Stay in the know about wildlife, water quality, and ecosystems on Sanibel and Captiva Islands and in Southwest Florida
How Calibration Ensures Accurate Water Quality Science
The SCCF Marine Lab measures three key parameters to assess and discuss Southwest Florida’s water quality: chlorophyll a, colored dissolved organic matter (CDOM), and phycocyanin.
- Chlorophyll a is essentially a measure of the algal content
- CDOM impacts light penetration to submerged aquatic environments in addition to staining the water brown
- Phycocyanin is a pigment specific to freshwater algae allowing us to determine species composition
The instrument used to measure these water quality parameters is called the Turner Trilogy Laboratory Fluorometer.
“Simply put, this instrument uses photons at specific wavelengths and the emission of photons to measure the concentration of a constituent in a sample,” explained SCCF Research Assistant Rachel Wynn. “This instrument presents us with data about what is happening in the water around us, which is why it’s so important that the results are accurate, scientifically sound, and consistent with other labs throughout the world.”
Last week, the Marine Lab held a Turner calibration event, where they created a standard operating procedure for water quality measurements and performed the first Turner calibration of the year! Above, Researchers Amy Oxton, Mark Thompson, and Rachel Wynn perform the Turner Calibration.
Calibrations are performed on a recurring basis while using the same standard operating procedure. Typically, multi-point calibrations are performed with standards of differing but known concentrations.
“We are able to tell the machine exactly what is contained within the given standard which the machine can then use to calculate and compare against samples of unknown concentrations,” said Wynn.
The Marine Lab relies heavily on the accuracy of the Trilogy Fluorometer in monitoring regional water quality, which provides sound science to back SCCF’s water management advocacy.
“We’re happy to say that the calibration event was a success and we look forward to continuing to provide accurate water analyses in the future,” said Wynn.