| Monitoring
the Plankton of Narragansett Bay A university funded research assistantship |
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Phytoplankton: Weekly surface, bottom and net tow samples are collected from a station in Narragansett Bay, RI (lat. 41 34.2N, long. 71 23.4W, click for map). Equal volumes of surface and bottom samples are combined for counting, or surface and bottom samples are counted seperately (count type is indicated with data). Phytoplankton cells are enumerated under a compound microscope using a Sedgewick-Rafter counting chamber. Samples are counted live and unconcentrated. A 20 micrometer net tow sample is also examined. Species observed in the net sample are recorded as present but not counted. Species identifications are mostly based on their appearance in the Sedgewick-Rafter chamber, supplemented with permanent mounts examined with phase contrast and interference contrast optics. The accurate identification of very small and problematic species is not guaranteed. Chlorophyll: Chlorophyll and phaeophytin concentrations are measured in surface and bottom samples for total and less than 20um size fractions. Chlorophyll is extracted from filtered samples with 90% acetone and concentrations are measured with a Turner fluorometer. (Jeffrey, S.W. et.al. 1997. Phytoplankton Pigments in Oceanography: Guidelines to Modern Methods. UNESCO publishing.) For the period of 1999 to June 2008, chlorophyll samples were filtered and then stored frozen at -20C prior to extraction and analysis. Beginning in May 2007, samples were also analyzed using immediate extraction methods. Comparison of the two protocols from June 2007 to June 2008 indicated a significant loss of chlorophyll a in samples that were frozen and stored. Significant linear regressions between the two methods allowed us to adjust chlorophyll a values collected from 1999-2007 to more accurately reflect the standing stock of chlorophyll a at Station 2. Adjusted and non-adjusted values for earlier samples are provided in the worksheet. The immediate extraction protocol is the method used since July 2008. Cell count data and chlorophyll data are available for download as Microsoft Excel spreadsheets. Cell count data in spreadsheets are cells per liter. Chlorophyll data is in micrograms/liter. Data available here starts in January 1999. Data from the period 1955-1998 is not available at this time. Zooplankton: Weekly vertical net tows are taken from 5 m to surface with a ¼ m diameter, 64 micron mesh net from the same station at which phytoplankton are collected in the lower West passage of Narragansett Bay, RI (lat. 41 34.2N, long. 71 23.4W). Volume filtered is 0.25 m3. The sample is preserved immediately in 4% buffered formalin-seawater solution. Zooplankton are identified and enumerated under a dissecting microscope from a subsample taken with a wide bore pipette calibrated in mls. The subsample volume is chosen to ensure counting of at least 200 organisms. Species identification is made for all copepodite stages of copepods. Copepod nauplii lumped. Other taxa are identified to species when known, or if not (as for benthic larvae) to order. Gelatinous species are collected with a separate vertical tow taken with a ½ m diameter 1 mm mesh net with a flowmeter. Sample volume is 1.1 m3. This sample is returned to the laboratory and counted alive immediately to ensure that ctenophores, which do not withstand preservation, can be accurately enumerated. Diameter of medusae and ctenophores are measured and all are identified to species. Drained volume of the sample is recorded. Sampling began in 1999 but samples were stored and only those from October 2001 to the present have been counted with funding from the National Science Foundation and the Vetleson Foundation Grants to Barbara K. Sullivan. As a courtesy to fellow scientists, please e-mail Tatiana Rynearson e-mail to indicate how you are using this data so that efforts are not duplicated. Comments and suggestions as to the website and its data are also welcome.
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| Supervisor: Dr. Tatiana Rynearson |
Current Students:
Caitlyn Lawrence (since August 2009) |
 Zooplankton: zooplankton data zooplankton plot Zooplankton material is based upon work supported
by the National Science Foundation under Grant No. 0115177. ____________________________________________  Nutrient analyzer used by B. Buckley in Nixon Lab |
Data: phytoplankton counts and species list through 9 November 2009 chlorophyll through 9 November 2009
Time Series Plots of Phytoplankton Data:
Photo by Mike Salerno
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Nutrients:
nutrients from
surface and bottom depths
DIN & DIP May 2003-Jan 2009 Silica Feb 2003-Sept 2008 methods summary
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Links To More Information: Jan Rines & Paul Hargraves' diatom flora site Narragansett Bay Benthic Survey The Coastal Institute EPA's Narragansett Bay site National Estuarine Reserve Dr. Kester's Narragansett Bay website Save the Bay Narrbay.org Narragansett Bay Estuary Program <>Previous Students: Laura Windecker: Aug. 2008- Aug. 2009 Jason Graff: May 2007 - Aug. 2008 Matt Horn: May-Aug. 2007 Laura Windecker: Aug 2006-May 2007 Haley Brew: Aug. 2005- Aug. 2006 Kelly Henry: May 2005- Aug 2005 Jason Graff: Sept. 2003 - May 2005 Angela Allen: May 2003-Sept. 2003 Kris Joppe-Mercure: Sept. 2001 - May 2003 Malcolm McFarland: Sept. 1999 - August 2001 Andrew Staroscik: January 1999 - August 1999 |
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Pertinent References: Karentz, D. & T.J. Smayda. 1984. Temperature and seasonal occurence patterns of 30 dominant phytoplankton species in Narragansett Bay over a 22-year period (1959-1980). Marine Ecology Progress Series 18: 277-293. Pratt, D.M. 1959. The Phytoplankton of Narragansett Bay. Limnology & Oceanography 4: 425-440. Smayda, T.J. 1998. Patterns of variability characterizing marine phytoplankton with examples from Narragansett Bay. ICES Journal of Marine Science 55: 562-573. |
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