TITLE:
The Impact of Nitrogen and Phosphorus Dynamics on the Kinneret Phytoplankton: II: Chlorophyta, Cyanophyta, Diatoms and Peridinium
AUTHORS:
Moshe Gophen
KEYWORDS:
Chlorophyta, Diatoms, Cyanobacteria, Nitrogen, Phosphorus, Kinneret
JOURNAL NAME:
Open Journal of Modern Hydrology,
Vol.7 No.4,
October
26,
2017
ABSTRACT: Lake Kinneret long-term data of
the epilimnetic concentrations (ppm) and loads (tones) of the total Nitrogen
(TN), total Phosphorus (TP), total inorganic Nitrogen (TIN), total Dissolved
Phosphorus (TDP), Phytoplankton groups’ biomass, water level (WL) and Jordan
River Discharge were analyzed. Previously collected data compiled aimed at an
insight into the causative background for the modification of Phytoplankton
community change. The study was carried out by searching for relations between
algal groups’ densities and nutrient conditions in the Epilimnion by the use of
statistical methods (Simple and Fractional Polynomial Regressions). The study
is aimed at analyzing the relations between algal biomass and nutrient
contents. It was found that Nitrogen decline and slight increase of phosphorus
were followed by Peridinium (Photo 1)decline and biomass increase of non-peridinium
algae. It is suggested that nitrogen supply for algal growth is mostly from
external sources, and the reduction of nitrogen in the epilimnion
was caused by external removal. Contrary to nitrogen, phosphorus sourcing is
only partly external (dust deposition, drainage basin) and mostly internal
through double channels: Microbial mineralization of bottom sediments and Peridinium
cysts mediation. The resulted complexity of the Kinneret ecosystem structure is
nitrogen limitation, and enhancement of Non-peridinium algal growth, mostly Cyanobacteria.