The paper shows the changes in the dates (complete freeze-up, ±5 days/°C and complete ice clearance, ±3 days/°C) of the ice regime in Lake Onego depending on changes in average air temperature within the preceding two-month periods (autumn and spring). The regression equations for their calculation based on previous three- and four-month periods according to the 2000-2018 data are also provided. Indicative dates of ice regime based on accumulated air temperatures within the ice period of Lake Onego were also established (early formation of ice phenomena, complete freeze-up phase, beginning of the break-up phase and complete ice clearance). Together with the data on expected air temperature above the lake’s surface, these dependencies enable us to predict the indicative dates of the ice regime.
{"title":"Variations of indicative dates of ice regime on Lake Onego based on ground air temperature","authors":"V. Baklagin","doi":"10.4081/AIOL.2019.8198","DOIUrl":"https://doi.org/10.4081/AIOL.2019.8198","url":null,"abstract":"The paper shows the changes in the dates (complete freeze-up, ±5 days/°C and complete ice clearance, ±3 days/°C) of the ice regime in Lake Onego depending on changes in average air temperature within the preceding two-month periods (autumn and spring). The regression equations for their calculation based on previous three- and four-month periods according to the 2000-2018 data are also provided. Indicative dates of ice regime based on accumulated air temperatures within the ice period of Lake Onego were also established (early formation of ice phenomena, complete freeze-up phase, beginning of the break-up phase and complete ice clearance). Together with the data on expected air temperature above the lake’s surface, these dependencies enable us to predict the indicative dates of the ice regime.","PeriodicalId":37306,"journal":{"name":"Advances in Oceanography and Limnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4081/AIOL.2019.8198","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47509644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microbial degradation of high molecular weight organic matter in the marine environment is dependent on the synthesis and activity of hydrolytic exoenzymes. These can be found both associated to the cell (i.e., attached to cell-wall or in the periplasmic space) and cell-free, dissolved in the surrounding waters. Recent evidences suggest that exoenzymes location is linked to different foraging strategies. ‘Selfish’ bacteria use cell-bound enzymes to obtain large oligomers which are then further degraded in the confined periplasmic space, whereas cell-free enzymes are thought to be advantageous for particle-attached prokaryotes, consequently ‘sharing’ the hydrolysis product with other members of the degrading consortium. We examined whether different bacterial isolates exhibit different exoenzymatic activity profiles when exposed to different growth condition. Seven bacterial strains, isolated from the Ross Sea, were screened for the production of β-glucosidase, alkaline-phosphatase, lipase, chitinase and leucine aminopeptidase, assaying the hydrolysis rates of both cell-bound and cell-free exoenzymatic fractions. Furthermore, to test whether bacteria growing on particles are more prone to produce cell-free exoenzymes, we set up a controlled experiment, amending one of the bacterial isolates with phytodetritus, in order to promote the colonization of aggregates. Cell specific hydrolytic rates were highly variable and different isolates expressed different dominant hydrolytic activities. These results demonstrate a specialization for different substrates in different bacteria, further suggesting that some of the tested isolates may have an intrinsic potential to copiously produce cell-free exoenzymes. Moreover, our results suggest that this specialization is not strictly genetically determined but varies according to growth conditions. The experiment performed with phytodetrital particles highlighted an increasing contribution of the dissolved exoenzymatic activity in samples bearing aggregates and associated bacteria. Also, the tested isolate further modulated its hydrolytic machinery, expressing a different enzymatic profile when exposed to phytodetrital particles. The continuation of these experimental activities, testing the response of different bacterial isolates to different substrates, will help to determine the conditions under which different hydrolysis patterns develop, deepening the current knowledge on the organic matter cycling in the ocean.
{"title":"Modulation of hydrolytic profiles of cell-bound and cell-free exoenzymes in Antarctic marine bacterial isolates","authors":"V. Manna, P. Negro, M. Celussi","doi":"10.4081/AIOL.2019.8240","DOIUrl":"https://doi.org/10.4081/AIOL.2019.8240","url":null,"abstract":"Microbial degradation of high molecular weight organic matter in the marine environment is dependent on the synthesis and activity of hydrolytic exoenzymes. These can be found both associated to the cell (i.e., attached to cell-wall or in the periplasmic space) and cell-free, dissolved in the surrounding waters. Recent evidences suggest that exoenzymes location is linked to different foraging strategies. ‘Selfish’ bacteria use cell-bound enzymes to obtain large oligomers which are then further degraded in the confined periplasmic space, whereas cell-free enzymes are thought to be advantageous for particle-attached prokaryotes, consequently ‘sharing’ the hydrolysis product with other members of the degrading consortium. We examined whether different bacterial isolates exhibit different exoenzymatic activity profiles when exposed to different growth condition. Seven bacterial strains, isolated from the Ross Sea, were screened for the production of β-glucosidase, alkaline-phosphatase, lipase, chitinase and leucine aminopeptidase, assaying the hydrolysis rates of both cell-bound and cell-free exoenzymatic fractions. Furthermore, to test whether bacteria growing on particles are more prone to produce cell-free exoenzymes, we set up a controlled experiment, amending one of the bacterial isolates with phytodetritus, in order to promote the colonization of aggregates. Cell specific hydrolytic rates were highly variable and different isolates expressed different dominant hydrolytic activities. These results demonstrate a specialization for different substrates in different bacteria, further suggesting that some of the tested isolates may have an intrinsic potential to copiously produce cell-free exoenzymes. Moreover, our results suggest that this specialization is not strictly genetically determined but varies according to growth conditions. The experiment performed with phytodetrital particles highlighted an increasing contribution of the dissolved exoenzymatic activity in samples bearing aggregates and associated bacteria. Also, the tested isolate further modulated its hydrolytic machinery, expressing a different enzymatic profile when exposed to phytodetrital particles. The continuation of these experimental activities, testing the response of different bacterial isolates to different substrates, will help to determine the conditions under which different hydrolysis patterns develop, deepening the current knowledge on the organic matter cycling in the ocean.","PeriodicalId":37306,"journal":{"name":"Advances in Oceanography and Limnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4081/AIOL.2019.8240","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43152347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The only population of the pseudodiaptomid copepod Calanipeda aquaedulcis Kritschagin, 1873 to date reported to occur in Sicily disappeared at the beginning of the XXI century due to deep environmental changes which affected the single site (Lake Biviere di Gela) known for this species on the island. In that site C. aquaedulcis is now replaced by Copidodiaptomus numidicus (Gurney, 1909), a diaptomid copepod whose distribution has been greatly increasing since the second half of the last century. In the present note, the occurrence of C. aquaedulcis in 12 novel water bodies spread throughout Sicily is reported, and some environmental data on the sites where the species was collected are provided. Moreover, in a few sites C. aquaedulcis was found to co-occur with Copidodiaptomus numidicus. The recorded co-occurrence of these two species and the replacement of C. aquaedulcis with C. numidicus in Lake Biviere di Gela are briefly discussed.
据报道，西西里岛上唯一的假足桡足类Calanipeda aquaedulcis Kritschagin(1873年)种群在21世纪初消失，原因是深层环境变化影响了岛上已知的该物种的单一地点(Biviere di Gela湖)。在该地点，C. aquaedulcis现在被Copidodiaptomus numidicus (Gurney, 1909)所取代，这是一种自上世纪下半叶以来分布大大增加的双掌类桡足类。本文报道了在西西里岛分布的12个新水体中发现水蛭的情况，并提供了该物种采集点的一些环境数据。此外，在少数地点，还发现水浒苔与努米icus Copidodiaptomus共生。简要讨论了这两种物种在Biviere di Gela湖的共栖记录，以及在湖泊中被numidicus取代的情况。
{"title":"On the occurrence and distribution of Calanipeda aquaedulcis Kritschagin, 1873 (Copepoda, Calanoida, Pseudodiaptomidae) in Sicily, Italy, with some notes on coexistence and species replacement in calanoid copepods","authors":"L. Vecchioni, F. Marrone, Luigi Naselli-Flores","doi":"10.4081/AIOL.2019.8177","DOIUrl":"https://doi.org/10.4081/AIOL.2019.8177","url":null,"abstract":"The only population of the pseudodiaptomid copepod Calanipeda aquaedulcis Kritschagin, 1873 to date reported to occur in Sicily disappeared at the beginning of the XXI century due to deep environmental changes which affected the single site (Lake Biviere di Gela) known for this species on the island. In that site C. aquaedulcis is now replaced by Copidodiaptomus numidicus (Gurney, 1909), a diaptomid copepod whose distribution has been greatly increasing since the second half of the last century. In the present note, the occurrence of C. aquaedulcis in 12 novel water bodies spread throughout Sicily is reported, and some environmental data on the sites where the species was collected are provided. Moreover, in a few sites C. aquaedulcis was found to co-occur with Copidodiaptomus numidicus. The recorded co-occurrence of these two species and the replacement of C. aquaedulcis with C. numidicus in Lake Biviere di Gela are briefly discussed.","PeriodicalId":37306,"journal":{"name":"Advances in Oceanography and Limnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4081/AIOL.2019.8177","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42833100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sediment is the main factor that limits the reservoir lifetime. Therefore, sediment classification is an essential tool for planning and operating reservoir management measures. There has been important development in the hydroacoustic classification of lakebed, especially with linear systems. The main restrictions while using linear hydroacoustic systems for lakebed classification are the shallow penetration in high-frequency applications or the low vertical and horizontal resolution when using low frequencies. With the new developments in the area of echo sounders, parametric systems can achieve high penetration while preserving the high vertical and lateral resolution. To investigate the performance of parametric systems, a new lakebed classification approach was implemented by using a SES2000 Compact. The area studied was the Passauna reservoir in Parana State, Brazil. We used the first echo division method for processing the acoustic data combined with sediment core and grab sampling. The two physical parameters investigated, were the share of the finest fraction (<63 µm) and wet bulk density (WBD). The results showed a high correlation between the primary frequency of 100 kHz (166 µs pulse length) and the physical parameters. Additionally, a significant correlation was observed with the acoustic parameters at 10 kHz frequency. The best correlating acoustic parameter was Attack/Decay (E1´/E1). The gas presence was found to be an important factor determining the penetration depth of the parametric system and the performance of the classification. The advantages of parametric systems, such small directivity and layering effect, represent the major restrictions in sediment classification applications.
{"title":"Sediment classification in a Brazilian reservoir: Pros and cons of parametric low frequencies","authors":"Klajdi Sotiri, S. Hilgert, S. Fuchs","doi":"10.4081/AIOL.2019.7953","DOIUrl":"https://doi.org/10.4081/AIOL.2019.7953","url":null,"abstract":"Sediment is the main factor that limits the reservoir lifetime. Therefore, sediment classification is an essential tool for planning and operating reservoir management measures. There has been important development in the hydroacoustic classification of lakebed, especially with linear systems. The main restrictions while using linear hydroacoustic systems for lakebed classification are the shallow penetration in high-frequency applications or the low vertical and horizontal resolution when using low frequencies. With the new developments in the area of echo sounders, parametric systems can achieve high penetration while preserving the high vertical and lateral resolution. To investigate the performance of parametric systems, a new lakebed classification approach was implemented by using a SES2000 Compact. The area studied was the Passauna reservoir in Parana State, Brazil. We used the first echo division method for processing the acoustic data combined with sediment core and grab sampling. The two physical parameters investigated, were the share of the finest fraction (<63 µm) and wet bulk density (WBD). The results showed a high correlation between the primary frequency of 100 kHz (166 µs pulse length) and the physical parameters. Additionally, a significant correlation was observed with the acoustic parameters at 10 kHz frequency. The best correlating acoustic parameter was Attack/Decay (E1´/E1). The gas presence was found to be an important factor determining the penetration depth of the parametric system and the performance of the classification. The advantages of parametric systems, such small directivity and layering effect, represent the major restrictions in sediment classification applications.","PeriodicalId":37306,"journal":{"name":"Advances in Oceanography and Limnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4081/AIOL.2019.7953","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42258938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dr. Alvise Vittori was a well-known Italian ichthyologist, limnologist and all-round ecologist.
Alvise Vittori博士是意大利著名的鱼类学家、湖沼学家和全能生态学家。
{"title":"Remembering Alvise Vittori (Riva del Garda 1932 – Trento 2018)","authors":"G. Flaim, F. Ciutti","doi":"10.4081/AIOL.2019.8286","DOIUrl":"https://doi.org/10.4081/AIOL.2019.8286","url":null,"abstract":"Dr. Alvise Vittori was a well-known Italian ichthyologist, limnologist and all-round ecologist.","PeriodicalId":37306,"journal":{"name":"Advances in Oceanography and Limnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4081/AIOL.2019.8286","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43109979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The heavy metals/trace elements contents of sediment samples from Owalla Reservoir were analyzed every three months in two annual cycles (March 2011 – February 2013). The main aim was to measure concentrations of selected elements in sediment samples, their variations in space and seasons and the level of pollution and/or contamination. The bottom sediment samples were collected with a Van Veen Grab and the elemental analysis in the laboratory was based on air-dried samples following standard methods. The overall hierarchy of heavy metals/trace elements in the sediments of the reservoir was in the decreasing order of concentrations: Fe > Mn > As > Zn > Ni > Co > Cr > Cu > Pb > Cd. The concentrations of the heavy metals did not follow any definite pattern from the upstream-downstream basin, although most of them (Cu, Fe, Mn, Zn, and Co) showed significant differences (P<0.05) in their horizontal variations. Mn, Pb, Co, Fe, Ni, and Zn were significantly (P<0.05) higher at the open water region than in the littoral region. All the elements except Ni did not show significant seasonal variations (P>0.05). Most of the elements in the reservoir sediment have concentrations within the background levels and concentrations defined in environmental regulations and guidelines, except for As and Cd. The contamination factors (Cf) for most metals (Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) suggested low contamination in the sediments (Cf < 1.0). Conversely, the sediments were moderately contaminated with Cd (Cf = 2.41) and very highly contaminated with As (Cf = 19.33).
{"title":"The heavy metals/trace elements contents of sediments from Owalla Reservoir, Osun State, Southwest Nigeria","authors":"A. I. Aduwo, I. Adeniyi","doi":"10.4081/AIOL.2018.7576","DOIUrl":"https://doi.org/10.4081/AIOL.2018.7576","url":null,"abstract":"The heavy metals/trace elements contents of sediment samples from Owalla Reservoir were analyzed every three months in two annual cycles (March 2011 – February 2013). The main aim was to measure concentrations of selected elements in sediment samples, their variations in space and seasons and the level of pollution and/or contamination. The bottom sediment samples were collected with a Van Veen Grab and the elemental analysis in the laboratory was based on air-dried samples following standard methods. The overall hierarchy of heavy metals/trace elements in the sediments of the reservoir was in the decreasing order of concentrations: Fe > Mn > As > Zn > Ni > Co > Cr > Cu > Pb > Cd. The concentrations of the heavy metals did not follow any definite pattern from the upstream-downstream basin, although most of them (Cu, Fe, Mn, Zn, and Co) showed significant differences (P<0.05) in their horizontal variations. Mn, Pb, Co, Fe, Ni, and Zn were significantly (P<0.05) higher at the open water region than in the littoral region. All the elements except Ni did not show significant seasonal variations (P>0.05). Most of the elements in the reservoir sediment have concentrations within the background levels and concentrations defined in environmental regulations and guidelines, except for As and Cd. The contamination factors (Cf) for most metals (Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) suggested low contamination in the sediments (Cf < 1.0). Conversely, the sediments were moderately contaminated with Cd (Cf = 2.41) and very highly contaminated with As (Cf = 19.33).","PeriodicalId":37306,"journal":{"name":"Advances in Oceanography and Limnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4081/AIOL.2018.7576","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45618758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Federica Rotta, L. Cerasino, A. Occhipinti‐Ambrogi, M. Rogora, R. Seppi, M. Tolotti
Glacier melting and permafrost thawing are the most evident effects of the current climate change that is strongly affecting high mountain areas, including the European Alps. As the thawing rate of subsurface ice is lower than for glacier ice, it is expected that, while glaciers retreat, an increasing number of Alpine headwaters will become more influenced by permafrost degradation during the 21st century. Despite the expected change in the relative importance of glacier and permafrost in determining Alpine hydrology, studies addressing effects of permafrost thawing on chemical and, especially, biological features of adjacent surface waters are still scarce. The present study contributes to characterise the epilithic and epiphytic diatom diversity in a set of permafrost-fed headwaters in three sub-catchments differing in bedrock lithology of the Italian Central Alps (Trentino Alto-Adige) in relation to water chemistry and habitat features. In addition, it explores chemical and biological differences between permafrost-fed streams and headwaters with no direct contact to permafrost, namely glacier-fed (kryal) and precipitation-/groundwater-fed (rhithral) streams. Permafrost-fed waters showed higher electrical conductivity and enhanced ion concentrations than glacier- and precipitation-fed waters, while concentration of trace elements (e.g. Sr, Ni, Zn, As) were more irregularly distributed among waters of different origin, though they showed a tendency to reach higher levels in permafrost-fed waters. Diatom species richness and diversity were lower in permafrost-fed headwaters, and were principally related to water pH and trace metal concentrations. Epiphytic diatom assemblages were more diverse than epilithic ones, independently from the water origin, while differences in species composition were not sufficient to unequivocally identify a typical diatom composition for the different water types considered in this study.
{"title":"Diatom diversity in headwaters influenced by permafrost thawing: First evidence from the Central Italian Alps","authors":"Federica Rotta, L. Cerasino, A. Occhipinti‐Ambrogi, M. Rogora, R. Seppi, M. Tolotti","doi":"10.4081/AIOL.2018.7929","DOIUrl":"https://doi.org/10.4081/AIOL.2018.7929","url":null,"abstract":"Glacier melting and permafrost thawing are the most evident effects of the current climate change that is strongly affecting high mountain areas, including the European Alps. As the thawing rate of subsurface ice is lower than for glacier ice, it is expected that, while glaciers retreat, an increasing number of Alpine headwaters will become more influenced by permafrost degradation during the 21st century. Despite the expected change in the relative importance of glacier and permafrost in determining Alpine hydrology, studies addressing effects of permafrost thawing on chemical and, especially, biological features of adjacent surface waters are still scarce. The present study contributes to characterise the epilithic and epiphytic diatom diversity in a set of permafrost-fed headwaters in three sub-catchments differing in bedrock lithology of the Italian Central Alps (Trentino Alto-Adige) in relation to water chemistry and habitat features. In addition, it explores chemical and biological differences between permafrost-fed streams and headwaters with no direct contact to permafrost, namely glacier-fed (kryal) and precipitation-/groundwater-fed (rhithral) streams. Permafrost-fed waters showed higher electrical conductivity and enhanced ion concentrations than glacier- and precipitation-fed waters, while concentration of trace elements (e.g. Sr, Ni, Zn, As) were more irregularly distributed among waters of different origin, though they showed a tendency to reach higher levels in permafrost-fed waters. Diatom species richness and diversity were lower in permafrost-fed headwaters, and were principally related to water pH and trace metal concentrations. Epiphytic diatom assemblages were more diverse than epilithic ones, independently from the water origin, while differences in species composition were not sufficient to unequivocally identify a typical diatom composition for the different water types considered in this study.","PeriodicalId":37306,"journal":{"name":"Advances in Oceanography and Limnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4081/AIOL.2018.7929","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44625438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. López-Soriano, Sergio Quiñonero-Salgado, C. Cappelletti, F. Faccenda, F. Ciutti
Lake Garda, the largest Italian lake, is suffering from the introduction of several non-indigenous species during the last decades and can now be considered one of the main European freshwater hotspots of xenodiversity. Among the Bivalvia (Veneroidea, Cyrenidae), Corbicula fluminea and Corbicula fluminalis were first recorded in 2002 and 2008 respectively, and are now widespread in the southern part of the basin. Recent observation of specimens that did not resemble either of these taxa, suggested that the populations of invasive Corbicula of Lake Garda could include some other taxa not previously recorded. With this aim, a thoroughly characterization of Corbicula shells found at Lake Garda was made. By studying morphometric parameters and comparing them with specimens collected in Spain (Ebro and Ter rivers), the presence in Lake Garda of two other related species not previously recorded in Italy, namely C. leana and C. largillierti, has been confirmed. The syntopic presence of at least four species of this genus in a single environment is a singular occurrence both in Italy and Europe.
{"title":"Unraveling the complexity of Corbicula clams invasion in Lake Garda (Italy)","authors":"J. López-Soriano, Sergio Quiñonero-Salgado, C. Cappelletti, F. Faccenda, F. Ciutti","doi":"10.4081/AIOL.2018.7857","DOIUrl":"https://doi.org/10.4081/AIOL.2018.7857","url":null,"abstract":"Lake Garda, the largest Italian lake, is suffering from the introduction of several non-indigenous species during the last decades and can now be considered one of the main European freshwater hotspots of xenodiversity. Among the Bivalvia (Veneroidea, Cyrenidae), Corbicula fluminea and Corbicula fluminalis were first recorded in 2002 and 2008 respectively, and are now widespread in the southern part of the basin. Recent observation of specimens that did not resemble either of these taxa, suggested that the populations of invasive Corbicula of Lake Garda could include some other taxa not previously recorded. With this aim, a thoroughly characterization of Corbicula shells found at Lake Garda was made. By studying morphometric parameters and comparing them with specimens collected in Spain (Ebro and Ter rivers), the presence in Lake Garda of two other related species not previously recorded in Italy, namely C. leana and C. largillierti, has been confirmed. The syntopic presence of at least four species of this genus in a single environment is a singular occurrence both in Italy and Europe.","PeriodicalId":37306,"journal":{"name":"Advances in Oceanography and Limnology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4081/AIOL.2018.7857","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41513976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Consoli, M. Mangano, G. Sarà, T. Romeo, F. Andaloro
In this work the influence of habitat complexity on fish assemblages associated with extractive platforms in the Mediterranean Sea was investigated. More specifically, at large spatial scale we tested the differences in fish assemblage between 4-legs vs 8-legs platforms, whereas at medium scale we evaluated, within each platform, the differences between internal structures with increasing complexity degrees (respectively: the water volume without any pillar - complexity “0”; the junction of two pillars - “1”; the junction of four pillars - “2”). Both univariate and multivariate analyses showed highly significant differences for each of the tested factors, as well as for their interaction. In general, at both medium and large spatial scales, mean species richness and abundance were positively correlated with the increasing habitat complexity with the highest values associated with 8-legs platforms and with the most complex internal structures within each platform. According to our findings, a more complex structure is able to attract more fish species and specimens than a less complex one, supporting previous studies carried out on different man-made structures outside the Mediterranean Sea. The study will integrate the still poor available knowledge baseline on the attractive potential of extractive platforms with strong implications for the environmental management under the incoming light of decommission in the basin.
{"title":"The influence of habitat complexity on fish assemblages associated with extractive platforms in the central Mediterranean Sea","authors":"P. Consoli, M. Mangano, G. Sarà, T. Romeo, F. Andaloro","doi":"10.4081/AIOL.2018.7918","DOIUrl":"https://doi.org/10.4081/AIOL.2018.7918","url":null,"abstract":"In this work the influence of habitat complexity on fish assemblages associated with extractive platforms in the Mediterranean Sea was investigated. More specifically, at large spatial scale we tested the differences in fish assemblage between 4-legs vs 8-legs platforms, whereas at medium scale we evaluated, within each platform, the differences between internal structures with increasing complexity degrees (respectively: the water volume without any pillar - complexity “0”; the junction of two pillars - “1”; the junction of four pillars - “2”). Both univariate and multivariate analyses showed highly significant differences for each of the tested factors, as well as for their interaction. In general, at both medium and large spatial scales, mean species richness and abundance were positively correlated with the increasing habitat complexity with the highest values associated with 8-legs platforms and with the most complex internal structures within each platform. According to our findings, a more complex structure is able to attract more fish species and specimens than a less complex one, supporting previous studies carried out on different man-made structures outside the Mediterranean Sea. The study will integrate the still poor available knowledge baseline on the attractive potential of extractive platforms with strong implications for the environmental management under the incoming light of decommission in the basin.","PeriodicalId":37306,"journal":{"name":"Advances in Oceanography and Limnology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4081/AIOL.2018.7918","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70144086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Time series of composition and fluxes of settling particles in the marine environment, obtained by sediment traps, contribute to define the main processes driving the dynamics of particulate matter and of the time/space variability of benthic-pelagic exchanges. With this aim, the composition and seasonal and annual fluxes of settling matter, obtained from different projects and from published papers, at 8 sites of the Northern Adriatic shelf were estimated. The mean yearly particulate fluxes varied from 2763 to 14,447 g m-2 y-1, from 66 to 236 gC m-2y-1 for organic carbon (OC) flux, from 861 to 7525 g m-2y-1 for carbonates and from 12 to 42 gN m-2y-1 for nitrogen (N). The fluxes were characterized by high seasonal variations with marked increase in autumn or in winter with respect to spring or summer. The sink of particles occurs in relatively short episodes as about 50% of annual particle flux settles in less than 1-2 months in the western coastal area. This seasonality can be related to the riverine discharges, primary production and wind regimes of the basin. Utilizing the N/OC ratio as an index for discriminating the different origin of organic matter (i.e., resuspended/riverine and autochthonous), the primary marine carbon flux was estimated to range from 10 to 28% of the OC fluxes and accounted for 8-40% of the primary production, depending on the site. Then, due to the shallow waters of the basin and to the relevant riverine inputs, the total fluxes near the sea bottom were highly dependent on resuspension and advective transport processes. The important contribution of these last processes as source of organic matter is suggested also by the comparison between fluxes determined by sediment traps with mass accumulation rates (MAR) in sediments, derived from radionuclide measurements. Indeed, the fraction of OC fluxes which is not buried in the sediment is sufficient to support the benthic respiration processes.
通过沉积物捕集器获得的海洋环境中沉降颗粒组成和通量的时间序列有助于确定驱动颗粒物质动态和底-上层交换的时间/空间变异性的主要过程。为此目的，从不同的项目和发表的论文中获得了北亚得里亚海陆架8个地点的沉降物的组成和季节和年通量。年平均颗粒物通量为2763 ~ 14447 g m-2y-1，有机碳(OC)通量为66 ~ 236 gC m-2y-1，碳酸盐通量为861 ~ 7525 g m-2y-1，氮(N)通量为12 ~ 42 gN m-2y-1，季节变化明显，秋季和冬季较春夏季显著增加。在西部沿海地区，每年约50%的颗粒通量在不到1-2个月的时间内沉降，颗粒汇的周期相对较短。这种季节性可能与河流排放、初级生产和盆地风力有关。利用N/OC比率作为区分不同有机质来源(即重悬浮/河流和原生)的指标，根据不同的地点，估计初级海洋碳通量占OC通量的10%至28%，占初级产量的8-40%。其次，由于盆地的浅水和相关的河流输入，海底附近的总通量高度依赖于再悬浮和平流输送过程。沉积物圈闭确定的通量与放射性核素测量得出的沉积物质量积累率(MAR)之间的比较也表明了最后这些过程作为有机质来源的重要贡献。事实上，未埋在沉积物中的部分有机碳通量足以支持底栖生物的呼吸过程。
{"title":"Fluxes of particulate matter, carbonates, organic carbon and nitrogen in the northern Adriatic continental shelf: A synthesis overview","authors":"M. Giani, J. Miquel, A. D. Lazzari, A. Boldrin","doi":"10.4081/aiol.2018.7601","DOIUrl":"https://doi.org/10.4081/aiol.2018.7601","url":null,"abstract":"Time series of composition and fluxes of settling particles in the marine environment, obtained by sediment traps, contribute to define the main processes driving the dynamics of particulate matter and of the time/space variability of benthic-pelagic exchanges. With this aim, the composition and seasonal and annual fluxes of settling matter, obtained from different projects and from published papers, at 8 sites of the Northern Adriatic shelf were estimated. The mean yearly particulate fluxes varied from 2763 to 14,447 g m-2 y-1, from 66 to 236 gC m-2y-1 for organic carbon (OC) flux, from 861 to 7525 g m-2y-1 for carbonates and from 12 to 42 gN m-2y-1 for nitrogen (N). The fluxes were characterized by high seasonal variations with marked increase in autumn or in winter with respect to spring or summer. The sink of particles occurs in relatively short episodes as about 50% of annual particle flux settles in less than 1-2 months in the western coastal area. This seasonality can be related to the riverine discharges, primary production and wind regimes of the basin. Utilizing the N/OC ratio as an index for discriminating the different origin of organic matter (i.e., resuspended/riverine and autochthonous), the primary marine carbon flux was estimated to range from 10 to 28% of the OC fluxes and accounted for 8-40% of the primary production, depending on the site. Then, due to the shallow waters of the basin and to the relevant riverine inputs, the total fluxes near the sea bottom were highly dependent on resuspension and advective transport processes. The important contribution of these last processes as source of organic matter is suggested also by the comparison between fluxes determined by sediment traps with mass accumulation rates (MAR) in sediments, derived from radionuclide measurements. Indeed, the fraction of OC fluxes which is not buried in the sediment is sufficient to support the benthic respiration processes.","PeriodicalId":37306,"journal":{"name":"Advances in Oceanography and Limnology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4081/aiol.2018.7601","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43633814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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