The leaf breakdown of Picramnia sellowii (Picramniales: Picramniaceae) as index of anthropic disturbances in tropical streams / Decomposição de folhas de Picramnia sellowii (Picramniales: Picramniaceae) como índice de distúrbio antrópicos em riachos tropicais

Abstract There are few studies in tropical regions exploring the use of leaf breakdown process as a functional tool to assess anthropic disturbance on aquatic ecosystems. We assessed the effects of water pollution due to human activities on the leaf breakdown rate of Picramnia sellowii in streams of the southeastern Brazil. The experiment was carried out for 60 days in three reference streams and three streams impaired by organic pollution and absence of riparian vegetation. Three litter bags were incubated in each stream containing 3 ± 0.05 g of P. sellowii leaves. The reference streams presented higher values of dissolved oxygen and lower values of nutrients, turbidity, electrical conductivity, total impermeable area and water temperature. The leaf breakdown rate (k) differed significantly between the reference (k = 0.014 ± 0.003 d–1) and impaired streams (k = 0.005 ± 0.001 d–1). The leaves incubated in the reference streams contained greater fungal biomass (measured as ergosterol concentration) and abundance of invertebrates, as well as greater presence of shredders, with k values being related to the biomass of these organisms. Overall, there were clear differences between the leaf mass loss in the reference and impaired streams. These results reinforce the negative effect of urbanization on leaf breakdown and fungal and shredder biomass.

Resumo Na região tropical são escassos os estudos que exploram o uso do processo de decomposição foliar como ferramenta funcional para avaliar os efeitos das perturbações antrópicas sobre os ecossistemas aquáticos. Nosso objetivo foi avaliar os efeitos dos impactos antrópicos sobre a taxa de decomposição de Picramnia sellowii em riachos no Sudeste do Brasil. O experimento foi realizado durante 60 dias em três riachos referências e três impactados por poluição orgânica e sem cobertura vegetal. Em cada riacho foram incubados três sacos contendo 3 ± 0,05 g de folhas secas de P. sellowii. Os riachos referência apresentaram maiores concentrações de oxigênio dissolvido e menores valores de nutrientes, turbidez, condutividade elétrica, TIA (área total impermeável) e temperatura. O coeficiente de decomposição (k) diferiu entre os riachos referência (k = 0,014 ± 0,003 d–1) e os impactados (k = 0,005 ± 0,001 d–1). Nas folhas incubadas nos riachos referência foi observada maior biomassa de fungos e abundância de invertebrados, assim como a presença de fragmentadores, estando o k relacionado com a biomassa destes organismos. A decomposição se mostrou sensível para avaliar impactos antrópicos nos ecossistemas aquáticos uma vez que foram observadas nítidas diferenças entre a perda de massa foliar nos riachos referências e impactados. Estes resultados reforçam o efeito negativo da urbanização sobre a decomposição e biomassa de fungos e fragmentadores.

Seasonal effects of wastewater to the water quality of the Caeté river estuary, Brazilian Amazon

Bragança's socioeconomic situation is highly dependent on estuarine and marine biological resources that are influenced by tidal cycles and climatology. Field measurements (hydrological, hydrodynamic and microbiological variables) were taken in the most urbanized zone from Caeté estuary to characterise the quality of the local environment. During the dry period, the estuary was more eutrophic and presented the highest temperature (30.5 °C in Oct./06), salinity (17 psu in Feb./07), pH (8.24 in Feb./07) and fecal coliform (> 1000 MPN/100 ml in Dec./06 and Feb./07) values. The phytoplankton Cyclotella meneghiniana, Coscinodiscus centralis and other r-strategist species were observed. The lack of basic hydric canalization was responsible for the local contamination, especially during the dry period when more concentrated wastewater from the city was emitted into the estuary, showing the human influence on the reduction of local estuarine water quality. In Bragança, the fishery is considered one of the main economic activities so, this contamination is worrisome because a large part of the local economy depends on biological resources and, thus, the contamination could negatively affect the environmental health of this Amazon ecosystem.

A situação socioeconômica de Bragança depende principalmente dos recursos biológicos estuarinos e marinhos, que são influenciados pelos ciclos de marés e climatologia. Coletas oceanográficas (com medidas de variáveis hidrológicas, hidro-dinâmicas e microbiológicas) foram realizadas na área mais urbanizada do estuário do Caeté, para caracterizar a qualidade das águas no setor estudado. Durante o período seco, o estuário foi mais eutrófico e apresentou os maiores valores de temperatura (30,5°C em Out./06), salinidade (17 psu em Fev./07), pH (8,24 em Fev./07) e coliformes fecais (>1000 MNP/ 100 ml em Dez./06 e Fev./07). As espécies fitoplanctô-nicas Cyclotella meneghiniana, Coscinodiscus centralis e outras espécies r-estrategistas também foram observadas. A falta de saneamento básico foi responsável pela contaminação local, especialmente durante o período seco, quando o esgoto foi lançado mais concentrado no estuário, mostrando a influência humana na redução da qualidade da água estuarina estudada. A pesca é considerada uma das principais atividades econômicas do município de Bragança e, portanto, esta contaminação poderá afetar negativamente a qualidade ambiental deste ecossistema amazônico.

Waterbirds and human-related threats to their conservation in Laguna Cuyutlán, Colima, México

Laguna Cuyutlán, the only large wetland in a span of 1 150 km along the Pacific coast of México, has been neglected as to its importance for waterbird conservation. At least 25 waterbird species nest there, with some of their colonies being very relevant, and at least 61 waterbird species use the lagoon during their nonbreeding season. This lagoon has been subject to several structural modifications, including levees and artificial channels which connect it to the sea, while water supply from continental sources has diminished, although its role has not been assessed yet. Salt extraction and artisanal fishery, the main economic activities, do not seem to pose a threat to waterbirds. Among potential threats to this acquatic ecosystem, are the raw sewage discharges that exist near urban areas, and pesticides from the surrounding agricultural lands might reach the lagoon. Seemingly, the most serious threat comes from waterway development in connection with a re-gasification plant to be built, and planned future port expansion, which could potentially increase water levels and alter important habitats for nesting and foraging. We recommend that: the area be declared an Important Bird Area; the development of the re-gasification plant and future port includes a levee to prevent alterations in water level in the remaining sections of the lagoon; supply of exogenous chemicals and waste products be prevented and monitored; alleged benefits from water interchange between the lagoon and the sea through artificial channels should be re-evaluated; and the role of fresh water supplies to the lagoon should be paid attention to. Rev. Biol. Trop. 57 (1-2): 1-12. Epub 2009 June 30.

Laguna Cuyutlán, el único humedal grande a lo largo de 1 150 km del Pacífico mexicano, no ha sido considerado un ecosistema natural importante para la conservación de aves acuáticas. Cuando menos 25 especies de aves acuáticas anidan ahí, y al menos 61 especies de aves acuáticas la usan fuera de la temporada reproductiva. Esta laguna ha sufrido varias modificaciones estructurales, y el aporte de agua dulce ha disminuido, sin que se conozcan sus consecuencias. La extracción de sal y la pesca artesanal, las principales actividades económicas, no parecen ser riesgo para las aves acuáticas. Entre los riesgos potenciales, están las aguas negras cerca de zonas urbanas y los plaguicidas de zonas agrícolas colindantes. Aparentemente, el riesgo más serio deriva del desarrollo marítimo asociado con una planta regasificadora a construirse pronto, y del desarrollo portuario futuro, que podrían incrementar los niveles de agua en la laguna y alterar los hábitats de las aves acuáticas. Recomendamos que: el área se declare como AICA; el desarrollo futuro incluya un dique para prevenir alteraciones en el nivel del agua en el resto de la laguna; el aporte de sustancias agroquímicas y aguas negras se monitoree; se reevalúen los supuestos beneficios del intercambio de agua entre la laguna y el mar por medio de canales artificiales; y se investigue científicamente los aportes de agua dulce a la laguna.

Effects of bacterial infestation caused by human wastes on the skin structures of Mugil platanus Günther, 1880 (Mugilidae) / Efeitos da infestação de bactérias provocada por resíduos humanos na pele de Mugil platanus Günther, 1880 (Mugilidae)

Manifestation of infectious pathologies in fishes usually increases in environments where organic wastes are disposed. Specimens of Mugil platanus Günther, 1880 and water samples collected at three points of the Tramandaí river were analyzed during a one year period. The macroscopic observation revealed ulcerations in the caudal peduncle area covered with a mass of amorphous and whitened tissues. Histopathologic analysis showed the presence of negative gram bacteria, probably responsible for alterations of the normal structure of the epidermic tissues. Non-parametric statistical analysis for ammonia concentration showed a significant variation among the three collected spots as well as in the multiple comparison between two spots. In this study, we describe cutaneous lesions observed in Mugil platanus specimens and tested their correlation with environmental ammonia concentration.

A manifestação de patologias infecciosas em populações de peixes costuma ser incrementada em ambientes onde são lançados despejos orgânicos. Exemplares da espécie Mugil platanus Günther, 1880 coletados em três pontos do rio Tramandaí foram utilizados para análise das alterações, e amostras de água foram tomadas durante o período de um ano para verificação da presença de bactérias. A observação macroscópica revelou ulcerações na região do pedúnculo caudal revestidas por uma massa de tecido amorfo e esbranquiçado. A análise histopatológica mostrou a presença de bactérias gram negativas, que provavelmente foram as responsáveis pela alteração da estrutura normal dos tecidos de revestimento do corpo. O resultado da análise estatística não paramétrica para a concentração de amônia mostrou variação significativa entre os três pontos amostrados bem como nas comparações múltiplas entre os pontos dois a dois. Este trabalho descreve as lesões cutâneas observadas em Mugil platanus e testa sua correlação com a concentração de amônia.

The fear of awful smell: risk perceptions among farmers in Vietnam using wastewater and human excreta in agriculture.

Vietnamese farmers' health-risk awareness, knowledge, and practices related to their use of wastewater and human excreta was investigated in an anthropological study by a multidisciplinary team in peri-urban Hanoi and Nghe An Province. Farmers identified health risks associated with their use of excreta and wastewater, but they viewed these as unavoidable risks related to production. They perceived the health risks as different for the use of wastewater and human feces. They perceived health risks from wastewater as non-serious because it remained on the skin and only caused skin problems, but they considered health risks from non-composted smelly feces serious because it entered the body through 'polluted' air. Most farmers were more aware of threats to health from 'dirt' entering the domestic environment than of the health risks during their work. The concept of 'dirt' should be separated from understanding of germs, viruses, and parasites so that it is understood that things that carrying health risks cannot always be identified by their 'dirtiness' or smell. Farmers mainly considered hygiene and health as women's issues. Men's responsibility for the health and hygiene of the family should therefore be emphasized.

Chemical Evaluation for western coast of Mediterranean Sea in Egypt

PH, dissolved oxygen, oxidizable organic matter, as well as nutrient salts [NH4, NO2, NO3, PO4, and SiO4] were studied in the water of western coast of the Mediterranean Sea in Egypt [west of Alexandria] at different depths ranging from 0-200 m depth for inshore and offshore stations during winter [31 January to 5 February] and summer [3-10 September], 2006. During the last three decades, many touristic cities were constructed along the study coastal area. These coastal areas are exhibiting sings of stress, population pressures, and coastal development may lead to: declining fisheries, proliferation of harmful algal blooms nourished by sewage and agricultural run off close to beaches harming fish and causing health problems. Thus, this paper aimed to assess the eutrophication level in the study area

Anthropic effects on the fish community of Ribeirão Claro, Rio Claro, SP, Brazil

The effect of anthropic alterations such as drain discharge on a fish community was studied in the Ribeirão Claro River, municipality of Rio Claro, State of São Paulo, southeastern Brazil. Samples were made monthly in three different points along the river (headwaters, mid course, and confluence) between December, 2003 and March, 2004, which is the reproductive period for the majority of the species. The fish community of the Ribeirão Claro River showed a fair composition and diversity, with species rarely observed in studies made in the region, such as Paravandellia oxyfera and Callichthys callichthys. Indices of diversity and equitability showed different results when weight or the number of individuals were considered. Moreover, these indices did not reveal the typical increase in diversity from the headwaters toward the confluence, nor the loss of richness in the part altered by drain discharge. An interpretation should be made with caution, taking into account the diverse factors included in the computation. Similar to the diversity indices, the Morisita-Horn similarity index did not reveal a great difference in the fish community of the confluence of the river, mainly in relation to its mid course. The decline of species richness and trophic composition alteration in the disturbed part is clear, which shows a great dominance of piscivorous species.

Com o objetivo de verificar o efeito de alterações antrópicas, como o despejo de esgotos sobre a comunidade de peixes do Ribeirão Claro, SP, foram feitas coletas mensais em três pontos ao longo do rio (cabeceira, meio e foz) entre dezembro de 2003 e março de 2004, período reprodutivo para a maioria das espécies da região. O Ribeirão Claro apresentou boa composição e variedade em sua comunidade íctia, possuindo espécies raramente observadas em trabalhos na região, como Paravandellia oxyfera e Callichthys callichthys. Os índices de diversidade e equitabilidade apresentaram diferentes resultados quando considerado o peso ou número de indivíduos, além de não evidenciarem o comportamento típico de aumento da diversidade no sentido cabeceira-foz, nem a conseqüente perda de riqueza taxonômica no trecho impactado pelo despejo de esgoto doméstico. Sua interpretação deve ser feita com cautela, considerando os diversos aspectos incluídos em seus cálculos. Assim como os índices de diversidade, a similaridade de Morisita-Horn não ressaltou a grande diferença na comunidade da foz do Ribeirão Claro, em especial com relação ao trecho médio do rio. Fica evidente o declínio na riqueza de espécies no trecho poluído e a alteração em sua composição trófica, apresentando alta dominância de espécies piscívoras.

Sewage input effects on the macroinvertebrate community associated to Typha domingensis Pers in a coastal lagoon in southeastern Brazil

This study was carried out at Imboassica Lagoon, located in an urban zone in the municipality of Macaé, Rio de Janeiro state, Brazil. This lagoon has been subject to anthropogenic impacts due to the increasing city population, such as the input of sewage. Areas of variable degree of anthropogenic influence in the lagoon were compared regarding the structure of the macroinvertebrate community associated to Typha domingensis leaves. For sampling, we used 35 x 20 cm net plastic bags, with 6.8 mm mesh containing T. domingensis leaves for colonization. Two different sampling stations were selected: station A, under direct input of sewage; and station B with lesser sewage influence. The bags were removed after 20, 40 and 75 days of colonization. For each sample the Shannon-Wiever Diversity, Pielou Evenness, Jaccard Similarity Indices, Correspondence Analysis and taxonomic richness were calculated. A total of 31,874 individuals were sampled, belonging to 34 taxa. The main taxonomical groups were: Oligochaeta (41 percent), Chironomidae (40 percent), Ancylidae (4.6 percent), Polymitarcyidae (4 percent) and Thiaridae (3 percent). At station A, the taxonomic richness, the Evenness and Diversity values were lower than in station B. On the other hand, the total density was three times higher in station A than in B. It was already possible to discriminate the community structure of each sampling station in the first sampling. Trichoptera and Ephemeroptera were the main exclusive groups of station B and are considered good water quality indicators due to their high sensibility to contamination. The major contribution to discriminate between the macroinvertebrate communities of the two sample stations came from Chironomidae, Oligochaeta and Ephemeroptera.

O presente estudo foi realizado na Lagoa Imboassica, localizada no perímetro urbano da cidade de Macaé, RJ, Brasil. Esta lagoa vem sofrendo impactos antrópicos com o aumento da cidade, como o aporte de esgotos sem tratamento. Areas com diferentes graus de influência antrópica na lagoa foram comparadas quanto à estrutura da fauna de macroinvertebrados associada a folhas de Typha domingensis. A amostragem da fauna foi realizada por meio de cestos de tela plástica de 35 x 20 cm e malha de 6,8 mm, com folhas de T. domingensis para colonização. Dois pontos amostrais foram selecionados: ponto A, sujeito a aporte direto de esgotos; e ponto B, sob menor influência de esgotos. Os cestos foram retirados após 20, 40 e 75 dias de colonização. Foram aplicados em cada amostra os índices de diversidade de Shannon-Wiever, equitabilidade de Pielou e similaridade de Jaccard, riqueza taxonômica e Análise de Correspondência. Foram encontrados 31.874 indivíduos, distribuídos em 34 táxons. Os principais grupos foram: Oligochaeta (41 por cento); Chironomidae (40 por cento); Ancylidae (4,6 por cento); Polimitarcyidae (4 por cento); e Thyaridae (3 por cento). No ponto A, os valores de riqueza taxonômica, equitabilidade e diversidade foram inferiores aos do ponto B. Por outro lado, a densidade total foi três vezes maior no ponto A. A estrutura da comunidade foi diferente nos dois pontos amostrais para todos os testes utilizados, desde a primeira retirada. Trichoptera e Ephemeroptera foram os principais grupos exclusivos do ponto B, sendo considerados indicadores da qualidade da água devido à sua sensibilidade. Chironomidae, Oligochaeta e Ephemeroptera foram os principais grupos a contribuir com as diferenças nas comunidades de macroinvertebrados entre os pontos amostrais.

Effects of an oil spill and discharge of domestic sewage on the insect fauna of Cururu stream, Manaus, AM, Brazil

As assembléias de insetos aquáticos e edáficos de três igarapés da Amazônia Central foram utilizadas para avaliar o impacto sofrido por um deles (igarapé Cururu), após um vazamento de óleo derivado de petróleo, ocorrido em agosto de 1999. O igarapé Cururu já era impactado pelo despejo de esgoto doméstico. A avaliação desses sistemas foi realizada em quatro diferentes períodos do ciclo hidrológico da região (vazante, seca, enchente e cheia), entre setembro de 2000 e maio de 2001. Os insetos foram coletados com draga Eckman, rede entomológica aquática e trado, e utilizados para estimar a riqueza taxonômica (nível de família) e a densidade de insetos em cada sistema. Os efeitos de anóxia e os efeitos da eutroficação foram mensurados pelas médias de concentração de oxigênio dissolvido, nitrogênio total e fósforo total, estimadas nos três sistemas. A riqueza e abundância da fauna de insetos foram maiores no igarapé Cristalino (não impactado) do que nos igarapés Bom Jardim (impactado pelo despejo de esgoto) e Cururu, com exceção das amostragens de insetos litorâneos. A concentração do oxigênio dissolvido no igarapé Cururu foi menor do que nos outros dois sistemas, enquanto as concentrações de nitrogênio total e fósforo total no igarapé Cururu foram maiores. Esses elementos tiveram valores inversos no igarapé Cristalino e intermediários no igarapé Bom Jardim. As concentrações de oxigênio dissolvido, nitrogênio total e fósforo total refletem as modificações provocadas pela eutroficação antropogênica nos sistemas Bom Jardim e Cururu. Isso ocorreu devido à liberação de efluentes domésticos pelas comunidades locais e pelo óleo introduzido no igarapé Cururu, influenciando negativamente a riqueza e abundância de insetos nesses igarapés.

Heavy metals in sediments, mussels and oysters from Trinidad and Venezuela

Abstract: The Gulf of Paria is bordered by both Trinidad and Venezuela,from which various metallic pollutants and other contaminants can originate.The Gulf is still a significant source of fish,crabs and shellfish for human consumption to both countries,where concerns over the quality of this marine environment have been long expressed but never properly addressed.In addition,the circulatory current patterns in the Gulf ensure that contaminants originating from either country are likely to affect both countries eventually.Heavy metals were determined in oysters (Crassostrea rhizophorae and C.virginica ),green mussels (Perna viridis )and sediments from the Gulf of Paria.Samples were obtained at four sites in Trinidad and three sites in Venezuela in the Gulf of Paria,in addition to comparative samples collected from three sites on the north coast of Venezuela.Edible tissues of twelve shellfish from each location were blended and aliquots digested with concentrated nitric acid, for extraction of cadmium,chromium,copper,lead,nickel and zinc.The solutions were analysed by flame atomic absorption spectroscopy.Mercury was extracted with a mixture of nitric,hydrochloric and sulphuric acids and determined by cold vapour atomic absorption.Sediments were oven-dried at 60°C, before being similarly extracted.Results showed that mercury in sediments at all sites in Trinidad and Venezuela exceeded NOAA and Canadian sediment quality guidelines,while cadmium, copper, nickel, lead and zinc also exceeded these guidelines at several sites.Heavy metal levels in oysters and green mussels varied widely with location. However,oysters from the Gulf of Paria contained significantly higher mean levels of cadmium,copper,nickel and zinc than those from the north coast of Venezuela, but this difference was not apparent in mussels.Cadmium, mercury and zinc in sediments were significantly correlated with those of mussels,but not of oysters,in which copper and zinc at several sites in the Gulf of Paria exceeded local maximum permissible levels (Cu =20 µg g-1 wet wt; Zn =50 µg g-1 wet wt)for human consumption. These findings indicate that while mussels may be better biological indicators of heavy metal pollution in sediments than oysters,the latter may provide copper and zinc contamination.Further research is needed to determine the most appropriate biological indicators of heavy metal and other pollutants in the local marine environment and to develop protocols for their use

Assessment of cadmium, lead, copper and zinc in fish species reared in treated Sewage effluents in Suez city

Levels of the heavy metals Cd, Pb, Cu and Zn in 8 organs of each of 2 reared fish species; namely, Oreochromis niloticus and Mugil seheli were measured using flame atomic absorption spectrophotometry. The results revealed that the level of the heavy metal concentrations is varying according to the fish species and to the examined organs. The order of abundance of these metals in these two fishes is: Pb > Zn > Cu > Cd, i.e. there is a pronounced elevation in Pb level in most organs of the two fish species, while cadmium recorded the lowest values. Zn and Cu are of higher values than Cd, but both are less than Pb. On the other hand, M. seheli accumulates all the heavy metals with the exception of Pb to greater extent than those in O. niloticus. Generally, muscles of both fishes consistently contain the low values of the metals

Coliforms as a measure of sewage pollution of Alexandria coastal water

The pollution of the coastal water of Alexandria, Egypt, was studied through one year period. Samples were collected monthly from four selected regions. Coliforms [fecal and nonfecal], as a measure of sewage contamination, were isolated and counted. Physical and chemical parameters of the water samples [temperature, pH, alkalinity, salinity, dissolved oxygen, organic matter, phosphate, nitrite, nitrate, ammonia, as well as calcium and magnesium] were determined and the interrelations between these parameters and coliform counts were also elucidated using statistical analyses

effect of sewage discharge on phytoplankton diversity in east of Alexandria coastal waters [Egypt]

Quantitative estimation of phytoplankton was carried out along the Eastern coast of Alexandria [Egypt] for three seasons, during 1991. The samples were collected from 7 sectors prependicular to the coast line from Kayet Bey to Assafra. Each sector included 3 stations situated at average water depths of 5,20 and 30 m respectively. The phytoplankton comprised 239 species included in 7 classes. the community was composed mainly of diatoms [60.3% of the total population]. The highest standing crop wad recorded in the Eastern Harbour [E.H] [30.8 x 10[3] units.1[-1]] and the lowest at Asafra [15.1 x 10[3] units. L[-1]]. The summer sustained the highest standing crop. The estimated diversity was inversely proportional to the degree of dominance of certain species and lineary related to the number of species contributing the standing crop with a simple regression equations. Multiple regression analysis illustrates also equation models for diversity in both the surface and subsrface water. Diversity index confirms a considerable improvement in the water quality of the investigated area after the construction of the new sewage system in May, 1988, which transferred the waste water discharge away from Alexandria beaches. It averaged 1.98 nats at the inshore stations and this was accompanied with a drop in the concentration of nutrients by about 36% than of the previous records in the same area, 15 years ago

Evaluation of the standing crop phytoplankton in some coasts of Alexandria, Egypt

The hydrographic conditions and phytoplankton communities of the four regions, namely, El-Agami, Kayet Bey, the E. H. And El-Shatbi were studied monthly from June 1991 to May 1992 in relation to the inland run off of sewage effluents and industrial wastes in the three latter regions, which create eutrophic conditions. The polluted regions of Kayet Bey, the E. H. and El-Shatbi are characterized by lower salinity, low dissolved oxygen, while the dissolved organic matter, total alkalinity and nutrient salts remained high and this was associated with high density of phytoplankton. On the other hand, El- Agami region which lies faraway from the effect of sewage pollution harbored lower density of phytoplankton which appeared more diversified. The phytoplankton composition in the investigated areas comprised 140 species, belonging to Bacillariophyceae [85], Dinophyceae [27], Chlorophyceae [14], Cyanophyceae [12], one Silicoflagellate and one Euglenophyceae. Although the communities were diversified by numerous species but the few of them formed the main bulk of the standing crop and these comprised Skeletonema costatum, Nitzschia closterium, Spirulina platensis and Asterionella japonica. The phytoplankton standing crop in Kayet Bey region attained higher density [105, 233 units L-1] than the other two polluted of the E. H. and El-Shatbi [70, 237 and 17, 443 units L-1] impacted by the highest amount of discharge of sewage water, while the minimum density was recorded at El-Agami region. Also, the seasonal variations of the phytoplankton communities in the polluted regions, controlled with the seasonal variations of the physicochemical conditions and they were more correlated to the amount of inland discharge. Generally, the present study indicated a high level of eutrophication, particularly at Kayet Bey due to the impact of big amounts of sewage effluents discharged into the area and they are usually loaded with high concentration of nutrient salt. Also, the richness in species was inversely proportional to the standing crop and the lowest number was recorded during the bloom times. Also, the dominant species all above consider as indicator for eutrophication and pollution, although the standing crop of phytoplankton was low compared to the other areas. It was recommended that sewage wastes must be treated before discharge into sea