Climate change and warm-water species at the north-western boundary of the Mediterranean Sea

2015 ◽  
Vol 36 (4) ◽  
pp. 897-909 ◽  
Author(s):  
Valeriano Parravicini ◽  
Luisa Mangialajo ◽  
Laure Mousseau ◽  
Andrea Peirano ◽  
Carla Morri ◽  
...  
Keyword(s):  
Climate Change ◽  
Mediterranean Sea ◽  
Warm Water ◽  
Western Boundary ◽  
Warm Water Species ◽  
The North ◽  
The Mediterranean ◽  
North Western ◽  
Water Species

scholarly journals Impact of air–sea coupling on the climate change signal over the Iberian Peninsula

2021 ◽  
Author(s):  
Alba de la Vara ◽  
William Cabos ◽  
Dmitry V. Sein ◽  
Claas Teichmann ◽  
Daniela Jacob
Keyword(s):  
Climate Change ◽  
Iberian Peninsula ◽  
Mediterranean Sea ◽  
Large Scale ◽  
Regional Distribution ◽  
Coupled Model ◽  
Climate Change Signal ◽  
The North ◽  
The Mediterranean ◽  
The Impact

AbstractIn this work we use a regional atmosphere–ocean coupled model (RAOCM) and its stand-alone atmospheric component to gain insight into the impact of atmosphere–ocean coupling on the climate change signal over the Iberian Peninsula (IP). The IP climate is influenced by both the Atlantic Ocean and the Mediterranean sea. Complex interactions with the orography take place there and high-resolution models are required to realistically reproduce its current and future climate. We find that under the RCP8.5 scenario, the generalized 2-m air temperature (T2M) increase by the end of the twenty-first century (2070–2099) in the atmospheric-only simulation is tempered by the coupling. The impact of coupling is specially seen in summer, when the warming is stronger. Precipitation shows regionally-dependent changes in winter, whilst a drier climate is found in summer. The coupling generally reduces the magnitude of the changes. Differences in T2M and precipitation between the coupled and uncoupled simulations are caused by changes in the Atlantic large-scale circulation and in the Mediterranean Sea. Additionally, the differences in projected changes of T2M and precipitation with the RAOCM under the RCP8.5 and RCP4.5 scenarios are tackled. Results show that in winter and summer T2M increases less and precipitation changes are of a smaller magnitude with the RCP4.5. Whilst in summer changes present a similar regional distribution in both runs, in winter there are some differences in the NW of the IP due to differences in the North Atlantic circulation. The differences in the climate change signal from the RAOCM and the driving Global Coupled Model show that regionalization has an effect in terms of higher resolution over the land and ocean.

Seawater warming at the northern reach for southern species: Gulf of Genoa, NW Mediterranean

2017 ◽  
Vol 98 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Carlo Nike Bianchi ◽  
Francesco Caroli ◽  
Paolo Guidetti ◽  
Carla Morri
Keyword(s):  
Mediterranean Sea ◽  
Native Species ◽  
Indigenous Species ◽  
Ligurian Sea ◽  
The North ◽  
Nw Mediterranean ◽  
The Mediterranean ◽  
Non Indigenous Species ◽  
Southern Species ◽  
North Western

Global warming is facilitating the poleward range expansion of plant and animal species. In the Mediterranean Sea, the concurrent temperature increase and abundance of (sub)tropical non-indigenous species (NIS) is leading to the so-called ‘tropicalization’ of the Mediterranean Sea, which is dramatically evident in the south-eastern sectors of the basin. At the same time, the colder north-western sectors of the basin have been said to undergo a process of ‘meridionalization’, that is the establishment of warm-water native species (WWN) previously restricted to the southern sectors. The Gulf of Genoa (Ligurian Sea) is the north-western reach for southern species of whatever origin in the Mediterranean. Recent (up to 2015) observations of NIS and WWN by diving have been collated to update previous similar inventories. In addition, the relative occurrences of both groups of southern species have been monitored by snorkelling between 2009 and 2015 in shallow rocky reefs at Genoa, and compared with the trend in air and sea surface temperatures. A total of 20 southern species (11 NIS and 9 WWN) was found. Two WWN (the zebra seabream Diplodus cervinus and the parrotfish Sparisoma cretense) and three NIS (the SW Atlantic sponge Paraleucilla magna, the Red Sea polychaete Branchiomma luctuosum, and the amphi-American and amphi-Atlantic crab Percnon gibbesi) are new records for the Ligurian Sea, whereas juveniles of the Indo-Pacific bluespotted cornetfish Fistularia commersonii have been found for the first time. While temperature has kept on increasing for the whole period, with 2014 and 2015 being the warmest years since at least 1950, the number of WWN increased linearly, that of NIS increased exponentially, contradicting the idea of meridionalization and supporting that of tropicalization even in the northern sectors of the Mediterranean basin.

scholarly journals Oxygen budget of the north-western Mediterranean deep- convection region

2021 ◽  
Vol 18 (3) ◽  
pp. 937-960
Author(s):  
Caroline Ulses ◽  
Claude Estournel ◽  
Marine Fourrier ◽  
Laurent Coppola ◽  
Fayçal Kessouri ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Mediterranean Sea ◽  
Atmospheric Oxygen ◽  
Deep Convection ◽  
Western Mediterranean ◽  
Biogeochemical Model ◽  
The North ◽  
Oxygen Budget ◽  
The Mediterranean ◽  
North Western

Abstract. The north-western Mediterranean deep convection plays a crucial role in the general circulation and biogeochemical cycles of the Mediterranean Sea. The DEWEX (DEnse Water EXperiment) project aimed to better understand this role through an intensive observation platform combined with a modelling framework. We developed a three-dimensional coupled physical and biogeochemical model to estimate the cycling and budget of dissolved oxygen in the entire north-western Mediterranean deep-convection area over the period September 2012 to September 2013. After showing that the simulated dissolved oxygen concentrations are in a good agreement with the in situ data collected from research cruises and Argo floats, we analyse the seasonal cycle of the air–sea oxygen exchanges, as well as physical and biogeochemical oxygen fluxes, and we estimate an annual oxygen budget. Our study indicates that the annual air-to-sea fluxes in the deep-convection area amounted to 20 molm-2yr-1. A total of 88 % of the annual uptake of atmospheric oxygen, i.e. 18 mol m−2, occurred during the intense vertical mixing period. The model shows that an amount of 27 mol m−2 of oxygen, injected at the sea surface and produced through photosynthesis, was transferred under the euphotic layer, mainly during deep convection. An amount of 20 mol m−2 of oxygen was then gradually exported in the aphotic layers to the south and west of the western basin, notably, through the spreading of dense waters recently formed. The decline in the deep-convection intensity in this region predicted by the end of the century in recent projections may have important consequences on the overall uptake of atmospheric oxygen in the Mediterranean Sea and on the oxygen exchanges with the Atlantic Ocean, which appear necessary to better quantify in the context of the expansion of low-oxygen zones.

A new Mediterranean ‘lithistid’ sponge, Aciculites mediterranea sp. nov. (Porifera: Demospongiae) from a dark marine cave in Sardinia

2006 ◽  
Vol 86 (4) ◽  
pp. 691-698 ◽  
Author(s):  
Renata Manconi ◽  
Annalisa Serusi ◽  
Andrzej Pisera
Keyword(s):  
New Species ◽  
Mediterranean Sea ◽  
Growth Form ◽  
First Record ◽  
Shallow Marine ◽  
The North ◽  
The Mediterranean ◽  
North Western ◽  
Lithistid Sponge ◽  
Diagnostic Traits

A first record of the genus Aciculites in the Mediterranean Sea and the description of Aciculites mediterranea sp. nov. are here presented from a faunistic survey in a dark shallow marine cave of the north-western Sardinian karstic area. The new species is characterized by a massive cerebellum-like growth form, and a peculiar distribution of inhalant and exhalant areas, respectively, in depressed and elevated portions of the sponge surface. Oscules show a long narrow atrial cavity. Ectosomal skeleton is made of tangential anisostrongyles on elevated areas, and more or less vertical tufts of anisostrongyles in depressed inhalant areas. Anisostrongyles are smooth or with tips ornated by irregular tubercles. Sigmaspire microscleres are lacking. Choanosomal skeleton with tubercled irregular rizhoclone desmas and few scattered and variably oriented anisostrongyles. A comparative analysis of Aciculites mediterranea sp. nov. versus morphological diagnostic traits, geographical range and habitat of the species hitherto ascribed to Aciculites confirms that the peculiar distribution of the genus supports its relic condition of an ancient Tethyan fauna in the Mediterranean Sea.

scholarly journals On the trophic regimes of the Mediterranean Sea: a satellite analysis

2008 ◽  
Vol 5 (4) ◽  
pp. 2959-2983 ◽  
Author(s):  
F. D'Ortenzio ◽  
M. Ribera d'Alcalà
Keyword(s):  
Mediterranean Sea ◽  
Spring Bloom ◽  
Marine Ecosystem ◽  
Chlorophyll Concentration ◽  
Western Mediterranean ◽  
Physical Forcing ◽  
The North ◽  
The Mediterranean ◽  
Satellite Analysis ◽  
North Western

Abstract. The ten years of the SeaWiFS satellite surface chlorophyll concentration observations, presently available, were used to characterize the biogeography of the Mediterranean Sea and the seasonal cycle of the surface biomass in different areas of the basin. The K-means cluster analysis was applied on the satellite time-series of chlorophyll concentration. The resulting coherent patterns were then explained on the basis of the present knowledge of the basin functioning. Winter biomass enhancements were shown to occur in most of the basin and last for 2–3 months depending on the region. Classical spring bloom regimes were also observed, regularly in the North Western Mediterranean, and intermittently in four others specific areas. The analysis confirmed that the Mediterranean Sea is an ideal area to evaluate the impacts of the external physical forcing on the marine ecosystem functioning.

scholarly journals Oxygen budget for the north-western Mediterranean deep convection region

2020 ◽  
Author(s):  
Caroline Ulses ◽  
Claude Estournel ◽  
Marine Fourrier ◽  
Laurent Coppola ◽  
Fayçal Kessouri ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Mediterranean Sea ◽  
Atmospheric Oxygen ◽  
Deep Convection ◽  
Western Mediterranean ◽  
Biogeochemical Model ◽  
The North ◽  
Oxygen Budget ◽  
The Mediterranean ◽  
North Western

Abstract. The north-western Mediterranean deep convection plays a crucial role in the general circulation and biogeochemical cycles of the Mediterranean Sea. The DEWEX (DEnse Water EXperiment) project aimed to better understand this role through an intensive observation platform combined with a modelling framework. We developed a 3 dimensional coupled physical and biogeochemical model to estimate the cycling and budget of dissolved oxygen in the entire north-western Mediterranean deep convection area over the period September 2012 to September 2013. After showing that the simulated dissolved oxygen concentrations are in a good agreement with the in situ data collected from research cruises and Argo floats, we analyze the seasonal cycle of the air-sea oxygen exchanges, as well as physical and biological oxygen fluxes, and we estimate an annual oxygen budget. Our study indicates that the annual air-to-sea fluxes in the deep convection area amounted to 20 mol m−2 yr−1. 88 % of the annual uptake of atmospheric oxygen, i.e. 18 mol m−2, occurred during the intense vertical mixing period. The model shows that an amount of 27 mol m−2 of oxygen, injected at the sea surface and produced through photosynthesis, was transferred under the euphotic layer, mainly during deep convection. An amount of 20 mol m−2 of oxygen was then gradually exported in the aphotic layers to the south and west of the western basin, notably, through the spreading of dense waters recently formed. The decline in the deep convection intensity in this region predicted by the end of the century in recent projections, may have important consequences on the overall uptake of atmospheric oxygen in the Mediterranean Sea and on the oxygen exchanges with the Atlantic Ocean, that appear necessary to better quantify in the context of the expansion of low-oxygen zones.

scholarly journals On the trophic regimes of the Mediterranean Sea: a satellite analysis

2009 ◽  
Vol 6 (2) ◽  
pp. 139-148 ◽  
Author(s):  
F. D'Ortenzio ◽  
M. Ribera d'Alcalà
Keyword(s):  
Mediterranean Sea ◽  
Spring Bloom ◽  
Chlorophyll Concentration ◽  
Temporal Trends ◽  
Western Mediterranean ◽  
Present Knowledge ◽  
The North ◽  
The Mediterranean ◽  
Satellite Analysis ◽  
North Western

Abstract. The ten years of the SeaWiFS satellite surface chlorophyll concentration observations, presently available, were used to characterize the biogeography of the Mediterranean Sea and the seasonal cycle of the surface biomass in different areas of the basin. The K-means cluster analysis was applied on the satellite time-series of chlorophyll concentration. The resulting coherent patterns were then explained on the basis of the present knowledge of the basin's functioning. Winter biomass enhancements were shown to occur in most of the basin and last for 2–3 months depending on the region. Classical spring bloom regimes were also observed, regularly in the North Western Mediterranean, and intermittently in four other specific areas. The geographical correspondence between specific clusters and regions showing high values of mean chlorophyll concentration indicates that, at least in the Mediterranean Sea, accumulations of phytoplankton are observed only where specific temporal trends are present.

Feeding ecology of striped dolphins, Stenella coeruleoalba, in the north-western Mediterranean Sea based on stable isotope analyses

2011 ◽  
Vol 92 (8) ◽  
pp. 1677-1687 ◽  
Author(s):  
A.M. Meissner ◽  
C.D. MacLeod ◽  
P. Richard ◽  
V. Ridoux ◽  
G. Pierce
Keyword(s):  
Stable Isotope ◽  
Mediterranean Sea ◽  
Trophic Level ◽  
Western Mediterranean ◽  
Stenella Coeruleoalba ◽  
The North ◽  
Western Mediterranean Sea ◽  
The Mediterranean ◽  
Isotope Analyses ◽  
North Western

The feeding ecology of striped dolphin, Stenella coeruleoalba, in the north-western Mediterranean Sea was studied using stable isotope analyses. Carbon and nitrogen stable isotope ratios were measured in skin and muscle tissues of stranded and by-caught dolphins from six geographical areas in the Mediterranean Sea and Atlantic Ocean. Variation in δ15N in relation to dolphin size is attributed to changes in diet. Nursing calves have a higher trophic level than weaned animals and their δ15N values decrease progressively until weaning, estimated to be at a body length of around 155 cm. δ15N values then increased for larger individuals which suggests changes in diet for mature dolphins. Geographical differences in diet were apparent between the Atlantic and the Mediterranean, although no clear differences were apparent between the five Mediterranean areas. Comparisons of the nitrogen isotope ratios of skin and muscle highlighted a higher fractionation in skin compared to the muscle tissue. Values of δ13C also increased with body length although it appears that this is not only driven by trophic level enrichment. δ13C increases before weaning and the difference in trophic level between newly-weaned and mature dolphins was twice as high for carbon as for nitrogen. Ontogenetic changes in carbon isotope composition may therefore be driven by feeding on deep water prey and dolphin movements outside the coastal feeding grounds. Indeed, seasonal variations in δ13C are suspected to be driven by migration within the Mediterranean basin.

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