bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Occurrence and Established Populations of the Alien Polychaete Polydora cornuta Bosc, 1802 (Polychaeta: Spionidae) in the Sea of Marmara and the Bosphorus Strait (Turkey)
Authors: KARHAN S.U. , KALKAN E. , SIMBOURA N. , MUTLU E. , BEKOLET M.
Published: May 2013

The present paper reports the first occurrence of Polydora cornuta in the Bosphorus Strait and its finding in a new locality in the Sea of Marmara, providing a link with its Aegean and Black Sea populations. The probable vector for the introduction of P. cornuta into the Sea of Marmara is shipping through the Dardanelles Strait. Both soft and hard-bottom populations were examined and the importance and prevalence of this species within the native macrozoobenthic communities were elucidated. Its abundance ranged between 40 and 3390 ind.m-2 (mean:1320 ±1199.45 SD) and its percent contribution to the total faunal populations ranged between 3.31 and 75.56 (mean:27.79 ±25.00 SD) in the Sea of Marmara softbottom community. During the sampling period, P. cornuta contributed little to the total faunal abundance of the hard-bottom communities in the Bosphorus Strait. Its mean abundance in the hard substrate ranged between 8.33 and 1000 ind.m-2 (mean:117.36 ±279.73 SD) and its percent contribution to the total faunal populations ranged between 0.02 and 21.86 (mean:2.07 ±6.25 SD).The role of this invasive species in the soft-bottom macrobenthic community at an organically enriched site examined in the Sea of Marmara is highlighted, and a comparison with Aegean Sea populations of the species is also included.
Fouling Bryozoa from some Alexandria harbours, EGYPT. (I) Erect species
Authors: ABDEL-SALAM KH.M. , RAMADAN SH.E.
Published: May 2013

The fouling erect Bryozoa settled on polystyrene test panels immersed half a meter deep in the water of Abu Qir Harbour, the Eastern Harbour and El-Dekheila Harbour were studied. The present study yields 5 species of erect bryozoa. These areAmathia pruvoti, Zoobotryon verticillatum, Bowerbankia gracilis,Bugula neritina and Bugula stolonifera. The first three ones pertain to 3 genera of the family Vesiculariidae belonging to suborder the Stolonifera; while the other two species affiliate to the genus Bugula belonging to the family Bugulidae of suborder Anasca. The present record of Amathia pruvoti is the first from the Egyptian Mediterranean waters. A re-description, supplied with full structural illustrations of the recorded species is given. Moreover, the temporal and spatial distributions of the species recorded are encountered.
A novel application of queueing theory on the Caulerpenyne secreted by invasive Caulerpa taxifolia (Vahl) C.Agardh (Ulvophyceae, Caulerpales): a preliminary study
Authors: KANDEMIR-CAVAS C. , CAVAS L. , BAKI YOKES M. , HLYNKA M. , SCHELL R. , YURDAKOC K.
Published: May 2013

Aquarium originated marine green alga Caulerpa taxifolia was introduced into the Mediterranean Sea accidentally in 1984. This invasion has been negatively affecting the sub-littoral ecosystem of the Mediterranean. One of the important reasons for its success in the Mediterranean is its secondary toxic metabolite called caulerpenyne (CPN). Furthermore, CPN has anti-proliferative and apoptotic activities, therefore, CPN can be considered as a potential native source in cancer therapy. For that reason, modeling this metabolite might be of importance. Increase and decrease of the CPN level before reaching the critical level can be expressed by means of a queueing system in which the number of ‘customers' increases and decreases. In fact, production of CPN shows fluctuations for many environmental reasons, which allow us to apply queueing theory. In the present study, the expected time to reach the maximum caulerpenyne level was analyzed and evaluated using queueing theory.
Potential impact of some abiotic parameters on a phytoplankton community in a confined bay of the Eastern Mediterranean Sea: Eastern Harbour of Alexandria, Egypt
Authors: ABDEL-HALIM A.M. , KHAIRY H.M.
Published: May 2013

The Eastern Harbour (E.H.) is sheltered from the sea by a breakwater with two main entrances through which exchange with the netitic Mediterranean water takes place. Some physico-chemical parameters of the study area showed that dissolved oxygen ranged from 6.57 to 11.4 mg l-1 at the open sea station and 5.08 to 11.71 mg l-1 for the E.H. stations. Higher nutrient concentrations were recorded in the E.H. than that at the open sea station, except for ammonia and nitrate. The phytoplankton flora of the E. H. stations was much richer in species than the adjacent open sea station, attaining 96 and 74 species, respectively. As well as the average phytoplankton density, it was higher in the surface water than near the bottom water layer. With regard to the total phytoplankton community, Bacillariophyceae dominated at all sites, whereas Dinophyceae, Chlorophyceae, Cyanophyceae and Euglenophyceae were rarely recorded. The highest average density of phytoplankton abundance was recorded during March, both at the surface. Correlation coefficient of biological factors with some physico-chemical parameters and a series of stepwise multiple regression equations describing the dependence of phytoplankton density on the changes of most abiotic prevailing conditions are provided and discussed.
First observations of two talitrid crustaceans (Amphipoda: Talitridae) from Gokceada island (NE Aegean Sea)
Authors: CAMUR-ELIPEK B. , ASLAN-CIHANGIR H.
Published: May 2013

The present paper reports the occurrence of Talitrus saltator (Montagu, 1808) and Orchestia gammarellus (Pallas, 1766) which are the first records from Gokceada (Imbroz) Island (NE Aegean Sea). It should be noted that, T. saltator is a new record for the Aegean Sea coast of Turkey.
Molecular characterization of 18S rDNA partial sequence in Microcosmus (Stolidobranchiata, Pyuridae)
Authors: FULGIONE D. , RIPPA D. , DE LUCA A. , MILONE M.
Published: May 2013

We present a 18S rDNA based molecular phylogeny of two species of the genus Microcosmus (M. sulcatus and M. claudicans) sampled in the Mediterranean, to investigate their phylogenetic position relative to species of the order Stolidobranchiata. The analysis is based on partial sequences (739 bp) of the 18S rDNA. Among the 18 variable sites found between the two species, 4 correspond to transitions (ts), 14 to transversions (tv) and 4 to deletions/insertions. In the considered Stolidobranchiata, we found 4.3% overall mean number of nucleotide differences and 0.06 (S.E. ±0.01) Kimura 2-parameter distance. The mean number of nucleotide differences between Microcosmus spp. and other Stolidobranchiata species was of 6% and 0.08 (S.E. ±0.01) Kimura 2-parameter distance. A molecular phylogeny obtained by Maximum Parsimony corroborates results of the traditional taxonomy.
Decapod crustaceans on the Gökçeada (Imbros) island continental shelf (north-eastern Aegean Sea)
Authors: ATES A.S. , KATAGAN T. , KOCATAS A. , SEZGIN M.
Published: May 2013

The present composition of decapod crustaceans found at the sublittoral depths (5-104 m) off the coast of the island of Gökçeada (north-eastern Aegean Sea) is presented. A total of 28 species (11 caridean shrimps, 1 thalassinid ghost crab, 7 anomurans and 9 brachyuran crabs) and 277 specimens were recorded. The caridean shrimp, Athanas nitescens had the highest abundance with a dominance value of 20.94% in samples. The dominant group is caridean, represented by a total of 11 species and an occurrence frequency of 39.29%.
Torquigener flavimaculosus Hardy and Randall, 1983 (Pisces: Tetraodontidae) off Rhodes island marine area: a new alien fish in the Hellenic waters
Authors: CORSINI-FOKA M. , MARGIES P. , KONDILATOS G. , ECONOMIDIS P.S.
Published: May 2013

The presence of the pufferfish Torquigener flavimaculosus was recorded during the winter 2006-2007 off Rhodes Island (SE Aegean Sea). The species, known from the western Indian Ocean, has established populations from the Levantine basin to Fethiye, Turkey. This finding expands the known range of the species in the Mediterranean to the south-eastern Aegean Sea.
Digestive proteases and carbohydrases along the alimentary tract of the stargazer, Uranoscopus scaber Linnaeus, 1753
Authors: PAPOUTSOGLOU E.S. , LYNDON A.R.
Published: May 2013

Digestive enzyme activity and capacity (activity x tissue weight) for protein (total protease assay, 25° C) and carbohydrates (total carbohydrase and alpha-glucosidase assay at 5, 18 and 25° C) was investigated for the carnivorous stargazer, Uranoscopus scaber along its digestive tract. Results indicated that whole gut total protease activity was highest at pH 1.5 (P<0.05) (25° C) in U. scaber, (6.64±2.55 mg tyrosine per g digestive tract per minute, pH 1.5). Total protease activity was apparent mainly in the stomach at pH 1.5 (9.73±3.3), and to a lesser degree in the anterior intestine (11.15±1.5, pH 10.0) and pyloric caeca (4.92±2.06, pH 10.0), especially at pH 9.0 and 10.0. Furthermore, 60% of total capacity for protein digestion derives from the stomach region, which takes up 65% of the digestive tract. Total carbohydrase activity and capacity levels were very low compared to other carnivorous teleosts, indicating very low tendency for complex, large molecular weight carbohydrate digestion. However, alpha-glucosidase levels were higher, a fact which combined with relevant data for other marine carnivorous teleosts suggests a possible role of disaccharide in relation to marine carnivorous fish dietary carbohydrate inclusion.
Factors affecting purse seine catches: an observer-based analysis
Authors: TSITSIKA E.V. , MARAVELIAS C.D.
Published: May 2013

A total of 72 fi shing trips were carried out by fi shery scientists onboard a purse seiner in the Pagasitikos Gulf (Greece) in an attempt to identify factors affecting total and individual species’ catches. As trawling is completely banned in the study area, purse seining is the main fi shing method. It was found that month, water depth and fi shing area affected total and Trachurus spp. catches of the purse seine fi shery, with month and water depth alone explaining 77.8% and 6.4% respectively of the total variation of the data. Signifi cant interactions observed indicate that the fl uctuations in total catches differed by month and fi shing area as well as fi shing area and water depth. Fishing area and water depth interaction were found to affect Trachurus spp. catches signifi cantly. Results also suggested that generalized linear modelling of the purse seine catches can be used to obtain representative abundance indices by reducing the observed variability. Fishery scientists’ onboard observations alongside fi sh market recordings during the same period confi rmed that each fi sher has developed an individual decision-making fi shing process. Fisher’s trip choice behaviour was found to be modulated by several factors, such as distance of fi shing grounds from the port, market demands (both in terms of species and market prices), weather conditions, alternative fi shing strategies, previously gathered information, economic pressure and personal skills. These fi ndings are discussed in the light of the need to incorporate additional quantitative information to stock abundance estimates if improved fi sheries management scenarios are to be advanced.
The Errors-in-Variables approach for the validation of the WAM wave model in the Aegean Sea
Authors: SOUKISSIAN T.H. , PROSPATHOPOULOS A.M.
Published: May 2013

In previous studies, wave fi elds from the 3rd-generation wave model WAM-Cycle 4 have been validated by using in situ buoy measurements in the Aegean Sea within the framework of the POSEIDON project; however, limitations of the data sets, concerning mainly the short distance of the buoys from the shore and the short length of the data, render those validation studies incomplete. In this work, signifi cant wave height forecasts obtained from WAM-Cycle 4 wave model are validated by means of TOPEX/Poseidon (T/P) data in specifi c offshore locations in the central part of the North Aegean Sea. The linear structural relationship between the two data sets has been modelled by implementing the Error- In-Variables approach, assuming that both T/P data and WAM results are subjected to errors. The underestimation of signifi cant wave height from WAM, which has been concluded from the comparison with buoys at near-shore points, is also observed from the WAM-T/P comparison at offshore locations, thus being considered of general validity for the Aegean Sea. In addition, a correction relation for the WAM model results, based on the linear structural relationship, is proposed and applied.
Distribution of dissolved inorganic carbon and related parameters in the Thermaikos Gulf (Eastern Mediterranean)
Authors: KRASAKOPOULOU E. , ANAGNOSTOU CH. , SOUVERMEZOGLOU E. , PAPATHANASSIOU E. , RAPSOMANIKIS S.
Published: May 2013

Data on the distribution of dissolved inorganic carbon (measured as TCO2) and related parameters in the Thermaikos Gulf were obtained during May 1997. High TCO2 concentrations were recorded close to the bottom, especially in the northern part of the gulf, as a result of organic matter remineralisation. The positive relatively good correlation between TCO2 and both apparent oxygen utilisation (AOU) and phosphate at the last sampling depth confi rmed the regenerative origin of a large proportion of TCO2. The comparatively conservative behaviour of alkalinity, together with the relatively low value of the homogenous buffer factor β (β = ∂lnfCO2/∂lnTCO2) revealed that calcifi cation or carbonate dissolution takes place on a very small scale, simultaneously with the organic carbon production. The correlations between fCO2 and chlorophyll α, as well as AOU and the surface temperature, revealed that the carbon dioxide fi xation through the biological activity is the principal factor that modulates the variability of fCO2. A rough first estimate of the magnitude of the air-sea CO2 exchange and the potential role of the Thermaikos Gulf in the transfer of atmospheric CO2 was also obtained. The results showed that during May 1997, the Thermaikos Gulf acted as a weak sink for atmospheric CO2 at a rate of -0.60 - -1.43 mmol m-2 d-1, depending on which formula for the gas transfer velocity was used, and in accordance to recent reports regarding other temperate continental shelves. Extensive study of the dissolved inorganic carbon and related parameters, and continuous shipboard measurements of fCO2 a and fCO2 w during all seasons are necessary to safely quantify the role of the Thermaikos Gulf in the context of the coastal margins CO2 dynamics.
Contribution of Nutrients and some Trace Metals from a Huge Egyptian Drain to the SE-Mediterranean Sea, west of Alexandria
Authors: EL-RAYIS O.A. , ABDALLAH M.A.M.
Published: May 2013

In 2003 the MAP Technical Report Series 141, mentioned the lack of data concerning the flux of water, sediments and pollutants from North-African rivers and from the land-based sources to the Mediterranean Sea.In Egypt, the Omoum drain, after the construction of the Aswan High Dam and the controlling of the Nile River water fl ow, has become one of the main land-based sources regularly discharging its waters (fl ow rate 2547.7 x 106 m3/year) directly into the Mediterranean Sea at EL-Mex Bay, west of Alexandria. Downstream, before it reaches the sea, its water mixes with water effl uent (surplus water) from a neighboring sewage-polluted lake called Lake Maryout, rate 262.8 x 106 m3/year.The present work is a monthly study over a year of levels of concentration of some mainly trace elements (nutrients and some heavy metals) in the proper water of the drain before mixing and in the effl uent from the lake, and calculations of both the concentrations and the corresponding expected loads of these elements contributed by the drain to the sea. The results revealed that the respective loads to the sea are 77380 ton/year for total suspended matter, 823 tons/year for dissolved PO4 -P, 4745 tons/year for inorganic N, 23.7 tons/year for Fe, 3.28 tons/year for Mn, 5.84 tons/year for Cu, 2.9 ton/year for Cd, and 24 tons/year for Zn. The elements loaded by the lake effl uent represent values ranging between 8 and 57.5% of the total load contributed by the drain to the sea. The plant nutrients (ammonia and reactive phosphorus) are of values exceeding 44%.
On the enigmatic origin of the Mediterranean invasive Caulerpa racemosa (Caulerpales, Chlorophyta)
Authors: PANAYOTIDIS P.
Published: May 2013

The successful sexual reproduction of the Mediterranean invasive species Caulerpa racemosa could explain not only its rapid expansion during the last decade of the 20th century, but also its origin, through hybridation and genetic recombination of preexisting varieties. This paper argues on the cryptogenic origin of the Mediterranean invasive Caulerpa racemosa.
Eutrophication patterns in an eastern Mediterranean coastal lagoon: Vassova, Delta Nestos, Macedonia, Greece
Authors: ORFANIDIS S. , STAMATIS N. , RAGIAS V. , SCHRAMM W.
Published: May 2013

The results of an intensive monitoring study of main eutrophication parameters in relation to fish farming management, climate and hydrography in the Vassova coastal lagoon (Nestos Delta) are presented. The overall aim is to produce basic knowledge in order to contribute to the management of eutrophication of coastal lagoons at local and national levels. Due to extensive spatiotemporal variability of the measured parameters correlation and regression polynomial analysis was used to identify patterns (p<0.05). Freshwater was the main source of nitrate and phosphate in the lagoon. This finding has justified the reduction of freshwater inflow in the past, which, however, has increased mean salinity to 30 PSU and reduced spatial salinity gradients. Maximum nitrate values in winter coincided with adverse climatic and hydrographic conditions (high precipitation, strong NE to E winds and low tide) and fish farming management that hinder water circulation. Dissolved phosphorus variability indicated the combination of the external (freshwaters) and internal (sediment) P-sources. N/P water values indicated nitrogen being the most important nutrient for primary producers throughout the year, except in winter, when phosphorus was the most important nutrient. Practical measures for improving fish farming practices to decrease “eutrophication risk” during winter are suggested. Existing nutrient data from the Vassova and from other Greek lagoons in comparison were also presented and discussed.
A review on the biodiversity of hard substrate invertebrate communities in the Aegean Sea
Authors: CHINTIROGLOU C. , ANTONIADOU C. , VAFIDIS D. , KOUTSOUBAS D.
Published: May 2013

This review attempts to estimate the biodiversity of the macrobenthic communities that develop on hard bottoms in the Aegean Sea. Literature analysis revealed that 1,171 species inhabit the hard substrate communities, constituting 20.9% of the total Mediterranean species. The hierarchical cluster analysis of the available data identified five major types: (1) the supralittoral communities, (2) the midlittoral communities, (3) the port communities, (4) the various facies of the photophilic algae community, and (5) the facies of the sciaphilic algae community. Thus, hard bottom communities in the Aegean seem to be separated mainly according to vertical zonation. A total of 68 hard-bottom species are under multiple exploitation, providing considerable economic profit. Taking into account the structural complexity of hard substrate benthic communities and their sensitivity to disturbances, it is essential to preserve the biodiversity of these biotopes.
Set up and application of an underwater Α-ray spectrometer for radioactivity measurements
Authors: TSABARIS C. , VLACHOS S. , PAPADOPOULOS C.T. , VLASTOU R. , KALFAS C.A.
Published: May 2013

The set up and control of an underwater measuring instrument for radioactivity pollution in the marine environment is described. The detection system is based on a NaI scintillator (RADAM III) with modifications for use in the marine environment with on-line measurements. The system is simple, has low power consumption and is stable for long-term monitoring (10 months). Before its deployment, the sensor was calibrated in the laboratory in a tank full of water to reproduce the marine environment. The calibrations were performed, by detecting the 661keV and 1461 keV gamma rays of known activity liquid sources 137 Cs and 40 K, respectively. The measured spectra in the laboratory were compared with spectra from a similar detector as acquired in the field. The analysis of the parallel measurement gave satisfactory agreement for the concentration of the potassium (40 K), as calculated from the salinity in the seawater, thus enabling the system for quantitative measurement of the seawater radioactivity.
A preliminary study of an eastern Mediterranean coastal ecosystem: Summer Resorts and Benthic ecosystems
Authors: REIZOPOULOU S. , ZENETOS A.
Published: May 2013

The present study investigates whether coastal benthic communities are affected by tourist activities along the coast, which persist for a limited time period. The analysis of benthic macrofauna is based on the ecological parameters (quantitative analyses) as well as on the ecological identity of the species (qualitative analyses). Microbial contamination and some population statistics are correlated with ecological parameters. The disturbance of benthic communities in the vicinity of summer resorts is summarized by a reduction in species number and dominance of opportunistic species characteristic of disturbed and polluted environments. It is found that community diversity and evenness of distribution decrease with the deterioration of water quality, expressed as grade of microbial contamination, which implies that benthic community is also a significant element in assessing the quality of coastal waters. The above parameters were statistically negatively correlated with the number of tourists.
Gametogenesis and spawning of Spirobranchus tetraceros (Polychaeta, Serpulidae) in Abu Kir Bay, Egypt
Authors: SELIM S. A. , ABDEL NABY F. , GAB-ALLA A.A. F.A. , GHOBASHY A.
Published: May 2013

The serpulid polychaete Spirobranchus tetraceros of Red Sea / Indo-pacific origin, recently has succeeded to establish a foothold in Alexandria Mediterranean waters. Worms were monthly scraped from submerged iron substrates at Abu Kir Bay during the period December 2000 – November 2001. Both light and TEM were used to study gametogenesis and time of spawning of S. tetraceros.Gametogenesis was asynchronous and oogenesis could be divided into two previtellogenic, two vitellogenic and a spawning stage. Oocyte development took about 8 months, from October to June. Spawning occurred from late May - early June until October. Thus S. tetraceros is a long period spawner. The maximum diameter of ripe oocyte is 78 mm. The spermatogenic phase could be divided into three stages: spermatogonia, spermatocytes and spermatids (including spermatozoa). The duration of sperm development took about 8 months. Spermatocytes persist from October to March. By March the sperms grew rapidly until they became spermatozoa in May. The sperm could be considered ect-aquasperm with regard to its fertilization biology.
Seeking the factors to stimulate the users in coastal zones planning. Case study: Open discussions with mussel farmers in the Axios river (GR)
Authors: ZANOU B. , ANAGNOSTOU CH. , PAPATHANASSIOU E.
Published: May 2013

In the framework of an integrated coastal zone management, the involvement of users is required and “open discussions” is one of the techniques used for their participation. The authors used this technique during a project for the sustainable development of mussel-culture in the coastal zone of the Axios Delta. Open discussion contributed to the acceptance of the scientific results by the users of the aquatic environment (mussel-farmers) who addressed trade-offs in their own way. The majority of their arguments were incorporated in the formation of the management rules, presented in the final report of this project. The present paper summarizes this experience as well as the existing ways for the involvement of users in a decision planning process and demonstrates how open discussion is a prerequisite factor for the success of sustainable development planning in Greece.
Fisheries in the Mediterranean
Authors: PAPACONSTANTINOU C. , FARRUGIO H.
Published: May 2013

The aim of this paper is to give a description of the Mediterranean fisheries, and its level of exploitation and to address the main questions dealing with its management. The Mediterranean is a semi-enclosed marine area with generally narrow continental shelves. The primary production of the Mediterranean is among the lowest in the world (26-50g C m-2 y-1). The Mediterranean fisheries can be broken down into three main categories: small scale fisheries, trawling and seining fisheries, which operated on demersal, small pelagic and large pelagic resources. After a general description of the state of the resources in the different areas of the Mediterranean it is concluded that (a) the overall pictures from the western to the eastern Mediterranean are not considerably different, (b) the total landings in the Mediterranean have been increased the last decades, and (c) from the perspective of stock assessment, the very few available time series data show stable yield levels. In general fisheries management in the Mediterranean is at a rela- tively early stage of development, judging by the criteria of North Atlantic fisheries. Quota systems are generally not applied, mesh-size regulations usually are set at low levels relative to scientific advice, and effort limitation is not usually applied or, if it is, is not always based on a formal resource assessment. The conservation/management measures applied by the Mediterranean countries can be broadly separated into two major categories: those aiming to keep the fishing effort under control and those aiming to make the exploitation pattern more rational. The most acute problems in the management of the Mediterranean resources are the multispecificity of the catches and the lack of reliable official statistics.
Distribution characteristics of pandalid shrimps (Decapoda: Caridea: Pandalidae) along the Central Mediterranean Sea
Authors: FANELLI E. , COLLOCA F. , BELLUSCIO A. , ARDIZZONE G.D.
Published: May 2013

The genus Plesionika is represented in the Mediterranean Sea by eight species, six of which,Plesionikaacanthonotus, P. antigai, P. edwardsii, P. gigliolii, P. heterocarpus and P. martia, are very common on muddy bottoms of the continental slope. During nine experimental trawl surveys a total of 29,038 individuals of these six pandalid species, was collected off the central western coasts of Italy (central Mediterranean) in order to study population structure and spatial distribution. P . antigaiinhabits the shelf break and upper slope; P. heterocarpus shows a wide bathymetric distribution, from the shelf-break to the upper slope; P. edwardsii and P. gigliolii occur in the upper slope. P. acanthonotus and P. martia occur in the deepest depths investigated. Segregation by size is revealed for the species that inhabit the same bottoms. The non-homogenous spatial distribution of Plesionikaspecies in the study area was probably related to the spatial differences in the magnitude of primary production in the area.
Modeling of the upwelling hydrodynamics in the Aegean Sea
Authors: SAVVIDIS Y.G. , DODOU M.G. , KRESTENITIS Y.N. , KOUTITAS C.G.
Published: May 2013

The special features of the hydrodynamic circulation in the Aegean Sea referring to the development of regional upwelling coastal zones are studied by means of a mathematical model. The modeling effort is focused on the tracing of coastal areas, where upwelling events are frequently observed during the summer meteorological conditions. These areas are characterized by the enrichment of surface waters with nutrients and, consequently, increased fish production. The phenomenon is studied by the use of a two-layer mathematical model comprising the surface heated zone and the rest of the water column. The numerical solution of the model is based on the finite differences method. The wind shear applied over the stratified basin, with predefined density stratification and initial water-layers thickness, and the gravity and Coriolis forces taken into account, constitute the basic external factors for the generation of the hydrodynamic circulation in the area of the Aegean Sea. The calibration and the validation of the model are performed by the comparison of the model output to the data and observations reported in valid scientific sources. The aim of the paper is to demonstrate the significant contribution of numerical models to the better understanding of the hydrodynamics governing the Aegean water circulation as well as the tracing of upwelling zones.
Distribution of trace metals in the sediments of Elefsis Gulf
Authors: MAVRAKIS A. , THEOHARATOS G. , ASIMAKOPOULOS D.N. , CHRISTIDES A.
Published: May 2013

The present work examines the temporal evolution of industrial contamination in sediments caused by trace metals in the Elefsis Gulf, Greece. The current state of contamination as well as the related sources can be obtained from the study of the sediments. Trace metals, namely Ni, Cu, Fe, and Mn, were collected during 1984-2003 by the local monitoring network. The statistical analysis of the data and the contaminants isopleths patterns support the following conclusions: There is a strong correlation between the nearby coastal industrial activities and the distribution of the trace metals’ concentration in sediments. There is no seasonal or annual variation of the distribution. The sediments’ concentration of Mn in all sampling points and Cu in the center of the Gulf has decreased during the last years.
Heterotrophic bacterial growth and substrate utilization in the oligotrophic Eastern Mediterranean (Aegean Sea)
Authors: CHRISTAKI U. , WAMBEKE F.V. , BIANCHI M.
Published: May 2013

Heterotrophic bacterial growth and substrate utilization were studied in March and September of 1997 in the oligotrophic Aegean Sea. Maximum velocities of ectoproteolytic activity (ectoaminopeptidase ctivity, EAP), as well as amino acid assimilation and respiration rates (AA-A, AA-R) were measured along with bacterial production (protein synthesis). At the northern stations which are influenced by the input of the Black Sea waters, rates at 5 m depth of EAP, AA-A and bacterial production were 2 to 3 times higher than at southern stations. Influenced by the Black Sea water, mean bacterial numbers in the 0-100 m layer showed typical oceanic concentrations averaging 0.7 x 10 6 cells ml -1 . These values, along with low bacterial production rates (30 ng C l -1 h -1 ) implied slow growth for bacteria and/or that a large number among them were inactive. Neither bacterial abundance nor production were correlated with primary production. The percentage of amino acids respired was higher in September compared to March, particularly in the northern Aegean (mean 69 %). The enzyme kinetic analysis showed a biphasic model, the transition between the high and low affinity enzymes being obtained at 50 ΜM. Ectoaminopeptidase activity was weakly correlated with bacterial production (p < 0.05), but strongly correlated with respiration rates of amino acids (p < 0.001), suggesting that the substrate used was devoted to maintain energy requirements.
First Occurrence Of The Tilapia Oreochromis Niloticus Niloticus (Linnaeus, 1758) In Lesina Lagoon (Eastern Italian Coast)
Authors: SCORDELLA G. , LUMARE F. , CONIDES A. , PAPACONSTANTINOU C.
Published: May 2013

Individuals of the tilapia species Oreochromis niloticus niloticus(Linnaeus, 1758) were caught in Lesina Lagoon during experimental sampling for the shrimp Penaeus kerathurus using fyke net traps from December 1999 to September 2000. The species O. niloticusis not native in Italian coastal waters, although attempts of tilapia culture in land-based aquaculture farms were occasionally carried out in the past. The number of individuals captured in the samples suggests a colonization of the area of Lesina lagoon. The highest catches were observed during July. In July, the individuals caught represented the 22.3±4.1 % of the total catch weight. Such colonization of a marine environment byO. niloticusniloticus is the first case reported for Italy. The occurrence of the species in Lesina lagoon is attributed to fish which escaped from fish farms in the area and entered the lagoon through the numerous streams and irrigation-drainage channels that outflow along the south coastline.
Variability of environmental factors of an eastern Mediterranean Sea river influenced coastal system
Authors: KORMAS K.AR. , NICOLAIDOU A. , THESSALOU-LEGAKI M.
Published: May 2013

Spercheios River discharge rates of nutrients, suspended particulate matter (SPM) and particulate organic carbon (POC) and seawater concentrations of these parameters as well as chlorophyll a(chl a) were measured in the Maliakos Gulf, Greece, on a monthly basis between 1992-1993. From all the nutrients measured, silicate showed the highest discharge rates followed by nitrate, phosphate and nitrite. The river introduced significant amounts of SPM (8.5 – 35.5 Kg d -1 ) with very low POC content (<3%). Most of the variables measured showed no gradient from the river to the outer gulf, which could be attributed to fast mixing of the incoming water. However, chl a had higher concentrations in the inner (0.3 – 4.9 Μg l -1 ) and lower in the outer gulf (0.05 – 2.5 Μg l -1 ). It is suggested that the nutrients introduced by the river are consumed faster in the inner gulf and that a number of temporal streams and non-point sources at the periphery of the gulf prevent the formation of a gradient.
Cephalopods distribution in the southern Aegean Sea
Authors: LEFKADITOU E. , PERISTERAKI P. , BEKAS P. , TSERPES G. , POLITOU C.Y. , PETRAKIS G.
Published: May 2013

The present study concerns faunal composition and distribution of cephalopods in the southern Aegean Sea (35Ζ 13’ 19’’- 37Ζ 55’ 25’’ N, 23Ζ 00’ 15’’ - 28Ζ 15’ 37’’ E). Samples were collected from 708 hauls, obtained by an experimental bottom trawl net during eight surveys carried out in the summers of the years 1994-2001, as well as by commercial trawl net during four surveys carried out in September 1995, December 1995, May and September 1996. The hauls were performed at depths ranging from 16 to 778 m. A total of 34 species of cephalopod in 12 families were identified, including 11 oegopsid squid, 3 myopsid squid, 7 octopod, 3 cuttlefish and 10 sepiolid. Trawling with the experimental net resulted in the capturing of some uncommon pelagic species, such as Ctenopteryx siculaand Octopoteuthis sicula, which were recorded for the first time in the Aegean Sea. Most of the species showed a wide depth and geographical range. The species: Sepia officinalis, Sepietta neglecta, Sepietta obscuraand Sepiola rondeletiwere caught only on the continental shelf, whereas the Ancistroteuthis lichtensteini, Bathypolypous sponsalis, Brachioteuthis riisei, Chiroteuthis veranyi, Ctenopteryx sicula, Heteroteuthis dispar, Histioteuthis reversa, Neorossia caroli and Pyroteuthis margaritiferawere found only on the slope. The rest of the species extended in both continental shelf and slope. The spatial distribution of different species groups is discussed in relation to the hydrology and topography of the study area and the species ecology.
Benthic indicators to use in Ecological Quality classification of Mediterranean soft bottom marine ecosystems, including a new Biotic Index
Authors: SIMBOURA N. , ZENETOS A.
Published: May 2013

A general scheme for approaching the objective of Ecological Quality Status (EcoQ) classification of zoobenthic marine ecosystems is presented. A system based on soft bottom benthic indicator species and related habitat types is suggested to be used for testing the typological definition of a given water body in the Mediterranean. Benthic indices including the Shannon-Wiener diversity index and the species richness are re-evaluated for use in classification. Ranges of values and of ecological quality categories are given for the diversity and species richness in different habitat types. A new biotic index (BENTIX) is proposed based on the relative percentages of three ecological groups of species grouped according to their sensitivity or tolerance to disturbance factors and weighted proportionately to obtain a formula rendering a five step numerical scale of ecological quality classification. Its advantage against former biotic indices lies in the fact that it reduces the number of the ecological groups involved which makes it simpler and easier in its use. The Bentix index proposed is tested and validated with data from Greek and western Mediterranean ecosystems and examples are presented. Indicator species associated with specific habitat types and pollution indicator species, scored according to their degree of tolerance to pollution, are listed in a table. The Bentix index is compared and evaluated against the indices of diversity and species richness for use in classification. The advantages of the BENTIX index as a classification tool for ECoQ include independence from habitat type, sample size and taxonomic effort, high discriminative power and simplicity in its use which make it a robust, simple and effective tool for application in the Mediterranean Sea.
Response of free-living Nematodes to the quality of water and sediment at Bou Chrara Lagoon (Tunisia) during winter 2000
Authors: MAHMOUDI E. , BEYREM H. , BACCAR L. , AISSA P.
Published: May 2013

The Bou Ghrara lagoon, a stretch of water in southeastern Tunisia, has shown an alarming reduction of its fishery resources since 1993. In order to study the response of free-living nematodes to the water and sediment quality of this area, thirteen stations have been sampled. According to this study, the heavy metal, organic carbon and hydrocarbon content of sediments are key factors negatively influencing the density, biomass and diversity of the nematofauna.
Circulation and hydrological characteristics of the North Aegean Sea: a contribution from real-time buoy measurements
Authors: NITTIS K. , PERIVOLIOTIS L.
Published: May 2013

In the framework of the POSEIDON Project, a network of open sea oceanographic buoys equipped with meteorological and oceanographic sensors has been operational in the Aegean Sea since 1998. The analysis of upper-ocean physical data (currents at 3m, temperature and salinity at 3-40m depths) collected during the last 2 years from the stations of the North Aegean basin indicates a strong temporal variability of flow field and hydrological characteristics in both synoptic and seasonal time scales. The northern part of the basin is mainly influenced by the Black Sea Water outflow and the mesoscale variability of the corresponding thermohaline fronts, while the southern stations are influenced by the general circulation of the Aegean Sea with strong modulations caused by the seasonally varying atmospheric forcing.
Nutrient exchange fluxes between the Aegean and Black Seas through the Marmara Sea
Authors: TUGRUL S. , BESIKTEPE T. , SALIHOGLU I.
Published: May 2013

Long-term data obtained in the Turkish Strait System (TSS) including the Sea of Marmara, the Dardanelles and Bosphorus straits, during 1990-2000, have permitted us to calculate seasonal and annual fluxes of water and nutrients (nitrate, phosphate) exchanged between the Aegean and Black Seas through the TSS. Two-layer flow regimes in the TSS introduce the brackish waters of the Black Sea into the Aegean basin of the northeastern Mediterranean throughout the year. A counter flow in the TSS carries the salty Mediterranean water into the Black Sea via the Marmara deep basin. The annual volume influx from the Black Sea to the Marmara upper layer is nearly two-fold the salty water exported from the Marmara to the Black Sea via the Bosphorus underflow. The brackish Black Sea inflow is relatively rich in nitrate and phosphate in winter, decreasing to the lowest levels in late summer and autumn. Biologically labile nutrients of Black Sea origin are utilized in photosynthetic processes in the Marmara Sea and are partly exported to the Marmara lower layer. Eventually, the brackish Black Sea waters reach the Dardanelles Strait, with modified bio-chemical properties. On the other hand, the salty Mediterranean waters with low concentrations of nutrients enter the Marmara deep basin. During threir 6-7 year sojourn in the Marmara basin, the salty waters become enriched in nitrate (DIN) and phosphate (DIP), due to oxidation of planktonic particles sinking from the Marmara surface layer. The annual nutrient inputs from the Black Sea to the Marmara basin were estimated as 8.17x108 moles of DIN and 4.25x107 moles of DIP, which are much less than the importation from the Marmara lower layer via the Bosphorus undercurrent. The salty Aegean water introduces nearly 6.13x108 moles of DIN and 2.79x107 moles of DIP into the Marmara lower layer. The estimated DIP outflux from the Aegean Sea is nearly 2 times less than the importation from the Marmara Sea via the Dardanelles Strait.
Hydrography, nutrients and plankton abundance in the hot spot of Abu Qir Bay, Alexandria, Egypt
Authors: ABDEL-AZIZ N.E. , FAHMY M.A. , DORGHAM M.M.
Published: May 2013

The hydrography, nutrient levels and plankton abundance were investigated monthly for a complete annual cycle in the southwestern part of Abu Qir Bay, the most polluted and biologically productive area on the Egyptian Mediterranean coast. Intense temporal and spatial variability was observed in all measured parameters characteristic of the effects of several effluents discharged into the bay. Based on the present investigation, the southwestern Bay can be divided ecologically and biologically into two parts: one including the near shore strip, which is directly affected by the waste waters, and a second comprising the southwestern part of the coastal strip and the offshore stations, both of which are relatively far away from the land-based effluents.The Bay water was characterized by low transparency (monthly average: 64-280 cm), dissolved oxygen (monthly average 2.0-6.8 mg/l) and surface salinity (monthly average: 24.8-37.9 ppt), the highest limits usually being in the offshore section. Water fertility and plankton production were high in the Bay indicating an occasionally acute degree of eutrophication, particularly nearshore. Great variations occurred in the concentrations of nutrients throughout the year, with monthly averages of 0.8-50.88 mM for ammonia, 0.42-3.28 mM for nitrite, 1.29-17.36 mM for nitrate, 0.32-3.61 mM for reactive phosphate and 1.09-33.34 mM for reactive silicate. Similarly, the abundance of both phytoplankton and zooplankton showed pronounced temporal and spatial variability, whereas the monthly average chlorophyll-a fluctuated between 2.06 and 52.64 mg/l and zooplankton between 31x103 and 248.6x103 ind./m3. However, the absolute values of all parameters indicated remarkably wider ranges of variations.Significant correlation was found between chlorophyll-a and some ecological parameters like temperature, salinity, transparency, dissolved oxygen, nitrite and between zooplankton and temperature, while there was a significant correlation between nutrient concentrations and salinity changes.
Ecological evaluation of transitional and coastal waters: A marine benthic macrophytes-based model
Authors: ORFANIDIS S. , PANAYOTIDIS P. , STAMATIS N.
Published: May 2013

A model to estimate the ecological status and identify restoration targets of transitional and coastal waters was developed. Marine benthic macrophytic species (seaweeds, seagrasses) were used to indicate shifts in the aquatic ecosystem from the pristine state with late-successional species (Ecological State Group I) to the degraded state with opportunistic (ESG II) species. The first group comprises species with a thick or calcareous thallus, low growth rates and long life cycles (perennials), whereas the second group includes sheet-like and filamentous species with high growth rates and short life cycles (annuals). Seagrasses were included in the first group, whereas Cyanophyceae and species with a coarsely branched thallus were included in the second group.The evaluation of ecological status into five categories from high to bad includes a cross comparison in a matrix of the ESGs and a numerical scoring system (Ecological Evaluation Index). The model could allow comparisons, ranking and setting of priorities at regional and national levels fulfilling the requirements of the EU Water Frame Directive. A successful application of the model was realized in selected lagoons of the Macedonian and Thrace region (North Greece) and in the Saronic Gulf coastal ecosystems (Central Greece).
A fractal theory approach to the initial examination of normal faulting in Central Corinthian Gulf, Greece
Authors: KONDYLAKIS J.C. , PAPOULIA J.E.
Published: May 2013

An application of fractal theory in geological formations in the central Corinthian Gulf, Greece, is presented in an attempt to study the nature of presently active deformation. Fault patterns are approximated under the perspective of fractal theory concept, leading to the conclusion that fractal approach can be considered valid for the region of study. Nevertheless, homogeneity may be expected with the reservation that there are no considerable changes in the viscosities of the ductile layers in the region, so that the characteristic exponent b+1-a is less than zero.
Catch composition and management of daytime purse seine fishery on the Southern Mediterranean Sea Coast, Abu Qir Bay, Egypt
Authors: EL-HAWEET A.
Published: May 2013

The present work aimed to obtain precise data on the catch of the purse seine net operating at daytime from sunrise till noon in Abu Qir Bay during 1997 and 1998. Sardine, anchovy, mullet and rabbitfish were recorded as the main target fish groups. Twenty-seven species were recorded as by-catch species. Catch per unit effort was estimated to be 93 kg/day/boat. The percentage of each target species in the catch and its length frequency distribution were presented. The length range of by-catch species and the season of catch were recorded. Daytime purse seine in Abu Qir Bay is an effective method but should regulated by directing the fishing to deeper waters outside the bay rather than the inshore coastal area to conserve many economic species of this important fishery.
Preliminary results on Macroalgae distribution in destructive processes
Authors: OSKOLSKAYA O.I. , TORSKAYA A.V. , TIMOFEEV V.A.
Published: May 2013

It has been shown, that the destruction of the coastal strip in region of action of Mikhailovsky landslide results in change of species structure and dominant species photophilous Cystoseira barbara on sciophylous Gracilaria verrucosa. In accordance with increasing sediments amount in sea water biomass and the morpho-functional parameters of the photophilous species are reducing, and at the sciophylous are growing. Progressing phenomenon of epiphytism is observed in algal populations in the southern part of researched region which is possible to consider as response reaction, leads to increase a synthesizing surface. Decreasing physiological activity is compensated by growth of the total surface of macrophytes. The increase of a sea water sediments leads to lowering ratio of long and shortwave pigments level of ATP-ase activity and raising concentration of the total sum of pigments in thalli.
The Cystoseira spp. Communities from the Aegean Sea (NE Mediterranean)
Authors: MONTESANTO B. , PANAYOTIDIS P.
Published: May 2013

A synthetic study of qualitative and quantitative data from some algal communities dominated by different species of the genus Cystoseira has been carried out in three coastal areas of the Aegean Sea. Seasonal samples were taken from 10 stations and a list of 30 species presenting coverage values > 1% was dressed. Ecological indices, such as Shannon Diversity Index, Pielou Eveness and Bray-Curtis Similarity Index were calculate using the PRIMER software. The results from the Aegean Sea were compared with other Mediterranean areas, and the use of Cystoseira communities as ecological quality indicators was discussed.