Southeastern Mediterranean Sea Research Articles

Maturity of the pufferfish Lagocephalus sceleratus in the southeastern Mediterranean Sea

SEDAO Sexuality and Early Development in Aquatic Organisms Contact the journal Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections SEDAO 1:35-44 (2014) - DOI: https://doi.org/10.3354/sedao00005 Maturity of the pufferfish Lagocephalus sceleratus in the southeastern Mediterranean Sea Maria Rousou1,2, Konstantinos Ganias2,*, Demetris Kletou1,3, Alexandros Loucaides1, Markos Tsinganis2 1Marine and Environmental Research (MER) Lab Ltd, Nicosia, Cyprus 2School of Biology, Aristotle University of Thessaloniki, 54 124 Thessaloniki, Greece 3School of Marine Science and Engineering, University of Plymouth, Plymouth, UK *Corresponding author: kganias@bio.auth.gr ABSTRACT: The present study assesses maturity and reproductive dynamics of pufferfish Lagocephalus sceleratus (Gmelin, 1789) off Cyprus (southeastern Mediterranean Sea), in relation to regional differences in oceanographic conditions, habitat characteristics and fishing activity. In addition, the allometric pattern of gonadal growth was studied to validate the use of the gonadosomatic index (GSI) in assessments of the reproductive cycle. To do so, 4743 pufferfish were sampled between May and October 2010 so as to cover the reproductive period of the population, which peaks from late spring to middle summer. Analysis of GSI data showed a clear differentiation between 2 pufferfish populations residing in the southwestern (SWA) and the south-east (SEA) coastal areas of Cyprus. Specifically, the SWA population was mainly dominated by immature individuals and exhibited a more delayed and narrow reproductive period. Moreover, generalized linear model analysis (GLM) showed that the SWA population exhibited significantly smaller size at 50% maturity, L50 (41.9 cm), compared to the SEA population (48.8 cm). These differences in reproductive seasonality and L50 were not found to be related to differences in sea surface temperature (SST) between the 2 regions, whilst mature individuals almost entirely disappeared from both areas outside the reproductive period. The latter could not be attributed to overfishing of the larger size classes since the fishery was not shown to be selective to pufferfish size. These results indicate that L. sceleratus may be a spawning migratory species that visits Cyprus southeastern coasts to reproduce and then migrates to other warm areas of the eastern Levantine basin. KEY WORDS: Lagocephalus sceleratus · Maturity · Lessepsian migrant · Invasive species · Eastern Mediterranean Full text in pdf format PreviousNextCite this article as: Rousou M, Ganias K, Kletou D, Loucaides A, Tsinganis M (2014) Maturity of the pufferfish Lagocephalus sceleratus in the southeastern Mediterranean Sea. Sex Early Dev Aquat Org 1:35-44. https://doi.org/10.3354/sedao00005 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in SEDAO Vol. 1, No. 1. Online publication date: April 17, 2014 Print ISSN: 2195-2736; Online ISSN: 2195-2744 Copyright © 2014 Inter-Research.

Variability of spatial and temporal distribution of zooplankton communities at Matrouh beaches, south-eastern Mediterranean Sea, Egypt

The objectives of this work are to determine the main environmental drivers of zooplankton variability in water of Matrouh beach, south-eastern Mediterranean Sea and to evaluate the differences in zooplankton abundance and population structure in relation to chemical and biological parameters. Samples were collected seasonally from summer 2009 to summer 2010 at 10 sampling beaches. The zooplankton community was characterized by its high variability, and lower diversity. Zooplankton variability primarily responded to seasonal changes in water temperature and variation in salinity. In total, 49 zooplankton species were quantified; most of them were protozoans (22 species) and copepods (14 species). The average zooplankton abundance was 36.0×103ind.m−3, where copepods were dominant, making up 72.4% of the total population. Protozoa formed the second group, comprising 11.7%. Differences in species diversity were analysed in a zooplankton community, where the dominance of a single species was frequent. The Shannon–Wiener Diversity Index classified Matrouh water as being between moderately polluted and polluted, whereas the WQI demonstrated that it was between good and excellent. It can be concluded that, the index based on WQI is currently more suitable than the zooplankton species index for assessing the quality of water of Matrouh beaches.

Biometry and reproductive biology of Pseudonereis anomala Gravier 1901 (Polychaeta: Nereididae) on the Alexandria coast, Egypt

The biometric characteristics and reproductive biology of the nereid polychaete Pseudonereis anomala were studied monthly from August 2009 to July 2010 at two ecologically different sites (Abu-Qir and El-Mex) on the Alexandria coast, south-eastern Mediterranean Sea. The maximum body length and weight showed different values at the two sites: 9.8 and 11.9cm, and 0.77 and 1.3g respectively. The formula of the length-weight relationship indicated allometric growth, whereas the regression equation between length to the 6th segment and weight reflected isometric growth. Immature individuals were the major component of the worm population at the two sites, making up 69.1% at Abu Qir and 66.9% at El Mex; the respective percentages of males and females at these sites were 5.8–8.1% and 22.8–27.3%. Spawning was observed all the year round with female fecundity conspicuously lower at Abu-Qir (annual average: 26556±999 eggs per female) than at El-Mex (annual average: 47 955±2916 eggs per female). However, oocyte size was greater at Abu Qir (diameter: up to 250μm) than at El Mex (diameter: up to 220μm).

AVS-SEM relationships and potential bioavailability of trace metals in sediments from the Southeastern Mediterranean sea, Egypt

In risk assessment of aquatic sediments, much attention is paid to the difference between acid volatile sulfide (AVS) and simultaneously extracted metals (SEM) as indicators of metal bioavailability. Distribution of AVS and SEM (Cd, Cu, Ni, Pb and Zn) were determined in 20 representative sampling sites collected along the Egyptian Mediterranean coast. Total SEM concentration [ΣSEM] ranged from 0.012 to 0.241 μmoleg−1. AVS concentrations were much more variable, showing significant spatial variations. The values ranged from 0.015 to 31.326 μmoleg−1. The different relationships between AVS and SEM to establish mechanical models such as the ratio of ΣSEM and AVS [ΣSEM/AVS], the difference between the ΣSEM and AVS [ΣSEM–AVS], or the organic carbon normalised difference between SEM and AVS [ΣSEM-AVS]/foc models were used as parameters to evaluate potential bioavailability. Considering SEM/AVS model, sediments at the Western Harbour, Eastern Harbour, Ras El-Burr, El-Gamil East, and Port Said stations are occasionally toxic, while according to SEM-AVS model, no indication of associated adverse toxic effect would occur at any of the sampling sites. Calculated [ΣSEM-AVS]/foc was<130 μmoleg−1 in the sediments indicating that sediments should pose a low risk of adverse biological effects owing to cadmium, copper, lead, nickel and zinc. Association of adverse effects to aquatic organisms was determined, using the classification of the sediments according to the Sediment Quality Guidelines (SQGs). The marine Threshold Effect Levels (TEL) and Probable Effect Levels (PEL) were used in this work and in order to obtain a more realistic measure of predicted toxicity, mean PEL quotients (PELq) were calculated. The mean PELq calculated for the sampling sites was (0.11–1.5) and categorised as slightly toxic at all stations except Baghoush, Nobarreya and western harbour, which had PELq<0.1 and categorised as non-toxic. The obtained data concluded that the remobility and bioavailability of trace metals contained in surfacial sediments of the Egyptian Mediterranean coastal area are low.

Dynamic Properties of Some Eastern Mediterranean Marine Sediments

Abstract A series of resonant column tests on sediments from offshore Haifa, Israel are presented in this paper. Samples were obtained from both the Akhziv submarine canyon and the undisturbed slope located on the continental terrace of Northern Israel in the Eastern Mediterranean using a gravity corer in 59 to 699 m of water depth. The continental shelf of northern Sinai, Israel, and Lebanon is made of 1–2-km-thick Nile-derived sediments of the Pliocene–Quaternary age that were transported to the northeast by the counterclockwise contour current system of the Southeastern Mediterranean Sea, and accumulated along the continental margin. The sediments tested consist of dark grey silty clays (MH/CH). The sedimentological pattern over the continental shelf and the adjacent parts of the deep-sea Levant Platform essentially consists of continuous hemipelagic sedimentation of the Nile-derived sediments along the continental margin and frequent episodic earthquake triggered sediment slumping with redistribution down slope. The soft sediments described in this paper were trimmed for use in the resonant column apparatus using an osmotic knife in the shape of a split mold. The resonant column utilized in this study was a fixed free apparatus. The total unit weight of the specimens ranged from 14.31 to 17.98 kN/m3, whereas the water content varied from 40 % to 95 %. Maximum shear modulus varied with depth of water, location on the shelf and in the canyon. For the undisturbed slope, the maximum shear modulus is approximately 25 to 29 MPa. For the canyon flank, the modulus ranged from 4.2 to 17.2 MPa. This is in contrast to the canyon bed where shear modulus ranged from 220 to 334 MPa. The increase in shear modulus of the canyon bed sediments is believed a result of either or both internal structure or slight cementation in the Akhziv material based on a combination of previous triaxial testing and site geology. The corresponding damping ratio ranges from 0.5 % to 4 % as a function of shear strain and effective stress. Modulus and damping test results are compared with other marine sediments: offshore Eureka, CA; Navarin Basin, Bering Sea; Gulf of Mexico; and Casablanca and the Santa Barbara Channel California.

The impact of long-range-transport on PM1 and PM2.5 at a Central Mediterranean site

Water soluble ions, methanesulfonate, organic and elemental carbon, and metals in PM2.5 and PM1 samples were analysed by Positive Matrix Factorization to identify and quantify major sources of fine particles at a Central Mediterranean site. The cluster analysis of four-day back trajectories was used to determine the dependence of PM2.5 and PM1 levels and composition on air-flows. The cluster analysis has identified six, six, and seven distinct air-flow types arriving at 500, 1500, and 3000 m above sea level (asl), respectively. Slow-west (Wslow) and north-eastern (NE) flows at 500 and 1500 m asl were the most frequent and were associated with the highest PM2.5 and PM1 concentrations. The PM concentrations from combustion sources including biomass burning were at their maximum under north-western (NW) flows. Similarly, the ammonium sulphate source was enhanced under Wslow and NE flows. South-eastern Mediterranean Sea air-flows were associated with the highest PM2.5 concentrations due to the heavy-oil-combustion source and the highest PM2.5 and PM1 concentrations due to the secondary marine source. PM2.5 concentrations due to the reacted dust and traffic source and PM1 concentrations due to the nitrate with reacted dust and mixed anthropogenic source showed no clear dependence on air-flows. This work highlights the different impact of aerosol sources on PM2.5 and PM1 fractions, being PM1 more adequate to control anthropogenic emissions from combustion sources.

First records of polychaetes new to Egyptian Mediterranean waters

Nineteen benthic polychaete species were recorded for the first time in the intertidal zone of the Alexandria coast, south-eastern Mediterranean Sea. They belong to Syllidae (7 species), Hesionidae (3 species), Serpulidae (2 species) and 7 other families (one species each). Of these species Eunice miurai Carrera-Parra & Salazar-Vallejo 1998 appears to be new to the Mediterranean Sea, while four of the alien species earlier recorded in the Mediterranean were found for the first time in Egyptian waters: Opisthosyllis brunnea Langerhans 1879, Loimia medusa Savigny 1822, Syllis schulzi Hartmann-Schröder 1960, Phyllodoce longifrons Ben-Eliahu 1972.The newly recorded species demonstrated markedly different patterns of frequency of occurrence and numerical abundance. Spirobranchus triqueter Linnaeus 1758, S. schulzi, L. medusa and Salvatoria clavata Claparède 1863 were permanent and abundant species in fouling samples along the Alexandria coast. Saccocirrus papillocercus Bobretzky 1872 persisted in the sediments at two sites, with a much higher count at the stressed one, while Protodrilus sp. inhabited sediments at two other sites throughout the year, sometimes in very high numbers. In addition, the alien species found earlier, Brania arminii Langerhans 1881, Odontosyllis fulgurans Audouin & Milne-Edwards 1833 and O. brunnea Langerhans 1879, were frequently observed along the Alexandria coast.

General Trend of Wind Anomalies in the South Eastern Mediterranean Sea

General Trend of Wind Anomalies in the South Eastern Mediterranean Sea

The distribution of Moho depths beneath the Arabian plate and margins

Abstract In this study three new maps of Moho depths beneath the Arabian plate and margins are presented. The first map is based on the combined gravity model, EIGEN 06C, which includes data from satellite missions and ground-based studies, and thus covers the whole region between 31°E and 60°E and between 12°N and 36°N. The second map is based on seismological and ground-based gravity data while the third map is based only on seismological data. Both these maps show gaps due to lack of data coverage especially in the interior of the Arabian plate. Beneath the interior of the Arabian plate the Moho lies between 32 and 45 km depth below sea level. There is a tendency for higher Pn and Sn velocities beneath the northeastern parts of the plate interior with respect to the southwestern parts of the plate interior. Across the northern, destructive margin with the Eurasian plate, the Moho depths increase to over 50 km beneath the Zagros mountains. Across the conservative western margin, the Dead Sea Transform (DST), Moho depths decrease from almost 40 km beneath the highlands east of the DST to about 21–23 km under the southeastern Mediterranean Sea. This decrease seems to be modulated by a slight depression in the Moho beneath the southern DST. The constructive southwestern and southeastern margins of the Arabian plate also show the Moho shallowing from the plate interior towards the plate boundaries. A comparison of the abruptness of the Moho shallowing between the margins of the Arabian plate, the conjugate African margin at 26°N and several Atlantic margins shows a complex picture and suggests that the abruptness of the Moho shallowing may reflect fundamental differences in the original structure of the margins.

Occurrences of large sharks in the open waters of the southeastern Mediterranean Sea

Analysing large pelagic fisheries data from the open waters of the southeastern Mediterranean Sea during 1998 to 2005, we identified no more than 10 species of large sharks, although most updated literature cites more than twice this number in the region. We identified a statistically significant decline in species richness, with the probability of shark occurrence reducing to its lowest level in the most recent years. Blue shark was the predominant species, comprising approximately 70% of all large sharks encountered. A Milk shark was observed for the first time in the region. Based on their capture location, a series of maps depicting the spatial distribution of large sharks is provided. It seems as if currently the continuity of the presence of some species in the region may be questionable or that some species may have become too rare to be detected in the course of a conventional monitoring survey.

New length-weight relationships and Lmaxvalues for fishes from the Southeastern Mediterranean Sea

Summary Length–weight relationships (LWR) of fish serve as building blocks in ichthyology and fishery science. In this study LWR knowledge is extended to some species, regions and sizes of fish either incomplete or missing from the literature or from the online databank (FishBase). For several species data are presented for the first time, while other entries are improved and expanded. Organisms were captured by trawl from the continental shelf of the Israeli coast, where fishes were hypothesized as being small due to low productivity and high water temperatures – a phenomenon called ‘Levantine Nanism’. Despite this, for nine of the 43 species presented here the maximum length values exceeded their Lmax in FishBase. The dominance of fishes of Indo-Pacific origin among the species with exceptionally large specimens (7 of 9) is in agreement with Bergmann's rule; it is thus hypothesized here that these large specimens result from the low temperatures in the Mediterranean compared to their warm Indo-Pacific sources. This is an example of the superb adaptation of tropical species to the Mediterranean and suggests that Levantine Nanism may be limited to indigenous species.

The utilization of seismic interpretation to identify and describe the shallow subsurface structures in the southeastern Mediterranean Sea

The shallow subsurface structures of the offshore Nile Delta particularly in the southeastern Mediterranean were dealt through the interpretation of 40 two-dimensional seismic reflection lines. The interpretations of seismic reflection data indicated that the principle sedimentary processes affecting the study area include three main structural groups according to their origin and development. The first group of structures comprises of gravity-driven structures, which include slides, slumps, turbidities, and debris flow. Slides are present in three different forms on seismic sections: slide sheets, slides with scar, and wedges of slide materials. Slumps have many geometrical shapes: lenses, spoon-shaped slumps, and slumped blocks bound by growth faults. Debris flows are present as transparent unit (due to the dispersion of seismic waves at debris boundaries), whereas turbidities appear on the seismic profiles, which are formed of closely spaced parallel thin reflectors analogous to their thin stratified bedded layers. The second group of structures is syn-depositional structures, which include growth faults, and tilted and rotated fault blocks. Growth faults are listric in shape and usually dip seaward; displacements along the fault plane increase with depth. Some of these faults are incipient, and some are complicated and intersected by secondary antithetic faults. Most of the growth faults soles out basin wards and in the evaporites layer. Fault blocks are formed due to the Messinian evaporite movement vertically and horizontally due to its mobility as a consequence to the pressure resulted from the overloading of Pliocene sediment. The third group of structures comprises evaporite flow structures such as diapiric structures and graben collapse structures. The surface of the Messinian evaporites was folded during its flow as a consequence to the lateral compression acted on the mobile strata of the Messinian evaporites to form diapiric triangular structures and creates a stress zone faulting and fractures system. These conditions led to the formation of collapse structures or graben collapse structures.

Long term sea-level variation in the south-eastern Mediterranean Sea: A new approach of examination

Using 33 years (1974–2006) of hourly sea-level data, this paper plots the trend of long-term variation in the sea-level off Alexandria, representing the south-eastern Mediterranean Sea. Both linear and quadratic model equations describing the rate of variation in the mean monthly sea-level (0.212cm/year) and in the mean monthly sea-level anomaly (0.209cm/year) are produced.The long-term variations in the mean monthly and mean monthly sea-level anomaly reflect very weak cyclic trends. The rate of sea-level variation is controlled not only by the cyclic oceanographic factors but also by the land subsidence process. The latter has much more impact (⅔) than the former (⅓). The total land subsidence, starting from the last year in Cleopatra VII’s life and for 2040 years, is 4.325m. This coincides with the given depth of the present submerged monuments within Alexandria Eastern Harbour.The sea-level rise within the South-eastern Mediterranean basin, associated with climate change, is not as severe as considered by many.

Estimation of Mercury Intake from Selected Fish Species Commercialized in Alexandria, Southeastern Mediterranean Sea, Egypt

ABSTRACT Total Hg concentrations were determined in muscle tissue of some fishes with different feeding habits (12 fish species) obtained from the main fishing locations along the Alexandria coast, a region particularly impacted by historic industrial Hg activities. Health risks to human via dietary intake of the edible portion of fish were assessed by the target hazard quotients (THQs). Mercury maximum concentrations corresponding to fish muscle tissue were found in L. mormyrus, S. rivulatus, and S. luridus (3.56, 2.94, and 1.35 μg g−1 wet weight, respectively). Thence most of these three species bass (75% of L. mormyrus, 76% of S. rivulatus, and 54% of S. luridus) were greater than a 0.47 μg g−1 threshold corresponding to a 1 meal per month consumption limit. M. cephalus, S. aurita, S. chrysotaenia, B. boops, and A. djedaba bass (100%) were less than a 0.12 μg g−1 threshold corresponding to a 4 meals per month safe consumption limit. Mercury THQs values, ranging from 0.11–1.76, were of concern. In particular, the health risk was mainly ascribed to consumption of S. rivulatus (1.72) and L. mormyrus (1.76), although also the TEQs values caused by consuming S. luridus (0.64) were rather high, being close to 1.

Reproductive biology of Argyrosomus regius (Asso, 1801) inhabiting the south eastern Mediterranean Sea, Egypt

The aim of the current work is to study the reproductive biology of Argyrosomus regius (Asso, 1801) collected from the wild catch of Egyptian Mediterranean coast. This is to give a clear image about the spawning season, length at first sexual maturity, and to identify gonadal maturation using histological analysis in respect to steroid hormone concentration throughout 1 year period. The present results revealed that wild meagre has a protracted spawning season starting in April and ending in July. The length at first sexual maturity of female fishes started at larger lengths than males 47 cm for females and 45 cm for males. By comparing calculated gonadosomatic index (GSI) to histological analysis it is clear that male fishes started gonadal maturation before female fishes. Plasma steroid level showed fluctuations in its mean concentration as Testosterone showed massive increase during male gonadal maturation and ripening stages. Plasma Progesterone and Estradiol levels displayed different patterns in their mean concentration during developmental stages throughout the maturation period of ovaries and testes. They showed significant declination in mature fish plasma followed by an insignificant increase during nearly ripe and ripening periods. The current data showed that wild meagre displays a gonochoristic group-synchronous oocyte maturation pattern. More investigation on this important fish species is recommended to establish a breeding protocol for aquaculture purpose.

Contamination by polychlorinated biphenyls (PCBs) in striped dolphins (Stenella coeruleoalba) from the Southeastern Mediterranean Sea

Concentrations of polychlorinated biphenyls (PCBs) including dioxin-like PCBs (non-ortho, PCB 77, PCB 126, and PCB 169 and mono-ortho, PCB 105, PCB 118, and PCB 156) were measured in different organs and tissues (melon, blubber, liver, kidney, lung, heart, and muscle tissue) of striped dolphins (Stenella coeruleoalba) from the Eastern Mediterranean Sea (Adriatic Sea). The mean highest levels were in blubber and melon, followed by liver, kidney, lung, heart, and muscle tissue. PCB profiles were similar in all tissues and organs being dominated by the higher chlorinated homologues (hexa-CBs, 55.8-62.1%; penta-CBs, 15.4-20.0%; and hepta-CB PCB 180, 12.7-16.5%). Major PCBs in all tissues were congeners 138 and 153 collectively accounting for 50.6-58.3% of the total PCB concentrations, followed by PCB 101, 105, 118, and 180 constituting from 27.0% to 31.0%. PCB levels were higher in adult males than in adult females. The estimated 2,3,7,8-TCDD toxic equivalents of non- and mono-ortho PCBs were much higher than the threshold level above which adverse effects have been observed in other marine mammals species, suggesting that striped dolphins in this region are at risk for toxic effects.

Phytoplankton and environmental variables as a water quality indicator for the beaches at Matrouh, south-eastern Mediterranean Sea, Egypt: an assessment

This study was carried out to determine the water quality of the beaches at Matrouh, south-eastern Mediterranean Sea, Egypt, by studying environmental variables as well as phytoplankton abundance and community structure. Surface water samples were monitored from a series of beach sites over a period of five seasons during 2009–2010. A total of 203 phytoplankton species were identified from seven algal divisions. Seasonal differences in the quantitative and qualitative composition of the phytoplankton communities in the different sites were marked. Nutrient concentrations and phytoplankton abundances were found to be poorer than those of many other areas along Egyptian coast. The Shannon-Wiener Diversity Index classified Matrouh water as being between clean and moderately polluted, whereas the WQI demonstrated that it was between good and excellent. It can be concluded that the index based on WQI is currently more suitable than the phytoplankton species index for assessing the quality of the water of the Matrouh beaches.

Changes in Atlantic Water characteristics in the south-eastern Mediterranean Sea as a result of natural and anthropogenic activities

The paper investigates the changes in the characteristics of Atlantic Water (AW) flowing eastwards along the Egyptian coast in the south-eastern Mediterranean during the period 1959–2008.Vertically, only one water mass could be observed in winter in the upper 200m layer, whereas in summer, there were three distinct water masses. The subsurface water mass, of Atlantic origin, occupying the 50–150m layer and characterized by low salinities from < 38.60 to 38.80 PSU, moves throughout the study area from west to east and spreads over a range of density between 27.5 and 28.5σt.Temperature and salinity have indicated increasing trends for both temperature and salinity during the last 25years (1983–2008), reaching 0.85°C decade−1 and 0.073 PSU dec−1, respectively, for the Mediterranean surface waters. For the Atlantic water, the trends were 0.28°C dec−1 for temperature and 0.014 PSU dec−1 for salinity.

Organochlorine residues (PCBs and DDTs) in two Torpedinid species liver from the Southeastern Mediterranean Sea

Polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and PCB congeners accumulation profile were measured in the liver of two torpedinid species (Torpedo nobiliana and Torpedo marmorata) from the Mediterranean Sea (Adriatic Sea) in order to investigate the relative toxicological impact of these highly toxic PCBs in the organisms in question. A Thermo Trace GC connected to a Thermo PolarisQ MS operated in electron impact ionization (EI) mode was used to quantify PCBs and DDTs. The method performance was assessed through participation in interlaboratory studies organized by QUASIMEME. PCBs emerged as the most abundant pollutants, followed by DDTs. Contaminant load was higher in T. nobiliana (PCBs, 1,040ngg(-1) lipid weight; DDTs, 234ngg(-1) lipid weight) than in T. marmorata (PCBs, 434ngg(-1) lipid weight; DDTs, 78ngg(-1) lipid weight). PCB 118, 138, 153, and 180 were the dominant congeners accounting for over 95.0% of the total PCBs. Among DDTs, p,p'-DDE was detected in both species, always with a greater concentration than other pesticides. This study provides, for the first time, data regarding levels of organochlorine contamination in torpedinid species from the Mediterranean Sea. The comparability of TEQ levels with those encountered in predators at top of trophic chains constitutes a warning signal that should not be underestimated.

Climatological Trend of Air Temperature Anomalies in the South Eastern Mediterranean Sea

Climatological Trend of Air Temperature Anomalies in the South Eastern Mediterranean Sea