Climate changes are increasingly affecting marine ecosystem having general negative effect on their functioning, stability and potentially their resilience against multiple stressors. In this context, analysing decomposition rate in different ecosystems represent an important step to be studied to assess changes in nutrient cycling and carbon dynamic that may play a crucial role on ecosystem multifunctionality i.e. referring to the ability of an ecosystem to sustain multiple function and services simultaneously. Despite the importance of decomposition rate, global climate predictions continue to be hindered by limited data due to the high costs and efforts associated with comparative litter decomposition studies. Here we took advantage of the tea bags decomposition index (TBI) to study pattern of decomposition rate in a lagoon of the Stagnone di Marsala, Western Sicily, by deploying tea bags following a density gradient of seagrass. A seagrass ecosystem has been selected as target testing marine ecosystem as pivotal in services such habitat forming or carbon sequestration and being of the ecosystems facing challenges from climate change and anthropogenic pressures. TBI represents an innovative and cost-effective techniques based on a well standardized curve of decomposition and stabilization rate of two commercially available teas. This represents a cost-effective method allowing for an increased replication in field experiments and, more importantly, the standardized nature of TBI facilitates comparable data collection across different ecosystems. Additionally, due to its high accessibility, the methodology is suitable for sharing with the public and for large-scale application also in citizen science context. Involving the public in this kind of experiments could lead to an increase in data across multiple ecosystems, allowing for more useful replications to enhance comparisons between different ecosystems and achieve more robust results. In this context, TBI represent a salient tool to strength the science-stakeholders interface and facilitate the translational ecology.

Coralligenous reefs are biodiversity hotspots and crucial benthic ecosystems in the Mediterranean Sea due to the valuable ecological services they provide. However, they are highly vulnerable to human-induced stressors such as sediment re-suspension, eutrophication, and mechanical disturbances from fishing, anchoring and scuba diving. Additionally, warming events have significantly impacted these reefs, causing mortality among various species, including gorgonians. Among these, Paramuricea clavata is a key structuring species of the coralligenous, as it creates three-dimensional habitats that foster the development of ecological niches and increase assemblage complexity. Despite numerous studies documenting various aspects of these reefs, further research is needed to fully understand the ecological role of P. clavata on the structure of coralligenous benthic communities under different thermal conditions. To investigate the influence of P. clavata on species/taxa richness and composition of the associated benthic community, photographic sampling of coralligenous reefs was conducted during two periods in 2023 (early summer and early autumn) at several Mediterranean sites (Sardinia, Campania, and Sicily) and depths (from 20 to 40 meters) in areas characterized both by the presence and the absence of P. clavata. The thermal environment was continuously measured using temperature loggers throughout the whole study period. The presence of P. clavata was positively associated to taxa richness and the abundance of Alcyonacea, hydroids, encrusting sponges, ramified bryozoans and serpulids, and negatively to the abundance of turf, green and red algae, and massive sponges. Generalized linear latent variable model revealed the combined effects of period, heating event duration, and temperature on the community, also highlighting groups of species/taxa that exhibited similar responses. Identifying functional groups influenced by the presence of a habitat-forming species, alongside the influence of the thermal environment, can provide valuable insights for formulating recommendations for the effective conservation of this priority habitat, highly sensitive to climate change.

Heatwaves are extended periods of abnormally warm temperatures that exceed typical conditions. This phenomenon is occurring with increasing frequency worldwide, particularly in the Mediterranean area. Global warming is linked to the rise of heatwaves, and projections suggest they will become even more severe in the future.

While a growing body of research explores how climate variability affects food web structure, trophic interactions, and potential changes in ecosystem functioning, less is known about the effects of extreme events like summer heatwaves on vulnerable environments. Such environments include Mediterranean coastal lagoons and artificial lakes, which deserve attention as they provide essential goods and ecosystem services.

In this scientific proposal we report the experimental set up and the preliminary results of laboratory experiments performed in summer 2024, with the aim ofstudying the experimental effects of a summer heatwave on two different natural plankton communities collected from an artificial lake (Bidighinzu Lake) and a coastal lagoon (Cabras Lagoon) located in Sardinia (West Mediterranean). The two natural plankton communities include different trophic levels (picoplankton, nanoplankton, microplankton, and mesoplankton) and are incubated separately in laboratory at an increased temperature treatment (+5 °C), in presence and in absence of mesozooplankton. Respectively, mesozooplankton (such as copepods/cladocera) or microzooplankton (namely ciliates) represent the plankton food web top consumers. Different analysis techniques are applied, such as microscopy, flow cytometry and Next-Generation Sequencing.

While most studies have monitored the effects of natural heatwaves on plankton communities, only a few experimental studies have been undertaken to simulate a heatwave in order to mimic a perturbation and to follow its effect on a natural community under controlled conditions in a reproducible manner. Our research aims to fill this gap.

Wetlands have a crucial role as carbon (C) pools. Current wetland degradation negatively impacts their capacity to store carbon and could transform them into strong carbon dioxide (CO₂) and methane (CH₄) sources. This could be the case of the Bosco della Mesola (Ferrara), a remnant floodplain forest in the Po Delta, where climate change is already inducing other degradation phenomena like saltwater intrusion and biodiversity loss. Assessing the vertical C fluxes at the water-atmosphere interface might help to understand and possibly reduce CO₂ and CH₄ release by appropriate restoration actions. The study aims to qualitatively determine the trends of the C fluxes and monitor the ecologic impact of climate change in this area. Using a floating flux chamber equipped with a LICOR IRGA, we investigated CO₂ and CH₄ fluxes in 4 different lentic sites, 2 ponds and 2 canals, with salinity gradient, presence/absence of macrophytes, and different bottom sediment organic matter. We will also explore the role of freshwater input in the two canals. The study also lays the basis for the future development of a simplified model that will support the analysis of wetlands carbon fluxes in future climate change scenarios and in response to restoration activities.

This research aims to define an innovative approach for a more efficient, reliable, and integrated study of the coastal marine environment, which can host numerous microorganisms, including enteric pathogens from human or animal feces. It focuses on chemical and microbiological pollutants from human activities and climate change, assessing fecal and pesticide contamination in river and coastal marine environments and evaluating biodiversity impacts by analyzing indicator species in sediments. The fecal bacteria will be characterized at the genetic level to identify their host or environment of origin, serving as indicators of contamination sources. To determine the source of the faecal contamination, water and sediment samples were collected from various locations along the Arzilla River (North Marche coast) and adjacent beach during periods of higher rainfall associated to dramatic drought. A new integrated methodological approach is performed for the determination of fecal indicator bacteria, divided into a traditional cultural method and a molecular diagnostic approach. The former involves isolating pure colonies of Escherichia coli, used to identify phylogroups originating from different animals, while the latter involves the extraction of genomic DNA from bacteria in water and sediment samples, and the q-PCR detection of species-specific Bacteroides associated with MST (Microbial Source Tracking) primers for human, domestic animals, livestock, birds. Preliminary results showed higher levels of faecal bacteria at sites upstream of the Arzilla River after intense rainfall events, suggesting that these areas have significant inputs, likely from point sources of faecal pollution, to Arzilla River, which receives faecally contaminated water. This information can be used to implement corrective actions to minimize risks to public health and the environment. The insights gained from this approach can also inform future research and policy to address the combined effects of climate change impacts.

Climate change is significantly impacting Arctic ecosystems, particularly through the 'Arctic greening'. This process, driven by increased temperatures and precipitation, enhances terrestrial productivity, herbivore density, and associated nutrient inputs. However, effects of increased inputs on Arctic lacustrine ecosystems, which are crucial carbon sinks and biodiversity hotspots despite being strongly N-limited, remain poorly understood.

This study investigates the impact of changes in terrestrial vegetation and organic inputs from migratory geese on the basal food sources supporting lake food webs. We analyzed nine shallow lakes along a gradient from the coastline to glaciers on the Brøgger Peninsula, Svalbard, using C and N isotopic analysis to assess nutrient sources in sediment and aquatic vegetation. Bayesian mixing models were employed to quantify the contributions of terrestrial and aquatic vegetation, geese, and aquatic animals to the organic matter (OM) in sediments.

Our findings indicate that nitrogen inputs from geese increased with terrestrial vegetation cover around lakes, directly correlating with N concentrations in aquatic vegetation and sediment. δ15N values in algae also increased with goose density, suggesting their potential as bioindicators of bird-mediated eutrophication in Arctic lakes. The contribution of goose droppings to sediment OM varied between 0 and 22%, increasing with terrestrial vegetation cover. Aquatic animal necromass was the main source of OM, contributing between 30-60% regardless of vegetation cover, highlighting a robust mechanism of internal nutrient recycling in these N-limited ecosystems, driven by the winter freezing of lakes.

Our space-for-time approach suggests that climate change-induced increases in goose density will enhance nutrient inputs in Arctic lakes, characterized by sophisticated internal recycling mechanisms. Increased nutrient concentrations in basal food sources are likely to have cascading effects on higher trophic level consumers. Further research is needed to understand how these changes will affect food web structures and associated ecosystem services under climate change scenarios.

The Italian subalpine lakes are some of the most impacted ecosystems by climate change, leading to increased water stratification. This reduces the amount of dissolved oxygen in the deepest part of the water column, leading to hypoxia and anoxia, which affect all the biologically relevant nutrient cycles. Deep anoxia could manifest effects in the whole lake leading to depleted fish stocks, the emergence of toxic algal blooms, and the decrease in the value of ecosystem services provided. To predict the effects of stratification on the nitrogen cycle, sediment cores from two different lakes (Iseo and Idro) that manifest deep anoxia were sampled and incubated ex-situ keeping temperature and dissolved oxygen concentration as close as possible to in-situ conditions. Cores from oxic and anoxic stations were compared after being analyzed for their physical-chemical properties, solutes and dissolved gas profiles along depth using rhizons and microsensors, quantification of net nutrient fluxes at the sediment-water interface, and the application of the isotope pairing technique to quantify rates of denitrification, dissimilative nitrate reduction to ammonium and anammox. Nitrification rates were quantified by the 15N dilution technique. The results evidenced how anoxic sediments lose the capacity to nitrify. Accordingly, the lack of nitrate significantly decreases denitrification compared to oxic sediments. The anoxic benthic system loses the capacity to release nitrogen as gaseous molecular nitrogen. Instead, the particulate organic nitrogen that settles on anoxic sediments is almost completely recycled and released as ammonia due to mineralization. The accumulation of ammonia in the deep hypolimnion at concentrations of almost ~150 µM poses a serious risk of eutrophication of the euphotic layer if partial or complete mixing of the water column were to happen.

The risk screening toolkit Aquatic Species Invasiveness Screening Kit (AS-ISK), integrated with local experts’ ecological knowledge, was used to evaluate the level of invasiveness of two decapod species, namely Callinectes sapidus and Procambarus clarkii in three assessment areas in Southern Italy: Lesina lagoon, Acquatina lagoon (Apulia) and Stagnone di Marsala (Sicily). These target lagoons were identified in the PRIN - TROPHYC project as specific areas to investigate the biology, trophic ecology, invasion history and impacts of C. sapidus in the Mediterranean Sea.

The blue crab currently occurs in all the three areas, while the red swamp crayfish only in one of them (Lesina), but a future colonisation of the other two target areas cannot be totally excluded considered the high bio-ecological plasticity of the crayfish and the presence of suitable environmental conditions. For example, in the freshwater courses around Acquatina lagoon, P. clarkii is already quite abundant while, in Stagnone di Marsala, it is not reported yet. Thus, to quantify the level of invasiveness of these species in all the three areas, the same information on local ecological context was used, and both species were assessed according to their specific biological and ecological traits and classified by specific threshold values provided by AS-ISK.

Results indicate high level of invasiveness for both species, providing similar scores for the environmental impacts and species nuisance traits in all the three lagoons, with C. sapidus displaying higher scores than P. clarkii. The main difference between the two species is due to the impacts on the commercial sector, which is notably higher in C. sapidus, particularly in Lesina and Acquatina lagoons.

These results confirm that both decapods have the potential to be invasive, but their impacts are mainly related to the local environmental and socio-economic characteristics of the assessment areas.

Sea warming is causing severe physical and chemical changes in marine ecosystems worldwide, which, in turn are affecting the biology and ecology of marine organisms.

To implement the Regional Strategy of Adaptation to Climate Change of the Sardinia Region, safeguarding commercial and/or protected marine species, habitat suitability maps along the Sardinian coastline were created for current and projected (2050) temperature ranges in different IPCC scenarios (RCP 4.5, RCP8.5). Based on different functional traits, thermal tolerance curves were reconstructed from the literature for a bivalve (Mytilus galloprovincialis), two echinoderms (the sea urchin Paracentrotus lividus and the sea cucumber Holothuria tubulosa), a seagrass (Posidonia oceanica), and a fish (Mullus barbatus).

For each species, potential variations in habitat suitability for the current period (1987-2010) and the above-mentioned IPCC scenarios (2021-2050) were estimated in terms of quality (from lethal to optimal) and quantity (percentage of change).

In both scenarios, we report a summer decrease in habitat suitability for M. galloprovincialis, with a more pronounced contraction under the warmest scenario. P. lividus could be exposed to a habitat improvement in May, but a decline in summer, more marked under the warmest scenario. In both scenarios H. tubulosa could face an anticipated good habitat condition for reproduction and, again, much worsened conditions in summer. P. oceanica, due to its considerable thermal tolerance, showed minimal habitat contractions (<20%) in August for both scenarios. In both scenarios, males of M. barbatus are expected to face a decreased habitat suitability from May to November and females from June to October, suggesting a considerable variation in the availability of optimal temperature conditions for their recruitment.

Our results, though missing weights for other potential covariates, suggest the need of urgent actions to put in place a strategy to manage exploitation and conservation of the investigated species in the warming future.

In the past two centuries, fossil energy storages accumulated over millions of years have been exploited at an increasing rate to support human economy. Fossil fuels were formed over millions of years from the burial of photosynthetic organisms, including plants on land (mainly generating coal) and plankton in the oceans (mainly generating oil and natural gas). To grow these organisms carbon dioxide was removed from the atmosphere and the ocean, and their burial inhibited the movement of that carbon through the carbon cycle. Burning fossil fuels returns CO₂ back into the atmosphere at a rate that is hundreds to thousands of times faster than it took to be buried, and much faster than it can be removed by the carbon cycle. This affects the Earth system in a variety of ways and represents the primary cause of the current climate change due to the massive emission of greenhouse gases altering the Earth’s dynamics at a global scale. Nearly two-thirds of carbon dioxide emissions, along with a significant amount of nitrous oxide and methane, derive from the burning of fossil fuels such as oil, natural gas, and coal. This scenario has a strong impact on both human and ecosystem health. In this paper, we review the global scientific literature on energy security with a special focus on biophysical limits, identifying main pathways and possible solutions to ensure long-term environmental sustainability.

Global warming is significantly altering the structure and functioning of aquatic ecosystems. The Mediterranean region is identified as one of the most vulnerable areas to global warming, with artificial lakes and coastal lagoons representing particularly susceptible environments that are crucial for the provision of essential ecosystem goods and services. Predictions indicate rising temperatures as cause of plankton biodiversity loss, favouring smaller species, with profound consequences for the structure and efficiency of the pelagic food web.

With the project "a warmer Future world: effects on plankton communities and pathogens in mediterranean vUlneRable ecosystems" (2022PRIN call - FUTURE), we are studying the effects of climate warming on natural plankton communities in the Mediterranean, including different trophic levels, from picoplankton to mesozooplankton, and applying a traditional approach, mainly optical microscopy and flow cytometry, together with a more advanced molecular basedapproach, mainly Next-Generation Sequencing. We are considering natural plankton communities from two different Mediterranean ecosystems: an artificial lake (Bidighinzu Lake) and a coastal lagoon (Cabras Lagoon) located in Sardinia (West Mediterranean) and part of the Italian Long-Term Ecological Research Network.

With this contribution, we present preliminary results on the seasonal dynamics of different plankton size classes in relation to seasonal variations of water temperature and algal nutrients during the first six months of field activity in the artificial lake and the costal lagoon. These data are essential for planning laboratory experiments to be performed in summer 2024 and aimed at investigating plankton responses to extreme climate events, such as heat waves.

One of the major problems of our century is the rising of the ocean temperatures, causing several consequences on marine ecosystems. One of the most evident phenomena is the coral bleaching, which modify the symbiotic relationship between the polyp and unicellular algae, necessary for the energy balance and survival of the coral system. This project was focused on the development of an innovative experimental method, to be evaluated on a laboratory scale, to study the impact of rising temperatures on coral metabolism, specifically on the pigments in symbiotic algae and on non-polar metabolites. Extractions were performed on two coral species cultivated in the Aquarium of Genoa, Pocillopora damicornis and Stylophora pistillata, following indications from the literature. The pigment analysis was conducted using an HPLC-DAD instrument, detecting the continuous wavelengths in the visible spectrum in the 350 to 700nm window. For non-polar metabolites, an organic solvent extraction and purification procedure was carried out and then analyzed by gas chromatography coupled with mass spectrometry (GC MS) in non-target mode. The collected data were subjected to a statistical analysis and referring to the pigments analysis, significant differences in the medians of the distributions were searched for using the Mann-Whitney tests. For non-polar metabolites, a statistical analysis was carried out comparing the differences between stressed and non-stressed (control) samples and the metabolites identified were put under different classes. In conclusion, this work has shown that the expression of both photosynthetic pigments and non-polar metabolites undergoes significant variations when corals are subjected to temperature variations. Future studies could be conducted eventually, involving more species and more replicates could be tested to ensure statistical robustness and predictive adoption of the selected markers.

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