1. Coastal Ecosystems Saving Chesapeake Bay? Lecture 19 Mar 27 http://books.nap.edu/ ; NASA: Phytoplankton pigment concentration data collected with the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). Excellent resource for info. on Chesapeake Bay and its struggles. http://www.chesapeakebay.net/ http://www.chesapeakebay.net/ Extra Credit Letter Due Apr. 4 th (Angel Dropbox) The Wreck of the Edmund Fitzgerald --Gordon Lightfoot Shark in the Water --VV Brown Texas Flood Stevie Ray Vaughan

2. Homework 3 due Apr 1 Required Reading: Endangered sharks and rays win a modicum of protection Appendix II of the Convention on International Trade in Endangered Species (CITES) Read Chapter 15 and Website notes Thanks to Rebecca W.

3. I understand that extra credit letters are worth up to 5% of my final course grade, and: A.are due Apr 4 th and will be subject to electronic plagiarism checking and against previous papers submitted for this class B.must be submitted as a file named with my name, for example Albert Einstein’s file would be: Einstein_Albert.doc or Einstein_Albert.pdf C.are submitted via Angel Dropbox by uploading my file. I will not copy the text of my letter and paste it into the Angel page. D.All of the above E.I do not intend to submit and Extra Credit Letter

4. Corals forming reefs require: a) Clear, warm, shallow waters and sunlight b) High nutrients supplied in upwelling zones c) Abundant dissolved silicon for their skeletons d) Cold water and dark conditions e) a and b Too many Nutrients: Parrot fish eating blue- green algae which is growing over coral

5. Corals : a) Don’t need nutrients and sunlight because they are really just rocks and are not alive. b) East mainly Small fish and shrimp c) Obtain 98% of their food from symbiotic, photosynthetic algae d) Thrive in environments where suspended sediment is high, such as near river mouths e) None of the above

6. The Chesapeake Bay watershed includes the Susquehanna River drainage (shown in green!) Pennsylvania's massive Susquehanna river is Chesapeake bay's biggest tributary Coastal Ecosystems Eutrophication & Hypoxia

7. Chesapeake Bay: Is there a problem? (yes!) Susquehanna River flooding, Port Deposit, Md Pennsylvania's massive Susquehanna river is Chesapeake bay's biggest tributary …Teeming with raw sewage, animal waste and fertilizer runoff, yet responsible for half the Chesapeake Bay's fresh water, the Susquehanna River is the most endangered river in the United States, according to a recent report by American Rivers, a national conservation group

8. Recall: Marine Photosynthesis 6CO 2 + 6H 2 O + energy --> C 6 H 12 O 6 + 6O 2 Requires Nutrients: such as Carbon/Nitrogen/Phosphorous And the sources of these nutrients? In the Oceans: Rivers, Upwelling, Mixing. But too much of a good thing isn’t good! Eutrophication & Hypoxia

9. The Chesapeake Bay Watershed The Chesapeake Bay watershed includes the Susquehanna River system and the Potomac among other smaller rivers and tributaries. In all, parts of 6 states, including some large cities (e.g. Baltimore, Washington DC, Richmond) and industrial regions as well as extensive agricultural tracts, compose the watershed Chesapeake Bay is a drowned estuary, incised by rivers during the last glacial sealevel lowstand and flooded during glacial melting and accompanying sea level rise (by about 6 kyrs. ago)

10. You are in the Chesapeake Bay watershed The Susquehanna River drains into Chesapeake Bay PennState practices impact the Bay (you can “act locally”)

11. Key Definitions Hypoxia-- development of low concentrations of dissolved oxygen. Primarily occurs near bottom and is deleterious to organisms (different organisms have different tolerances) Eutrophication-- an environmental nutrient excess. Occurs when algal production of organic matter exceeds that which can be respired without reducing available dissolved oxygen below dangerous levels

12. Eutrophication-- nutrient excess that leads to excess algal production of organic matter

13. The vicious cycle (Example of Chesapeake Bay): 1.Excess nutrients supplied in rivers to the Bay support luxurious blooms of phytoplankton (microscopic plants) 2.sinking organic matter (that is, the phytoplankton, but sewage and sludge have the same net effect) is oxidized by bacteria, thereby consuming oxygen 3.oxygen deficits occur in bottom waters--these are harmful to benthic organisms, many of which have economic value 4.the nutrients released during respiration in deeper waters are cycled back to the surface and produce more blooms and further organic matter loading a lack of mixing (stratification) resulting from seasonally strong salinity and temperature gradients (surface to bottom) prohibits oxygenation of bottom waters. A Major Problem: Eutrophication

14. Linkages in the Bay How does it work?

15. Phytoplankton Blooms in an Eutrophic Estuary Top panel--May 16, 1995 (source NOAA) Note gradient of chlorophyll concentrations (mg/liter)with highest values near river mouths Eutrophication leads to blooms of nuisance phytoplankton (low food value) and/or toxic “ red tides ” Note Ceratium dinoflagellate to right as an example.

16. Which of the following is/are true A.Fishes and other animals require dissolved oxygen to live in seawater B.Many species of fishes require dissolved oxygen levels of 4 mg/L or higher C.Hypoxia and low levels of dissolved oxygen in the bottom waters of Chesapeake Bay are exacerbated by thermal stratification of the Bay water. D.All of the above E.None of the above Watershed for Chesapeake bay

17. Which of the following is/are true about Eutrophication A.It starts with excess nutrients, which cause blooms of algae B.It involves bacteria that use (and eventually severely deplete) dissolved oxygen in the process of decomposing organic matter C.It can be cause by sewage discharge into streams and lakes D.the nutrients released during respiration in deeper waters are cycled back to the surface and produce more blooms and further organic matter loading E.All of the above

18. The vicious cycle (Example of Chesapeake Bay): 1.Excess nutrients supplied in rivers to the Bay support luxurious blooms of phytoplankton (microscopic plants) 2.sinking organic matter (that is, the phytoplankton, but sewage and sludge have the same net effect) is oxidized by bacteria, thereby consuming oxygen 3.oxygen deficits occur in bottom waters--these are harmful to benthic organisms, many of which have economic value 4.the nutrients released during respiration in deeper waters are cycled back to the surface and produce more blooms and further organic matter loading a lack of mixing (stratification) resulting from seasonally strong salinity and temperature gradients (surface to bottom) prohibits oxygenation of bottom waters. A Major Problem: Eutrophication

19. The Energy Cycle Note that photosynthesis (and formation of plant organic matter) requires sunlight and nutrients Organic matter is consumed by animals and plants (respiration), supporting their growth Nutrients must be “recycled” (excreted by animals, “regenerated” by bacteria) to be reused by plants Photosynthesis Consumers nutrients

20. Prolonged periods of dissolved oxygen below ~ 2 mg/L eliminate most “ seafood ” from the affected region Each organism has its own tolerance limits Values of dissolved oxygen at or above 5 mg/L are considered “ healthy ” During the summer, 30- 40 % of the volume of the Bay experiences values <5 mg/L A Major Problem: Hypoxia Dissolved Oxygen Concentrations

21. Oxygen Concentrations in Chesapeake Bay, Hypoxia Plan view and cross sections down the Bay showing seasonal contrasts (top March, bottom July) in dissolved oxygen concentration. March July

22. Oxygen Concentrations in Chesapeake Bay, Hypoxia Plan view and cross sections down the Bay showing seasonal contrasts (top March, bottom July) in dissolved oxygen concentration. Oxygen concentrations drop in July because of thermal stratification (reduced mixing) and increased deep respiration. March July

23. Dissolved Oxygen in Bottom Waters, Hypoxia Dissolved oxygen at the bottom varies over the seasons and by region in Chesapeake Bay. Note that summer warming and stratification can bring stressful or lethal conditions. The upper panel provides measurements for 2001-2 at the Bay Bridge, while the bottom panel shows measurements in the Potomac R. sector. Generally, oxygen deficiencies are more severe in the upper Bay.

24. Dissolved oxygen at the bottom varies over the seasons and by region in Chesapeake Bay. Note that summer warming and stratification can bring near lethal conditions.

25. Which of the following are true? A) Rainwater from State College ends up in The Chesapeake Bay B) Excess nutrients in The Bay, and other bodies of water, can cause Eutrophication, which means that dissolved oxygen becomes very low C) Hypoxia is primarily caused by strong winds, which blow away the clouds and evaporation D) All of the above E) (A) and (B)

26. Oxygen Concentrations in Chesapeake Bay A.Are generally higher in surface waters, because oxygen mixes into the water from the air B.Are generally lower in bottom waters C.Generally increase in bottom waters during summer when thermal stratification is strongest D.All of the above E.(A) and (B)

27. Oxygen Concentrations in Chesapeake Bay A.Can become dangerously low during winter when thermal stratification is strongest B.Are especially low near the surface because of wind, waves and mixing C.Become higher during periods of extreme eutrophication D.Are only important for larger fishes; clams and snails can use oxygen from the H20 molecule E.None of the above

28. Eutrophication and Hypoxia Dissolved oxygen in bottom waters varies over the seasons and by region in Chesapeake Bay. Note that summer warming and stratification can bring stressful or lethal conditions. Generally, oxygen deficiencies are more severe in the upper Bay.

29. What’s the source of the problem? Source of Nutrients and Sediment Clearly, agricultural operations are a major source of nutrients on a per acre basis. Widespread adoption of “ best practice ” methods of tilling and fertilizer application would reduce runoff of nutrients Increasing forested regions and/or forest or wetland “ buffers ” along streams could also help reduce nutrient runoff.

30. Excess Nutrients and Sediment in the Bay

31. The Role of Forests and Wetlands When colonists first arrived virtually 100 % of the Chesapeake Bay watershed was forested. By 1850, about 50% of the forests were gone--to clearing for agriculture, timber harvested for building and for fuel.

32. Forests and Forest Buffers When colonists first arrived virtually 100 % of the Chesapeake Bay watershed was forested. By 1850, about 50% of the forests were gone--to clearing for agriculture, timber harvested for building and for fuel. Whole hillsides were stripped of cover and sediment eroded and carried to the Bay in the mid- 19th Century. Seagrass beds and suitable habitats for Blue Crabs, oysters and other shellfish were destroyed as a result. Riparian woodlands are being replanted in new programs.

33. Progress in reducing Nutrient Discharges Phosphorus discharges were reduced after the early 1970s as result of ban on P in laundry detergents! (see, activism can help!). Nitrogen inputs, however, increased but have now started to level off. What are sources of N that could be reduced?

34. Progress in reducing Nutrient Discharges http://www.chesapeakebay.net/indicators/indicator/reducing_nitrogen_pollution

35. Progress in reducing Nutrient Discharges http://www.chesapeakebay.net/indicators/indicator/reducing_nitrogen_pollution

36. When colonists first arrived virtually 100 % of the Chesapeake Bay watershed was forested. By 1850, about 50% of the forests were gone--to clearing for agriculture, timber harvested for building and for fuel. Whole hillsides were stripped of cover and sediment eroded and carried to the Bay in the mid- 19th Century. Seagrass beds and suitable habitats for Blue Crabs, oysters and other shellfish were destroyed as a result. Riparian woodlands are being replanted in new programs. Forests and Forest Buffers

37. Other Impacts Sedimentation (particulates carried by rivers) and shading by phytoplankton blooms has contributed to reductions of the area of Bay grasses, which are habitats for many organisms, especially during larval stages. Bay grass distribution at present is probably only about 20% of the area once inhabited in the Bay. Some recovery is occurring as the result of efforts to reduce sediment and nutrient flux.

38. Oysters in Chesapeake Bay Once plentiful in banks or reefs in the Bay, oysters have been seriously overharvested and have declined for other reasons as well. Commercial landing plummeted around 1980 and have remained low (gray is MD, blue is VA data) Two viral diseases (MSX and Dermo) presently infect Bay oyster populations. In addition, bottom conditions have changed significantly over the past several decades (increased sedimentation, low oxygen). Source: www.assateague.com

39. Blue Crab Holding Pattern Blue crab (Callinectes sapidus, meaning “ beautiful swimmer ” ) stocks are presently on the verge of a potential decline in Chesapeake Bay. Fishing limits have been imposed, but more “ management ” may be necessary to preserve this resource. Read William Warner ’ s “ Beautiful Swimmers ” for a great treatment of Chesapeake Bay ecology as it existed in the 1970s.

40. American Shad (a shad tale?) Once very abundant in mid- Atlantic region rivers, they nearly disappeared. Now making a slow recovery (note: well below carrying capacity) as result of restocking, harvest moratoriums and improved “ fish passages. ” Shad are very bony fish but delectable when cooked properly. Shad roe is a delicacy. See 2002 New Yorker article by John McPhee for very well written description and shad recipes.

41. Evidence of Improvement Increased access to spawning grounds, moratoriums on catches and/or strict limits on harvest have increased striped bass stocks!

42. The Chesapeake Bay Program Encourages Better Practices Voluntary programs of nutrient management appear to have worked to reduce nitrogen levels in many tributaries. New targets need to be set to continue the beneficial trend and to eliminate “ hot spots. ” Remember, you can make a difference!

43. Gulf of Mexico “Dead Zone” Gulf of Mexico, associated with Mississippi River “Hypoxia”: large area of oxygen- deficient seawater Excess nutrients to blame?

44. Hypoxia in Long Island Sound Decreasing area of habitable seafloor as result of increasing oxygen deficiency Factors: poor circulation (restricted exchange with open waters) and eutrophication resulting from progressively increasing inputs of nutrients from land. Decreasing area of habitable seafloor as result of increasing oxygen deficiency Factors: poor circulation (restricted exchange with open waters) and eutrophication resulting from progressively increasing inputs of nutrients from land.

45. http://www.chesapeakebay.net/

46. Nutrients that cause Eutrophication and, ultimately, Hypoxia include A.Nitrogen B.Calcium C.Phosphorous D.Gatorade E.(A) and (C)

47. Why are oxygen concentrations during times of eutrophication generally lowest in the upper Chesapeake Bay? A.This is where the water is deepest? B.This is where thermal stratification is weakest C.This is where nutrients enter the bay, from the Susquehanna and other rivers D.All of the above E.None of the above

48. Effects of Climate Change or Development?

49. Chesapeake Bay “Report Card”

50. Eutrophication A.Is a sign of a healthy ecosystem B.Results from an excess of solar energy C.Is accompanied by low surface-water productivity D.Results from an excess of nutrients E.All of the above

51. Which of the following typically cause(s) excess nutrient and pollutant flows to rivers? A.Croplands A.Clearcut forest tracts A.Storm water runoff A.Automobile emissions A.All of the above

52. A. higher in the winter, in part because bacteria migrate south in winter B. higher in the winter, in part because sunlight is stronger in winter C. lower in the summer, in part because thermal stratification is greatest in summer D. lower in the summer, in part because thermal stratification is weakest in summer A. higher in the winter, in part because bacteria migrate south in winter B. higher in the winter, in part because sunlight is stronger in winter C. lower in the summer, in part because thermal stratification is greatest in summer D. lower in the summer, in part because thermal stratification is weakest in summer Eutrophication causes dissolved oxygen levels to be __: