Polycyclic Aromatic Hydrocarbons' (PAHs) toxicity is enhanced by the presence of ultraviolet radiation (UVR), which levels have arisen due to the thinning of the ozone layer. In this study, PAHs' phototoxicity for natural marine phytoplankton was tested. Different concentrations of a mixture of 16 PAHs were added to natural phytoplankton communities from the Mediterranean Sea, Atlantic, Arctic and Southern Oceans and exposed to natural sunlight received in situ, including treatments where the UVR bands were removed. PAHs' toxicity was observed for all the phytoplankton groups studied in all the waters and treatments tested, but only for the pico-sized group a synergetic effect of the mixture and UVR was observed (p=0.009). When comparing phototoxicity in phytoplankton from oligotrophic and eutrophic waters, synergy was only observed at the oligotrophic communities (p=0.02) where pico-sized phytoplankton dominated. The degree of sensitivity was related to the trophic degree, decreasing as Chlorophyll a concentration increased.
Regions of the occurrence of different phenomena related to the development of baroclinic disturbances are reviewed for the Northern Hemisphere extratropics, using National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data. The occurrence of height lows appears to be related to the orography near the earth's surface and with surface- and upper-air cyclogenesis in the upper troposphere. Over the cyclone tracks, the surface maxima appear to be trapped by land masses, whereas over the Mediterranean Sea they are located on the lee side of mountain ranges. The forcing terms of the geopotential tendency and omega equations mark the genesis (and, by the vorticity advection terms, the path) of the extratropical cyclones on the storm track. They occur mostly over the western coast of the oceans, beginning and having maxima on the lee side of the Rocky Mountains and the Tibetan Plateau. Their associated fronts form from the cold air coming from the continents and converging with the warm air over the Gulf and Kuroshio currents. Evident trends are found only for the Atlantic cyclone track (positive) and the Pacific cyclone track (negative) until the last decade when the tendency reverses. Over the southern Pacific, the number of fronts is lower during 1978-1997, coinciding with a period of strong El Ni?o Southern Oscillation episodes. This information is important for validating numerical models in order to predict changes associated with climate change and to study the behavior of extratropical cyclones and fronts.
An investigation of large tintinnids was carried out during the Arctic-Antarctic cruise aboard the S/V "Croatian Tern" in the period from 1994 to 1997. Samples were collected at 33 stations by vertical tows with a Nansen net with a 53 µm mesh size in the Mediterranean Sea, North Atlantic, Labrador Sea, Baffin Bay, the Beaufort, Chukchi and Bering Seas, East North Pacific, South Pacific, South East Pacific, Scotia Sea, and South West Atlantic. A total of 47 species of tintinnids were found, with the greatest diversity in the Tropical areas of the Pacific, Arctic and Subarctic. A very high total abundance was registered in the Bering Sea of 247,393 ind.m-3 and in the South-eastern Pacific of 66,211 ind.m-3. The dominant species in the northern areas was Ptychocylis obtusa and in the southern areas Eutintinnus rugosus.
A 32-basepair deletion polymorphism in the CCR5 chemokine receptor gene (CCR5 TROKUT 32) could increase the resistance to HIV-1 infection or delayed progression to AIDS. This mutant allele is common among Caucasians of Western European descent, but has not been observed in people of African or Asian ancestry. Genetic studies provided in European countries have shown a highest prevalence in Nordic countries and the lowest in the Southern European and Mediterranean populations. We genotyped 303 randomly selected healthy Croatians for the prevalence of CCR5 TROKUT 32 mutation. CCR5 TROKUT 32 allele frequency in Croatia of 7.1% fits in the observed European north/south gradient. This first report of CCR5 TROKUT 32 mutation in Croatian population provides additional information on its frequency and geographical distribution in Slavic populations in South-Eastern Europe. Moreover, our data may have important implications for the prediction and prevention of HIV/AIDS in a tourist country such as Croatia.
Università degli Studi di Cagliari, Dipartimento di Scienze della Vita e dell'Ambiente, Via Tommaso Fiorelli 1, 09126, Cagliari, Italy; Consorzio Interuniversitario per le Scienze del Mare, CoNISMa, ULR Cagliari, Cagliari, Italy. Electronic address: firstname.lastname@example.org.
Ingestion of microplastics (MPs) has been documented in several marine organisms, but their occurrence in deep-sea species remains almost unknown. In this study, MPs were investigated in two economically and ecologically key crustaceans of the Mediterranean Sea, the Norwegian lobster Nephrops norvegicus and the shrimp Aristeus antennatus. Both the species were collected from 14 sites around Sardinia Island, at depths comprised between 270 and 660?m. A total of 89 and 63 stomachs were analysed for N. norvegicus and A. antennatus respectively, and more than 2000?MPs-like particles were extracted and sorted for identification and characterization by µFT-IR. In N. norvegicus, 83% of the specimens contained MPs, with an average abundance of 5.5?±?0.8?MPs individual-1, while A. antennatus showed a lower frequency of ingestion (67%) and a lower mean number of MPs (1.66?±?0.1?MPs individual-1). Composition and size of particles differed significantly between the two species. The non-selective feeding strategy of N. norvegicus could explain the 3-5 folds higher numbers of MPs in its stomach, which were mostly composed of films and fragments derived by polyethylene and polypropylene single-use plastic items. Contrarily, most MPs in the stomachs of A. antennatus were polyester filaments. The MPs abundance observed in N. norvegicus is among the highest detected in Mediterranean species considering both fish and invertebrates species, and provides novel insights on MPs bioavailability in deep-sea habitats. The overall results suggest that both N. norvegicus and A. antennatus, easily available in common fishery markets, could be valuable bioindicators and flagship species for plastic contamination in the deep-sea.
Perfluorooctane sulfonate (PFOS) and other perfluorinated alkylated substances (PFAS) were determined in liver, kidney, muscle, brain, and blubber samples of 31 harbor porpoises (Phocoena phocoena relicta) of different age and sex stranded along the Ukrainian coast of the Black Sea. In all individuals and in all tissues, PFOS was the predominant PFAS, accounting for on average 90% of the measured PFAS load. PFOS concentrations were the highest in liver (327+/-351 ng/g wet wt) and kidney (147 +/-262 ng/g wet wt) tissue, and lower in blubber (18+/-8 ng/g wet wt), muscle (41+/-50 ng/g wet wt), and brain (24 +/-23 ng/g wetwt). No significant differences could be determined between males and females, nor between juvenile and adult animals (p > 0.05). Perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, and perfluorododecanoic acid could be detected in liver tissue of approximately 25% of the individuals. Perfluorobutane sulfonate, perfluorobutanoic acid, and perfluorooctanoic acid were not detected in any of the porpoise livers. Although we investigated a potential intraspecies segregation according to the source of prey, using stable isotopes, no statistically significant correlation between PFOS concentrations and stable isotopes could be determined. It is, however, noteworthy that the contamination by PFOS in the Black Sea harbor porpoises is comparable to levels found in porpoises from the German Baltic Sea and from coastal areas near Denmark and, therefore, might pose a threat to this population.
Reproductive biology of female Norway lobster, Nephrops norvegicus (Linnaeus, 1758) Leach, in Icelandic waters during the period 1960-2010: comparative overview of distribution areas in the Northeast Atlantic and the Mediterranean.
Maturity size, reproductive cycle, sex ratio and fecundity of female Nephrops were investigated at SW, S and SE Iceland for the period 1960-2010. Time series of biological parameters and fisheries data displayed significant relationships. In addition, female biological data from 20 areas in the Atlantic and Mediterranean were compared. Fifty percentage maturity estimates had an overall range of 23.9-34.4mm CL with some anomalies in the 2000s. The reproductive cycle in Iceland has been biennial during the whole study period from mid-1960s to 2010 with minor change in phase in the 2000s. Biennial moulting retards female growth more than annual spawning, and the length of incubation and hatch time of year show significant relationships with latitude and sea temperature. Variations in sex ratio were observed and relationships found between female sex ratio and CL, CPUE and stock biomass during 1961-2010, displaying apparent fishery-induced effects on sex ratio. Potential and realized fecundity estimates in Iceland are 35-50% of those reported from more southerly waters. Biennial spawning and low fecundity limit the number of progeny in Icelandic Nephrops and necessitate lower fishing mortality. Ambient temperature in Icelandic waters has risen by 1°C since the late 1990s, generating around 30 days shorter incubation time in the 2000s, but around 3°C rise is necessary for possible annual spawning.
It is essential to gain knowledge about the causes and extent of migratory connectivity between stationary periods of migrants to further the understanding of processes affecting populations, and to allow efficient implementation of conservation efforts throughout the annual cycle. Avian migrants likely use optimal routes with respect to mode of locomotion, orientation and migration strategy, influenced by external factors such as wind and topography. In self-powered flapping flying birds, any increases in fuel loads are associated with added flight costs. Energy-minimizing migrants are therefore predicted to trade-off extended detours against reduced travel across ecological barriers with no or limited foraging opportunities. Here, we quantify the extent of detours taken by different populations of European nightjars Caprimulgus europaeus, to test our predictions that they used routes beneficial according to energetic principles and evaluate the effect of route shape on seasonal migratory connectivity. We combined data on birds tracked from breeding sites along a longitudinal gradient from England to Sweden. We analysed the migratory connectivity between breeding and main non-breeding sites, and en route stopover sites just south of the Sahara desert. We quantified each track's route extension relative to the direct route between breeding and wintering sites, respectively, and contrasted it to the potential detour derived from the barrier reduction along the track while accounting for potential wind effects. Nightjars extended their tracks from the direct route between breeding and main non-breeding sites as they crossed the Mediterranean Sea-Sahara desert, the major ecological barrier in the Palaearctic-African migration system. These clockwise detours were small for birds from eastern sites but increased from east to west breeding longitude. Routes of the tracked birds were associated with partial reduction in the barrier crossing resulting in a trade-off between route extension and barrier reduction, as expected in an energy-minimizing migrant. This study demonstrates how the costs of barrier crossings in prevailing winds can disrupt migratory routes towards slightly different goals, and thereby promote migratory connectivity. This is an important link between individual migration strategies in association with an ecological barrier, and both spatially and demographic population patterns.