Freshwater Feeders: Studying Food Webs In Freshwater
Rivers Lakes Ponds and Streams Earth’s surface is more than 70 percent water but only 1 percent is freshwater Freshwater contains very little salt Lakes ponds rivers and streams are freshwater resources Besides drinking water they provide water for sanitation industry agriculture recreation and food Lakes are large bodies of water surrounded by land Ponds are smaller Rivers and streams have flowing water Each type of freshwater has its own ecosystem An ecosystem is made up of plants and animals and non-living things such as water and nutrients The most important part of any ecosystem is its energy source usually the Sun 4 on This UNITED Chew Scientists often study small samples of water so they can better understand how ecosystems work in nature
Erie Ontario Lake Lake Superior Huron Lake Michigan Lake Lake STATES The Great Lakes Huron Ontario Michigan Erie and Superior contain almost 20 percent of the world’s freshwater supply Lake Michigan is the only Great Lake located completely within the United States 5
Salmon have adapted to swim upstream to spawn or lay eggs Some freshwater animals feed on phytoplankton Phytoplankton are tiny free floating plants and plant-like organisms Algae are phytoplankton but are not true plants since they do not have roots stems and leaves Both phytoplankton and plants produce energy when zapped by sunlight This process is called photosynthesis Phytoplankton and plants are primary producers They are the only organisms to make their own food on This Chew More marine biologists study phytoplankton and zoo plankton than study whales 6
A crowd of kokanee salmon make their way upstream in a northern California waterway 7
