TITLE:
Competitive Consumption of the Lake Kinneret (Israel) Plankton by Hypophthalmichthys molitrix and Sarotherodon galilaeus
AUTHORS:
Moshe Gophen
KEYWORDS:
S. galilaeus, H. molitrix, Lake Kinneret, Plankton Consumption
JOURNAL NAME:
Open Journal of Ecology,
Vol.4 No.9,
June
9,
2014
ABSTRACT: An outdoor tank
experiment was carried out for the assessing of the impacts of Sarotherodon
galilaeus (Galilee Saint Peter’s Fish; Cichlidae) (SG) and Hypophthalmichthys
molitriox (Silver Carp; Cyprinidae) (SC) on Lake Kinneret (Israel)
plankton. In order to evaluate the interaction effect, the experiments were of
replicated 2 × 2 factorial design: TG × SC. A lot of interaction effects were
indicated showing that the effects of the two fishes were not independent and
potentially competitors. SG suppressed most crustaceans and rotifers while
increasing gross and net primary production and chlorophyll concentration. SC
had less intense effects on zooplankton than SG. Although SC suppressed most
crustaceans and rotifers, it had less interaction effects than SG. SC had no
statistically significant effects on phytoplankton production or chlorophyll
concentration. It is suggested that these experiments indicate that although
the plankton community impacts of SG and SC do differ, both fishes utilize
similar food resources in Lake Kinneret. Fingerlings of SG and SC are planted
in Lake Kinneret annually aimed at the improvement of fishermen’s income and
prevention of water quality deterioration. SC is known as efficient consumer of Microcystis. It is therefore recommended to limit SC introduction to
periods when Microcystis is abundant.