Aquatic Ecosystems

1. Aquatic Ecosystems Ch 7 & more

2. Aquatic Ecosystem Food Webs • plankton: tiny organisms that drift with the currents • basis of all aquatic ecosystems • Phytoplankton • Autotrophs • Algae • Zooplankton • Tiny animals or protozoa • Heterotrophs • Eat phytoplankton http://www.lhup.edu/smarvel/Seminar/FALL_2000/Picking/Picking.htm

3. Aquatic Ecosystem Food Webs • Nekton = Free-swimming organisms • Fish, turtles, etc. • Benthos = bottom-dwelling organisms • Mussels, worms, barnacles, etc • Often are attached to bottom surfaces • Decomposers

4. Freshwater vs. Saltwater Salinity = the amount of salt in water • Salt water = marine ecosystems • Coastal ecosystems • Estuaries • Salt marshes • Mangrove swamps • Barrier islands • Coral reefs • Open ocean • Freshwater = no salt • Ponds, lakes & rivers • Marshes and wetlands

5. Ponds and lakes • No current • Levels are divided horizontally • by amount of light • and proximity to shore • Littoral zone: (think light) • Lots of life • Near shore, rooted plants provide food • Off shore, phytoplankton are base • Benthic zone: Bottom • Decomposers (bacteria) • detrivores (eat small bits of organic matter on bottom) • Filter feeders • Shrimp, clams, sponges, crabs etc. http://environment.nationalgeographic.com/environment/photos/freshwater-plants-animals/#/mexican-water-lilly_289_600x450.jpg

6. Threats to Ponds and Lakes Eutrophication (review) • Excess nutrients enter water • Algae bloom, overcrowd and die • Bacteria decompose algae, using up oxygen • Other organisms die for want of oxygen http://www.waterencyclopedia.com/A-Bi/Algal-Blooms-in-Fresh-Water.html

7. Prevention of Eutrophication (review) Agricultural: • Buffer zones between farms and waterways • Control of runoff in areas of high manure concentration • High tech fertilizer application (only as-needed)

8. Eutrophication Prevention Domestic • Lawn-free landscaping

9. Eutrophication Prevention Domestic • Buy phosphate-free products

10. Eutrophication Prevention Domestic • Repair leaky sewer and septic systems

11. Wastewater vs. Stormwater Sources of wastewater: • Dishwasher • Washer • Sink • Shower • bathtub • Toilet • In short, anything that goes down the drain Wastewater goes down sewer lines to a wastewater treatment plant

12. Wastewater vs. Stormwater Stormwater • Water that collects outdoors and gets sent into storm drains • Catch basins are design to collect this runoff

13. Runoff Catch basins take much more than storm water • Oils from cars • Industrial chemicals • Soil from construction sites • Nonpoint-source pollution – cannot be traced back to any single source • Point source pollution: can be traced to a specific source

14. Stormwater runoff • Most stormwater goes directly to a waterway

15. Combined Sewer • Stormwater and wastewater use same system of pipes and get run to water treatment plant http://www.epa.ohio.gov/dsw/cso/csoindex.aspx

16. Combined Sewer Overflow • It works…until it rains hard • In heavy rains, the combined stormwater and wastewater overflow and go directly to the waterways, polluting them • CSO = combined sewer overflow

17. Combined Sewer Overflow Treatment • Extra waste water treatment plant at point where CSO runoff gets to waterway • Stop-gap Better solution: • Separate sewers and stormwater systems

18. Permeability • The ability to allow substances flow through • A permeable surface allows rain to percolate (seep) into the ground. • Examples: • Grass or other plants • Gravel • Dirt • Ground cover like pine straw or wood chips

19. Permeability • Rain washes/flows over an impermeable surface and does not get absorbed into the ground. • Ex: • Rooftops, • roads, • parking lots

20. Permeability permeable impermeable The more impermeable surfaces we have, the more runoff goes straight into the waterways and takes pollutants with it.

21. Wetlands • Areas of nearly constant moisture that contain great biodiversity • Wetlands are often found in estuaries: “where rivers meet the sea” • Large mostly flat areas • Salinity changes with tides • As tide comes in (gets higher), salinity ↑ • As tide goes out (gets lower), salinity ↓ http://bio1152.nicerweb.com/Locked/media/ch52/aquatic-estuary.html

22. Estuaries • Nutrient mixing with tides • Salt water is ______ than fresh water • Heavier/denser • Due to tides and salt/fresh water mixing, nutrients get “trapped” in estuaries. http://www.wwu.edu/salishsea/estuary.shtml

23. Estuaries in Georgia

24. Estuaries in Gulf of Mexico

25. Freshwater Wetlandstwo main types Marshes Swamps Dominated by trees and shrubs • Mostly non-woody plants such as grasses, reeds and cattails

26. swamps Trees have “knees” or buttresses, probably for support in mushy ground Saltwater swamps are mangroves Freshwater swamp http://inchinapinch.com/hab_pgs/marine/mangrove/mangrove.htm

27. Benefits of Wetlands • Filter pollutants • Control flooding • Act as giant sponge, absorbing and slowing water as it flows through • Buffer shorelines against erosion (absorb impact) • Spawning grounds, migration stop and habitat for: • commercially important shellfish and fish • Native species (some rare, endangered) • Recreation

28. Wetlands: Human Impact • Less than ½ of original US wetlands remain • Causes of destruction include • Ports (remember, wetlands are usually in estuaries) • Development (NYC, Miami, Shanghai, New Orleans…etc) • Dams, levees, canals, channels • Pollution from runoff and wastewater • Non-native plants and animals • Sanitary landfills • Mosquito control (drainage, channelization, poisoning) • Channelization: digging channels/canals to drain land

29. Wetlands: Human Impact • Draining wetlands results in: • Loss of benefits stated earlier • Subsidence: ground sinks due to drying out • Salt water intrusion: as wetlands are drained, saltwater seeps in from ocean • This is also a cause of further destruction (positive feedback loop)

30. Wetland Loss Solutions • Mitigation program: • Creating wetlands in new areas to replace their destruction for development (1983) • Mitigation bank: sells newly created wetlands to developers who have to mitigate • Disallow wetland destruction for agriculture (1985)

31. Barrier Islands • Protect mainland and coastal wetlands http://geology.rockbandit.net/2008/09/15/how-barrier-islands-such-as-galveston-work/

32. Barrier islands take the brunt of storms Tuesday, October 30, 2012 Superstorm Sandy: Tuesday A Portion of Harvey Cedars on Long Beach Island, New Jersey is underwater Tuesday, Oct. 30, 2012, a day after Hurricane Sandy blew across the New Jersey barrier islands. http://seattletimes.com/html/photogalleries/nationworld2019559529/