Water Quality Database

Water Quality

The Shannon Point Marine Center has been collecting water quality data (dissolved oxygen, temperature, salinity, and pH) on a weekly basis since 1973. The measurements were expanded in 1990 to include chlorophyll a, phaeopigments, orthophosphate, nitrate, and ammonium. Recently, silicates and photosynthetically active radiation (PAR) measurements were begun. The lab has also been collecting water quality data seasonally at eight other sites in the San Juan Archipelago. Information on the following can be obtained by contacting Horng-Yuh Lee:

Physical/Chemical data

Temperature (April 1974-present)
Dissolved oxygen (Sept 1974-present)
Salinity (April 1974-present)
pH (April 1974-Dec 2001)
Turbidity (April 1974-March 1992)
Total Alkalinity (Aug 1977-March 1992)
Carbonate Alkalinity (Aug 1977-March 1992)
Carbon dioxide;(July 1977-March 1992)

Pigment Data

Chlorophyll a (Jan 1991-present)
Phaeopigments (Nov 1993-present)

Nutrient Data

Nitrate (Jan 1991-present)
Ortho-Phosphate (Jan 1991-present)
Ammonium (Jan 1991-Aug 2000)
Silicate (Feb 2002 – present)

Water Quality Data Online

SPMC is in the process of making the entire water quality data set available on this page.  A trial set of data from Nov. 18, 2010 to Nov. 22, 2011 is available as a comma delimited .txt file below.  Columns in the data set are date (MMDDYYY), time (HHMM), sampling location, replicate number, silicate concentration (µM), nitrate+nitrite concentration (µM), ortho-phosphate concentration (µM), chlorophyll concentration (µg/L), phaeopigment concentration (µg/L), salinity (PSU), dissolved oxygen (mg/L), and pH. Samples from the “Pump” location were taken from the spigot of the Shannon Point Marine Center seawater system (after the water had passed through the pumps).  Samples from the “Deep” location were taken in front of the intake to the Shannon Point Marine Center seawater system. Samples from the “Surface” location were taken at approximately 1 m depth in the surface waters above the “Deep” sample.  "ND" indicates no data. The data is freely available for use.  If you publish any part of it, please acknowledge the Shannon Point Marine Center Water Quality Program. 

SPMC water quality data 2011 (.txt file)