Because of their direct link and sensitivity to nutrient loading,
phytoplankton growth is considered a direct effect and one of the
primary symptoms indicative of eutrophication (Bricker et al., 2003)
and, as such, phytoplankton represents a good indicator for nutrientrelated
impacts. Typically, measurements of chlorophyll a are used to
represent phytoplankton biomass in coastal systems, but other measures,
such as the abundance and species composition, and the changes
in the frequency and duration of blooms are also informative of the
condition and health of the estuaries