15. 1 Humans eat at all trophic levels Only about 1 percent of the solar energy A food pyramid reaching the Earth's Fishers surface is used in Large fish eg. sharks photosynthesis producing 170 billion small fish eg. whiting tons of organic Small invertebrates eg crabs, puppies material per year carbon dioxide; water→→ sugars+ oxygen+ energy Trophic structure(food k业速2W业速 chains Producers, eg mangroves seagrasses or algae Sun's energy15.1 Humans eat at all trophic levels • Only about 1 percent of the solar energy reaching the Earth’s surface is used in photosynthesis, producing 170 billion tons of organic material per year. • Trophic structure (food chains)