Search results for "ocean"
showing 10 items of 2919 documents
Formation of microbial organic carbonates during the Late Jurassic from the Northern Tethys (Amu Darya Basin, Uzbekistan): implications for Jurassic …
2020
23 pages; International audience; The Late Jurassic was a period of major global carbon cycle perturbations with episodes of anoxia leading to regional accumulation of organic matter in sediments worldwide. The Tubiegatan section (SW Gissar Mountains, Uzbekistan) located in the Northern Tethys, shows atypical organic-rich limestone and marl deposits (up to 6% of total organic carbon) marked by pronounced negative excursions of δ13Ccarb (amplitude of ca. 12‰) and δ13Corg (amplitude of ca. 4‰) recorded during the Middle Oxfordian (Transversarium Zone). A transdisciplinary approach including sedimentology, palynofacies characterization, mineralogy, organic and inorganic geochemistry was carrie…
Greater mitochondrial energy production provides resistance to ocean acidification in "winning" hermatypic corals
2021
Coral communities around the world are projected to be negatively affected by ocean acidification. Not all coral species will respond in the same manner to rising CO2 levels. Evidence from naturally acidified areas such as CO2 seeps have shown that although a few species are resistant to elevated CO2, most lack sufficient resistance resulting in their decline. This has led to the simple grouping of coral species into “winners” and “losers,” but the physiological traits supporting this ecological assessment are yet to be fully understood. Here using CO2 seeps, in two biogeographically distinct regions, we investigated whether physiological traits related to energy production [mitochondrial e…
Inter-laboratory differences in the apparent quantum yield for the photochemical production of dissolved inorganic carbon in inland waters and implic…
2022
Solar radiation initiates photochemical oxidation of dissolved organic carbon (DOC) to dissolved inorganic carbon (DIC) in inland waters, contributing to their carbon dioxide emissions to the atmosphere. Models can determine photochemical DIC production over large spatiotemporal scales and assess its role in aquatic C cycling. The apparent quantum yield (AQY) spectrum for photochemical DIC production, defined as mol DIC produced per mol chromophoric dissolved organic matter-absorbed photons, is a critical model parameter. In previous studies, the principle for the determination of AQY spectra is the same but methodological specifics differ, and the extent to which these differences influenc…
Unveiling the Relationship Between Sea Surface Hydrographic Patterns and Tuna Larval Distribution in the Central Mediterranean Sea
2021
Thunnus thynnus (Atlantic bluefin tuna, ABT) and other tuna species reproduce in the Mediterranean Sea during the summer period. Despite the Central Mediterranean Sea, the Strait of Sicily in particular, being a key spawning site for many tuna species, little is known on the effects of oceanographic variability on their larval distribution in this area. The abundance and presence-absence of larval specimens for three tuna species (ABT, bullet tuna and albacore) were modeled in order to examine their relationships with environmental factors, by analysing historical in situ information collected during seven annual surveys (2010–2016). The results revealed that most tuna larvae for the three …
Vasseuromys rambliensis sp. nov. (Gliridae, Mammalia) from the Ramblian (Lower Miocene) of the Tudela Formation (Ebro basin, Spain)
2012
In this paper, a new species of Vasseuromys, V. rambliensis sp. nov., from the locality Pico del Fraile 1 (PF1, Ebro basin, North-eastern Spain) is described. The association of Ligerimys, Peridyromys murinus and Simplomys simplicidens, and the absence of Eucricetodon and Democricetodon, allows dating of the PF1 locality as Late Ramblian (Early Miocene, MN3, local zone A). Main diagnostic features of V. rambliensis sp. nov. are the presence of four extra ridges in the lower molars, a very reduced anterotropid and a metaloph connected to the posteroloph and not to the protocone. The size and morphology of V. rambliensis sp. nov. are very close to V. bacchius from the upper part of unit MN2, …
Diversity, ecology and biogeography of Antarctic benthic hydrozoans: the Weddell Sea and the Scotia Arc as study cases
2017
Introducció: Les comunitats bentòniques que es desenvolupen a les aigües antàrtiques són altament singulars com a resultat d’un ambient relativament estable i aïllat. Tal aïllament és degut, entre altres factors, a la presència de la convergència Antàrtica, una forta barrera (o filtre) de temperatura i salinitat, que circumscriu de forma efectiva un dels ecosistemes marins més discrets i isolats geogràficament. Els factors abans esmentats han jugat un paper important en el desenvolupament d'un dels ecosistemes més rics del món pel que respecta a diversitat de fauna marina sèssil. Així doncs, la plataforma Antàrtica, més profunda que qualsevol altra plataforma continental, està constituïda p…
Effects of reduced pH on shell integrity of a common whelk from a natural undersea CO2 vent community off Vulcano Island, Italy.
2014
Hexaplex trunculus is a widespread Mediterranean gastropod mollusc that plays a crucial role in benthic ecosystem dynamics. Individuals occur in shallow, sublittoral habitats near Vulcano Island, Italy, where an undersea CO2 vent provides a gradient of seawater acidification mimicing future predicted levels of ocean acidification. Individuals were collected from three sites with declining pH [ambient ( pH 8.18), medium (pH 8.05) and low (pH 7.49)]. Dissolution of shells was clearly evident at the medium (smoothing of outer shell ) and low (pitting and holes) pH sites. Scanning electron microcroscopy will provide a qualitative comparative assessment of micro-scale impacts of shell dissolutio…
Taking the acid test: Mediterranean limpets face up to climate change
2014
Impacts of climate change involve the interactions of multiple stressors on intertidal organisms, but rarely are the impacts of these stressors examined together. Many tests are also conducted in artificial, controlled laboratory conditions, without making use of natural opportunities to test performance of organisms under different environmental stressors. Given its small tidal range, the Mediterranean Sea provides such an opportunity, with a very fine scale environmental gradient and species living very close to each other over the tidal gradient. The vertical distribution of the limpets, Patella rustica and P. caerulea overlap in Palermo, Sicily, but despite this they have different ther…
Respiration and growth rates of F0 and F1 larval and juvenile European seabass Dicentrarchus labrax in response to ocean acidification and warming
2022
Ongoing climate change is leading to warmer and more acidic oceans. The future distribution of fish within the oceans depends on their capacity to adapt to these new environments. Only few studies have examined the effects of ocean acidification (OA) and warming (OW) on the metabolism of long-lived fish over successive generations. We therefore aimed to investigate the effect of OA on larval and juvenile growth and metabolism on two successive generations of European sea bass (Dicentrarchus labrax L.) as well as the effect of OAW on larval and juvenile growth and metabolism of the second generation. European sea bass is a large economically important fish species with a long generation time…