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vol-19PHYTOPLANKTON STANDING CROP, DIVERSITY AND STATISTICAL MULTISPECIES ANALYSIS IN
LAKE BUROLLUS, EGYPT.
By
ZEINAB M. EL-SHERIF
• National Institute of Oceanography and Pisheries, Alexandria, Egypt.
Key Words: Phytolpankton, Standing crop, Diversity, Multivariate analysis Egypt.
ABSTRACT
Spatial and seasonal distribution of phytoplankton standing crop 1n
Lake Burollus were estimated the period from January, 1987 to Harch,
1988 which was prevailed by decreased influx of fresh water as
compared to the previous records.
The phytoplankton standing crop showed a remarkable decline to
about 1.04 I 10′ units/1 and it represented about 1/3 of the records
obtained during the period 1978-1979. The phytoplankton was
represented mainly by Bacillariophyceae (49.1 \ by number to the total
standing crop) and Chlorophyceae (31.6 \) while Cyanophyceae (1.7 \),
Euglenophyceae (2.6 \), Dinophyceae (2.2 \) and Cryptophyceae (12.7 \)
were infrequently observed. The increased counts of the latter class
was attributed to a bloom of Cryptomonadales sp. which was confined to
the polluted area infront of Baltim City (St. 1) during Hay. This was
met with lowest diversity in the lake (0.38). The highest phytoplankton counts were recorded in spring and summer and were dominated
by the diatoms Nitzschia spp. and ~loteLLa me~ghini~na, the green
algae S~~rr~g~~m~ spp, ~kJ~J~Qg~~!U\..l~ spp and T~t~~eMQJl spp, beside
Crytomonadales sp. at St. 1. Generally, the lake is regarded as
unpolluted habitat except at station 1 and this was reflected by the
high phytoplankton diversity. The data dealing with clustering and
Nulti-Dimensional Scaling (MDS) of the phytoplankton community gave a
good example of some statistical analysis.
Results indicate that Lake Burollus tends to mesotrophy as regards
to phytoplankton production. ~his is attributed to the decreased
amount of drain water flowing into the lake and the increased density
of the submerqed hydrophytes. particularly r
