In October 2006, Marine Extension Service specialists conducted an initial survey of the St. Mary's River. Depth, time, GPS, temperature, salinity, dissolved oxygen, and pH data were collected during the initial survey. From this information, 5 sites were selected to be monitored monthly through September 2007.
St. Mary's data Nov. 2006 - Sept. 2007 Excel Spreadsheet
St. Mary's Final Report
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Measuring physical parameters with the
Hydrolab Quanta. |
Field sampling was conducted from a 23-foot R/V Sea Ox. Physical parameters, including temperature, salinity, pH and dissolved oxygen, were measured using a Hydrolab Quanta Ò . Wind speed and direction and air temperature were recorded from a digital anemometer and current information was measured using a Model 2135 Flowmeter from General Oceanics, Inc. Light attenuation was measured using a research radiometer with a photodetector (International Light) and secchi depth was measured using a secchi disk. Surface and bottom water samples were collected in various sampling containers for laboratory analysis of biological oxygen demand (BOD), total organic carbon (TOC), total nitrogen (TN), nutrients, chlorophyll-a, ATP, Enterococcus and fecal coliform bacteria, and total suspended solids (TSS).
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Collecting river water with a
Niskin-style sampling device. |
Nutrient interactions were evaluated by measuring orthophosphate (PO 4 3- ), nitrate (NO 3 - ) and nitrite (NO 2 - ), silicate (SiO 2 ), ammonia (NH 3 ), total dissolved phosphorous (TDP), total organic carbon (TOC) and total nitrogen (TN) concentrations. Orthophosphate, nitrate, nitrite, silicate and ammonia were measured using a Lachat QuikChem 8000 FIA+ auto analyzer (Hach Company) . Filtered samples for TDP analysis were sent to Avery Laboratories in Savannah , Ga. to be properly digested and analyzed. TOC and TN were measured by High Temperature Combustion on an Apollo 9000 TOC/TN analyzer (Tekmar Dohrmann).
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Preparing nutrient reagents in the laboratory.
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Datasonde 3 was used to collect temperature, salinity, dissolved oxygen and pH measurements every thirty minutes at several stations on the St. Mary's River. These data, once collected, were downloaded from the instrument upon its return to the laboratory and the information was transferred to and stored in Microsoft Excel spreadsheets. These data provide a look at fluctuations in salinity and other physical factors over numerous tidal cycles.
