scholarly journals Distribution patterns of shallow water polychaetes (Annelida) along the Alexandria coast, Egypt (eastern Mediterranean)

2014 ◽  
Vol 15 (3) ◽  
pp. 635 ◽  
Author(s):  
M. M. DORGHAM ◽  
R. HAMDY ◽  
H. H. EL RASHIDY ◽  
M. M. ATTA ◽  
L. MUSCO
Keyword(s):  
Grain Size ◽  
Eastern Mediterranean ◽  
Distribution Patterns ◽  
Spatial And Temporal Variation ◽  
Soft Bottom ◽  
Levantine Sea ◽  
Physical Chemical ◽  
Structural Variables ◽  
Levant Basin ◽  
Relevant Factors

Shallow hard bottom and intertidal soft bottom polychaete assemblages of the Alexandria coast, southeastern 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 other 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 assemblages’ distribution. The present study is the southeastern-most one dealing with 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.

Spatio-temporal sublittoral macrobenthic distribution and dominant species in Guanabara Bay, Rio de Janeiro, Brazil

2020 ◽  
Author(s):  
L. A. Pessoa ◽  
P. C. Paiva ◽  
R. R. Paranhos ◽  
C. A. Echeverría ◽  
Marcos A. V. Freitas
Keyword(s):  
Annual Cycle ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Rainfall Regime ◽  
Guanabara Bay ◽  
Soft Bottom ◽  
Gravity Corer ◽  
Structural Variables ◽  
High Dominance ◽  
Spatio Temporal

Abstract Soft-bottom macrobenthic invertebrates are sensitive to natural or anthropogenic changes in aquatic ecosystems. The distribution patterns of sublittoral macrobenthic species in Guanabara Bay were studied from 2005 to 2007. Samples were collected at ten stations during six surveys throughout the rainfall regime (dry, early and late rainy). Ten replicates were collected at each station by Gravity corer or skin diving. Van Dorn bottles (bottom water) and by Ekman sediment sampler (granulometry) provided material for abiotic data. Stations were grouped into sectors (Entrance, Intermediary and Inner) based on abiotic data and location. The Redundancy Analysis (RDA) and Parsimonious RDA for all years and each annual cycle showed indicator taxa with high dominance in each sector. PERMANOVA indicated a regular seasonality between the surveys for the first annual cycle (p <0.05), and an atypical pattern for the second (p> 0.05), possibly due the low rainfall observed during this period. The mosaic of soft-bottom substrates infers structural variables, and patterns of temporal distribution were basically influenced by parameters those indicating pollution and the SACW (South Atlantic Central Water) intrusion, as well as ecological attributes among species, such as: predation, competition. The Ervilia concentrica and Cypridinidae could be used as indicators for anthropic and natural impacts in the Guanabara Bay for the Entrance sector, while Cyprideis salebrosa and Cyprideis sp. for the Intermediary sector and Heleobia australis for the Inner sector.

scholarly journals Disentangling relationships among eastern Mediterranean Cymbalaria including description of a novel species from the southern Peloponnese (Greece)

2021 ◽  
Vol 307 (2) ◽  
Author(s):  
Pau Carnicero ◽  
Núria Garcia-Jacas ◽  
Llorenç Sáez ◽  
Theophanis Constantinidis ◽  
Mercè Galbany-Casals
Keyword(s):  
Eastern Mediterranean ◽  
Phylogenetic Analyses ◽  
Taxonomic Revision ◽  
Distribution Patterns ◽  
Morphological Characters ◽  
Molecular Data ◽  
Morphological Data ◽  
Long Distance ◽  
Aegean Islands ◽  
Molecular Phylogenetic

AbstractThe eastern Mediterranean basin hosts a remarkably high plant diversity. Historical connections between currently isolated areas across the Aegean region and long-distance dispersal events have been invoked to explain current distribution patterns of species. According to most recent treatments, at least two Cymbalaria species occur in this area, Cymbalaria microcalyx and C. longipes. The former comprises several intraspecific taxa, treated at different ranks by different authors based on morphological data, evidencing the need of a taxonomic revision. Additionally, some populations of C. microcalyx show exclusive morphological characters that do not match any described taxon. Here, we aim to shed light on the systematics of eastern Mediterranean Cymbalaria and to propose a classification informed by various sources of evidence. We performed molecular phylogenetic analyses using ITS, 3’ETS, ndhF and rpl32-trnL sequences and estimated the ploidy level of some taxa performing relative genome size measures. Molecular data combined with morphology support the division of traditionally delimited C. microcalyx into C. acutiloba, C. microcalyx and C. minor, corresponding to well-delimited nrDNA lineages. Furthermore, we propose to combine C. microcalyx subsp. paradoxa at the species level. A group of specimens previously thought to belong to Cymbalaria microcalyx constitute a well-defined phylogenetic and morphological entity and are described here as a new species, Cymbalaria spetae. Cymbalaria longipes is non-monophyletic, but characterized by being glabrous and diploid, unlike other eastern species. The nrDNA data suggest at least two dispersals from the mainland to the Aegean Islands, potentially facilitated by marine regressions.

Macroalgal distribution patterns in a shallow, soft-bottom lagoon, with emphasis on the nonnativeGracilaria vermiculophylla andCodium fragile

2006 ◽  
Vol 29 (3) ◽  
pp. 465-473 ◽  
Author(s):  
Mads Solgaard Thomsen ◽  
Karen J. McGlathery ◽  
Anna Christina Tyler
Keyword(s):  
Distribution Patterns ◽  
Soft Bottom

scholarly journals Structural characteristics and petroleum exploration of Levant Basin in Eastern Mediterranean

2017 ◽  
Vol 44 (4) ◽  
pp. 573-581
Author(s):  
Xiaobing LIU ◽  
Guangya ZHANG ◽  
Zhixin WEN ◽  
Zhaoming WANG ◽  
Chengpeng SONG ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
Structural Characteristics ◽  
Petroleum Exploration ◽  
Levant Basin

scholarly journals Source rock characterization of mesozoic to cenozoic organic matter rich marls and shales of the Eratosthenes Seamount, Eastern Mediterranean Sea

2018 ◽  
Vol 73 ◽  
pp. 49 ◽  
Author(s):  
Sebastian Grohmann ◽  
Susanne W. Fietz ◽  
Ralf Littke ◽  
Samer Bou Daher ◽  
Maria Fernanda Romero-Sarmiento ◽  
...  
Keyword(s):  
Organic Matter ◽  
Mediterranean Sea ◽  
Source Rock ◽  
Eastern Mediterranean ◽  
Source Rocks ◽  
Eastern Mediterranean Sea ◽  
Potential Source Rock ◽  
Levant Basin ◽  
Rock Characterization ◽  
Rock Eval

Several significant hydrocarbon accumulations were discovered over the past decade in the Levant Basin, Eastern Mediterranean Sea. Onshore studies have investigated potential source rock intervals to the east and south of the Levant Basin, whereas its offshore western margin is still relatively underexplored. Only a few cores were recovered from four boreholes offshore southern Cyprus by the Ocean Drilling Program (ODP) during the drilling campaign Leg 160 in 1995. These wells transect the Eratosthenes Seamount, a drowned bathymetric high, and recovered a thick sequence of both pre- and post-Messinian sedimentary rocks, containing mainly marine marls and shales. In this study, 122 core samples of Late Cretaceous to Messinian age were analyzed in order to identify organic-matter-rich intervals and to determine their depositional environment as well as their source rock potential and thermal maturity. Both Total Organic and Inorganic Carbon (TOC, TIC) analyses as well as Rock-Eval pyrolysis were firstly performed for the complete set of samples whereas Total Sulfur (TS) analysis was only carried out on samples containing significant amount of organic matter (>0.3 wt.% TOC). Based on the Rock-Eval results, eight samples were selected for organic petrographic investigations and twelve samples for analysis of major aliphatic hydrocarbon compounds. The organic content is highly variable in the analyzed samples (0–9.3 wt.%). TS/TOC as well as several biomarker ratios (e.g. Pr/Ph < 2) indicate a deposition under dysoxic conditions for the organic matter-rich sections, which were probably reached during sporadically active upwelling periods. Results prove potential oil prone Type II kerogen source rock intervals of fair to very good quality being present in Turonian to Coniacian (average: TOC = 0.93 wt.%, HI = 319 mg HC/g TOC) and in Bartonian to Priabonian (average: TOC = 4.8 wt.%, HI = 469 mg HC/g TOC) intervals. A precise determination of the actual source rock thickness is prevented by low core recovery rates for the respective intervals. All analyzed samples are immature to early mature. However, the presence of deeper buried, thermally mature source rocks and hydrocarbon migration is indicated by the observation of solid bitumen impregnation in one Upper Cretaceous and in one Lower Eocene sample.

scholarly journals Forecasting circulation in the Cilician Basin of the Levantine Sea

2006 ◽  
Vol 3 (5) ◽  
pp. 1481-1514 ◽  
Author(s):  
E. Özsoy ◽  
A. Sözer
Keyword(s):  
Boundary Conditions ◽  
Initial Conditions ◽  
Eastern Mediterranean ◽  
Model Performance ◽  
Surface Flux ◽  
Mediterranean Coast ◽  
Open Boundary ◽  
Surface Boundary ◽  
Open Boundary Conditions ◽  
Levantine Sea

Abstract. The Cilician Basin/Shelf Model is adapted for studying the shelf circulation in the Cilician Basin – Gulf of İskenderun region of the Levantine Basin of the Eastern Mediterranean between the Turkish Mediterranean coast, Syria and the island of Cyprus. The model initial conditions and open boundary conditions are supplied by the ALERMO regional model of the Levantine Sea, while interactive surface flux boundary conditions are specified by an atmospheric boundary layer sub-model using calculated water properties and surface atmospheric variables supplied by the Skiron atmospheric model, within the nested modelling approach of the MFSTEP (Mediterranean Forecasting System: Towards Environmental Predictions) project. Sensitivity tests are performed for alternative surface boundary conditions. Model performance for shelf/meso-scale forecasts is demonstrated.

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