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R Danovaro - One of the best experts on this subject based on the ideXlab platform.
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Organic matter pools, C turnover and Meiofaunal biodiversity in the sediments of the western Spitsbergen deep continental margin, Svalbard Archipelago
Deep Sea Research Part I: Oceanographic Research Papers, 2016Co-Authors: A. Pusceddu, L. Carugati, C. Gambi, J. Mienert, B. Petani, A. Sanchez-vidal, M. Canals, S. Heussner, R DanovaroAbstract:We investigated organic matter (OM) quantity, nutritional quality and degradation rates, as well as abundance and biodiversity of Meiofauna and nematodes along the deep continental margin off Spitsbergen, in the Svalbard Archipelago. Sediment samples were collected in July 2010 and 2011 along a bathymetric gradient between 600 m and 2000 m depth, and total mass flux measured at the same depths from July 2010 to July 2011. In both sampling periods sedimentary OM contents and C degradation rates increased significantly with water depth, whereas OM nutritional quality was generally higher at shallower depths, with the unique exception at 600 m depth in 2010. Meiofaunal abundance and biomass (largely dominated by nematodes) showed the highest values at intermediate depths (ca 1500 m) in both sampling periods. The richness of Meiofaunal higher taxa and nematode species richness did not vary significantly with water depth in both sampling periods. We suggest here that patterns in OM quantity, C degradation rates, and Meiofauna community composition in 2011 were likely influenced by the intensification of the warm West Spitsbergen Current (WSC). We hypothesize that the intensity of the WSC inflow to the Arctic Ocean could have an important role on benthic biodiversity and functioning of deep-sea Arctic ecosystems.
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structural and functional response of Meiofauna rocky assemblages to sewage pollution
Marine Pollution Bulletin, 2006Co-Authors: Simonetta Fraschetti, Cristina Gambi, Adriana Giangrande, Luigi Musco, Antonio Terlizzi, R DanovaroAbstract:Despite Meiofauna being one of the most popular tool for detecting the ecological effects of different sources of impact, the application of structured experimental designs to this benthic component is typically neglected, especially in subtidal rocky shores. In this study, an asymmetrical design was used to detect hard-bottom Meiofaunal abundance and biodiversity response to sewage discharge. Sampling was carried out at a depth of 3-4 m by SCUBA diving, by means of a modified manual corer. Six replicate cores were collected at three sites (80-100 m apart), at each of three locations (one purportedly impacted [I] and two controls [Cs]). A total of 84,994 specimens were collected. The outfall affected Meiofaunal assemblages in terms of taxon richness, by determining a significant reduction of the number of taxa in the disturbed location, and community structure, by causing functional changes in terms of a decrease of the abundance of nematodes and an increase of the hydrozoan component. Nematodes and syllid polychaetes showed significant lower average abundance at I. Multivariate analyses showed that both Meiofaunal assemblage and syllids were significantly different at I compared with Cs. The sewage outfall also affected patterns of spatial distribution at the scale of site (100 m apart) and of replicate units (centimetres apart), both in syllids and in nematodes. Our results provide evidence that the selection of multiple controls is crucial to prevent the widespread risk of Type II error, highlighting the need of more accurate experimental designs when dealing with Meiofauna.
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Meiofauna response to a dynamic river plume front
Marine Biology, 2000Co-Authors: R Danovaro, Cristina Gambi, Elena Manini, Mauro FabianoAbstract:The benthic response to a plume front was studied in two areas of the northern Adriatic (Mediterranean Sea) differently influenced by the Po River freshwater input. Sediment samples were collected in June 1996 and February 1997 from 12 stations. The adopted sampling strategy was able to identify the front line in real time by satellite images and to locate sampling stations along an inner–outer plume gradient in order to cover the benthic area beneath the river plume, where enhanced biological production was expected, and open-sea sediments not directly influenced by freshwater inputs. Meiofaunal parameters were compared to the physical conditions and to phytodetritus inputs, organic matter accumulation and bacterial secondary production. The sediments of the Adriatic Sea were characterised by high concentrations of phytopigments (0.6 to 13.9 μg g−1 for chlorophyll a and 1.2 to 17.7 μg g−1 for phaeopigments) and biopolymeric organic carbon (0.15 to 3.02 mg g−1). The plume system extended for a large sector of the northern Adriatic. In the northern area, a large and highly dynamic plume area was coupled with a sediment organic matter concentration significantly higher than in open-sea sediments. In the southern sector, where the plume area and the front line did not change markedly during the year, plume–benthic coupling was evident only in the sediments beneath the front, and corresponded to phaeopigment accumulation. Bacterial parameters and secondary production were high and significantly higher in the frontal area than at open-sea stations. Meiofauna density (1342 to 8541 ind. 10 cm−2) did not change either by season or between areas and was significantly correlated with phaeopigments and bacterial secondary production. Meiofauna displayed different responses to plume inputs in the two sampling areas. In the northern sector, Meiofauna density was coupled with organic matter distribution and displayed highest values beneath the plume. In the southern sector, the densities of copepods, turbellarians and kinorhynchs displayed highest values under the front in summer, and the same applied to total Meiofauna density in winter. Juvenile decapods and copepod nauplii significantly increased their densities in sediments beneath the front. Data presented in the present study suggest that plume inputs and frontal systems, enhancing phytodetritus accumulation and benthic bacterial response, might influence density, composition and distribution of Meiofaunal assemblages. As river plumes are highly variable systems affecting the trophic characteristics of the sediments underneath, their dynamics should be considered when analysing mesoscale spatial changes of Meiofaunal assemblages.
Walter Traunspurger - One of the best experts on this subject based on the ideXlab platform.
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Preface: Patterns and processes of Meiofauna in freshwater ecosystems
Hydrobiologia, 2020Co-Authors: Nabil Majdi, Jenny M. Schmid-araya, Walter TraunspurgerAbstract:Never heard of harpacticoids, ostracods, gastrotrichs or microturbellarians? This is no surprise, they are so tiny! Yet these taxa and many others more famous (nematodes, rotifers, or tardigrades) show complex behaviours and extraordinary physiologies that allow them to colonize inland waters worldwide. This exuberant fauna is better known as the Meiofauna (or meiobenthos). Meiofaunal organisms have been fascinating study objects for zoologists since the seventeenth century and recent research has demonstrated their intermediate role in benthic food webs. This special issue highlights how Meiofauna can help freshwater ecologists to describe and predict species distribution patterns, to assess production of biomass and trait functions relationships, as well as to examine the trophic links between microscopic and macroscopic worlds and to better understand species’ resilience to environmental extremes. Overall, Meiofaunal organisms are bridging scales, and as such they deserve better integration to develop more comprehensive concepts and theories in ecology.
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Biomass and production of freshwater Meiofauna: a review and a new allometric model
Hydrobiologia, 2020Co-Authors: Jenny M. Schmid-araya, Peter E. Schmid, Nabil Majdi, Walter TraunspurgerAbstract:Freshwater Meiofauna occupies a central role in stream food webs, not always as intermediary but also as top consumers. Consequently, the Meiofauna’s transient dynamical patterns and turnover are vital to understand its contribution to the overall production and energy flow within benthic freshwater systems. Here, we revise the current methodological procedures used to estimate production in benthic Meiofauna, and compare their biomass and production data (a) to other benthic taxa, (b) in different habitats and systems, and (c) at the species level. Given the phyla diversity and when including temporary Meiofauna (i.e. small insect larvae), care must be taken in selecting a production method and/or relying on published generation times. A handful of studies demonstrate that Meiofaunal production values are well within the range displayed by macrofauna. We show that temperature-adjusted production and biomass of Meiofaunal species from lakes, wetlands, and streams display a positive linear relationship with an exponent around 0.9, whereby biomass explains 90% of the variation in production. Further studies on Meiofauna production should test the validity of our proposed allometric model for stream ecosystems and, thus, its possible generality.
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Are Meiofauna a standard meal for macroinvertebrates and juvenile fish?
Hydrobiologia, 2020Co-Authors: Christoph Ptatscheck, Sebastian Weber, Henrike Brüchner-hüttemann, Bianca Kreuzinger-janik, Walter TraunspurgerAbstract:Due to the lack of empirical data, Meiofauna are often underestimated as prey for freshwater animals and are commonly regarded as trophic dead ends. Here we present a synthesis of recent evidence showing that Meiofauna are significant as prey, not only for many benthic macroinvertebrates (chironomids, shrimps, and flatworms) but also for juveniles of widespread freshwater bottom-feeding fish species (e.g., carps, gudgeons, catfish). In this review, we focus on the following questions: (1) Which groups consume Meiofauna? (2) In what amounts are Meiofauna ingested? (3) Does predatory feeding behavior influence natural Meiofaunal communities? (4) Are Meiofauna organisms actively ingested or are they bycatch? To answer these questions, we focused on studies that included gut/feces analyses of potential predators and empirical investigations conducted in the laboratory (e.g., functional response experiments and microcosm studies) and in the field (enclosure/exclosure settings). We were able to demonstrate that Meiofauna taxa are consumed in high numbers by a wide range of larger organisms. This predation can significantly shape Meiofaunal communities, by reducing the abundance, biomass, and production of certain members of the investigated assemblages. However, in most cases, it remains unclear if there is an active predation of Meiofauna or a passive ingestion by unselective feeding.
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Examining the diet of Meiofauna: a critical review of methodologies
Hydrobiologia, 2019Co-Authors: Nabil Majdi, Jenny M. Schmid-araya, Walter TraunspurgerAbstract:Meiofaunal organisms are diverse, and so is their diet comprising bacteria, fungi, micro-algae, flagellates, ciliates, and other Meiofauna. Studies have inferred diet from correlative evidences, observations of feeding or gut contents. Incubation experiments have also helped to link Meiofauna’s role to microbially mediated ecosystem processes, reporting in most cases beneficial effects on microbial activity. Nevertheless, our knowledge of Meiofauna’s trophic ecology still lags far behind that of other aquatic fauna (i.e. zooplankton, macroinvertebrates, vertebrates), probably because the small-size and the cryptic nature of the Meiofauna becomes an issue when it comes to detect their isotopic or lipid composition. Here, we provide a critical review of diverse methodologies used while examining Meiofaunal diets. Observation of feeding, incubation experiments, gut content analyses, calorimetry, stable isotopic and fatty acid analyses are very helpful and some modifications of standard materials and methods can help reduce the time-consuming sorting of individuals. Other analytic tools used by microbial ecologists like compound-specific stable isotopic analysis, DNA-stable isotopic probing, confocal laser scanning microscopy, coherent anti-stokes Raman spectrometry and nanoscale secondary ion mass spectrometry have the potential to unravel hidden trophic channels between Meiofauna and microbes.
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Influence of the ornamental red cherry shrimp Neocaridina davidi (Bouvier, 1904) on freshwater Meiofaunal assemblages
Limnologica, 2016Co-Authors: Sebastian Weber, Walter TraunspurgerAbstract:Abstract Meiofauna serves as a link between microbial production and higher trophic levels, such as macroinvertebrates and juvenile fish. However, the role of Meiofauna in the freshwater food web has not been accurately evaluated, and the influence of shrimp predation on freshwater Meiofaunal assemblages is unknown. In this study, the predation effects of Neocaridina davidi , an ornamental freshwater shrimp native to inland water bodies in Asia, on Meiofaunal density, biomass, structure, and secondary production were examined using model ecosystems (microcosms) that were sampled repeatedly over 42 days. Shrimp predation altered the structure of the Meiofaunal community over the course of the experiment, in particular the density, biomass, and secondary production of nematodes, microcrustaceans, and oligochaetes. An analysis of the stomach contents of N. davidi indicated a high degree of omnivory and the frequent consumption of Meiofaunal organisms. The results indicated that predation by the freshwater shrimp N. davidi depresses the overall abundance, biomass, and secondary production of Meiofaunal assemblages. Moreover, they also provide insights into food-web ecology and the first evidence of freshwater shrimp predation on Meiofaunal assemblages.
Roberto Danovaro - One of the best experts on this subject based on the ideXlab platform.
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biodiversity loss and turnover in alternative states in the mediterranean sea a case study on Meiofauna
Scientific Reports, 2016Co-Authors: Silvia Bianchelli, Roberto Danovaro, Emanuela Buschi, Antonio PuscedduAbstract:In the Mediterranean Sea hard-bottom macroalgal meadows may switch to alternative and less-productive barrens grounds, as a result of sea urchins overgrazing. Meiofauna (and especially nematodes) represent key components of benthic ecosystems, are highly-diversified, sensitive to environmental change and anthropogenic impacts, but, so-far, have been neglected in studies on regime shifts. We report here that sedimentary organic matter contents, Meiofaunal taxa richness and community composition, nematode α- and β-biodiversity vary significantly between alternative macroalgal and barren states. The observed differences are consistent in six areas spread across the Mediterranean Sea, irrespective of barren extent. Our results suggest also that the low biodiversity levels in barren states are the result of habitat loss/fragmentation, which is associated also with a lower availability of trophic resources. Furthermore, differences in Meiofaunal and nematode abundance, biomass and diversity between macroalgal meadow and barren states persist when the latter is not fully formed, or consists of patches interspersed in macroalgal meadows. Since barren grounds are expanding rapidly along the Mediterranean Sea and Meiofauna are a key trophic component in marine ecosystems, we suggest that the extension and persistence of barrens at the expenses of macroalgal meadows could also affect resilience of higher trophic level.
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Meiofauna assemblages of the Condor Seamount (North-East Atlantic Ocean) and adjacent deep-sea sediments
Deep Sea Research Part II: Topical Studies in Oceanography, 2013Co-Authors: Daniela Zeppilli, Lucia Bongiorni, Antonio Cattaneo, Roberto Danovaro, Ricardo Serrao SantosAbstract:Seamounts are currently considered hotspots of biodiversity and biomass for macro- and megabenthic taxa, but knowledge of Meiofauna is still limited. Studies have revealed the existence of highly diverse Meiofauna assemblages; however most data are mainly qualitative or focused only on specific groups, thus preventing comparisons among seamounts and with other deep-sea areas. This study, conducted on Condor Seamount (Azores, North-East Atlantic Ocean), describes variation in abundance, biomass, community structure and biodiversity of benthic Meiofauna from five sites located on the Condor Seamount: and one site away from the seamount. While the summit of the seamount hosted the highest alpha biodiversity, the flanks and the bases showed a rich Meiofauna assemblage in terms of abundance and biomass. The observed marked differences in grain size composition of sediments reflected the oceanographic conditions impacting different sectors of the Condor seamount, and could play an important role in the spatial distribution of different Meiofaunal taxa. Trophic conditions (biochemical composition of organic matter) explained 78% of the variability in the Meiofauna biomass pattern while sediment grain influenced the vertical distribution of Meiofauna and only partially explained Meiofaunal taxa composition. This study provides a further advancement in the knowledge of Meiofaunal communities of seamounts. Only a deeper understanding of the whole benthic communities (including Meiofauna) will allow to elaborate effective management and conservation tools for seamount ecosystems.
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fish farm impact on metazoan Meiofauna in the mediterranean sea analysis of regional vs habitat effects
Marine Environmental Research, 2010Co-Authors: Simone Mirto, Cristina Gambi, Silvia Bianchelli, Maja Krzelj, Antonio Pusceddu, Mariaspina Scopa, Marianne Holmer, Roberto DanovaroAbstract:The worldwide exponential growth of off-shore mariculture is raising severe concerns about the impacts of this industry on marine habitats and their biodiversity. We investigated the metazoan Meiofaunal response to fish-farm impact in four regions of the Mediterranean Sea. Meiofaunal assemblages were investigated in two habitats (seagrass meadows of Posidonia oceanica and non-vegetated soft bottoms) comparing sites receiving faeces and uneaten food pellets from fish farms to control sites. We report here that, consistently across different regions, the Meiofaunal abundance typically responded positively to fish-farm effluents. Biodeposition caused also significant changes in assemblage structure and the reduction in the richness of higher Meiofaunal taxa, but the multivariate analysis of variance revealed that the effects were region- and habitat-specific. In non-vegetated systems, three of the four regions investigated displayed significant effects of the fish farms on richness of Meiofaunal taxa. In vegetated habitats, Meiofauna did not respond to biodeposition (except in one region), suggesting that seagrass meadows can mask the effects of fish-farm effluents on benthic biodiversity. We conclude that different indicators of fish-farm impact are needed in vegetated and non-vegetated benthic systems.
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Fish-farm impact on metazoan Meiofauna in the Mediterranean Sea: analysis of regional vs. habitat effects
Marine Environmental Research, 2009Co-Authors: Simone Mirto, Cristina Gambi, Silvia Bianchelli, Maja Krzelj, Antonio Pusceddu, Mariaspina Scopa, Marianne Holmer, Roberto DanovaroAbstract:The worldwide exponential growth of off-shore mariculture is raising severe concerns about the impacts of this industry on marine habitats and their biodiversity. We investigated the metazoan Meiofaunal response to fish farm impact in four regions of the Mediterranean Sea. Meiofaunal assemblages were investigated in two habitats (seagrass meadows of and non-vegetated soft bottoms) comparing sites receiving faeces and uneaten food pellets from fish farms to control sites. We report here that, consistently across different regions, the Meiofaunal abundance typically responded positively to fish-farm effluents. Biodeposition caused also significant changes in assemblage structure and the reduction in the richness of higher Meiofaunal taxa, but the multivariate analysis of variance revealed that the effects were region- and habitat- specific. In non-vegetated systems, three of the four regions investigated displayed significant effects of the fish farms on richness of Meiofaunal taxa. In vegetated habitats, Meiofauna did not respond to biodeposition (except in one region), suggesting that seagrass meadows can mask the effects of fish-farm effluents on benthic biodiversity. We conclude that different indicators of fish-farm impact are needed in vegetated and non-vegetated benthic systems.
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influence of artificial reefs on the surrounding infauna analysis of Meiofauna
Journal of Materials Science, 2002Co-Authors: Roberto Danovaro, Cristina Gambi, Antonio Mazzola, Simone MirtoAbstract:We adopted a bottom-up approach in studying the effect of two artificial reefs in contrasting environmental conditions (sandy-mud and meso-eutrophic in the Adriatic Sea versus coarse sands and oligotrophic in the Tyrrhenian Sea) on the surrounding environment by assessing changes in the Meiofauna. The spatial distribution of Meiofaunal assemblages was established along a transect running from within each reef to well outside its direct sphere of influence, along with information on the trophic conditions of sediments (chloropigments, proteins, carbohydrates, and total organic matter). Although total densities were significantly higher in the Adriatic than in the Tyrrhenian, the Meiofauna displayed a similar spatial distribution at the two sites, with highest densities being reached between 2 and 20 m away from the reef area and lowest densities among the reef blocks. This pattern corresponded largely with variations in grain size and oxygen penetration in the sediment. Total densities inside the reef areas were significantly lower than at the control station 50 m from the reef, suggesting that processes influencing Meiofaunal assemblages largely reflect the interaction between reef and surrounding soft sediments, independently of differences in latitude, sediment texture, and trophic conditions. The results indicate that the proximity of artificial structures altered the composition of Meiofaunal assemblages significantly, with potentially important implications for their role in secondary production and energy transfer to higher trophic levels. 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd.
Cristina Gambi - One of the best experts on this subject based on the ideXlab platform.
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fish farm impact on metazoan Meiofauna in the mediterranean sea analysis of regional vs habitat effects
Marine Environmental Research, 2010Co-Authors: Simone Mirto, Cristina Gambi, Silvia Bianchelli, Maja Krzelj, Antonio Pusceddu, Mariaspina Scopa, Marianne Holmer, Roberto DanovaroAbstract:The worldwide exponential growth of off-shore mariculture is raising severe concerns about the impacts of this industry on marine habitats and their biodiversity. We investigated the metazoan Meiofaunal response to fish-farm impact in four regions of the Mediterranean Sea. Meiofaunal assemblages were investigated in two habitats (seagrass meadows of Posidonia oceanica and non-vegetated soft bottoms) comparing sites receiving faeces and uneaten food pellets from fish farms to control sites. We report here that, consistently across different regions, the Meiofaunal abundance typically responded positively to fish-farm effluents. Biodeposition caused also significant changes in assemblage structure and the reduction in the richness of higher Meiofaunal taxa, but the multivariate analysis of variance revealed that the effects were region- and habitat-specific. In non-vegetated systems, three of the four regions investigated displayed significant effects of the fish farms on richness of Meiofaunal taxa. In vegetated habitats, Meiofauna did not respond to biodeposition (except in one region), suggesting that seagrass meadows can mask the effects of fish-farm effluents on benthic biodiversity. We conclude that different indicators of fish-farm impact are needed in vegetated and non-vegetated benthic systems.
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Fish-farm impact on metazoan Meiofauna in the Mediterranean Sea: analysis of regional vs. habitat effects
Marine Environmental Research, 2009Co-Authors: Simone Mirto, Cristina Gambi, Silvia Bianchelli, Maja Krzelj, Antonio Pusceddu, Mariaspina Scopa, Marianne Holmer, Roberto DanovaroAbstract:The worldwide exponential growth of off-shore mariculture is raising severe concerns about the impacts of this industry on marine habitats and their biodiversity. We investigated the metazoan Meiofaunal response to fish farm impact in four regions of the Mediterranean Sea. Meiofaunal assemblages were investigated in two habitats (seagrass meadows of and non-vegetated soft bottoms) comparing sites receiving faeces and uneaten food pellets from fish farms to control sites. We report here that, consistently across different regions, the Meiofaunal abundance typically responded positively to fish-farm effluents. Biodeposition caused also significant changes in assemblage structure and the reduction in the richness of higher Meiofaunal taxa, but the multivariate analysis of variance revealed that the effects were region- and habitat- specific. In non-vegetated systems, three of the four regions investigated displayed significant effects of the fish farms on richness of Meiofaunal taxa. In vegetated habitats, Meiofauna did not respond to biodeposition (except in one region), suggesting that seagrass meadows can mask the effects of fish-farm effluents on benthic biodiversity. We conclude that different indicators of fish-farm impact are needed in vegetated and non-vegetated benthic systems.
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structural and functional response of Meiofauna rocky assemblages to sewage pollution
Marine Pollution Bulletin, 2006Co-Authors: Simonetta Fraschetti, Cristina Gambi, Adriana Giangrande, Luigi Musco, Antonio Terlizzi, R DanovaroAbstract:Despite Meiofauna being one of the most popular tool for detecting the ecological effects of different sources of impact, the application of structured experimental designs to this benthic component is typically neglected, especially in subtidal rocky shores. In this study, an asymmetrical design was used to detect hard-bottom Meiofaunal abundance and biodiversity response to sewage discharge. Sampling was carried out at a depth of 3-4 m by SCUBA diving, by means of a modified manual corer. Six replicate cores were collected at three sites (80-100 m apart), at each of three locations (one purportedly impacted [I] and two controls [Cs]). A total of 84,994 specimens were collected. The outfall affected Meiofaunal assemblages in terms of taxon richness, by determining a significant reduction of the number of taxa in the disturbed location, and community structure, by causing functional changes in terms of a decrease of the abundance of nematodes and an increase of the hydrozoan component. Nematodes and syllid polychaetes showed significant lower average abundance at I. Multivariate analyses showed that both Meiofaunal assemblage and syllids were significantly different at I compared with Cs. The sewage outfall also affected patterns of spatial distribution at the scale of site (100 m apart) and of replicate units (centimetres apart), both in syllids and in nematodes. Our results provide evidence that the selection of multiple controls is crucial to prevent the widespread risk of Type II error, highlighting the need of more accurate experimental designs when dealing with Meiofauna.
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influence of artificial reefs on the surrounding infauna analysis of Meiofauna
Journal of Materials Science, 2002Co-Authors: Roberto Danovaro, Cristina Gambi, Antonio Mazzola, Simone MirtoAbstract:We adopted a bottom-up approach in studying the effect of two artificial reefs in contrasting environmental conditions (sandy-mud and meso-eutrophic in the Adriatic Sea versus coarse sands and oligotrophic in the Tyrrhenian Sea) on the surrounding environment by assessing changes in the Meiofauna. The spatial distribution of Meiofaunal assemblages was established along a transect running from within each reef to well outside its direct sphere of influence, along with information on the trophic conditions of sediments (chloropigments, proteins, carbohydrates, and total organic matter). Although total densities were significantly higher in the Adriatic than in the Tyrrhenian, the Meiofauna displayed a similar spatial distribution at the two sites, with highest densities being reached between 2 and 20 m away from the reef area and lowest densities among the reef blocks. This pattern corresponded largely with variations in grain size and oxygen penetration in the sediment. Total densities inside the reef areas were significantly lower than at the control station 50 m from the reef, suggesting that processes influencing Meiofaunal assemblages largely reflect the interaction between reef and surrounding soft sediments, independently of differences in latitude, sediment texture, and trophic conditions. The results indicate that the proximity of artificial structures altered the composition of Meiofaunal assemblages significantly, with potentially important implications for their role in secondary production and energy transfer to higher trophic levels. 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd.
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Meiofauna response to a dynamic river plume front
Marine Biology, 2000Co-Authors: R Danovaro, Cristina Gambi, Elena Manini, Mauro FabianoAbstract:The benthic response to a plume front was studied in two areas of the northern Adriatic (Mediterranean Sea) differently influenced by the Po River freshwater input. Sediment samples were collected in June 1996 and February 1997 from 12 stations. The adopted sampling strategy was able to identify the front line in real time by satellite images and to locate sampling stations along an inner–outer plume gradient in order to cover the benthic area beneath the river plume, where enhanced biological production was expected, and open-sea sediments not directly influenced by freshwater inputs. Meiofaunal parameters were compared to the physical conditions and to phytodetritus inputs, organic matter accumulation and bacterial secondary production. The sediments of the Adriatic Sea were characterised by high concentrations of phytopigments (0.6 to 13.9 μg g−1 for chlorophyll a and 1.2 to 17.7 μg g−1 for phaeopigments) and biopolymeric organic carbon (0.15 to 3.02 mg g−1). The plume system extended for a large sector of the northern Adriatic. In the northern area, a large and highly dynamic plume area was coupled with a sediment organic matter concentration significantly higher than in open-sea sediments. In the southern sector, where the plume area and the front line did not change markedly during the year, plume–benthic coupling was evident only in the sediments beneath the front, and corresponded to phaeopigment accumulation. Bacterial parameters and secondary production were high and significantly higher in the frontal area than at open-sea stations. Meiofauna density (1342 to 8541 ind. 10 cm−2) did not change either by season or between areas and was significantly correlated with phaeopigments and bacterial secondary production. Meiofauna displayed different responses to plume inputs in the two sampling areas. In the northern sector, Meiofauna density was coupled with organic matter distribution and displayed highest values beneath the plume. In the southern sector, the densities of copepods, turbellarians and kinorhynchs displayed highest values under the front in summer, and the same applied to total Meiofauna density in winter. Juvenile decapods and copepod nauplii significantly increased their densities in sediments beneath the front. Data presented in the present study suggest that plume inputs and frontal systems, enhancing phytodetritus accumulation and benthic bacterial response, might influence density, composition and distribution of Meiofaunal assemblages. As river plumes are highly variable systems affecting the trophic characteristics of the sediments underneath, their dynamics should be considered when analysing mesoscale spatial changes of Meiofaunal assemblages.
Simone Mirto - One of the best experts on this subject based on the ideXlab platform.
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influence of environmental factors and biogenic habitats on intertidal Meiofauna
Hydrobiologia, 2018Co-Authors: Francesca Ape, Gianluca Sara, Laura Airoldi, Francesco Paolo Mancuso, Simone MirtoAbstract:This study investigated the influence of physical and chemical conditions and biotic factors on the distribution and diversity of Meiofauna in intertidal zone along a geographical gradient. At 11 sites along the Italian coast, we studied the concurring role of environmental variables, trophic resources and the presence of habitat-forming species (macroalgae vs. mussels) in controlling the Meiofaunal communities. The increase of water temperature combined with local thermal conditions was associated with a decrease in nematodes and copepods, with a consequent decrease in Meiofaunal abundance towards the south. However, the increase in salinity, as geographical gradient decreases, and local thermal conditions favoured the settlement of a greater number of taxa, influencing communities’ composition. The presence of macroalgae or mussels differently influenced the community structure of Meiofauna on intertidal substrates and their response to environmental factors. From our results, the presence of macroalgae coverage appeared to reduce the impact of thermal stress on Meiofauna and was associated with higher levels of Meiofaunal diversity with respect to mussels. This work highlighted the importance of considering the interplay among biotic and abiotic factors, resulting in local combinations of environmental conditions, in order to understand the pattern of diversity and distributions of marine organisms.
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fish farm impact on metazoan Meiofauna in the mediterranean sea analysis of regional vs habitat effects
Marine Environmental Research, 2010Co-Authors: Simone Mirto, Cristina Gambi, Silvia Bianchelli, Maja Krzelj, Antonio Pusceddu, Mariaspina Scopa, Marianne Holmer, Roberto DanovaroAbstract:The worldwide exponential growth of off-shore mariculture is raising severe concerns about the impacts of this industry on marine habitats and their biodiversity. We investigated the metazoan Meiofaunal response to fish-farm impact in four regions of the Mediterranean Sea. Meiofaunal assemblages were investigated in two habitats (seagrass meadows of Posidonia oceanica and non-vegetated soft bottoms) comparing sites receiving faeces and uneaten food pellets from fish farms to control sites. We report here that, consistently across different regions, the Meiofaunal abundance typically responded positively to fish-farm effluents. Biodeposition caused also significant changes in assemblage structure and the reduction in the richness of higher Meiofaunal taxa, but the multivariate analysis of variance revealed that the effects were region- and habitat-specific. In non-vegetated systems, three of the four regions investigated displayed significant effects of the fish farms on richness of Meiofaunal taxa. In vegetated habitats, Meiofauna did not respond to biodeposition (except in one region), suggesting that seagrass meadows can mask the effects of fish-farm effluents on benthic biodiversity. We conclude that different indicators of fish-farm impact are needed in vegetated and non-vegetated benthic systems.
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Fish-farm impact on metazoan Meiofauna in the Mediterranean Sea: analysis of regional vs. habitat effects
Marine Environmental Research, 2009Co-Authors: Simone Mirto, Cristina Gambi, Silvia Bianchelli, Maja Krzelj, Antonio Pusceddu, Mariaspina Scopa, Marianne Holmer, Roberto DanovaroAbstract:The worldwide exponential growth of off-shore mariculture is raising severe concerns about the impacts of this industry on marine habitats and their biodiversity. We investigated the metazoan Meiofaunal response to fish farm impact in four regions of the Mediterranean Sea. Meiofaunal assemblages were investigated in two habitats (seagrass meadows of and non-vegetated soft bottoms) comparing sites receiving faeces and uneaten food pellets from fish farms to control sites. We report here that, consistently across different regions, the Meiofaunal abundance typically responded positively to fish-farm effluents. Biodeposition caused also significant changes in assemblage structure and the reduction in the richness of higher Meiofaunal taxa, but the multivariate analysis of variance revealed that the effects were region- and habitat- specific. In non-vegetated systems, three of the four regions investigated displayed significant effects of the fish farms on richness of Meiofaunal taxa. In vegetated habitats, Meiofauna did not respond to biodeposition (except in one region), suggesting that seagrass meadows can mask the effects of fish-farm effluents on benthic biodiversity. We conclude that different indicators of fish-farm impact are needed in vegetated and non-vegetated benthic systems.
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influence of artificial reefs on the surrounding infauna analysis of Meiofauna
Journal of Materials Science, 2002Co-Authors: Roberto Danovaro, Cristina Gambi, Antonio Mazzola, Simone MirtoAbstract:We adopted a bottom-up approach in studying the effect of two artificial reefs in contrasting environmental conditions (sandy-mud and meso-eutrophic in the Adriatic Sea versus coarse sands and oligotrophic in the Tyrrhenian Sea) on the surrounding environment by assessing changes in the Meiofauna. The spatial distribution of Meiofaunal assemblages was established along a transect running from within each reef to well outside its direct sphere of influence, along with information on the trophic conditions of sediments (chloropigments, proteins, carbohydrates, and total organic matter). Although total densities were significantly higher in the Adriatic than in the Tyrrhenian, the Meiofauna displayed a similar spatial distribution at the two sites, with highest densities being reached between 2 and 20 m away from the reef area and lowest densities among the reef blocks. This pattern corresponded largely with variations in grain size and oxygen penetration in the sediment. Total densities inside the reef areas were significantly lower than at the control station 50 m from the reef, suggesting that processes influencing Meiofaunal assemblages largely reflect the interaction between reef and surrounding soft sediments, independently of differences in latitude, sediment texture, and trophic conditions. The results indicate that the proximity of artificial structures altered the composition of Meiofaunal assemblages significantly, with potentially important implications for their role in secondary production and energy transfer to higher trophic levels. 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd.
