1. Test #2 Results by Next Week

2. Chapter 10: Biological Productivity

3. Conditions for Life in the Sea Consider the main biochemical reaction for life in the sea, and on earth in general: 6H 2 O + 6CO 2 + energy + nutrients = C 6 H 12 O 6 + 6O 2 Focus on left side of equation What is in short supply in the sea and thus limits the amount of life in the ocean??

4. Absorbing Nutrients 6H 2 O + 6CO 2 + energy + nutrients = C 6 H 12 O 6 + 6O 2  Phytoplankton are base of the food chain  Most important primary producers of complex sugars and oxygen Lauderia sp.

5. The Marine Food Web

6. Absorbing Nutrients  Nutrients absorbed by plants through diffusion across a semi-permeable membrane Lauderia sp.

7. Diffusion: molecules move from high to low concentrations

8. Which Nutrients are in Short Supply?  Nitrogen (N) as Nitrate NO 3 (-2)  Phosphorus (P) as Phosphate PO 4 (-2)  Silicon (Si) as Silicate SiO 4 (-2)

9. Phosphate and Nitrate in the Pacific

10. Silicate in the Pacific

11. Biolimiting Nutrients  N, P, and Si are exhausted first in Eq. surface waters during photosynthesis  Essential to the growth of phytoplankton  If these biolimiting nutrients increase in sea water, life increases  If these biolimiting nutrients decrease in sea water, life decreases  Where would you expect to find the highest biomass in the Pacific??

12. CZCS Global Primary Production

13. How Does Nutrient Distribution Compare w/ Dissolved Oxygen?

14. Dissolved O 2 Reverse of Nutrients  O 2 is high in the surface and mixed layer  O 2 decreases to a minimum at base of thermocline  O 2 then steadily increases with depth

15. Why is the Concentration of Oxygen High in the Mixed Layer?? Hint #1: How and where is oxygen produced in the sea??? 6H 2 O + 6CO 2 + energy + nutrients = C 6 H 12 O 6 + 6O 2 Hint #2: How can oxygen be mixed downward from the atmosphere into the ocean?

16. How is Oxygen Removed from the Thermocline & Slightly Below??

17. Dead and decaying organic matter sinks downward from surface waters  Rate of sinking decreases as it encounters the cold, dense water of the thermocline  Material decays (oxidizes) at the thermocline, which strips O 2 out of the water and returns nutrients to the sea  Cold, nutrient-rich water of the thermocline is returned to sunlit surface waters by way of upwelling

18. CZCS Global Primary Production

19. Marine Ecology Chapter 9

20. Classification of Organisms by Environment  horizontal: neritic | oceanic  vertical: –epipelagic (top) / euphotic (good) –mesopelagic (middle) / disphotic (low) –bathypelagic (deep) / aphotic (without) –abyssopelagic (“bottomless”)

21. Divisions of the Marine Environment Figure 9-1

22. Classification of Organisms by Lifestyle  Scientists have established another classification scheme to categorize biota on the basis of lifestyle. The major groups are: –plankton (floaters) –nekton (swimmers) –benthos (bottom dwellers)

23. Plankton  Plankton are weak swimmers, and are known as drifters, unable to counteract currents. The group includes: –Phytoplankton (plants) –Zooplankton (animals)

24. Nekton  Nekton are active swimmers capable of counteracting currents. The group includes a diversity of organisms including: –Fish –Squids –Reptiles –Birds –Mammals

25. Distribution of Marine Lifestyles  16.7% of Earth’s animals are marine  2% inhabit pelagic environment (most of the oceans are cold and dark)  98% are benthic!

26. Benthos  The benthos includes organisms attached to or living on or in the sea bed. This group includes plants and animals. –Epiflora or epifauna live on the sea bottom. –Infauna live in the sea bottom.  Benthic plants are restricted to shallow waters because of their requirement for light.  Benthic animals occur everywhere from shallow depths to the deep sea.

27. Basic Ecology  physical and chemical parameters distribution and abundance  An ecosystem includes both the living (biotic) and non-living (abiotic) portions of the environment. –Examples include: salt marshes, estuaries, coral reefs, the North Pacific Gyre.

28. Temperature Figure 9-10  controls rates of chemical reactions and thus metabolic rates, growth rates, feeding rates, etc.

29. Salinity  Salinity is a basic property of seawater and it too affects marine organisms. –Many of the elements in seawater are utilized by marine organisms for growth. –Salinity tolerance is also important in limiting distribution.

30. Diffusion: molecules move from high to low concentrations

31. Diffusion/Osmoregulation Figure 9-12 Some organisms can regulate the movement of water into and out of the cells by osmoregulation.

32. Hydrostatic Pressure  Pressure caused by the height of water.  Function of water height and water density  Pressure generally increases at a rate of 1 atm per 10 m of water. ( or 16 psi per 10 m depth)

33. Think You’re Under Pressure Now?

34. Hydrostatic Pressure (Cont.)  enormous in the deep sea yet animals live there.  Animals do not contain gases.  However, mesopelagic fish which have gas-filled swim bladders to help maintain neutral buoyancy –unable to move rapidly between depths –pressure change could cause bladder explode.

35. Oregon Coast Field Trip - Sat., May 21st dusk.geo.orst.edu/oceans/field.html u Be here by 7:00 a.m. u 7:15 - Busses leave from Wilkinson lot u 8:30 - Seal Rock volcanic rocks and tide pools u 11:00 - Lunch at Seal Rock park (bring your own) u 12:00 - HMSC Visitor Center u 1:30ish - Return to Corvallis u Back by 2:30-3:00

36. Required Field Trip Guide dusk.geo.orst.edu/oceans/field.html u Answers to bolded questions in guide –Turn assignment in to your TA –Due by 5:00 p.m., June 3rd

37. Extra Credit #1A - Climate Change Lecture  Bruce Wielicki, NASA, April 4, 2005 –Not enough room in LaSells that evening  Watch DVD finally on reserve in library, VR 695 –1-page reaction paper, typed, double-spaced –Overview, your reaction, and how content relates to this course  Due by 5:00, Thursday, June 2nd –Hand in to your TA please !!! –Worth up to 10 pts. on final exam