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Alberto Basset - One of the best experts on this subject based on the ideXlab platform.
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sensitivity of phytoplankton metrics to sample size a case study on a large Transitional Water dataset wiser
Ecological Indicators, 2017Co-Authors: Francesco Cozzoli, E Stanca, Geza B Selmeczy, Ioanna Varkitzi, Alberto BassetAbstract:Abstract Phytoplankton is a key element for the assessment of ecological and environmental status of aquatic ecosystems, also in the frame of the MSFD. The methods used to analyse phytoplankton communities are mainly based on time consuming cell counts, dictating a trade-off between the number of cells counted and the number of phytoplankton samples in a monitoring plan, whenever the financial budget, the available personnel or the response time are limited. We investigated the optimal sample size effort, intended as number of phytoplankton cells enumerated per sampling station, of many commonly used metrics. To this aim, precision and uncertainty of the metrics as a function of the sample size have been addressed using a case study carried out in the Lesina lagoon (Apulia, Italy), where 12000 cells per sample have been enumerated within five sampling stations. Overall, we show that some of the commonly used indices/metrics for the description of phytoplankton communities are strongly dependent upon the sampling effort (as number of enumerated individuals per sample), while other metrics are relatively independent. Metrics based on the number of taxa only (e.g. Taxonomic richness), on the ratio between number of taxa and number of individuals (e.g. Margalef's diversity index) or on the species evenness (e.g. Pielou's evenness index) strongly depend on the sample size and their uncertainty (in term of sampling variance) is usually large. On the other hand, metrics of taxonomic diversity accounting for the proportional abundance of each taxa (e.g. Shannon-Wiener's diversity index), metrics accounting for the dominance of the most abundant taxa (e.g. Berger-Parker's dominance index) and metrics derived from the individual size distribution (e.g. Index of Size spectra Sensitivity, ISS Phyto) are able to achieve high precision and low uncertainty already at small sample sizes (virtually less than 200 enumerated cells) and thus they minimize the allocated effort vs. the gained information. Accordingly to our observations, we provide recommendations about the metric selection and the optimal effort per sample to be allocated in phytoplankton monitoring plans.
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decoding size distribution patterns in marine and Transitional Water phytoplankton from community to species level
PLOS ONE, 2015Co-Authors: Leonilde Roselli, Alberto BassetAbstract:Understanding the mechanisms of phytoplankton community assembly is a fundamental issue of aquatic ecology. Here, we use field data from Transitional (e.g. coastal lagoons) and coastal Water environments to decode patterns of phytoplankton size distribution into organization and adaptive mechanisms. Transitional Waters are characterized by higher resource availability and shallower well-mixed Water column than coastal marine environments. Differences in physico-chemical regime between the two environments have been hypothesized to exert contrasting selective pressures on phytoplankton cell morphology (size and shape). We tested the hypothesis focusing on resource availability (nutrients and light) and mixed layer depth as ecological axes that define ecological niches of phytoplankton. We report fundamental differences in size distributions of marine and freshWater diatoms, with Transitional Water phytoplankton significantly smaller and with higher surface to volume ratio than marine species. Here, we hypothesize that mixing condition affecting size-dependent sinking may drive phytoplankton size and shape distributions. The interplay between shallow mixed layer depth and frequent and complete mixing of Transitional Waters may likely increase the competitive advantage of small phytoplankton limiting large cell fitness. The nutrient regime appears to explain the size distribution within both marine and Transitional Water environments, while it seem does not explain the pattern observed across the two environments. In addition, difference in light availability across the two environments appear do not explain the occurrence of asymmetric size distribution at each hierarchical level. We hypothesize that such competitive equilibria and adaptive strategies in resource exploitation may drive by organism’s behavior which exploring patch resources in Transitional and marine phytoplankton communities.
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biodiversity partitioning for Transitional Water ecosystems
METMA VII and GRASPA14 Conference. Torino (IT) 10-12 September 2014, 2014Co-Authors: Jona G Lasinio, Alessio Pollice, Ilaria Rosati, Serena Arima, G Castaldelli, E A Fano, Alberto BassetAbstract:Biodiversity partitioning means that the biodiversity of all individuals in a given meta- community may be split into the diversity within and between local communities. In this work we adopt diversity measures based on the deformed exponential transformation of the Tsallis entropy to analyze biodiversity partitioning in the Po River Delta. Several measures are investigated with varying importance given to rare species. Mixed effects models are then used to investigate the variation of diversity measures with fixed effects such as vegetation cover and sediment type and random effects ruled by nested sources of variability.
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ability of phytoplankton trait sensitivity to highlight anthropogenic pressures in mediterranean lagoons a size spectra sensitivity index iss phyto
Ecological Indicators, 2013Co-Authors: Maria Rosaria Vadrucci, Elena Stanca, Cristina Mazziotti, Serena Fonda Umani, Assimakopoulou Georgia, Snejana Moncheva, Antonella Romano, Roberto Bucci, Nicola Ungaro, Alberto BassetAbstract:Abstract Size spectra exhibit common patterns of variation and predictable responses to pressures across ecosystem types, functional guilds and taxonomic groups. Here, we extend the size spectra approach to phytoplankton ecological status assessment in Transitional Waters by developing, testing and validating a multi-metric index of size spectra sensitivity (ISS-phyto), which integrates size structure metrics with others such as phytoplankton diversity, biomass and sensitivity of size classes to anthropogenic disturbance. The ability of various theoretical models of size spectra sensitivity to discriminate between disturbed and undisturbed ecosystems and levels of anthropogenic stress was evaluated. We used data on phytoplankton samples collected in 14 Mediterranean and Black sea Transitional Water ecosystems (coastal lagoons) from Italy, Albania, Greece, Bulgaria and Romania, and compared the models’ efficiency by looking at their pressure–impact response along salinity and enrichment gradients, the latter quantified as variations in dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP). Data from a fifteenth Mediterranean lagoon was used for external validation purposes. Right asymmetric models of size class sensitivity, implying higher sensitivity of smaller cell size classes, were found to contribute to the ISS-phyto multimetric tool more effectively than symmetric and left asymmetric models, distinguishing disturbed from undisturbed lagoons and disturbed from undisturbed stations within the same lagoon. When based on right asymmetric sensitivity models, i.e., those that were most efficient in identifying anthropogenic impacts, ISS-phyto also showed the best fit of pressure–response relationships along the salinity and enrichment gradients; at low to high levels of impact ISS response was driven by size class sensitivity and at very high impacts by phytoplankton biomass. A scheme for the classification of Ecological Quality Status based on ISS-phyto is proposed and validated. The validation procedure found that ISS-phyto is an effective and sensitive monitoring tool, robust, easy to apply and to inter-calibrate among laboratories.
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estimation of benthic macroinvertebrates taxonomic diversity testing the role of sampling effort in a mediterranean Transitional Water ecosystem
Transitional Waters Bulletin, 2013Co-Authors: Gabriele Marini, Maurizio Pinna, Alberto Basset, Giorgio MancinelliAbstract:1 - The accurate evaluation of benthic macroinvertebrate taxonomic diversity in Transitional Water ecosystems is strictly related to sampling effort and, usually, biomonitoring protocols define the sampling effort needed to the elaboration of a specific ecological indicator. The time-lag between the sampling event and the final assessment of ecological status, and to overall costs for sampling, personnel and sample treatment suggest a reduction of sampling effort. 2 - How to simplify methods and to reduce efforts without compromising the ecological validity of taxonomic diversity indicators is a topic recurrently debated in the procedures for sampling protocol implementation. Regarding this topic, the identification of optimal sample unit size (SUS) and sieve mesh size (SMS) is still lacking, mainly for benthic macroinvertebrates of Mediterranean Transitional Water ecosystems. 3 - The present study analyzes the effect of the increasing the sampling effort in terms of sample unit size (SUS; 0.0225 m2, 0.0450 m2, 0.0675 m2, 0.0900 m2) and sieve mesh size (SMS; 0.5 mm, 1 mm, 2 mm) on the estimation of taxonomic diversity in a Mediterranean lagoon. Benthic macroinvertebrates were collected in September 2009 at two locations, considering a perturbed and a relatively unperturbed study site of Lesina lagoon (South-East Italy). Samples were sieved on a column of three decreasing mesh sizes of sieves. Taxonomic richness (S), Shannon–Weaver index (H’), Simpson index (λ) and Taxonomic distinctness (TD) were calculated for each study site, SUS and SMS combination, and replicate. The difference between perturbed and relatively unperturbed site was tested according to the variation of sampling effort using three-way ANOVA tests. 4 - As expected, the accuracy of the results increased with increasing of SUS and SMS, the difference between perturbed and relatively unperturbed study site were always highlighted by each taxonomic diversity index, independently by used SUS and SMS. The variation of taxonomic diversity indicators seems to depend mainly by used sieve mesh size suggesting the reduction of sampling effort through the reduction of sample unit size. 5 - Finally, this contribution could be useful in harmonizing sampling methodologies for the cost-effectiveness taxonomic diversity estimation and biomonitoring programs.
Cristina Munari - One of the best experts on this subject based on the ideXlab platform.
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sediment carbon variations in the venice lagoon and other Transitional Water systems of the northern adriatic sea
Water, 2020Co-Authors: Adriano Sfriso, Alessandro Buosi, Michele Mistri, Cristina Munari, Yari Tomio, Abdulsalam Juhmani, Stefania Chiesa, Marta Greco, Chiara Gazzola, Andrea SfrisoAbstract:The concentrations of inorganic, organic and total carbon, and some sedimentary parameters (sediment density, fines, pH, and shell fragments), have been analyzed in surface sediments of the Venice Lagoon since 1987. Environmental scenarios, characterized by different anthropogenic impacts, have been considered, especially in the central basin where more information is available. Data collected in 2009 in the lagoons and ponds of Po Delta, in Comacchio Valleys and Pialassa della Baiona have been also considered and analyzed together with those recorded in the whole Venice Lagoon in 2011. The results show a strong correlation of the inorganic carbon (Cinorg) with the carbonatic or siliceous origins of the sediments and changes of both Cinorg and organic carbon (Corg) according to different anthropogenic impacts, especially eutrophication and clam-fishing activities. Higher sediment density, grain-size, and pH were associated to good-high ecological conditions and the higher presence of inorganic carbon of biological origin (shell fragments and calcified macroalgal fragments). Conversely, Corg, which is associated to eutrophic conditions, was strongly affected by the sediment disturbance and the presence of high concentrations of bivalves which enhance its consumption.
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microcalcareous seaweeds as sentinels of trophic changes and co2 trapping in Transitional Water systems
Ecological Indicators, 2020Co-Authors: Adriano Sfriso, Isabella Moro, Marion Adelheid Wolf, Alessandro Buosi, Katia Sciuto, Emanuela Molinaroli, Michele Mistri, Cristina Munari, Andrea SfrisoAbstract:Abstract Microcalcareous epiphytic seaweeds (MES) are macroalgae more sensitive than aquatic angiosperms to environmental degradation and, with their presence/absence, these species act like sentinels providing useful information on the ecological status of environments. In this study, we analyzed the environmental parameters in Water column and surface sediments in relation to macrophyte variables from 257 sites, distributed in the main Italian Transitional Water systems (TWS). The results showed that MES are strongly correlated to pH changes, the main parameter that regulates their presence/absence. The optimal growth range is between pH 7.80 and 8.35; out of these values their growth is reduced or hampered. In oxidized sediments the carbonate crusts, composed by Mg-Calcite (an unstable compound that in the sediments quickly turns into calcite), can permanently trap up to 2.47 tonnes ha−1 yr−1 of CO2, increasing sediment thickness of approx. 0.06–0.21 mm yr−1.
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management and exploitation of macroalgal biomass as a tool for the recovery of Transitional Water systems
Frontiers in Ecology and Evolution, 2020Co-Authors: Adriano Sfriso, Alessandro Buosi, Michele Mistri, Cristina Munari, Andrea SfrisoAbstract:Aquatic angiosperms favor the development of ecosystems services, the welfare of marine organisms and people. Generally the presence of angiosperms in Transitional systems are indicators of good ecosystem status. Presently, these environments are densely populated and often are so highly degraded that angiosperms have almost disappeared, replaced by tionitrophilic macroalgae responsible of anoxic events that deteriorate the environment furtherly. Although this trend is hardly reversible because the anthropogenic impact is increasing and the restoring of damaged environments within a reasonable time is difficult, recent studies have shown that by managing the harvesting of the natural algal species of commercial interest a progressive environmental recovery is achievable. Biomass-harvesting can contribute both to the removal of high amounts of nutrients and the generation of economic revenues for a sustainable, self-financed environmental restoration. In fact, unlike clam-farming which destroys the seabed and re-suspends large amounts of sediments, the proper management of the macroalgal biomass, can favour the nutrient abatement and the recolonization of aquatic angiosperms which help restore the conditions necessary for the conservation of the benthic and fish fauna and birds, and produce valuable economic resources.
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assessing the effectiveness of surrogates for species over time evidence from decadal monitoring of a mediterranean Transitional Water ecosystem
Marine Pollution Bulletin, 2018Co-Authors: Stanislao Bevilacqua, Michele Mistri, Antonio Terlizzi, Cristina MunariAbstract:The use of higher taxa or alternative approach to species surrogacy, such as the BestAgg procedure, could represent cost-effective solutions to avoid expensive species-level identifications in monitoring activities, especially on the long term. However, whether a set of surrogates would be effective in subsequent reiteration of the same assessment remains largely unsolved. We used a long-term dataset on macro-benthic assemblages to test the hypothesis that family-level and BestAgg surrogates which are effective for a limited period of monitoring could be successfully applied to quantify community patterns also in subsequent monitoring programmes. The effectiveness of surrogates in detecting temporal variations in assemblage structure as at species level remained basically unaffected over a decade. Recognizing once and for all if species surrogacy may have a practical value for monitoring will strongly depend on future assessments of the potential of surrogates to reflect community changes and to retain this prerogative over time.
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comparison of benthic indices for the evaluation of ecological status of three slovenian Transitional Water bodies northern adriatic
Marine Pollution Bulletin, 2017Co-Authors: Valentina Pitacco, Michele Mistri, Lovrenc Lipej, Borut Mavric, Cristina MunariAbstract:Benthic indicators are important tools for the classification of coastal and Transitional Water bodies. The aim of the work was to assess for the first time the Environmental Status (ES) of Slovenian Transitional Waters, comparing the following biotic indices: richness, Shannon-Weaver diversity, AMBI, M-AMBI, BENTIX and BITS indices. A total of 13 stations were sampled with a Van Veen grab, in three ecosystems in the northern Adriatic. Samples were sieved and sorted, invertebrates identified and counted. The anthropogenic impact was estimated with professional judgement. Richness and diversity showed a good response to anthropogenic pressure. Conversely, indices based on sensitivity/tolerance groups did not showed a clear distinction between more and less impacted ecosystems. In particular BENTIX underestimated the ES, while with BITS there was a overestimation. The best evaluation was obtained with M-AMBI, because even if based on a sensitivity/tolerance approach, it considered also the structural aspect of the community.
Adriano Sfriso - One of the best experts on this subject based on the ideXlab platform.
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environmental restoration by aquatic angiosperm transplants in Transitional Water systems the venice lagoon as a case study
Science of The Total Environment, 2021Co-Authors: Adriano Sfriso, Chiara Facca, Marion Adelheid Wolf, Alessandro Buosi, Andrea Sfriso, Yari Tomio, Abdulsalam Juhmani, Piero Franzoi, Luca Scapin, Emanuele PonisAbstract:Abstract The paper reports the results obtained after 4 years of aquatic angiosperm transplants in areas of the Venice Lagoon (North Adriatic Sea, Mediterranean) where meadows almost disappeared due to eutrophication, pollution and overexploitation of clam resources. The project LIFE12 NAT/IT/000331-SeResto, funded by the European Union, allowed to recolonize the Habitat 1150* (coastal lagoons) in the northernmost part of the lagoon, by extensive manual transplants of small sods or single rhizomes of Zostera marina, Zostera noltei, Ruppia cirrhosa and, in some stations also of Cymodocea nodosa. Over the 4 years of the project more than 75,000 rhizomes were transplanted in 35 stations with the support of local stakeholders (fishermen, hunters and sport clubs). Plants took root in 32 stations forming extensive meadows on a surface of approx. 10 km2 even if some failures were recorded in areas affected by outflows of freshWater rich in nutrients and suspended particulate matter. The rapid recovery of the ecological status of the involved areas was the result of this meadow restoration, which was in compliance with Water Framework Directive (WFD 2000/60/EC) objectives. Moreover, the monitoring of environmental parameters in the Water column and in surface sediments allowed to identify the best conditions for successful transplants. Small, widespread interventions and the participation of local stakeholders in the environmental recovery, make this action economically cheap and easily transposable in other similar environments.
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sediment carbon variations in the venice lagoon and other Transitional Water systems of the northern adriatic sea
Water, 2020Co-Authors: Adriano Sfriso, Alessandro Buosi, Michele Mistri, Cristina Munari, Yari Tomio, Abdulsalam Juhmani, Stefania Chiesa, Marta Greco, Chiara Gazzola, Andrea SfrisoAbstract:The concentrations of inorganic, organic and total carbon, and some sedimentary parameters (sediment density, fines, pH, and shell fragments), have been analyzed in surface sediments of the Venice Lagoon since 1987. Environmental scenarios, characterized by different anthropogenic impacts, have been considered, especially in the central basin where more information is available. Data collected in 2009 in the lagoons and ponds of Po Delta, in Comacchio Valleys and Pialassa della Baiona have been also considered and analyzed together with those recorded in the whole Venice Lagoon in 2011. The results show a strong correlation of the inorganic carbon (Cinorg) with the carbonatic or siliceous origins of the sediments and changes of both Cinorg and organic carbon (Corg) according to different anthropogenic impacts, especially eutrophication and clam-fishing activities. Higher sediment density, grain-size, and pH were associated to good-high ecological conditions and the higher presence of inorganic carbon of biological origin (shell fragments and calcified macroalgal fragments). Conversely, Corg, which is associated to eutrophic conditions, was strongly affected by the sediment disturbance and the presence of high concentrations of bivalves which enhance its consumption.
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microcalcareous seaweeds as sentinels of trophic changes and co2 trapping in Transitional Water systems
Ecological Indicators, 2020Co-Authors: Adriano Sfriso, Isabella Moro, Marion Adelheid Wolf, Alessandro Buosi, Katia Sciuto, Emanuela Molinaroli, Michele Mistri, Cristina Munari, Andrea SfrisoAbstract:Abstract Microcalcareous epiphytic seaweeds (MES) are macroalgae more sensitive than aquatic angiosperms to environmental degradation and, with their presence/absence, these species act like sentinels providing useful information on the ecological status of environments. In this study, we analyzed the environmental parameters in Water column and surface sediments in relation to macrophyte variables from 257 sites, distributed in the main Italian Transitional Water systems (TWS). The results showed that MES are strongly correlated to pH changes, the main parameter that regulates their presence/absence. The optimal growth range is between pH 7.80 and 8.35; out of these values their growth is reduced or hampered. In oxidized sediments the carbonate crusts, composed by Mg-Calcite (an unstable compound that in the sediments quickly turns into calcite), can permanently trap up to 2.47 tonnes ha−1 yr−1 of CO2, increasing sediment thickness of approx. 0.06–0.21 mm yr−1.
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management and exploitation of macroalgal biomass as a tool for the recovery of Transitional Water systems
Frontiers in Ecology and Evolution, 2020Co-Authors: Adriano Sfriso, Alessandro Buosi, Michele Mistri, Cristina Munari, Andrea SfrisoAbstract:Aquatic angiosperms favor the development of ecosystems services, the welfare of marine organisms and people. Generally the presence of angiosperms in Transitional systems are indicators of good ecosystem status. Presently, these environments are densely populated and often are so highly degraded that angiosperms have almost disappeared, replaced by tionitrophilic macroalgae responsible of anoxic events that deteriorate the environment furtherly. Although this trend is hardly reversible because the anthropogenic impact is increasing and the restoring of damaged environments within a reasonable time is difficult, recent studies have shown that by managing the harvesting of the natural algal species of commercial interest a progressive environmental recovery is achievable. Biomass-harvesting can contribute both to the removal of high amounts of nutrients and the generation of economic revenues for a sustainable, self-financed environmental restoration. In fact, unlike clam-farming which destroys the seabed and re-suspends large amounts of sediments, the proper management of the macroalgal biomass, can favour the nutrient abatement and the recolonization of aquatic angiosperms which help restore the conditions necessary for the conservation of the benthic and fish fauna and birds, and produce valuable economic resources.
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aquatic angiosperm transplantation a tool for environmental management and restoring in Transitional Water systems
Water, 2019Co-Authors: Adriano Sfriso, A Bonometto, Chiara Facca, Alessandro Buosi, Andrea Sfriso, Yari Tomio, Abdulsalam Juhmani, Piero Franzoi, Luca Scapin, Emanuele PonisAbstract:Since the 1960s, the Venice Lagoon has suffered a sharp aquatic plant constriction due to eutrophication, pollution, and clam fishing. Those anthropogenic impacts began to decline during the 2010s, and since then the ecological status of the lagoon has improved, but in many choked areas no plant recolonization has been recorded due to the lack of seeds. The project funded by the European Union (LIFE12 NAT/IT/000331-SeResto) allowed to recolonize one of these areas, which is situated in the northern lagoon, by widespread transplantation of small sods and individual rhizomes. In-field activities were supported by fishermen, hunters, and sport associations; the interested surface measured approximately 36.6 km2. In the 35 stations of the chosen area, 24,261 rhizomes were transplanted during the first year, accounting for 693 rhizomes per station. About 37% of them took root in 31 stations forming several patches that joined together to form extensive meadows. Plant rooting was successful where the Waters were clear and the trophic status low. But, near the outflows of freshWater rich in nutrients and suspended particulate matter, the action failed. Results demonstrate the effectiveness of small, widespread interventions and the importance of engaging the population in the recovery of the environment, which makes the action economically cheap and replicable in other similar environments.
Michele Mistri - One of the best experts on this subject based on the ideXlab platform.
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sediment carbon variations in the venice lagoon and other Transitional Water systems of the northern adriatic sea
Water, 2020Co-Authors: Adriano Sfriso, Alessandro Buosi, Michele Mistri, Cristina Munari, Yari Tomio, Abdulsalam Juhmani, Stefania Chiesa, Marta Greco, Chiara Gazzola, Andrea SfrisoAbstract:The concentrations of inorganic, organic and total carbon, and some sedimentary parameters (sediment density, fines, pH, and shell fragments), have been analyzed in surface sediments of the Venice Lagoon since 1987. Environmental scenarios, characterized by different anthropogenic impacts, have been considered, especially in the central basin where more information is available. Data collected in 2009 in the lagoons and ponds of Po Delta, in Comacchio Valleys and Pialassa della Baiona have been also considered and analyzed together with those recorded in the whole Venice Lagoon in 2011. The results show a strong correlation of the inorganic carbon (Cinorg) with the carbonatic or siliceous origins of the sediments and changes of both Cinorg and organic carbon (Corg) according to different anthropogenic impacts, especially eutrophication and clam-fishing activities. Higher sediment density, grain-size, and pH were associated to good-high ecological conditions and the higher presence of inorganic carbon of biological origin (shell fragments and calcified macroalgal fragments). Conversely, Corg, which is associated to eutrophic conditions, was strongly affected by the sediment disturbance and the presence of high concentrations of bivalves which enhance its consumption.
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microcalcareous seaweeds as sentinels of trophic changes and co2 trapping in Transitional Water systems
Ecological Indicators, 2020Co-Authors: Adriano Sfriso, Isabella Moro, Marion Adelheid Wolf, Alessandro Buosi, Katia Sciuto, Emanuela Molinaroli, Michele Mistri, Cristina Munari, Andrea SfrisoAbstract:Abstract Microcalcareous epiphytic seaweeds (MES) are macroalgae more sensitive than aquatic angiosperms to environmental degradation and, with their presence/absence, these species act like sentinels providing useful information on the ecological status of environments. In this study, we analyzed the environmental parameters in Water column and surface sediments in relation to macrophyte variables from 257 sites, distributed in the main Italian Transitional Water systems (TWS). The results showed that MES are strongly correlated to pH changes, the main parameter that regulates their presence/absence. The optimal growth range is between pH 7.80 and 8.35; out of these values their growth is reduced or hampered. In oxidized sediments the carbonate crusts, composed by Mg-Calcite (an unstable compound that in the sediments quickly turns into calcite), can permanently trap up to 2.47 tonnes ha−1 yr−1 of CO2, increasing sediment thickness of approx. 0.06–0.21 mm yr−1.
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management and exploitation of macroalgal biomass as a tool for the recovery of Transitional Water systems
Frontiers in Ecology and Evolution, 2020Co-Authors: Adriano Sfriso, Alessandro Buosi, Michele Mistri, Cristina Munari, Andrea SfrisoAbstract:Aquatic angiosperms favor the development of ecosystems services, the welfare of marine organisms and people. Generally the presence of angiosperms in Transitional systems are indicators of good ecosystem status. Presently, these environments are densely populated and often are so highly degraded that angiosperms have almost disappeared, replaced by tionitrophilic macroalgae responsible of anoxic events that deteriorate the environment furtherly. Although this trend is hardly reversible because the anthropogenic impact is increasing and the restoring of damaged environments within a reasonable time is difficult, recent studies have shown that by managing the harvesting of the natural algal species of commercial interest a progressive environmental recovery is achievable. Biomass-harvesting can contribute both to the removal of high amounts of nutrients and the generation of economic revenues for a sustainable, self-financed environmental restoration. In fact, unlike clam-farming which destroys the seabed and re-suspends large amounts of sediments, the proper management of the macroalgal biomass, can favour the nutrient abatement and the recolonization of aquatic angiosperms which help restore the conditions necessary for the conservation of the benthic and fish fauna and birds, and produce valuable economic resources.
-
assessing the effectiveness of surrogates for species over time evidence from decadal monitoring of a mediterranean Transitional Water ecosystem
Marine Pollution Bulletin, 2018Co-Authors: Stanislao Bevilacqua, Michele Mistri, Antonio Terlizzi, Cristina MunariAbstract:The use of higher taxa or alternative approach to species surrogacy, such as the BestAgg procedure, could represent cost-effective solutions to avoid expensive species-level identifications in monitoring activities, especially on the long term. However, whether a set of surrogates would be effective in subsequent reiteration of the same assessment remains largely unsolved. We used a long-term dataset on macro-benthic assemblages to test the hypothesis that family-level and BestAgg surrogates which are effective for a limited period of monitoring could be successfully applied to quantify community patterns also in subsequent monitoring programmes. The effectiveness of surrogates in detecting temporal variations in assemblage structure as at species level remained basically unaffected over a decade. Recognizing once and for all if species surrogacy may have a practical value for monitoring will strongly depend on future assessments of the potential of surrogates to reflect community changes and to retain this prerogative over time.
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comparison of benthic indices for the evaluation of ecological status of three slovenian Transitional Water bodies northern adriatic
Marine Pollution Bulletin, 2017Co-Authors: Valentina Pitacco, Michele Mistri, Lovrenc Lipej, Borut Mavric, Cristina MunariAbstract:Benthic indicators are important tools for the classification of coastal and Transitional Water bodies. The aim of the work was to assess for the first time the Environmental Status (ES) of Slovenian Transitional Waters, comparing the following biotic indices: richness, Shannon-Weaver diversity, AMBI, M-AMBI, BENTIX and BITS indices. A total of 13 stations were sampled with a Van Veen grab, in three ecosystems in the northern Adriatic. Samples were sieved and sorted, invertebrates identified and counted. The anthropogenic impact was estimated with professional judgement. Richness and diversity showed a good response to anthropogenic pressure. Conversely, indices based on sensitivity/tolerance groups did not showed a clear distinction between more and less impacted ecosystems. In particular BENTIX underestimated the ES, while with BITS there was a overestimation. The best evaluation was obtained with M-AMBI, because even if based on a sensitivity/tolerance approach, it considered also the structural aspect of the community.
Andrea Sfriso - One of the best experts on this subject based on the ideXlab platform.
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environmental restoration by aquatic angiosperm transplants in Transitional Water systems the venice lagoon as a case study
Science of The Total Environment, 2021Co-Authors: Adriano Sfriso, Chiara Facca, Marion Adelheid Wolf, Alessandro Buosi, Andrea Sfriso, Yari Tomio, Abdulsalam Juhmani, Piero Franzoi, Luca Scapin, Emanuele PonisAbstract:Abstract The paper reports the results obtained after 4 years of aquatic angiosperm transplants in areas of the Venice Lagoon (North Adriatic Sea, Mediterranean) where meadows almost disappeared due to eutrophication, pollution and overexploitation of clam resources. The project LIFE12 NAT/IT/000331-SeResto, funded by the European Union, allowed to recolonize the Habitat 1150* (coastal lagoons) in the northernmost part of the lagoon, by extensive manual transplants of small sods or single rhizomes of Zostera marina, Zostera noltei, Ruppia cirrhosa and, in some stations also of Cymodocea nodosa. Over the 4 years of the project more than 75,000 rhizomes were transplanted in 35 stations with the support of local stakeholders (fishermen, hunters and sport clubs). Plants took root in 32 stations forming extensive meadows on a surface of approx. 10 km2 even if some failures were recorded in areas affected by outflows of freshWater rich in nutrients and suspended particulate matter. The rapid recovery of the ecological status of the involved areas was the result of this meadow restoration, which was in compliance with Water Framework Directive (WFD 2000/60/EC) objectives. Moreover, the monitoring of environmental parameters in the Water column and in surface sediments allowed to identify the best conditions for successful transplants. Small, widespread interventions and the participation of local stakeholders in the environmental recovery, make this action economically cheap and easily transposable in other similar environments.
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sediment carbon variations in the venice lagoon and other Transitional Water systems of the northern adriatic sea
Water, 2020Co-Authors: Adriano Sfriso, Alessandro Buosi, Michele Mistri, Cristina Munari, Yari Tomio, Abdulsalam Juhmani, Stefania Chiesa, Marta Greco, Chiara Gazzola, Andrea SfrisoAbstract:The concentrations of inorganic, organic and total carbon, and some sedimentary parameters (sediment density, fines, pH, and shell fragments), have been analyzed in surface sediments of the Venice Lagoon since 1987. Environmental scenarios, characterized by different anthropogenic impacts, have been considered, especially in the central basin where more information is available. Data collected in 2009 in the lagoons and ponds of Po Delta, in Comacchio Valleys and Pialassa della Baiona have been also considered and analyzed together with those recorded in the whole Venice Lagoon in 2011. The results show a strong correlation of the inorganic carbon (Cinorg) with the carbonatic or siliceous origins of the sediments and changes of both Cinorg and organic carbon (Corg) according to different anthropogenic impacts, especially eutrophication and clam-fishing activities. Higher sediment density, grain-size, and pH were associated to good-high ecological conditions and the higher presence of inorganic carbon of biological origin (shell fragments and calcified macroalgal fragments). Conversely, Corg, which is associated to eutrophic conditions, was strongly affected by the sediment disturbance and the presence of high concentrations of bivalves which enhance its consumption.
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microcalcareous seaweeds as sentinels of trophic changes and co2 trapping in Transitional Water systems
Ecological Indicators, 2020Co-Authors: Adriano Sfriso, Isabella Moro, Marion Adelheid Wolf, Alessandro Buosi, Katia Sciuto, Emanuela Molinaroli, Michele Mistri, Cristina Munari, Andrea SfrisoAbstract:Abstract Microcalcareous epiphytic seaweeds (MES) are macroalgae more sensitive than aquatic angiosperms to environmental degradation and, with their presence/absence, these species act like sentinels providing useful information on the ecological status of environments. In this study, we analyzed the environmental parameters in Water column and surface sediments in relation to macrophyte variables from 257 sites, distributed in the main Italian Transitional Water systems (TWS). The results showed that MES are strongly correlated to pH changes, the main parameter that regulates their presence/absence. The optimal growth range is between pH 7.80 and 8.35; out of these values their growth is reduced or hampered. In oxidized sediments the carbonate crusts, composed by Mg-Calcite (an unstable compound that in the sediments quickly turns into calcite), can permanently trap up to 2.47 tonnes ha−1 yr−1 of CO2, increasing sediment thickness of approx. 0.06–0.21 mm yr−1.
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management and exploitation of macroalgal biomass as a tool for the recovery of Transitional Water systems
Frontiers in Ecology and Evolution, 2020Co-Authors: Adriano Sfriso, Alessandro Buosi, Michele Mistri, Cristina Munari, Andrea SfrisoAbstract:Aquatic angiosperms favor the development of ecosystems services, the welfare of marine organisms and people. Generally the presence of angiosperms in Transitional systems are indicators of good ecosystem status. Presently, these environments are densely populated and often are so highly degraded that angiosperms have almost disappeared, replaced by tionitrophilic macroalgae responsible of anoxic events that deteriorate the environment furtherly. Although this trend is hardly reversible because the anthropogenic impact is increasing and the restoring of damaged environments within a reasonable time is difficult, recent studies have shown that by managing the harvesting of the natural algal species of commercial interest a progressive environmental recovery is achievable. Biomass-harvesting can contribute both to the removal of high amounts of nutrients and the generation of economic revenues for a sustainable, self-financed environmental restoration. In fact, unlike clam-farming which destroys the seabed and re-suspends large amounts of sediments, the proper management of the macroalgal biomass, can favour the nutrient abatement and the recolonization of aquatic angiosperms which help restore the conditions necessary for the conservation of the benthic and fish fauna and birds, and produce valuable economic resources.
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aquatic angiosperm transplantation a tool for environmental management and restoring in Transitional Water systems
Water, 2019Co-Authors: Adriano Sfriso, A Bonometto, Chiara Facca, Alessandro Buosi, Andrea Sfriso, Yari Tomio, Abdulsalam Juhmani, Piero Franzoi, Luca Scapin, Emanuele PonisAbstract:Since the 1960s, the Venice Lagoon has suffered a sharp aquatic plant constriction due to eutrophication, pollution, and clam fishing. Those anthropogenic impacts began to decline during the 2010s, and since then the ecological status of the lagoon has improved, but in many choked areas no plant recolonization has been recorded due to the lack of seeds. The project funded by the European Union (LIFE12 NAT/IT/000331-SeResto) allowed to recolonize one of these areas, which is situated in the northern lagoon, by widespread transplantation of small sods and individual rhizomes. In-field activities were supported by fishermen, hunters, and sport associations; the interested surface measured approximately 36.6 km2. In the 35 stations of the chosen area, 24,261 rhizomes were transplanted during the first year, accounting for 693 rhizomes per station. About 37% of them took root in 31 stations forming several patches that joined together to form extensive meadows. Plant rooting was successful where the Waters were clear and the trophic status low. But, near the outflows of freshWater rich in nutrients and suspended particulate matter, the action failed. Results demonstrate the effectiveness of small, widespread interventions and the importance of engaging the population in the recovery of the environment, which makes the action economically cheap and replicable in other similar environments.
