Search results for "ocean"
showing 10 items of 2919 documents
Structuring factors of the spatio-temporal variability of macrozoobenthos assemblages in a southern Mediterranean lagoon: How useful for bioindicatio…
2017
International audience; The authors investigated the impact of the extension of the El Kantra Channel on the composition and structure of macrobenthic assemblages in Boughrara Lagoon (Gulf of Gabes, Tunisia along with the use of 4 biotic indices (AMBI, BENTIX, M-AMBI and TUBI). Thirteen stations were sampled seasonally in 2012–2013. Forty-one species were found in 2012–2013 not recorded in 2009–2010, including 20 species of polychaetes belonging to the trophic groups of deposit-feeders and carnivores which are expected to increase in areas disturbed by organic pollution. During the survey, we recorded a high fish mortality, essentially caused by the development of harmful algal blooms (HAB)…
The challenge of habitat modelling for threatened low density species using heterogeneous data: The case of Cuvier’s beaked whales in the Mediterrane…
2018
We are grateful to the ACCOBAMS Secretariat for their support in this work, including a small grant for the analysis. The Mediterranean population of Cuvieŕs beaked whale (Ziphius cavirostris), a deep-diving cetacean, is genetically distinct from the Atlantic, and subject to a number of conservation threats, in particular underwater noise. It is also cryptic at the surface and relatively rare, so obtain robust knowledge on distribution and abundance presents unique challenges. Here we use multiplatform and multiyear survey data to analyse the distribution and abundance of this species across the Mediterranean Sea. We use a novel approach combining heterogeneous data gathered with different …
The Mediterranean Sea hosts endemic haplotypes and a distinct population of the dolphinfish Coryphaena hippurus Linnaeus, 1758 (Perciformes, Coryphae…
2017
Abstract The dolphinfish, Coryphaena hippurus Linnaeus, 1758, is an important target species for Mediterranean artisanal, recreational and commercial fisheries but to date only scarce genetic data are available for its Mediterranean population(s). The genetic variation of Mediterranean dolphinfishes was thus investigated through the sequencing of fragments of the cytochrome c oxidase subunit 1 (COI) gene and the NADH dehydrogenase subunit 1 (ND1) mitochondrial DNA markers with the explicit aims of (i) testing for significant genetic differentiation of the Mediterranean vs . non-Mediterranean populations of the species, and (ii) investigating the possible presence of molecular structuring wi…
Macroalgal forest vs sea urchin barren: Patterns of macro-zoobenthic diversity in a large-scale Mediterranean study.
2019
Abstract The study aimed at contributing to the knowledge of alternative stable states by evaluating the differences of mobile and sessile macro-zoobenthic assemblages between sea urchin barrens and macroalgal forests in coastal Mediterranean systems considering a large spatial scale. Six sites (100 s km apart) were selected: Croatia, Montenegro, Sicily (Italy), Sardinia (Italy), Tuscany (Italy), and Balearic Islands (Spain). A total of 531 taxa, 404 mobile and 127 sessile macro-invertebrates were recorded. Overall, 496 and 201 taxa were found in macroalgal forests and in barrens, respectively. The results of this large-scale descriptive study have met the expectation of lower macrofauna co…
Spatial variations in Ba/Cashell fingerprints of Glycymeris pilosa along the eastern Adriatic Sea
2020
Abstract The long living Glycymeris pilosa bivalve is an interesting target species for the sclerochronological research in the Mediterranean Sea. In this study, Ba/Cashell and Mg/Cashell variations were studied along the coast of the eastern Adriatic Sea. Specimens were collected alive by SCUBA and skin diving during several occasions in 2014, 2015 and 2016 from five sites including Pag, Pasman Channel, Cetina, Živogosce and Drace. Element-to-Cashell ratios were measured by LA-ICP-MS in line scan mode in three specimens of each site, ranging in age from 7 to 21. In addition, chemical analysis was conducted on three ontogenetically older specimens (68-97 years-old) from Drace. Mg/Cashell an…
Ecological function of phenolic compounds from mediterranean fucoid algae and seagrasses: An overview on the genus Cystoseira sensu lato and Posidoni…
2020
Biodiversity is undergoing rapid and worrying changes, partially driven by anthropogenic activities. Human impacts and climate change (e.g., increasing temperature and ocean acidification), which act at different spatial scales, represent the most serious threats to biodiversity and ecosystem structure and function. In the Mediterranean Sea, complex systems such as fucoid algae and seagrasses, characterized by a high associated biodiversity, are regularly exposed to natural and anthropogenic pressures. These systems, particularly sensitive to a variety of stressors, evolved several physiological and biochemical traits as a response to the different pressures which they are subjected to. For…
Consumption of pelagic tunicates by cetaceans calves in the Mediterranean Sea
2018
Gelatinous zooplankton, including jellyfish, ctenophores and pelagic tunicates, constitutes fragile marine animals that live in the water column, and represent an important resource for marine food webs through their seasonal pulses. Although there is scarce evidence on the occurrence of gelatinous zooplankton in stomach contents of apex, endothermic predators such as cetaceans, the ecological significance of such observations requires consideration. In this study, we report on the occurrence of pelagic tunicates in the stomach of three individual calves of two cetacean species from the western Mediterranean, and collate all previous reports of gelatinous zooplankton in cetacean diets. We t…
Environmental factors influencing the spatio-temporal distribution of Carybdea marsupialis (Lineo, 1978, Cubozoa) in South-Western Mediterranean coas…
2017
21 pages, 5 figures, 2 tables, supporting information 10.1371/journal.pone.0181611.s001, 10.1371/journal.pone.0181611.s002, 10.1371/journal.pone.0181611.s003, 10.1371/journal.pone.0181611.s004, 10.1371/journal.pone.0181611.s005, 10.1371/journal.pone.0181611.s006
Use of Lagrangian simulations to hindcast the geographical position of propagule release zones in a Mediterranean coastal fish
2018
International audience; The study of organism dispersal is fundamental for elucidating patterns of connectivity between populations, thus crucial for the design of effective protection and management strategies. This is especially challenging in the case of coastal fish, for which information on egg release zones (i.e. spawning grounds) is often lacking. Here we assessed the putative location of egg release zones of the saddled sea bream (Oblada melanura) along the southeastern coast of Spain in 2013. To this aim, we hindcasted propagule (egg and larva) dispersal using Lagrangian simulations, fed with species-specific information on early life history traits (ELTs), with two approaches: 1) …
Seascape connectivity of European anchovy in the Central Mediterranean Sea revealed by weighted Lagrangian backtracking and bio-energetic modelling
2020
AbstractEcological connectivity is one of the most important processes that shape marine populations and ecosystems, determining their distribution, persistence, and productivity. Here we use the synergy of Lagrangian back-trajectories, otolith-derived ages of larvae, and satellite-based chlorophyll-a to identify spawning areas of European anchovy from ichthyoplanktonic data, collected in the Strait of Sicily (Central Mediterranean Sea), i.e., the crucial channel in between the European and African continents. We obtain new evidence of ecosystem connectivity between North Africa and recruitment regions off the southern European coasts. We assess this result by using bio-energetic modeling, …