The measurement and distribution of living microscopic plant matter, commonly referred to as phytoplankton or algae, has been of interest to scientists, researchers, and aquatic resource managers for decades. An understanding of phytoplankton populations and their distribution enables researchers to draw conclusions about an aquatic system's health, composition, and ecological status.
Phytoplankton populations are typically estimated by measuring chlorophyll a, the primary photosynthetic pigment present in all forms of algae. Currently, chlorophyll can be estimated in lakes, rivers, reservoirs, and coastal and open ocean waters across the globe.
Downloads
Algae Management in Reservoirs and Lakes
Non-Acidification Technique for Extracted Chlorophyll a Analysis
Chlorophyll Non-Acidification Method (Welschmeyer)
Chlorophyll and Pheophytin
In Vivo Chlorophyll: Concepts & Concerns
In Vivo Chlorophyll Detection Using Red Excitation
An In-vivo Chlorophyll Procedure for the 10AU Field & Laboratory Fluorometer
(10AU) A procedure for measuring extracted chlorophyll a free from the errors associated with chlorophyll b and pheopigments
A topic that tends to pop up during application is can I use the Trilogy, AquaFluor, AquaFlash, or any of the handheld instruments Turner Designs produces to repeatedly read for the same sample of chlorophyll in vivo?
Fluorescence is a process where a sample is illuminated with light of a specific wavelength, causing it to emit light at a different wavelength. In algal samples, this means the algae absorb the excitation light and re-emit it as fluorescence. When the algal cells are excited, they may undergo changes that can lead to algal sample quenching—where they become less able to absorb additional light effectively. This often results in decreased fluorescence readings over time, as the cells release excess light and become less responsive. For detailed insights, Kromkamp and Forester’s work is an excellent resource, offering comprehensive data and extensive references.
Kromkamp, Jacco C., and Rodney M. Forster. "The use of variable fluorescence measurements in aquatic ecosystems: differences between multiple and single turnover measuring protocols and suggested terminology." European Journal of Phycology 38.2 (2003): 103-112.