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Explore the characteristics, organisms, and threats to freshwater ecosystems. Learn about the factors that define these ecosystems, the importance of plankton and nekton, and the impact of nutrient pollution and eutrophication. Discover the functions of wetlands and the diversity of estuaries.
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Environmental Science Aquatic Ecosystems Chapter 7
Objectives • Today we’ll review the section on Freshwater ecosystems. You should be able to: • Characterize aquatic ecosystems • Describe the organisms in aquatic ecosystems • Distinguish benefits of, and threats to the ecosystems.
Do Now! • Describe an aquatic ecosystem that you are familiar with – include biotic and abiotic factors. Be as descriptive as possible.
What are the 5 factors used to characterize aquatic ecosystems? • Temperature • Sunlight • Oxygen • Nutrients • SALINITY
Assignment 2 • Make up an acronym for the factors that characterize aquatic ecosystems. • The Stinky Omelett Never Sticks
SALINITY describes… The amount of dissolved salts (Not limited to halite – other mineral salts too) in water. • Freshwaterhas little salt content • Marinewater has great salt content
Aquatic Organisms • Plankton – live near or at surface - Phytoplankton (Microscopic Plants) - Zooplankton (Microscopic Animals) What is the function of plankton ?
Plankton • Zooplankton • Phytoplankton
Nekton ? IMPORTANCE ?
Littoral Zone – near the shore…. Benthic Zone – deep bottom area…. Freshwater Ecosystems
Excess nutrients stimulate plant growth, often called an algal bloom. This reduces dissolved oxygen when dead plant material decomposes and can cause other organisms to die. EutrophicationNutrient Pollution Eutrophic Pond
Eutrophication • Results in low Oxygen • Eventually kills fish
Where do the excess nutrients come from? • Fertilizers applied to agricultural fields • golf courses, and suburban lawns • nitrogen from the atmosphere • erosion of soil containing nutrients • sewage treatment plant discharges • Water with a low concentration of dissolved oxygen is called hypoxic.
WETLANDS • Areas of land covered in water for part of the year – What are two types of wetlands? • Marshes • Swamps - mangrove • Perform several IMPORTANT environmental functions. • Industrial and residential development are very hazardous to wetland ecosystems. • Nat Geo
WETLANDSPlants Swamps Marshes Woody shrubs and water loving trees. Non-woody plants, reeds, cattails, water lilies.
Environmental Functions of Wetlands • Trap and filter sediments and pollutants • Reduce the chance of flood • Protect shorelines against erosion • Provide spawning grounds for animals • Provide habitat for animals • Provide recreational areas • Bohemia wetlands
Assignment – • Review questions • Rivers of North America study geography website – this will be a paper test.
Waters importance on Civilization • Crash Course - John not Hank
Rivers • Usually originate from snow melt in mountains. • Fast, oxygen rich waters at the source and slower, calmer water farther downstream. • We’ll do a lab next week exploring watersheds.
The End – Section 1 • Use the remaining time to begin work.
DO NOW… for points • Have you ever been to a beach? • What do you like best about it? • What do you eat there? What animals do you see there? • Describe your perfect beach (please no naked people…) • What characteristics make a beach? • Think about other coastal areas ‘beach’ or not – what makes them a special environment?
Coastal Wetlands BACKGROUND • Areas of land covered by salt water for all or part of the year. DO NOW • What type of adaptations do the animals who live in coastal wetlands have? • What are some important environmental functions of wetlands? List below in notebook.
Estuaries • Fresh water from a river mixes with salt water in the ocean. • Results in mineral rich mud which in turn traps nutrients. So what is the benefit of nutrient rich mud?
Types of Estuaries • Salt Marsh • Mangrove Swamp • Coastal rocky and sandy shores • What characteristics make them different?
Types of Estuaries • These three wetland environments have many distinct differences based on water content and availability, plant life, and location.
Salt Marshes • Coastal , upper intertidal system between land and open sea water, low energy • Located on Atlantic coast, and high latitudes (mangroves in low lats) • Salt tolerant marsh grasses dominate • Consist of mudflats or tidal flats fed by rivers • water levels fluctuate with the tide • Trapping and binding sediments, depositional • Provides coastal protection
Mangrove Swamps • Saline environment ranges from 4% salt pure sea water to 9% due to evaporation. • Located in tropical and sub-tropical areas • Woodland, shrubland where mangrove trees dominate • protected estuary with low wave action • Depositional environment, high in organic sediments
Coastal Sandy Shores • Loose deposits of sand, gravel or shells, • Make up 2/3 of the world’s ice free coastlines • Beaches serve as a buffer zone or shock absorbers protecting the coastline.
Coastal Rocky Shores • Intertidal • Consists of solid ROCKS • Cliffs, pools , platforms and boulder fields • Continuously battered by waves and tide action, they are characterized by erosional features.
ESTUARIES Benefits of nutrient rich mud… Protected from the open ocean… Brackish water….
What IS an Estuary? • Estuaries are bodies of water and their surrounding coastal habitats - typically found where rivers meet the sea.
What is so special about an ESTUARY? • Estuaries harbor unique plant and animal communities because their waters are brackish—a mixture of fresh water draining from the land and salty seawater.
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