 Attenborough, David, 1926-
• 19 Discovery Channel (Firm)
• 11 Nihon Hōsō Kyōkai
• 4 Byatt, Andrew
• 3 Brownlow, Mark
• 3 Cordey, Huw
• 2 Berlowitz, Vanessa
• 2 Holmes, Martha, 1961-
• 2 Linfield, Mark
• 1 Allen, Penny, Dr
• 1 Keeling, Jonny

• 11 Earth (Planet)
• 1 Everest, Mount (China and Nepal)
• 1 Himalaya Mountains
• 1 Polar regions

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