(c) McGraw Hill Ryerson 2007 Scientists classify freshwater environments by how the water moves.  { rivers (fast moving)  lakes/ponds  marshes/wetlands (slow moving)}. The variety and productivity of organisms found in freshwater environments depends on certain factors Freshwater Environments

Freshwater Environments  How deep sunlight reaches, the nutrient content of the water, the depth of the water, the speed the water is moving, and the oxygen level in the water.  Some organisms need very specific conditions, and others (like stickleback) can adapt to many different environments. Stickleback fish (c) McGraw Hill Ryerson 2007

Life in Lakes and Ponds Life in lakes and ponds is often found near the shallow shore, where there are nutrients for plants and animals Plankton can live in the deeper, sunlit water Plankton are the beginning of many food chains. See page 441  Phytoplankton are plants that produce food by photosynthesis (energy from the sun).  Zooplankton are tiny animals that eat other plankton for food.

Life in Lakes and Ponds Lakes and ponds store run-off as a part of the water cycle, provide habitat for plants and animals, and allow rooted plants to grow and filter water through natural processes. (c) McGraw Hill Ryerson 2007

Wetlands Wetlands are found alongside other bodies of water. One quarter of all wetlands in the world is in Canada. Many wetlands have been destroyed because it was thought they only harboured pests. See page 442

Wetlands Wetlands are very important:  The vegetation removes pollutants from the water  They act as a reservoir to prevent flooding.  Many fish and animals live there.  Thick vegetation helps stabilize surrounding soils.  Many endangered species live parts of their lives there. (c) McGraw Hill Ryerson 2007

Rivers, Streams and Estuaries There are many plants and animals living in these moving waters. What can live in these moving waters depends on:  The temperature of the water  The speed the water is moving  The turbidity of the water Changes in variety or productivity of species in waterways can reveal potential problems. (c) McGraw Hill Ryerson 2007

Rivers, Streams and Estuaries See pages Estuaries are nutrient-rich, brackish water.  In BC, 80% of all coastal wildlife use estuaries, which make up only 3% of the total coastal area. Take the Section Quiz