Makers and Takers: Studying Food Webs In The Ocean
Water Water Everywhere Oceans may appear to be filled only with clear blue water but they’re brimming with life Scientists believe there is more life in oceans than on land Millions of plants animals and other organisms too tiny to see without special instruments live near the surface One of the many organisms is phytoplankton Since they are mainly one-celled organisms they are not considered plants Small animals called zooplankton feed on phytoplankton Some zooplankton are the larval form or young form of animals like crabs Zooplankton can go through many different forms before they become adults 4 ON THIS CHEW Early explorers named the deepest ocean Pacific because it looked peaceful to them
Without phytoplankton ocean animals could not exist Sometimes phytoplankton grows in such large numbers satellites detect it from space 5
Sweet As Honey As phytoplankton float on the surface they capture energy from sunlight and make glucose which is a sugar This is called photosynthesis Marine animals eat glucose to survive It’s the same glucose people taste when eating honey or apples The transfer of energy from the Sun to phytoplankton is the first link in the ocean’s food chain As animals eat phytoplankton energy is transferred from plant to animal forming a second food chain link Octopuses eat shrimp lobster crab and snails 6
Energy transfer occurs any time an animal eats phytoplankton plants or animals Each transfer links food together in a food chain Ocean animals often eat more than one type of food Some eat different foods at different stages of their life This causes the food chain to branch off into a tangled web of eating and being eaten Instead of a simple food chain the transfer of energy is actually many chains interconnected into a food web An Ocean Food Chain If ON THIS CHEW fishermen know where phytoplankton grow they can cast their lines and reel in fish after fish sunlight phytoplankton zooplankton fish 7
