الفهرس 
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Abstract
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SUHNARy
The present investigation was initiated to follow up
the changes that might take place in distribution and
species composition of phytoplankton community in some
aquatic ecosystems of the Nile at Qalubia governorate, in
relation to hydrological regime and eutrophication problems.
Accordingly, six ecologically different sampling
stations were selected to represent the different habitats
in this province. These stations were further grouped into
four habitats covering the whole study ,area.
Habitat I : (stations, I,ll)
The sites of these stations were distributed length
wise Damietta branch of the River Nile in the vicinity ot
Benha city.
Habitat II : (stations III~IV)
These stations were located at Elryah
stream.
Eltawfiky
Habitat III: (station V)
This station was selected to represent Elfailfaila
irrigation canal.
Habitat IV : (station VI)
These station represent the polluted drain (Qalubia
main drain) .
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Subsurface water samples were collected at regular
monthly intervals from these sites for a period of one
year extending from September 1990 up to August 1991. The
physico-chemical characters of water as well as identification
and counting of phytoplankton species in these
samples were carried out. Moreover, the effect of effluents
of oils and soap factory at Benha on phytoplankton
crop and species composition using synthetic media and
receiving water from
laboratory.
the Nile were assayed in the
The following is a summary of the results obtained I
1- The general climate of the stUdy area is that of the
moderate tropical zones. Mean monthly values of water
temperature ranged between 16·C to 29·C at all studied
habitats. Generally, no wide variations observed in
temperature maxima and minima between all stations.
2- The pH values at all sites lie on the alkaline side
being ranged between 7.5 to 9.2 in Damietta branch of
the Nile and irrigation canals, while the relatively
neutral pH values were recorded in polluted drain water
being fluctuated between ’7.4 to 8.3.
)- The average transparency values fluctuated between 48cm
and 123 cm at River Nile and Elryah Eltawfiky stream,
from 32 cm to 53 cm (Elfailfaila irrigation canal),
>
from 15 cm to 27 cm (polluted drain). Generally,
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stations of the polluted drain and narrow irrigation
canal showed always the lowest transparency levels,
mainly due to the increased turbidity of the
contaminated water.
4- Electrical conductivity fluctuated between 305 to 457
Micromhos in Damietta branch of the Nile and irrigation
canals habitats, and between 1148 to 1621 Micromhos at
the polluted drain.
5- Dissolved oxygen of surface water in polluted drain was
comparatively low being ranged between (4.7 and 7.4
mgl-I) compared with those of River Nile and irrigation
canals which ranged between (6.5 and 8.8 mgI-l).
6- The polluted drain habitat showed relatively higher
contents of total hardness and <the major nutrient
anions (P04’ N03, N°i, NH3, Si03, 5°4’ CI, C03 and
Heo) as compared with those of the Nile (Damietta
branch) and irrigation canals habitats. Similarly,
concentrations of monovalent (Na+, K+) and divalent
(ca2+, Mg2+) cations in the drain water exceeded always
that of the Nile and irrigation canals.
7- The chlorophyll (a) content of water at all sites
showed irrigular local seasonal variations.
8- standing crop of total phytoplankton at all stations
showed distinct seasonal variations. Thus, the average
maximum yield at Nile water (3334 org. ml-l) was
recorded during summer, while the average mimimum (2820
org. ml-li was attained during autumn. In Elryah
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Eltawfiky stream the total standing crop ranged between
minimum average (3016 org. ml-1) r~ached during autumn
and maximum average (3902 org. ml~l) exhibited during
winter. Similarly, in the narrow irrigation canal the
total·standing crop·attained maximum average (1002 org.
ml-l) during winter, while the minimum one (560 org.
ml-1) reached during autumn. In polluted·’drain the
total standing crop ranged between minimum average (355
org. ml-1) reached during autumn and maximum average
(1808 org. ml-I) during spring.
9- The main phytoplankton groups showed considerable
seasonal variations at all sites, Bacillariophyta was
the most influential group of phytoplankton counts,
where it show higher percentage during winter at all
studied habitats, Chlorophyta also represented higher
percentage during winter allthrough the stUdy habitats,
Cyanophyta contributed to higher percentage during
spring in Damietta branch and irrigation canals, and
during autumn in the polluted drain.
10- It is to be noted that the polluted drain waters and
the narrow irrigation canal harboured generally low
standing crop compared with other studied habitats,
since a total of 52 phytoplankton species were recorded
allthrough the study period at the polluted drain.
Out of these, 24 species belong to Bacillariophyta, 14
to Chlorophyta,l1 to Cyanophyta and only three species
to Euglenophyta.An average of 79 species were recorded
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in the narrow irrigation canal habitat. out of these,
25 belong to Bacillariophyta, 38 to Chlorophyta, 10 to
cyanophyta, two species to Dinophyceae an? 4 to Euglenophyta.
The number of species identified in Elryah
Eltawfiky stream was comparatively high (91 species).
out of this number, 32 belong to Bacillariophyta, 41
to Chlorophyta, 13 to cyanophyta, two species to
Dinophyceae and three species to Euglenophyta. The
number of species recovered in Damietta branch of the
River Nile was 83 species. out of these, 29 belong to
Bacillariophyta, 40 to Chlorophyta, 10 to cyanophyta,
and only two species to each of Dinophyceae and
Euglenophyta.
11- Some species such as : Navicula placentula~ Nitzschia
amphibia (Bacillariophyta), staurastrum paradqxum
(Chlorophyta), oscillatoria chalybea, oscillatoria
chlorina, spirulina major (cyanophyta), seemed to be
as pollutant indicator species since they were of high
occurrence in polluted waters. Another species such
as: Cyclotella meneqhainiana, cyclotella ocellata,
Melosira granulata, synedraYlnA (Bacillariophyta),
Dictyospherium pUlchellum~ Pediastrum simplex~
scenedesmus guadricuada (Chlorophyta), AnabaeDopsis
raciborskiiJ Gomphospherialacustris, Merismopedia
tenussima~ Microcystis Aeruginosa (cyanophyta), could
be considered as main component species of freshwater
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habitats, since they were recovered in all sampled
waters.
12- concerninq to the effect of industrial effluents of
oils and soap factory at Benha on the phytoplankton
communit~ growing under controlled conditions in
synthetic media, it was manifested in the form of a
rise in phytoplankton total count, chlorophyll (a),
dry weight gain and pH of the cultures media with
increasing effluent concentration along’ the
experimental period.
Melosira granulata (Bacillariophyta) and ~cenedesmus
guadricauda (Chlorophyta), were the most dominant
species and they induced vigorous growth as time
lasted with increasing effluent concentrations.
13- supplementation of the industrial effluent to the
water samples collected from Elryah Eltawfiky resulted
in rise of standing crop, dry weight gain and pH value
of cultures.
Melosira granulata~ Nitzschia kUtizingiana~ Synedra
ulna (Bacillariophyta), Scenedesmus guadricauda
(Chlorophyta), Anabaena ~onstricta (cyanophyta), were
the most dominant species recovered in treated water.
The propagules of such species tended to flourish with
elevation in effluent concentration and as time
prolonged.