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Lecture 18, 03 Nov 2003 Chapter 9 (Aquatic Ecosystems) Student Presentations Conservation Biology

Lecture 18, 03 Nov 2003 Chapter 9 (Aquatic Ecosystems) Student Presentations Conservation Biology ECOL 406R/506R University of Arizona Fall 2003 Kevin Bonine. Aquatic Ecosystems (CH9) 2. Thank you cards 3. Syllabus Shuffle (Bob Steidl back one class). Readings for Wed (SDCP):.

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Lecture 18, 03 Nov 2003 Chapter 9 (Aquatic Ecosystems) Student Presentations Conservation Biology

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  1. Lecture 18, 03 Nov 2003 Chapter 9 (Aquatic Ecosystems) Student Presentations Conservation Biology ECOL 406R/506R University of Arizona Fall 2003 Kevin Bonine

  2. Aquatic Ecosystems (CH9) • 2. Thank you cards • 3. Syllabus Shuffle (Bob Steidl back one class) Readings for Wed (SDCP): Overview of Reserve Design http://www.co.pima.az.us/cmo/sdcp/reports/d20/096OVE.PDF Listed Species Reserve http://www.co.pima.az.us/cmo/sdcp/reports/d10/021LIS.PDF

  3. Chapter 9 group presentations Monday: 8 minute highlights presentation, + 2 min QnA (board, or overhead, or powerpoint [late Sunday]) Pages: 230-234 Amy Tendick, Galia Bobman, Aurora Fabry-Wood, Leonides Corral 234-238 Ben Joslin, Andrea Vasquez, Bridget Barker, Louise Misztal 239-243 Christopher Deegan, Michael Gilliland, JD Friedrichs 243-248 Dana Backer, Cori Carveth, Sarah Hartwell, Jenna Ramsey 248-255 Erica Sontz, Meghan Jarvie, Ginny Newsome, Linh Nguyen 255-264 Maeveen Behan, Justin Dodds, Lauren Merin

  4. 230-234 Tendick Bobman Fabry-Wood Corral

  5. 234-238 Joslin Vasquez Barker Misztal

  6. Conservation Challenges in Freshwater Habitats • Eutrophication • Acidification • Habitat Alteration • Invasive plant species • Invasive invertebrates • Invasive vertebrates

  7. Conservation Challenges of Freshwater Habitat

  8. The Issues • Eutrophication • Acidification • Habitat Alteration by NIS’s • Plant • Animal

  9. Eutrophication • Natural process of the aging of a lake • In a young lake, the water is cold and clear, and supports little life • Streams drain into the lake, introducing nutrients such as nitrogen and phosphorus, which encourage the growth of aquatic organisms • The lake's fertility increases, and organic remains begin to be deposited on the lake bottom

  10. Eutrophication • Silt and organic debris increase on lake bottom, lake becomes shallower and warmer, less oxygen • Warm-water organisms supplant those that thrive in a cold environment • Marsh plants take root in the shallows and begin to fill in the original lake basin and the lake gives way to a bog, and finally into land • Depending on climate, size of the lake, and other factors, the natural aging of a lake may span thousands of years

  11. Eutrophication • Pollutants from man's activities can radically accelerate the natural aging process • Lakes have been severely eutrophied by sewage, agricultural and industrial wastes

  12. Eutrophication • Primarily from increased nitrates and phosphates, which act as plant nutrients • Stimulate the growth of algae • Cause unsightly scum and unpleasant odors • Reduction of dissolved oxygen, which is vital to other aquatic life • Other pollutants flowing into a lake may poison whole populations of fish • Decomposing remains further deplete the water's dissolved oxygen content

  13. Pollutants • In 1996, the EPA reported to Congress in the National Water Quality Inventory • Approximately 40% of the nation's surveyed lakes, rivers, and estuaries were too polluted for such basic uses as drinking supply, fishing, and swimming • The pollutants include grit, asbestos, phosphates and nitrates, mercury, lead, caustic soda and other sodium compounds, sulfur and sulfuric acid, oils, and petrochemicals

  14. Pollutants • Manufacturing plants pour off undiluted corrosives, poisons, and noxious byproducts • The construction industry discharges slurries of gypsum, cement, abrasives, metals, and poisonous solvents • A pervasive group of contaminants is polychlorinated biphenyl (PCB): components of lubricants, plastic wrappers, and adhesives • Hot water discharged by factories and power plants causes thermal pollution, lower oxygen

  15. Acidification • Hydrogen sulfide, NOx and SO2 from coal burning for electricity • Nitrous oxide from car exhaust • Combine with water to form sulfuric and nitric acid

  16. Acidification • Rain is slightly acidic • Buffering by carbonates, some freshwater systems are more susceptible to acidification • High acidity affects reproduction of fish, amphibians and invertebrates • Direct mortality • Change in chemical reactions, metallic ions may precipitate out of solution • Acidification can happen rapidly: pH from 7 to 4 in 24 hour period in Scotland during heavy rain, massive fish kill

  17. Habitat Alteration By Nonindigenous Species • Aquatic Enviroments Vulnerability • Recent disturbance • Predators absent • Effective Competitors absent • Invasion by Aquatic Plants • 1. IntroductionUsually by humans • 2. Dispersal occurs after survival and reproduction • 3. Adaptation via selection and establishment • 4. Colonization

  18. Eurasian Water Milfoil • Reproduces vegetatively • Often transported by Human activity • Reproduces Rapidly

  19. Distribution in the United States

  20. Other Aquatic Invaders 1. Purple Loosestrife • Chokes out natural vegetation in shallow water 2. Water hyacinth • forms dense mats in deep water

  21. Animal NIS’s in Freshwater • Properties: • High reproductive rates • Wide environmental tolerances • Large dispersal distances 3 Examples:

  22. The Zebra Mussel

  23. The Spread of…

  24. The Carp (Cyrinus carpio)

  25. The Nile Perch (Lates niloticus)

  26. The demise of the Haplochromis spp. of cichlid fish

  27. Take Home Lesson? • “Managers must consider that if (there are chemical alterations to a system or a) nonindigenous (species) enters a system, habitat management and conservation strategies may have to be fundamentally altered to preserve biodiversity.” Van Dyke 2003 (pg 238)

  28. 239-243 Deegan Gilliland Friedrichs

  29. Conserving Aquatic Habitats Managing Sedimentation & Eutrophication

  30. Why?

  31. Mmm ...

  32. … yummy!

  33. The Culprits • Us! (surprise)

  34. Primary Cause: Erosion • modern agricultural runoff • urban sewage & waste disposal • land development -- “impermeability”

  35. Sociopolitical causes need sociopolitical remedies: • We must enact laws & policies to: • Reduce chemical fertilizer use • Remove compounds from urban discharge • Reduce agricultural & landscaping erosion

  36. Urban Abatement no.1

  37. Urban Abatement no.2

  38. Restoration • Dredging • Chemistry • Biomanipulation

  39. Dredging • Remove & Purify Contaminated Sediments

  40. Chemistry -- Riplox method • Oxidize sediment surface to precipitate out phosphorus. • Additional reactions raise O2 levels, stabilize pH, & encourage denitrifying bacteria in the sediment to release excess nitrate as gas into the atmosphere.

  41. Bioremediation

  42. Bioremediation continued

  43. Alternative Stable States • Nutrient inputs • Fish populations • Macrophyte & Periphytic algal populations Turbidity is balanced by:

  44. Thanks.

  45. 243-248 Backer Carveth Hartwell Ramsey

  46. Legislation and Management for Freshwater Environments Sarah, Jenna, Cori and Dana Monday November 3, 2003

  47. The Wild and Scenic Rivers Act • Most significant legislation protecting streams and rivers • Introduced in 1968 Verde River, Arizona

  48. What is it?? • Under this act, a stream or section of a stream is designated as wild and scenic • Protected from any action by any federal agency that would adversely affect its water quality

  49. Problems… • 1990- Less than 2% of U.S. streams were deemed sufficient to merit protection under this act • This means that less than 100,000km out of 5.2 million km’s are protected San Pedro River, Arizona

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