Production and Life

1. Production and Life

2. Textbook HW read p214-221Answer the following questions Why is Detritus important ? Explain Nutrient Regeneration? How is primary production measured? What types of bacteria perform nitrogen fixation? What is a tertiary consumer?

3. Homework • The Oceans Primary Productivity • Study questions 1-14 • Page 4-13

4. Productivity Definitions

5. Primary Productivity • The rate of carbon fixation under a square meter of sea surface in a unit of time • Which means how much glucose is made in a set area during a set time.

6. What is Carbon Fixing Mean??? Carbon is “fixed” (built into an organic molecule) through the process of photosynthesis Carbon is added to hydrogen and oxygen to produce C6H12O6 aka_ glucose

7. Photosynthesis • Fixes carbon into glucose using the energy of sunlight • 6CO2 + 6H2O + sunlight  C6H12O6 + 6O2

8. Chemosynthesis • Fixes carbon into glucose using energy from chemical compounds found at hydrothermal vents (especially hydrogen sulfide) • Base of food chain that doesn’t require sunlight

9. Respiration • The breakdown of glucose in the presence of oxygen to release Energy for life processes • C6H12O6 + 6O2 6CO2 + 6H2O + energy

10. Gross vs Net • Gross primary productivity – total primary production (carbon fixed) • Net primary productivity – amount of primary production minus the amount used by respiration = amount available to support other trophic levels Trophic level ------ a feeding level

11. Biomass and Standing Crop • Biomass = the organic matter that is produced…Many times expressed as a weight • Standing crop = the total amount of plant biomass present in a given volume of water at a given instant • This helps us determine how much life can the area support –Remember Carrying Capacity?

12. Figure 14.1

13. Figure 14.4 Water column stability = less nutrients therefore less BIOMASS Note: Plenty of solar energy little nutrients – tropical location

14. How to measure primary productivity

15. Plankton Net • A fine mesh net used to collect samples of microscope Plankton Extra Credit Make a Plankton Net – 20 points

16. Plankton Net in Tow Plankton net is towed in water. Volume of water is calculated Plankton is collected in tube and is counted. How do they count it? Amount of plankton found in one ml or cc is compared with volume of water

17. Measure standing crop • 3 ways • Filtration of cells – plankton tow • Chlorophyll extraction • Chlorophyll fluorescence – satellite imagery • Drawbacks • Patchy distribution

18. Satellite Imagery One way to measure productivity Measures chlorophyll concentration per square meter of sea surface Only measures top meter of water Limited because blue light penetrates 100 m. That means ONLY1% of possible water column production is measured

20. Production is highest off of the land masses …WHY?

21. What time of year is this in NY?

22. Compensation depth • Depth where the rate of respiration = the rate of photosynthesis • Net productivity will be ZERO

23. Figure 14.8

24. Compensation depth decreases with phytoplankton growthMore Production! Result = reservoir of nutrients below compensation depth

25. The area in the water column where production equals consumption • Biomass • Standing Crop • Compensation depth • Photosynthesis

26. The total amount of plant biomass present in a given volume of water at a given instant • Biomass • Standing Crop • Compensation Depth • Water Column Stability

27. More Productivity in the Nertic Zones is a result of • Nutrient Runoff • More Light • Less Bacteria • Less Light

28. At Compensation Depth Net Productivity will be • 90% • 10% • 1% • 0

29. What percentage of water column productivity is measured in Satellite Imaging • 100% • 99% • 1% • 0%

30. Carbon fixing results in the production of • Carbon Dioxide • Methane • Glucose • Nitrates

31. Fastest Responders (in seconds)

32. Factors that affect primary productivity Light Nutrient availability Water column stability

33. Nutrients are brought by • Runoff (from land) OR • WITHIN THE WATER COLUMN THROUGH: • Upwelling (bottom water wells up as surface water moves away) • Overturn (denser sinks, less dense rises) • Mixing (wind stirs up water column)

34. How to access deep nutrient reservoir • Overturn • But strong winds may mix plankton too deep for photosynthesis • Upwelling • Ekman spiral • Divergence zones

36. Nutrient cycling returns nutrients to the food chain

37. Nutrients

38. Generalized cycle Available Nutrients Decomposition Producers Consumers

39. Nitrogen cycle (Again) Bacteria heavily involved Ammonia  nitrite  nitrate for use by producers N2 fixed for use by producers

40. Phosphate Cycling

41. Nitrogen Cycling

42. Limiting Nutrient The nutrient that runs out first and will limit growth Usually Nitrogen “N” N and P occur in similar concentrations, but producers need more N In Our fish tanks no fish = no nitrates = no algae

43. Redfield Ratio The elemental composition of marine organic matter (dead and living) is fairly constant. The ratios of carbon to nitrogen to phosphorus remaines the same from coastal (Neritic) to open ocean (Oceanic) regions. C :N :P = 106 : 16: 1 Carbon: Nitrogen : Phosphorus (This is molar ratio.)

44. Nutrient Profile versus distance from shore more nutrients less shore open ocean

45. M nutrients Nutrient Profile versus water depth Surface

46. Eutrophication Excess nutrients (N and P) from fertilizers, sewage, etc., cause bloom in producers. As nutrients are depleted, bloom dies all at once. Massive decomposition depletes oxygen  fish kills

47. Alive, healthy and Diverse Dead- Algae covered

48. Productivity in the World

49. What controls productivity by latitude? • Polar – light limits – 6 months of light or darkness • Mid latitudes – light and nutrients limit as they vary over the year • Tropics/ subtropics – nutrients limit

50. Figure 14.3 Peak points of both Nutrients and Solar energy = Peak Production