Abstract:
While production measured using nitrogen-15 nitrate and carbon-14 bicarbonate incorporation are common, the bulk values provide no significant information on which phytoplankton are most important to productivity. Although methods exist for taxon-specific productivity, these are usually laborious and costly. Size fractionation is a widely used strategy to provide information on the distribution of production among large (>5 μm) and total (>0.6 μm) phytoplankton. Such information is useful for biogeochemical modelers who typically divide phytoplankton into groups based on size. Data were collected during cruises PTS02 and PTS03 along the Mississippi-Alabama shelf from March to July, 2016. This dataset supports the publication: Dzwonkowski, B., Greer, A.T., Briseño-Avena, C., Krause, J.W., Soto, I.M., Hernandez, F.J., Deary, A.L., Wiggert, J.D., Joung, D., Fitzpatrick, P.J., O'Brien, S.J., Dykstra, S.L., Lau, Y., Cambazoglu, M.K., Lockridge, G., Howden, S.D., Shiller, A.M., and Graham, W.M. (2017). Estuarine influence on biogeochemical properties of the Alabama shelf during the fall season. Continental Shelf Research, 140: 96-109 doi: 10.1016/j.csr.2017.05.001. Related biogenic silica standing stock and productivity data can be found in GRIIDC dataset R4.x262.000:0037.
Suggested Citation:
Krause, Jeffrey W.; Acton, Sydney. 2018. Size-fractionated nitrate uptake and primary productivity on the Mississippi-Alabama Shelf, March to July, 2016. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N74B2ZVN
Purpose:
Rates of biological productivity were determined through a consortia partnership with the Alabama Center for Ecological Resilience (ACER) and Consortium for Oil Spill Exposure Pathways in Coastal River-Dominated Ecosystems (CONCORDE). The shared goal for each consortium was to understand the spatial and temporal variability in biological productivity rates. This information is critical for providing baseline information to understanding the potential effects of anthropogenic (e.g. oil spill) or natural (e.g. hurricane) disturbances on biological productivity in the Mississippi-Alabama shelf in the northern Gulf of Mexico.
Data Parameters and Units:
Cruise (PTS=Point Sur R/V), Event number (yyyymmddhhhh), Local time (hhhh), Type (Activity), Station, Latitude (degrees N), Latitude (decimal minutes), Longitude (degrees W), Longitude (decimal minutes), Bottom depth (m), Target depth (m), Size-fractionated nitrate uptake >5 microns (nmol N/L/h), Size-fractionated nitrate uptake >0.6 microns (nmol N/L/h), Size-fractionated primary production >5 microns (mg C/m^3/d), Size-fractioned primary production >0.6 microns (mg C/m^3/d) No data values indicated as -999 Analytical zero values indicated as 0
Methods:
Methodology has been published elsewhere including nitrate uptake (Shipe, R. F., & Brzezinski, M. A. (2003). Journal of marine systems, 42(3-4), 127-143) using calculations as in Dugdale and Wilkerson (1986, Limnology and Oceanography 31, no. 4: 673-689.) and primary production (Brzezinski, M. A., & Washburn, L. (2011). Journal of Geophysical Research: Oceans, 116(C12)). Shipe, R.F. and Brzezinski, M.A. (2003). Siliceous plankton dominate primary and new productivity during the onset of El niño conditions in the Santa Barbara Basin, California. Journal of Marine Systems, 42(3-4): 127-143 doi: 10.1016/S0924-7963(03)00071-X Dugdale, R.C. and Wilkerson, F.P. (1986). The use of 15N to measure nitrogen uptake in eutrophic oceans; experimental considerations. Limnology and Oceanography, 31(4): 673-689 doi: 10.4319/lo.1986.31.4.063 Brzezinski, M.A. and Washburn, L. (2011). Phytoplankton primary productivity in the Santa Barbara Channel: Effects of wind-driven upwelling and mesoscale eddies. Journal of Geophysical Research Oceans, 116: C12013 doi: 10.1029/2011JC007397
View Metadata