8-4 Why Are Freshwater Ecosystems Important? Concept 8-4 Freshwater ecosystems provide major ecological and economic services, and are irreplaceable reservoirs of biodiversity.

Water Stands in Some Freshwater Systems and Flows in Others (1) Two main types of freshwater life zones… Standing (___________) bodies of freshwater Lakes Ponds Inland wetlands Flowing (______________) systems of freshwater Streams Rivers lentic lotic

Fig. 8-15, p. 181 Natural Capital Freshwater Systems Ecological ServicesEconomic Services Climate moderationFood Nutrient cycling Drinking water Waste treatment Irrigation water Flood control Groundwater recharge Hydroelectricity Habitats for many species Transportation corridors Genetic resources and biodiversity Recreation Scientific informationEmployment

Water Stands in Some Freshwater Systems and Flows in Others (2) Lakes are large natural bodies of standing freshwater formed when precipitation, runoff, streams, and groundwater seepage fill ___________________ in the earth’s surface Deep lakes have four zones based on ___________ and ________________from shore depressions depth distance

Fig. 8-16, p. 182 Painted turtle Blue-winged teal Green frog Muskrat Pond snail Littoral zone Plankton Diving beetle Northern pike Yellow perch Bloodworms

Water Stands in Some Freshwater Systems and Flows in Others (2) 1._________________ zone Near shore where _______________ plants grow High biodiversity Turtles, frogs, crayfish, some fish 2._________________ zone Open, sunlight area ______________ from shore Main photosynthetic zone….produces most of the _________ and ________________ that support most of the lakes consumers Some larger fish Littoral rooted Limnetic away foodoxygen

Water Stands in Some Freshwater Systems and Flows in Others (3) 3._____________________ zone Deep water, too _____________ for photosynthesis Low oxygen levels Some fish 4.___________________ zone Decomposers Detritus feeders Some fish Nourished primarily by dead matter that _________ from upper layers Profundal dark Benthic sinks

Some Lakes Have More Nutrients Than Others Lakes with a small supply of plant nutrients are called ____________________ lakes Low levels of nutrients and low NPP Very clear water Often ___________ Fed by ___________ or mountain streams Can collect nutrients over time oligotrophic deep glaciers

Some Lakes Have More Nutrients Than Others Lakes with a large supply of plant nutrients are called ____________________ lakes High levels of nutrients and high NPP Typically ______________ and murky or green eutrophic shallow

Some Lakes Have More Nutrients Than Others ________________ eutrophication of lakes occurs when human input of nutrients _________________ the eutrophication of lakes. Many lakes fall somewhere between the two extremes and are called ____________________ lakes. Cultural accelerates mesotrophic

Freshwater Streams and Rivers Carry Water from the Mountains to the Oceans Precipitation that does not sink into the ground or evaporate is called ____________________. It becomes runoff when it ____________ into streams A __________________, or drainage basin is the land area that ________________ runoff, sediment, and dissolved substances to a stream Small streams join to form ________________, which flow down hill to the ocean. surface water flows watershed delivers rivers

Waterfall Lake Glacier Rain and snow Rapids Source Zone Transition Zone Tributary Flood plain Oxbow lake Salt marsh Delta Deposited sediment Ocean Water Sediment Floodplain Zone Stepped Art Fig. 8-18, p. 183 Three Zones of River Flow

Source Zone – source of the water Headwaters or highland streams are shallow, cold, clear and ______________ flowing Transition Zone – headwater streams merge to form ___________, deeper, and warmer streams Gentler slopes, slower flow = Increased ____________ Floodplain Zone – ______________ areas More accumulated silt and _______________ (murky) Leads to a ____________....deposited sediment is important for coastal ecosystems rapidly wider sediment low-lying sediment delta

Case Study: Dams, Deltas, Wetlands, Hurricanes, and New Orleans Coastal ecosystems provide ______________ protection against flood and wave damage When we remove these ecosystems, damage from storms and hurricanes is __________________ Dam building, for _____________________ power, also effects coastal ecosystems dams prevent ____________________ from moving along a river and making it to the _____________ area…many _______________ delta areas natural intensified hydroelectric sediment delta sinking

Fig. 8-19, p. 185 New Orleans, Louisiana Flooded by Hurricane Katrina

Fig. 8-20, p. 185 Projection of New Orleans if the Sea Level Rises 0.9 Meter

Freshwater Inland Wetlands Are Vital Sponges (1) Inland wetlands are lands located ________ from coastal areas that are covered with freshwater all or part of the time…excluding lakes, reservoirs and streams Marshes, swamps, prairie potholes Floodplains…receive ____________water during heavy rains Arctic tundra in the _______________ away excess summer

Freshwater Inland Wetlands Are Vital Sponges (2) Provide free ecological and economic services _____________ and degrade toxic wastes _______________ flooding and erosion in other areas Help to replenish ________________ and recharge __________________ aquifers Biodiversity Food and timber Recreation areas Filters Reduce streams groundwater

8-5 How Have Human Activities Affected Freshwater Ecosystems? Concept 8-5 Human activities threaten biodiversity and disrupt ecological and economic services provided by freshwater lakes, rivers, and wetlands.

Human Activities Are Disrupting and Degrading Freshwater Systems Dams and canals _______________ about 40% of the world’s largest rivers Flood control levees and dikes _______________ the rivers from their flood plains Pollutants from cities and farms add excess ________________ to streams, rivers, and lakes Many inland wetlands have been ______________ and replaced with crops or urban development fragment separate nutrients drained

Human Activities Are Disrupting and Degrading Freshwater Systems More than __________ of U.S. inland wetlands no longer exist 80% lost to crop _____________ The rest were lost to mining, logging, oil and gas extraction, highway construction, and urban development Another contributing factor to increased __________ damage in the U.S. half farming flood

Fig. 8-16, p. 182 Pond snail A Plankton Diving beetle Northern pike Yellow perch Bloodworms B C D Review Questions Identify the freshwater lake zones shown below.. Littorall Limnetic Profundal Benthic

Review Questions What are the three zones found along a river? How does dam building affect delta areas? Source, Transition, and Floodplain Zones Prevents sediment from traveling to deltas…sinking deltas