Shallow hard bottom and intertidal soft bottom polychaete assemblages of the Alexandria coast, south-eastern Mediterranean (Levantine Sea), were studied during a complete annual cycle in order to analyze spatial temporal patterns of variation in assemblages, and relevant factors related to polychaete distribution. The present study recorded a total of 73 species, belonging to Syllidae (22 species), Nereididae (9 species), Serpulidae (6 species), Eunicidae (5 species) and another 19 families. The assemblages experienced pronounced spatial and temporal variation throughout the study area, but spatial variation appeared more important in determining the observed patterns. Polychaete distribution related to variation of grain size and sessile macrobenthos cover suggesting that these structural variables accounted more than the physical-chemical ones (namely BOD, dissolved oxygen, organic carbon, organic matter, salinity, temperature, pH) in influencing the patterns of assemblage distribution. A total of 9 alien polychaete species were found solely on hard substrata, of which Pseudonereis anomala and Linopherus canariensis formed dense population in the area. The present study is the south-eastern-most one dealing with the ecology and distribution patterns of hard bottom polychaetes from the Mediterranean Sea, as well as one of the few studies dealing with intertidal soft bottom polychaetes in the Levant Basin.

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Resumen.-Se estudió la comunidad fitoplanctónica en un área históricamente y ecológicamente importante de la costa suroriental Mediterránea de Alejandría, Egipto. Se recolectaron muestras mensuales durante enero a diciembre 2009 de 2 áreas [Bahía Oriental (EH) y Kayet Bey (KB)]. Se identificó un total de 162 especies de fitoplancton en BO y 110 especies en KB, dominada por diatomeas en ambas áreas (100 y 64 especies, respectivamente). El conteo de fitoplancton tuvo un promedio anual de 1,387 x 10 6 células L -1 en BO y 0,108 x 10 6 células L -1 en KB, y la biomasa (clorofila a) de 2,4 y 2,0 g L -1 , respectivamente. Las diatomeas y dinoflagelados mostraron roles claramente diferentes en el ciclo del fitoplancton en las 2 áreas, con la ocurrencia persistente de varias especies tóxicas, algunas veces en alta abundancia, como la diatomea Pseudo-nitzschia delicatissima y el dinoflagelado Scrippsiella trochoidea, Pyrophacus horologium, Prorocentrum micans, Prorocentrum triestinium, Prorocentrum cordata, Gonyaulax catenata y Protoperidinium subinerme. A pesar de que detuvo gran parte de la descarga de desperdicios al área de estudio, aun hay eutroficación durante todo el año, indicado por las altas concentraciones de nutrientes y el intenso crecimiento del fitoplancton. Palabras clave: Bahía de Alejandría, nutrientes, diatomeas, algas tóxicas, dinoflageladosAbstract.-The phytoplankton community was studied in historically and ecologically important area on the southeastern Mediterranean coast at Alexandria, Egypt. Monthly samples were collected during January-December 2009 from 2 areas [Eastern Harbor (EH) and Kayet Bey (KB)]. A total of 162 phytoplankton species were identified in the EH and 110 species in the KB, dominated by diatoms in both areas (100 and 64 species, respectively). The phytoplankton count showed an annual average of 1.387 x 10 6 cells L -1 in the EH and 0.108 x 10 6 cells L -1 in the KB, and biomass (Chlorophyll a) of 2.4 and 2.0 g L -1 , respectively. Diatoms and dinoflagellates demonstrated clearly different roles in the phytoplankton cycle in the 2 areas, with the persistent occurrence of several toxic species, sometimes in high count, like the diatom Pseudo-nitzschia delicatissima and the dinoflagellates Scrippsiella trochoidea, Pyrophacus horologium, Prorocentrum micans, Prorocentrum triestinum, Prorocentrum cordata, Gonyaulax catenata and Protoperidinium subinerme. Regardless of the stopping of great part of the discharged wastes to the study area, it is still suffering from eutrophication all the year round, as indicated from high nutrient concentrations and intensive phytoplankton growth.

Spatio-temporal patterns of the distribution of crustaceans from shallow hard bottoms along the Alexandria coast (Egypt, Mediterranean Sea) were studied during a complete year cycle and also in relation to potential drivers of change (both biotic and abiotic), including variation in habitat-forming species. Overall, the crustacean assemblages appeared poor, including only 14 species belonging to Amphipoda (five species), Isopoda (five species), Tanaidacea (two species), Cirripedia and Decapoda (one species each). The distribution patterns of crustacean assemblages appeared significantly variable both in the spatial and in the temporal dimension on a rather unpredictable basis, albeit variation was related to changes in dominant algal and invertebrate habitat formers. High variability and low species richness observed suggest that the analyzed assemblages are selected by local unfavorable environmental conditions. In fact, the crustacean hard bottom fauna is composed by a bulk of tolerant forms, including the dominant Tanais dulongi, Apohyale perieri, Dynamene bidentata, Sphaeroma serratum, Elasmopus pectenicrus, and Jassa marmorata. Their spatio-temporal dynamics, as well as those of the remaining species, and correlations with the variation of habitat formers and environmental variables are reported. This is a baseline assessment of the crustacean diversity along the Mediterranean coast of Egypt, thus having paramount importance for understanding the predicted future changes of biodiversity for the area