Erwin Reguindin

Proposal Outline

1. Title Page
   1. The Effects of Suspended Glacial Sediments on Light Attenuation and the Implications on Primary Productivity in Glacier Bay, AK
   2. Erwin Reguindin

                                                              i.      School of Oceanography

University of Washington

Seattle, WA 98195-7940

(206) 786-7111

3. March 19, 2008 – March 22, 2008
1. Project Summary
   1. The objective of this study is to understand how glacial sediments (from here on referred to as glacial flour) suspended in the water affect the vertical light attenuation and the implications of light attenuation on phytoplankton primary productivity at Glacier Bay, Alaska.
   2. 8 full depth CTD profiles will be used in the West and East arms of Glacier Bay (surface, 10, 20, photosynthesis max, 50 and 100 meters deep)
   3. Primary production will be estimated via the carbon-14 (¹⁴C) method (Steemann, 1952)
   4. Light attenuation will be inferred using the transmissometer on the CTD
   5. Chlorophyll a will be detected by the in situ fluorometer to help distinguish between what is fluorescing and what isn't (chlorophyll a and sediments)
   6. Photosynthetically active radiation (PAR) will be measured using the in situ PAR sensor on the CTD
2. Introduction
   1. There are not a lot of studies about the distributions of primary production within Glacier Bay National Park.  Although there have been production studies for lakes and terrestrial ecosystems with in Glacier Bay, the oceanic perspective has been overlooked.  Phytoplankton blooms are a reoccurring phenomenon in Glacier Bay National Park, but understanding how light quality and attenuation is affected by glacial flour we can begin to understand the implications on how phytoplankton assimilate carbon with different light intensities.  As its name implies, the area is surrounded by glaciers and I intend to find out how sediments that have come from the glaciers affect light attenuation and primary production.
   2. Primary production by phytoplankton, the base of the food web in the oceanic ecosystem, regulates energy availability to higher trophic levels as well as carbon and oxygen fluxes between the ocean and the atmosphere.  Determining areas which are affected by light attenuation by glacial flour will help us understand how phytoplankton regulate primary productivity.
   3. My hypothesis is that glacial flour will increase light attenuation therefore decreasing available light and will limit phytoplankton primary production in areas more impacted by glacial retreat.
3. Proposed Research
   1. The objective of my research is to understand how primary production is affected by glacial flour.  Light attenuation in the water column will affect the intensities and quality of light to reach at depth.  My primary concern is to study both the West and East arms and compare the two to each other and with time permitting, I would like to study the primary productivity in the central Bay as the affects of light attenuation will be significantly reduced.  Primary production is the process at the beginning of the food web and regulates energy to higher trophic levels from copepods up to whales.  Understanding how light attenuation affect primary production in areas affected by glacial retreat can be used as a framework for future studies of the abundance patterns of higher trophic levels within Glacier Bay's estuarian system.
   2. Methods

                                                              i.      Full depth profile CTD casts will be used to measure conductivity, temperature and density of water

1.      4 full depth CTD profiles will be needed from the West and East arms and Central Bay totaling 12 profiles. 

                                                            ii.      Niskin bottles will  be used to sample water at specified depths.

                                                          iii.      Light attenuation will be measured using the transmissometer on the CTD.  It will measure the clarity of the water and I will be able to infer light attenuation.

1.      Using the transmissometer will not account for light attenuated by phytoplankton.

                                                          iv.      Fluorescence will be measured using the in situ fluorometer and will be used to account for what is chlorophyll a and sediment in the water

                                                            v.      Photosynthetic active radiation (PAR) will be measured using the PAR sensor on the CTD.  It will give me the light extinction coefficient.

1.      Maximum light availability is preferred for the most accurate data so CTD casts will need to be taken between the hours of 1030 and 1500 local time

2.      If cloudy days persist, the recorded PAR will be modeled around the PAR flux measured for that time.

                                                          vi.      Net Primary Production will be measured using the Carbon-14 method as proposed by Steemann, but using on deck incubations instead of in situ incubations.

1.      Carbon-14 radio-active tracer will be introduced to water samples as sodium bicarbonate (NaHCO₃)

2.      Incubations on deck will be for 24 hours to get net primary production which will account for respiration.

3.      b-radiation from plankton will be measured using a scintillation counter on board the Thompson.

4.      A dark bottle experiment/incubation will also be done to get better estimates for respiration.

3. Time schedule

                                                              i.      Full depth CTD casts will take between 45 minutes to 1 hour.  Since the in situ fluorometer and PAR sensor will be on the CTD, it is important to get my samples between the hours of 1030 and 1500 local time to take advantage of maximum light availability. 

                                                            ii.      According to the 2008 Almanac, sunrise and sunset will occur at 7:01 AM and 7:11 PM respectively.

                                                          iii.      Estimated ship/wire time is between 1030 and 1500 hours.

                                                          iv.      The radiation safe zone will be implemented 24 hours a day to meet safety regulations for ¹⁴C radiotracer work so ship time for this work is negligible.

4. Data collection and processing/analyzing

                                                              i.      The transmissometer will be used to determine the clarity of the water and be used to infer light attenuation.  This data will be compared to the PAR sensor data to see what light intensities are making through the water column.  This will give me an idea of how the transmissivity of the water with glacial flour is affecting light quality and allow me to put a quantitative number on light intensity.

1.      The in situ fluorometer is only used to help me determine what is fluorescing and what isn't when compared to the transmissometer data.

                                                            ii.      Water samples will be collected and incorporated with radio-active carbon-14 in the form of sodium bicarbonate.  This test will give me an estimate of the net primary production in the water.

5.  Charts and tables

                                                              i.          

                                       Proposed sampling stations in Glacier Bay National Park

6. There will be no need for any special considerations of analysis of samples from other investigators before my work can effectively be accomplished.  I should have my complete data as soon as I get off the research vessel.
4. Project Budget
   1. Provided at no cost

                                                              i.      $22,000/ day of the R/V Thompson

2. Project costs

                                                              i.      Deck incubator - $3.00/day

                                                            ii.      Transmissometer - $45.00/day

                                                          iii.      CTD - $45.00-135.00/day

1.      niskin bottles - $3-6/day

                                                          iv.      Fluorometer - $15.00/day

                                                            v.      Scintillation Counter - $0.00/day

                                                          vi.      Carbon-14 and testing supplies - $0.00/day

3. Analytical Costs

                                                              i.      I will be processing all of my own data (radiation safety) so no costs will be included in this portion of the outline.

6. References
   1. Behrenfeld, M. J., and Falkowski, P.G., 1997.  A consumer's guide to phytoplankton primary productivity models.  Limnology and Oceanography 42: 1479-1491.
   2. Bricaud, A., and Morel, A.  1986.  Light attenuation and scattering by phytoplankton cells: a theoretical modeling.  Applied Optics 25: 571-580.
   3. Forget, M. H. et al.  2007.  Extraction of photosynthesis-irradiance parameters from phytoplankton production data: demonstration in various aquatic systems.  Journal of Plankton Research 29: 249-262. 
   4. Furuya, K., Hasegawa, O., Yoshikawa, T., and Taguchi, S.  1998.  Photosynthesis-Irradience Relationships of Phytoplankton and Primary Productivity in the Vicinity of Kuroshio Warm Core Ring in Spring.  Journal of Oceanography 54: 545-552.
   5. Galloway, R. A.  1969.  The Use of Isotopes in Measuring Primary Productivity.  Chesapeake Science 10: 331-335.
   6. Halfhill, R. 2006.  Wavelength-specific light attenuation, chlorophyll concentration and phytoplankton communities in Puget Sound.  http://hdl.handle.net/1773/3219.
   7. Hooge, P. N., and Hooge, E. R., 2002.  Fjord Oceanographic Processes in Glacier Bay, Alaska handbook.  Available at www.absc.usgs.gov/glba/oceanography_handbook.pdf.  USGS Alaska Science Center, Glacier Bay Field Station, Gustavus, Alaska.
   8. Jensen, D. K., and Jensen, K. S.  1998.  Light Attenuation and Photosynthesis of Aquatic Plant Communities.  Limnology and Oceanography 43: 396-407.
   9. Lean, D. R. S., and Burnison, B. K.  1979.  An Evaluation of Errors in the 14C Method of Primary Production Measurement.  Limnology and Oceanography 24: 917-928.
   10. Litaker, W., Duke, C. S., Kenney, B. E., and Ramus, J.  1988.  Diel chl a and phaeopigment cycles in a shallow tidal estuary: potential role of Microzooplankton grazing.  Marine Ecology 47: 259-270.
   11. Miller, C. B.  2004.  Habitat determinants of primary production in the sea, p. 46-68.  Blackwell Publishing.  Biological Oceanography.
   12. Ryther, J. H., and Menzel, D. W.  1965.  Comparison of the 14C-Technique with Direct Measurement of Photosynthetic Carbon Fixation.  Limnology and Oceanography 10: 490-492.
   13. Ryther, J. H., and Yentsch, C.S.,  1957.  The Estimation of Phytoplankton Production in the Ocean from Chlorophyll and Light Data.  Limnology and Oceanography 2:  281-286.
   14. Schanz, F.  1985.  Vertical Light Attenuation and Phytoplankton Development in Lake Zurich.  Limnology and Oceanography 30: 299-310.
   15. Steemann, N. E.  1952.  The Use of Radio-active Carbon (C14) for Measuring Organic Production in the Sea.  Journal du Conseil  18: 117-140.
   16. Strutton, P. G., Mitchell, J. G., Parslow, J. S., and Greene, R. M.  1997.  Phytoplankton patchiness: quantifying the biological contribution using Fast Repetition Rate Fluorometry.  Journal of Plankton Research 19:1265-1274.
   17. Williamson, C. E., O. G. Olson, S. E. Lott, N. D. Walker, D. R. Engstrom, and B. R. Hargreaves. 2001. Ultraviolet radiation and zooplankton community structure following deglaciation in Glacier Bay, Alaska. Ecology 82: 1748–1760.
   18. Yentsch, C. S.  1962.  Measurement of Visible Light Absorption by Particulate Matter in the Ocean.  Limnology and Oceanography 7: 207-217.