The Autecology of Eudiaptomus cf drieschi (Poppe & Mrazek 1895 ...

divides the lake with a warm, oxygenated, CO 2 depleted epilimnion, and a cold, anoxic
hypolimnion with H 2 S and CO 2 .The general circulation patterns are seasonal and
determine the formation of the thermocline and movement of the internal seiche.
The main source of water to the Kinneret is the Jordan River system. There are also
thermal-mineral springs along the shores and on the lake bottom. These springs
influence the chloride concentration of the lake waters. The pH values of the lake water
are also seasonal, with the lowest values observed during the turnover and highest values
in late spring (7.5-8.9). Oxygen levels in the epilimnion and hypolimnion are influenced
by external weather conditions and consequently vary from year to year.
Bottom sediments are made up of a dark, flocculent upper layer of 2-5 cm. thickness,
and a more compact, gray material below. Sedimentation rates vary at specific locations:
higher in the north and lowest in the central deep waters. There is also a seasonal
difference in sediment deposition. (Serruya 1978).
Biota
There are over 250 species of phytoplankton in the Kinneret including the
dinoflagellate Peridinium spp. (Gophen & Pollingher 1985). The bloom season of the
Peridinium occurred with great regularity from late winter to early spring (February-
May) but the highest number of species in the lake is represented by the Chlorophytes.
The presence of such temperate species as Rhodomonas sp. and Cryptomonas sp.,
indicates that cold stenothermic forms can survive during the winter period in warm
lakes. The fall season is dominated by nanoplanktonic species with low species
diversity, however during the winter, species diversity is highest. Phytoplankton
biomass peaks in the spring and the diversity begins to decline. Summer shows a drastic
decrease in algal species diversity, with the nanoplanktonic green algae predominating