pdf WQ4 Rapid decline of phytoplankton in the Les Cheneaux Islands during a five-year period

Rapid decline of phytoplankton in the Les Cheneaux Islands during a five-year period.

Authors: R.A. Smith

Author Affiliation: LCWC

Journal: LCWC Report; April 2018

Abstract:

The balance between plankton and rooted aquatic plants is critical to a healthy aquatic ecosystem. Moreover, plankton species and population densities are important to the aquatic food web. Estimates of phytoplankton (free-floating algae) density for this study were made by measuring photosynthetic chlorophyll which was chemically extracted from phytoplankton contained in water samples collected monthly throughout Les Cheneaux during a five month period each year. Resulting chlorophyll concentrations, in this case Chlorophyll-a, were used to estimate phytoplankton population densities throughout the study. Following a 2013 peak concentration in Chlorophyll-a (Chl-a) (1) recorded from twelve different sites throughout LCI, a steady, annual decline in Chl-a was observed through 2017.