Search

The spatial patterns of planktonic protozoa communities were studied from April 2015 to March 2016 in Burullus Lake, Egypt, in order to assess its environmental status. Protozoa were sampled and 13 environmental variables were measured monthly at ten stations. Over the study area, non-tintinnid ciliates dominated the protozoa community (annual contribution 49.3%) followed, in order, by amoebozoans (31.6%), tintinnids (15.2%), and foraminiferans (3.9%). A total of 35 species of protozoa were identified, and four of these species formed the main bulk of the entire community (with a percentage >47%), namely Vasicola ciliata (14.55%), Centropexis aculeata (11.34%), Acropisthium mutabile (11.21%), and Amphileptus claparedie (10.29%). The highest species number and diversity index values (17 species, H′ = 2.03) were found at station I in the saline (average 29.4 ppt) and lowest trophic region of the lake. Univariate and multivariate analyses demonstrated that: (1) the environmental status of Burullus Lake fluctuated between eutrophic and hypertrophic; (2) the lake is divided into three main regions (A, B, and C) based on spatial similarities among environmental variables (the most stress-exposed was Region B, followed, in order, by C and A); (3) the spatial distribution of the protozoa communities was correlated with environmental variables, especially nitrogen nutrient concentrations and phytoplankton biomass in Region B, salinity and dissolved oxygen in Region A, and transparency in Region C; (4) Centropyxis aculeata and Vasicola ciliata were positively correlated with nutrients, and phytoplankton biomass in Region B, which receives large amounts of anthropogenic inputs. Thus, we proposed the use of these two protozoans as potential bioindicators of eutrophication in Burullus Lake.

Rotifers are one of the most common, abundant components of plankton in the coastal waters of the Mediterranean Sea, which means that they can be used as bio-indicators and provide useful information on the long-term dynamics of the El-Mex Bay ecosystem. Rotifera species were quantitatively and qualitatively assessed in the El-Mex Bay, west of Alexandria at eight stations to study spatial, temporal, dominance, and abundance of the rotifer community and their relation with changes in environmental conditions. Samples were collected seasonally from autumn 2011 to autumn 2012. Ecological parameters were determined and correlated with total rotifers abundance to gain information about the forces that structure the rotifer community in this dynamic environment. A total of 38 rotifer species were identified belonging to 16 genera within 12 families and 3 orders under one class and contributed about 12.1% of the total zooplankton in the study area with an average of 1077 specimens/m 3 . Maximum density was observed in summer 2012 with an average of 1445 specimens/m 3 . During autumn 2011 rotifers appeared in low density (434 specimens/m 3 ). The predominant species Ascomorpha saltans , Brachionus urceolaris , Synchaeta oblonga , Synchaeta okai , Synchaeta pectinata and Synchaeta tremula were recorded in all study stations of the bay. Salinity, temperature, depth, and chlorophyll- a concentration were the most important environmental factors co-related with the abundance of rotifers in the El-Mex Bay. A significant positive correlation between the total rotifer abundance and chlorophyll- a was observed during winter 2012 and summer 2012 ( r = 0.763 and r = 0.694, respectively, at p ⩽ 0.05).

Chromista and Protozoa ranked the 2 nd dominant group in the study area represent together 16.1 % of the total zooplankton with annual average of 1440 organisms/m 3 and expressed by 69 species. Distinct differences that appeared in the dynamics, patterns of occurrence and numbers of the species in these locations were attributed to differences in physical and chemical conditions.Several environmental conditions appear to control the regional and seasonal distribution of such organisms. Ballast water plays an important role in species mechanical transmission through shipping movements. In conclusion, the community composition of the two phyla and their significant dominance indicated that, El-Mex Bay is a highly eutrophic system which shows signs of partial pollution. Accordingly, it is recommended that the waste water should be treated and/ or recycled before discharge into this natural aquatic system. It was important to produce monograph inside this work containing the photos of the organisms.

El- Mex Bay is a relatively large coastal embayment west of Alexandria. The bay is an important fishery ground as well as recreation area. It includes both the Western Harbor and Dekhaila Harbor. It is one of heavily polluted areas on the Egyptian Mediterranean coast, receiving huge amount of agricultural, industrial, and sewage wastes from the adjacent Lake Mariut through El- Umoum Drain. According to different estimations in literatures the volume of the wastewaters varied between 7 × 106 and 8 × 106 m3day-1, which is supposed to increase with the growing population density of Alexandria city. These conditions cause pronounced eutrophication and drastic changes. Eutrophication-related problems in El- Mex Bay of Alexandria were studied seasonally from autumn 2011 to autumn 2012. Geographical information system (GIS) and remote sensing techniques were used together with the ground-based surveys to assess the vulnerability of the most important physical and eutrophication parameters along El- Mex Bay coast. As a result of increasing population and industrial development, poorly untreated industrial waste, domestic sewage, shipping industry and agricultural runoff are being released to the bay. With the rapid increase in the industries and population, changes in water quality would have potential consequences for the large rapidly growing population of the Alexandria region. Recom-mendations for environmental recovery and restoration are proposed for preservation of El- Mex Bay and harbors in order to facilitate development of environmental and tourist activities. Key words: El- Mex Bay, recreation area, El- Umoum drain, geographical information system (GIS, remote sensing, eutrophication, and restoration.

A /Tonthly variations of species composition and abundance of -^-^-zooplankton community in the Western harbour were studied during the period from April 1999 to March 2000 in relation to the effect of water circulation and the discharged waste waters. The results indicated significant role of freshwater species (39 spp.) in the zooplakton community (11 lspp.) in the harbour, providing the highest occurrence during the warm period (May- October) with the increase of discharged waters. However, spatially, the community structure showed a more or less homogenous distribution most of the year, reflecting the effect of water circulation pattern in the harbour. Except the relatively high density in July (48.4x103 ind./m3), the standing stock ( annual average: 26.7xl03 ind./m3) indicated low zooplankton production in the harbour. Copepods and tintinnids were the major component of the zooplankton stock, forming 46.4% and 24.8% of its total counts respectively, followed by freshwater ciliates and rotifers (7.5% and 7.2%). The abundance of total zooplankton as well as each group showed seasonal variations, with the exception of the minimum and maximum values, providing two periods of different production levels. The diversity index values revealed higher diversity of tintinnids than copepods.

The Damietta coast is part of the Egyptian Mediterranean coast off the Nile Delta and has recently been polluted as a result of intensive human activities.The environmental parameters and protozoan community in the area were studied biweekly from January to December 2007. The results of the environmentalparameters indicated low salinity, oxic and anoxic conditions, high nutrient levels and intensive phytoplankton growth. A total of 69 protozoan specieswere identified, belonging to Amoebozoa (8 species), Foraminifera (12 species), non-tintinnid ciliates (22 species) and tintinnids (27 species). The numerical density of protozoans was high over the whole area, with annual averages between 8.2 × 103 cells m-3 and 51.4 × 103 cells m-3.Spring was the most productive season for protozoans, but several distinct peaks were observed during the year at the sampling sites. The protozoangroups showed clearly different spatial patterns in both composition and abundance: whereas amoebozoans and non-tintinnid ciliates were dominant in themore polluted areas (sites IV and V), tintinnids dominated in the less polluted areas (sites, I, II and III). Several pollution indicators wererecorded: amoebozoans - Centropyxis aculeata, Centropyxis sp., Cochliopodium sp.,Difflugia sp.; non-tintinnids - Bursaridium sp., Frontonia atra,Holophrya sp., Paramecium sp., Paramecium bursaria,Vasicola ciliata, Vorticella sp., Strombidium sp.; tintinnids- Favella ehrenbergii, Helicostomella subulata, Leprotintinnus nordgvisti,Tintinnopsis beroidea, Stenosemella ventricosa, Tintinnopsis campanula,T. cylindrica, T. lobiancoi, Eutintinnus lusus-undae.

Seasonal abundance, biomass, and taxonomic composition of copepods in El-Mex Bay (Southeastern Mediterranean region) were studied from autumn 2011 to 2012. Most species within the copepod communities displayed a clear pattern of succession throughout the investigation period. Generally copepods were the predominant group. They contributed numerically 57% of the total zooplankton counts with an average of 5083 organisms/m 3 and a total number of 203,333 individuals. The bay harbored 50 species belonging to 28 genera within 19 families and 4 orders under one class. Calanoids were represented by 24 species which formed 31.6% of total copepods predominantly Acartia clausi , Calocalanus pavo , Clausocalanus furcatus , Eucalanus crassus , Nannocalanus minor , Paracalanus parvus , Eucalanus subcrassus , and Temora longicornis . Cyclopoids comprised 13 species of which Acanthocyclops americanus , Halicyclops magniceps , Oithona attenuata , and Oithona nana were the most abundant adult copepods. Eleven Harpacticoid species were also recorded with Euterpina acutifrons , Microsetella norvegica , Onychocamptus mohammed being the most prevalent. It was found however, that two Poecilostomatoida species were rarely encountered in the plankton Oncaea minuta and Corycaeus typicus . Copepod larvae and copepodite stages formed the main bulk of copepod Fauna as noticed in the El-Mex Bay during the investigation period. Their percentage was 36.7% of the total count and their total numbers were 74,629 individuals with an average of 1866 organisms/m 3 . The persistent relationships between total copepod counts, copepod orders, and physico-chemical variables suggested that physical factors operate on the copepod communities, either directly to limit maximum distribution along the bay, or indirectly on abundance.