Author: R.A. Smith
Author Affiliation: LCWC
Journal: Unpublished Report April 2020
From 2013 through 2019 water levels in the Les Cheneaux Islands have risen 63 inches (160 cm). During the same period, aver- age water temperatures dropped 3.5o to 4.5 o Centigrade ( 8o Fahrenheit). It was expected that these shifts in conditions would result in a related downward shift in phosphorus concentrations that are monitored each summer as part of our water quality program. This was not the case, however. Phosphorus values appeared to change little. Neither did it make sense that, while phosphorus concentrations remained level, the algae population densities decreased. Phosphorus is a primary food source for algae and if the phosphorus levels remained level, then algae concentrations would have been expected to remain within a constant range as well. Algae populations measured were phytoplankton, the free-living plankton that are found dispersed in the water column. The following paper examines this apparent disconnect between the expected and the actual.
Sincere appreciation is expressed to several people involved during this lengthy study, they include: