Search results for " Ocean acidification"
showing 10 items of 21 documents
Structural and functional organization of fish assemblages in a Mediterranean shallow CO2 vent.
2017
Gli effetti dell’acidificazione degli oceani a livello globale hanno richiamato l’attenzione degli scienziati su dei sistemi marini naturali quali i vent superficiali di CO₂. Si tratta di mesocosmi naturali, in quanto su piccole scale spaziali (anche di pochi metri) si osservano marcati gradienti di pH, dove poter testare ipotesi ecologiche dell’acidificazione delle acque marine. Obiettivo della tesi è studiare le risposte della popolazione ittica alla riduzione del pH in vent superficiali mediterranei utilizzando numerosi descrittori, quali la struttura di comunità, l’organizzazione trofica, le caratteristiche e la composizione chimica delle strutture carbonatiche. Inoltre poiché i vent so…
Distribution of sea urchins living near shallow water CO2 vents is dependent upon species acid-base and ion-regulatory abilities.
2013
To reduce the negative effect of climate change on Biodiversity, the use of geological CO2 sequestration has been proposed; however leakage from underwater storages may represent a risk to marine life. As extracellular homeostasis is important in determining species' ability to cope with elevated CO2, we investigated the acid-base and ion regulatory responses, as well as the density, of sea urchins living around CO2 vents at Vulcano, Italy. We conducted in situ transplantation and field-based laboratory exposures to different pCO2/pH regimes. Our results confirm that sea urchins have some ability to regulate their extracellular fluid under elevated pCO2. Furthermore, we show that even in cl…
Effect of explosive shallow hydrothermal vents on δ13C and growth performance in the seagrass Posidonia oceanica
2010
1. Explosive volcanic submarine activity is expected to affect seagrass communities due to sudden and dramatic changes in the physical and chemical features of sea water and sediments, with possibly large ecosystem effects. However, seagrass response to the harsh environmental conditions that arise due to explosive volcanism is as yet unexplored as it is not easy to predict when and where an eruption will occur. Here, we investigate the uptake of hydrothermal carbon within the seagrass Posidonia oceanica by the analysis of d13C and growth rates in tissue laid down before and after an exceptional and massive hydrothermal gas release in the Aeolian Islands (Italy, Mediterranean Sea). 2. Hydro…
Evidences on alterations in skeleton composition and mineralization in a site-attached fish under naturally acidified conditions in a shallow CO2 vent
2021
Abstract Background Ocean acidification may affect fish mineralized structures (i.e. otoliths and skeleton). Methods Here, we compared the elemental composition of muscle and skeleton and the mineral features of skeleton in the site-attached fish Gobius bucchichi naturally exposed to high pCO2/low pH conditions in a shallow CO2 vent with fish of the same species exposed to normal pH. Results Overall, no skeleton malformations were found in both pH conditions, but among-site differences were found in the elemental composition. Interestingly, higher Ca/P values, inducing a moderate skeleton maturation, were found in fish exposed to acidified conditions than in controls. Conclusion Our finding…
Effects of ocean acidification on rocky shore communities at Vulcano Island
2010
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…
Mediterranean bioconstructions along the Italian coast
2018
Marine bioconstructions are biodiversity-rich, three-dimensional biogenic structures, regulating key ecological functions of benthic ecosystems worldwide. Tropical coral reefs are outstanding for their beauty, diversity and complexity, but analogous types of bioconstructions are also present in temperate seas. The main bioconstructions in the Mediterranean Sea are represented by coralligenous formations, vermetid reefs, deep-sea cold-water corals, Lithophyllum byssoides trottoirs, coral banks formed by the shallow-water corals Cladocora caespitosa or Astroides calycularis, and sabellariid or serpulid worm reefs. Bioconstructions change the morphological and chemicophysical features of prima…
Altered epiphyte community and sea urchin diet in Posidonia oceanica meadows in the vicinity of volcanic CO2 vents
2017
Ocean acidification (OA) predicted for 2100 is expected to shift seagrass epiphyte communities towards the dominance of more tolerant non-calcifying taxa. However, little is known about the indirect effects of such changes on food provision to key seagrass consumers. We found that epiphyte communities of the seagrass Posidonia oceanica in two naturally acidified sites (i.e. north and south sides of a volcanic CO2 vent) and in a control site away from the vent at the Ischia Island (NW Mediterranean Sea) significantly differed in composition and abundance. Such differences involved a higher abundance of non-calcareous crustose brown algae and a decline of calcifying polychaetes in both acidif…
ROLE OF BEHAVIOUR IN MARINE ORGANISMS: POTENTIAL EFFECTS UNDER FUTURE OCEAN CONDITIONS.
2021
Over the last 250 years, the intensive burning of fossil fuels along with industrial processes and land uses (e.g. clearing forests and agriculture) has contributed to an increase in atmospheric CO2 from approximately 280 to 410 ppm, with a further increase (from 730 to 1020 ppm) projected by the end of this century. About 30% of the anthropogenic CO2 has been absorbed by the ocean, with a consequent decrease of the ocean’s surface pH causing a phenomenon better known as Ocean Acidification (OA). The average pH of the surface ocean has declined from 8.2 by 0.1 units since pre-industrial times as a result of CO2 emissions and a further reduction of 0.3–0.5 pH units is expected to occur by th…