Acidification, deoxygenation, and nutrient and biomass declines in a warming Mediterranean Sea

Biogeosciences, Journal Year: 2022, Volume and Issue: 19(17), P. 4035 - 4065

Published: Sept. 1, 2022

Abstract. The projected warming, nutrient decline, changes in net primary production, deoxygenation and acidification of the global ocean will affect marine ecosystems during 21st century. Here, climate change-related impacts on Mediterranean Sea middle at end century are assessed using high-resolution projections physical biogeochemical state basin under Representative Concentration Pathways (RCPs) 4.5 8.5. In both scenarios, analysis shows dissolved contents euphotic intermediate layers basin, phytoplankton respiration carbon stock (including phytoplankton, zooplankton, bacterial biomass particulate organic matter). also show uniform surface subsurface reductions oxygen concentration driven by warming water column increase ecosystem as well an signal upper linked to inorganic content due CO2 absorption from atmosphere respiration. stronger RCP8.5 (worst-case) scenario and, particular, eastern limited influence exchanges Strait Gibraltar that part basin. On other hand, RCP4.5 emission a tendency recover values observed beginning for several variables second half period. This result supports idea – possibly based existence system such certain buffer capacity renewal rate implementation policies reducing could indeed be effective contribute foundation sustainability science policies.

Language: Английский

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Ocean acidification research in the Mediterranean Sea: Status, trends and next steps

Frontiers in Marine Science, Journal Year: 2022, Volume and Issue: 9

Published: Sept. 27, 2022

Ocean acidification (OA) is a serious consequence of climate change with complex organism-to-ecosystem effects that have been observed through field observations but are mainly derived from experimental studies. Although OA trends and the resulting biological impacts likely exacerbated in semi-enclosed highly populated Mediterranean Sea, some fundamental knowledge gaps still exist. These at tributed to both uneven capacity for research exists between countries, as well subtle long-term biological, physical chemical interactions define impacts. In this paper, we systematically analyzed different aspects region based on two sources: United Nation’s International Atomic Energy Agency’s (IAEA) Acidification Coordination Center (OA-ICC) database, an extensive survey. Our analysis shows 1) there geographic research, illustrates Algero-Provencal Ionian sub-basins currently least studied areas, 2) carbonate system poorly quantified coastal zones, time-series sparse across which challenge studying its variability assessing trends, 3) most groups organisms autotrophs (algae, phanerogams, phytoplankton), mollusks, corals, while microbes, small mollusks (mainly pteropods), sponges among studied, 4) overall paucity socio-economic, paleontological, modeling studies 5) spite general resource availability agreement improved coordinated governance, lack consistent policies Sea. addition highlighting current status, work also provides recommendations, our literature assessment survey targeted scientific community. light ongoing 2021-2030 Nations Decade Science Sustainable Development, might provide guideline close research. Systematic Review Registration https://www.oceandecade.org/

Language: Английский

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Projected climate oligotrophication of the Adriatic marine ecosystems

Frontiers in Climate, Journal Year: 2024, Volume and Issue: 6

Published: Feb. 2, 2024

The Adriatic Sea hosts diverse marine ecosystems, characterized by rich biodiversity and unique ecological dynamics. Its intricate coastal habitats open waters support a range of species contribute to the region's economic significance. Unraveling consequences ongoing climate changes on this delicate environment is essential ensure future safeguard basin. To tackle problem, we developed biogeochemical model for entire basin, with horizontal resolution about 2 km 120 vertical levels, forced projections atmosphere, hydrology ocean circulation between 1992 2050, under emission scenario RCP8.5. projected 2031–2050 1992–2011 were evaluated ecoregions different trophic conditions, identified using k-medoid classification technique. results point toward generalized oligotrophication especially intense in northern estuarine areas, driven substantial decrease river discharge rivers Po Plain. This unproductive declining resources, together warming, salinization, acidification waters, cast doubt long-term resilience Northern food web structure, which has evolved thrive high conditions. outcome study provides stakeholders tool understand how potential decreases regimes Rivers could affect ecosystem its goods services future.

Language: Английский

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Future distribution of demersal species in a warming Mediterranean sub-basin

Frontiers in Marine Science, Journal Year: 2024, Volume and Issue: 11

Published: May 22, 2024

Predicting range shifts of marine species under different CO2 emission scenarios is paramount importance to understand spatial potential changes in a context climate change and ensure appropriate management, particular areas where resources are critical fisheries. Important tools which use environmental variables infer limits habitat suitability the distribution models or SDMs. In this work, we develop an ensemble model (e-SDM) assess past, present future distributions Representative Concentration Pathway (RCP) 8.5 nine demersal hotspot for their two life stages (adult juvenile) Adriatic Western Ionian Seas four time windows (1999-2003, 2014-2018, 2031-2035 2046-2050). The e-SDM has been developed using three (and sub-models), i.e. (i) generalized additive (GAM), (ii) linear mixed (GLMM), (iii) gradient boosting machine (GBM), through combination density data terms numbers individuals km 2 variables. Then, have determined aggregation hotspots distributions. Finally, gains losses (i.e. occupation area) scenario as new stages. results show that densities some key commercial species, such Merluccius merluccius (European hake), Mullus barbatus (red mullet), Lophius budegassa (anglerfish) will be shifting northwards.

Language: Английский

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Interactive effects of fishing effort reduction and climate change in a central Mediterranean fishing area: Insights from bio-economic indices derived from a dynamic food-web model

Frontiers in Marine Science, Journal Year: 2022, Volume and Issue: 9

Published: Aug. 12, 2022

Disentangling the effects of mixed fisheries and climate change across entire food-webs requires a description ecosystems using tools that can quantify interactive as well bio-economic aspects. A calibrated dynamic model for Sicily Channel food web, made up 72 functional groups including 13 fleet segments, was developed. temporal simulation until 2050 conducted to evaluate reduction bottom trawling fishing effort by exploring different scenarios combine fishery change. Our results indicate direct indirect produce net increase in biomass many with immediate decline trawlers’ catches economic incomes, followed long term mainly due rebuilding commercial species which lasts 5-10 years after reduction. Synergistic antagonistic caused changes characterize specific group’s response which, turn, modulate also catch income other fleets, especially those sharing target resources. However, trawler’s intra-fleet competition is higher than others effects. In medium term, are seem make exploitation marine resources more sustainable over time processes efficient improving ecosystem health.

Language: Английский

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Venice lagoon chlorophyll-a evaluation under climate change conditions: A hybrid water quality machine learning and biogeochemical-based framework

Ecological Indicators, Journal Year: 2023, Volume and Issue: 157, P. 111245 - 111245

Published: Nov. 10, 2023

Climate change presents a significant challenge to lagoon ecosystems, which are highly valued coastal environments known for their provision of unique ecosystem services. As important as fragile, lagoons vulnerable both natural processes and anthropogenic activities, this vulnerability is exacerbated by the impacts climate change, likely result in severe ecological consequences. The complexity water quality (WQ) processes, characterized compounding interconnected pressures, highlights importance adequate sophisticated methods estimate future on environments. In setting, hybrid framework introduced where Machine Learning (ML) biogeochemical (BGC) models integrated sequential modelling approach. This integration exploits strengths offered models. ML model allows capturing learning linear nonlinear correlations from historical data; BGC interprets simulates complex environmental systems subject compounded building identified causal relationships. Multi-Layer Perceptron (MLP) Random Forest (RF) algorithms trained, validated tested within Venice case study assimilate WQ data (i.e., temperature, salinity, dissolved oxygen) spatio-temporal information monitoring station location month), predict changes chlorophyll-a (Chl-a) conditions. Then, projections SHYFEM-BFM 2019, 2050, 2100 timeframes under RCP 8.5 into (composing ML-BGC model) evaluate Chl-a variations conditions forced projections. Moreover, standalone also used compare scenarios. Annual seasonal predictions developed classes based two classification modes (median quartiles) established descriptive statistics computed data. Results showed RF successfully classifies with an overall accuracy about 80% median 61% quartiles modes. Concerning scenarios, results revealed decreasing trend lowest values (below first quartile, i.e. 0.85 µg/l) moving far (2100), opposite rising highest (above fourth 2.78 µg/l). On level, summer remains season all although strong increase higher expected during springtime one. proposed represents valuable approach strengthen multivariate scenarios analysis, placing artificial intelligence-based alongside

Language: Английский

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Seasonal dynamics and annual budget of dissolved inorganic carbon in the northwestern Mediterranean deep-convection region

Biogeosciences, Journal Year: 2023, Volume and Issue: 20(22), P. 4683 - 4710

Published: Nov. 28, 2023

Abstract. Deep convection plays a key role in the circulation, thermodynamics, and biogeochemical cycles Mediterranean Sea, which is considered to be hotspot of biodiversity climate change. In framework DEWEX (Dense Water Experiment) project, seasonal annual budgets dissolved inorganic carbon deep-convection area northwestern Sea are investigated over period September 2012–September 2013 using 3D coupled physical–biogeochemical–chemical modeling approach. At scale, we estimate that Sea's region was moderate sink 0.5 mol C m−2 yr−1 CO2 for atmosphere. The model results show reduction oceanic uptake during deep its increase abrupt spring phytoplankton bloom following events. We highlight major roles budget both physical fluxes, amount −3.7 3.3 yr−1, respectively, 1 order magnitude higher than air–sea flux. upper layer (from surface 150 m depth) gained through vertical transport and, lesser extent, uptake, it lost lateral fluxes. region, covering 2.5 % Mediterranean, acted as source intermediate water masses Balearic southwestern could represent up 22 11 %, exchanges with Atlantic Ocean at Strait Gibraltar.

Language: Английский

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Mediterranean Sea general biogeochemistry

Elsevier eBooks, Journal Year: 2022, Volume and Issue: unknown, P. 387 - 451

Published: Oct. 21, 2022

Language: Английский

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Seasonal dynamics and annual budget of dissolved inorganic carbon in the northwestern Mediterranean deep convection region

Published: Nov. 15, 2022

Abstract. Deep convection plays a key role in the circulation, thermodynamics and biogeochemical cycles Mediterranean Sea, considered as hotspot of biodiversity climate change. In framework DEWEX (Dense Water Experiment) project, seasonal cycle annual budget dissolved inorganic carbon deep area northwestern Sea are investigated over period September 2012–September 2013, using 3-dimensional coupled physical-biogeochemical-chemical modeling approach. We estimate that region was moderate sink CO2 for atmosphere study period. The model results show reduction uptake during convection, its increase abrupt spring phytoplankton bloom following events. highlight dominant both biological physical flows budget. upper layer gained through vertical supplies and, to lesser extent, air-sea flux, lost lateral transport fluxes. region, covering 2.5 % Mediterranean, acted source surface intermediate water masses western southern Western could contribute up 10 20 exchanges with Eastern Atlantic Ocean.

Language: Английский

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Coupling habitat-specific temperature scenarios with tolerance landscape to predict the impacts of climate change on farmed bivalves

Marine Environmental Research, Journal Year: 2023, Volume and Issue: 188, P. 106038 - 106038

Published: May 29, 2023

Due to climate change, heatwaves are likely become more frequent, prolonged and characterized by higher peak values, compared with climatological averages. However, the thermal tolerance of organisms depends on actual exposure, which can be modulated environmental context microhabitat characteristics. This study investigated frequency occurrence mass mortality events in next decades for two species farmed bivalves, mussel Mytilus galloprovincialis clam Ruditapes philippinarum, a shallow coastal lagoon, characterised marked diurnal oscillations water temperature. The effect was estimated means landscape models, predict 50% based exposure intensity duration. Scenarios temperature up year 2100 were modelled combining mechanistic components, namely: 1) monthly mean temperatures, simulated using hydrodynamic model including heat budget; 2) daily oscillations, from harmonic analysis twenty year-long site-specific time series sediment cross-correlation model, as input one: parameters comprehensive set observations. results indicate that both risk rapidly increases starting 2060s. Furthermore, patterns seemed relevant, overnight it falls below predicted thresholds few hours. These findings suggest further studies should address: improvement order take into account integrated repeated non-lethal stress rate; prediction specific habitat, process-based data driven models.

Language: Английский

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