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Maurizio Pinna
Ruolo
Ricercatore
Organizzazione
Università del Salento
Dipartimento
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali
Area Scientifica
Area 05 - Scienze biologiche
Settore Scientifico Disciplinare
BIO/07 - Ecologia
Settore ERC 1° livello
LS - Life sciences
Settore ERC 2° livello
LS8 Evolutionary, Population and Environmental Biology: Evolution, ecology, animal behaviour, population biology, biodiversity, biogeography, marine biology, ecotoxicology, microbial ecology
Settore ERC 3° livello
LS8_1 Ecology (theoretical and experimental; population, species and community level)
Size spectra show common patterns of variation among ecosystem types, functional guilds and taxonomic groups, as well as predictable responses to pressures. Here, we extend the size spectra approach to macroinvertebrate ecological status assessment in transitional waters, by developing, testing and validating a multi-metric index of size spectra sensitivity (ISS), which integrates size structure metrics with metrics describing the sensitivity of size classes to anthropogenic disturbance and species richness measures. The ability of different theoretical models of size spectra sensitivity to discriminate between undisturbed and disturbed ecosystems and levels of environmental stress was evaluated. We have used data on benthic macroinvertebrates within 12 Mediterranean and Black Sea transitional water bodies (i.e. coastal lagoons) from Italy, Albania, Greece, Bulgaria and Romania and compared the models’ efficiency through their pressure-impact response along organic load and enrichment gradients. Data from a thirteenth Mediterranean lagoon was used for validation purposes. Asymmetric models of size class sensitivity, assuming higher sensitivity of larger body size classes, were found to be more effective than symmetric models, with higher sensitivity of less common size classes, in distinguishing undisturbed from disturbed lagoons and lagoon stations. The ISS based on the asymmetric sensitivity model that was most efficient in identifying the anthropogenic impacts also showed significant dose–response relationships along environmental parameters describing the organic load and enrichment gradients. A scheme for the classification of Ecological Quality Status based on the macroinvertebrate ISS is proposed and validated. The validation procedure found that ISS is an effective and sensitive monitoring tool, easy to apply and to inter-calibrate among laboratories. Moreover, the tests performed here over a very large ecoregional area have proved the spatial robustness of the new index.
Acquatina is a small lagoon ecosystem (0.45 km2) located on the Adriatic coast only 5 km north of Lecce (Italy). The lagoon has a freshwater input in the northern part and a connection with the sea at the south edge, being characterised by a latitudinal gradient of salinity and an internal patchiness of habitats. Here, we have used the lagoons as a model to study the influence of these sources of variation on the spatial distribution of macrobenthis and fish fauna, using both taxonomic and on taxonomic descriptors. Results showed a non random distribution of both species and functional traits of macroinvertebrate and fish fauna within the lagoon, despite the relatively small surface area. Salinity had an higher inflence than boItom habitat patchiness on both macroinvertebrates and fishes; moreover, spatial co-variance of the two guilds was observed both at the taxonomic and at the size level. As regards fishes, these patterns were common to the dominant species (Atherina Boyeri) and to the rest of the fish guild. Results emphasise that common non random distribution patterns are observed even in small lagoons and for different guilds, including vagile fauna, as fish are. It suggest the occurrence of high intra-specific and inter-specific divergence in lagoon ecosystem allowing resource use optimisation through niche specialisation, available energy partitioning and individual energy budget adaptation.
Assessing ‘natural’ variability of structural and functional components of ecosystems is a main target of MSFD, responding to the need of disentangling biological responses to anthropogenic stresses from those on which human impact is minimal. The scale and the extent of ecosystem components variability are main determinants of ecological patterns and process. Moreover, variability within ecosystems depends on both internal ecosystem dynamics and larger scale drivers and processes. Here we focus specifically on natural variability of biotic ecosystem components and ecosystem processes, which are either descriptors or parameters of relevance in the MSFD monitoring scheme. Metabolic theories have highlighted how the individual body size can be considered as a main, intrinsic driver of variation in populations and communities functional properties. Indeed, individual energetic and behaviour show body size dependent variation according to an x/4 rule. Cascading deterministic effects of individual level size-dependencies have been demonstrated on both population and community levels as well as on functional properties. In the presentation: i. We develop a conceptual analysis of the implication of body size dependencies of individual energetic and behaviour on scale and extent of natural variability in the individual, population and community parameters considered in the MSFD; ii. We present an example of phytoplankton parameter assessments with changing temporal scales of assessment in order to account for the natural variability of cell densities in the phytoplankton guilds; and iii. We infer from implications of biological parameter size dependencies on MSFD monitoring plan accounting for natural variability and derive operational proposals for adaptive monitoring plans.
The loss of species is known to have a negative effect on ecosystem functioning, but detailed mechanisms of this relationship are still far from being fully understood. Several hypotheses have been proposed in the past to explain the functional response of ecosystems to species loss, but many studies still rely on using community structure as a surrogate for ecosystem functioning. This study investigates how the spatio-temporal distribution patterns of polychaetes and their associated functional patterns in six Mediterranean coastal lagoons change under simulated scenarios of species loss. The results show that each lagoon responds differently to potential species loss: in stressed lagoons with few dominating species the change of patterns is extremely variable and unpredictable, whereas lagoons characterised by complementarity seem to be more robust towards changes. The patterns between community structure and functioning in each lagoon show strong similarities in the lagoons dominated by few species, but the patterns diverge in complementary communities. The findings highlight the importance of considering the ideosyncratic effects of species loss on ecosystem function as well as the risk of using structural patterns as surrogates for functional patterns when taking decisions at a managerial level.
Results of the PERMANOVA analysis on the differences in composition, functional organization and biological traits of macroinvertebrate assemblages in leaf-bags and Surber net samples of the River Aterno. p-values are based on 9999 permutations.
Littoral and transitional macrozoobenthic communities are characterized by a broad diversity in size and behavior. Because metabolic and geometric constraints underpin body-size scaling relationships, metabolic theory offers a useful framework to predict the numeric abundances of macrozoobenthic species. Cross Community Scaling Relationships (CCSR) expresses the relationship between the average size of an individual in an assemblage and the total number of individuals. Where resource availability or space is constant, the average amount of resource (or space) used per individual directly determines the number of individuals that can be supported. However, subsidiary factors can modulate the realized expression of metabolic/geometric scaling rules by modifying the resources accessibility/availability across the individual body size spectra. The mechanistic relevance of individual body-size on coexistence relationships still requires field and laboratory tests and community level scaling-up. Here, the influence of different physical constrains on CCSR descriptors is investigated through the analysis of a large transitional water macrozoobenthic dataset. Results show that, while the pro capite individual body size has a major role in determining the realized individual density, subsidiary physical factors can remarkably increase the accuracy of our predictions. We discuss and interpret the implications of our observations for theoretical and applied ecology.
The search for simple and effective descriptors of biological ecosystem components is a major challenge of monitoring aquatic ecosystem health. There have been discussed the relevance of body-size-related descriptors of benthic invertebrate guilds in monitoring the health of aquatic ecosystems. The rationale is that macroinvertebrate body-size relates individual responses to disturbance pressures through individual energetic, population dynamics and species coexistence responses. The mechanistic relevance of individual body-size on coexistence relationships still requires field and laboratory tests and community level scaling-up. The different proposed models of size abundance distributions offer promising approaches to scale-up and address the overall role of individual body size in community organisation. One of the relationships between body-size and abundance in ecology is the cross-community scaling relationship (CCSR), which use ecological energetics to evaluate the overall body size based responses to actors affecting energy flow in ecosystems; external perturbations and pollution are main anthropogenic-based factors acting on energy flow. Field experiments on freshwater and transitional water benthic macroinvertebrate guilds from perturbed and unperturbed ecosystems of Southern Italy (Apulia and Sardinia areas) were designed to test: i. the crosscommunity scaling relationship relevance of body-size-related constraints on the organization of detritus-based benthic guilds through the relationship between the average size of an individual in an assemblage and the total community density; ii. the sensibility of statistical CCSR descriptors to perturbed conditions, compared to unperturbed ones.
We investigated the cascading effects of chemical contaminants on alder leaf detritus quality and the exploitation of this feeding resource by benthic macroinvertebrates (isopods, gastropods, and mayfly nymphs). Trophic behavior and energetics of benthic macroinvertebrates were used to evaluate the effects of contaminants on detritus exploitation. A two-way factorial nested experimental design was used to statistically quantify how leaf detritus origin (polluted and unpolluted streams) and the pollution level of the site selected for microbial conditioning of the detritus could affect the feeding resource quality for aquatic benthic macroinvertebrates, as measured by their trophic behavior (i.e. food selection) and exploitation (i.e. food ingestion). Alder leaves collected from a polluted stream in a former mining area (South-Sardinia, Italy) had Cd, Pb, and Zn concentrations up to 10 times that of leaves collected from an unpolluted stream. When benthic macroinvertebrates were given the option to choose, they all selected leaves from the unpolluted stream and/or those conditioned in the unpolluted stream. Ingestion rates were also significantly affected by both considered factors: leaf origin and conditioning. In addition, synergistic effects strongly increased the chemical contaminant stress on the leaf detritus quality. These results show that the terrestrial component of land–water ecotones affected by mining can be a relevant indirect pathway of chemical stress to benthic macroinvertebrate species.
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.
The Marine Strategy Framework Directive (2008/56/EC) of the European Parliament and of the Council (17th June 2008) establishes a framework for community action in the field of marine environmental policy. A crucial issue will be to improve the existing marine monitoring programs to cover the MSFD requirements. The comparison and identification of gaps in the existent national monitoring is a first step to include new parameters and frequencies of observation according to all relevant Directives and specially to MSFD. Our report is a first, integrated, cross-state assessment of the present state of Mediterranean monitoring networks. Data on monitoring stations have been provided from all member states of IRIS-SES + Croatia and joint in a unique georeferenced dataset. We used the cross-classification to build contingency tables of the counts at each combination of factor levels. Distances from coastline, densities of sampling stations, spatial overlap across descriptors, were also reported. As main results, we observed a large heterogeneity across MS on the parameters measured for each descriptors, on the density of sampling stations and on the frequency of sampling. Larger gaps have been identified for the descriptors Mammals, Birds, Reptiles (D1, D4, D6), Litter (D10), Energy & Noise (D11). The outputs from this work will be included into a GIS planning tool (Activity 3) including many scales and levels on which the MSFD Directive has been built on, such as the characteristics level (e.g. biological features, physicochemical features), pressure and impact, indicator/threshold, spatial (location of monitoring stations) and temporal (frequency-periodicity) across regions-subregions-countries.
A major source of complexity in marine ecosystem monitoring is represented by the fact that ecosystem processes occurring across different spatial and temporal scales. The implementation of the monitoring strategies applied in accordance to Marine Framework Strategy Directive (MFSD, 2008/56/EC) is a step-by-step process, which should be focus on the potential of scale dependence in the observed dynamics and should be able to integrate the effect of mediating factors operating at different scale levels. Nevertheless, the correct definition of monitoring efforts for each indicator needs to reach a well-defined knowledge on the actual assessment of the “object” of monitoring including ranges of natural variability in terms of spatial and temporal natural fluctuations. Unluckily natural fluctuations are not yet well defined in marine environments for all of the MSFD indicators. For these reasons the achievement of MSFD goals could be severely affected by the lack of knowledge which led to the lack of clear and rationale criteria on the basis of which to align and cope the scale of the assessment with the ecosystem natural fluctuations. Hereby we address the design of monitoring programmes concerning water column and seabed habitats integrity indicators (Descriptors D1, D5, D6) by discussing spatial and temporal extent of monitoring based on their scales of natural variation. The multiple layer approach developed on mesoscales could allow reducing mistakes due to sampling and methodological limits and could allow reducing problems ranging within the comprehension of mechanisms to the anticipation of consequences. The opportune mesoscale is dependent on the indicator considered and range within 0.5 – 100 km for the spatial scale and from 0.2 to 12 months for the temporal scale.
Climate changes, geomorphologic modifications and the rise in water demand for human uses contribute to ‘‘aperiodic summer drought’’ (ASD) events in Mediterranean-type rivers. ASD results in a reach that flows in one summer, dries in next or more summers, and then flowing again. The ecological structure and function of streams affected by ASD are understudied, especially with respect to permanent and regular intermittent streams. We tested the drying memory in a reach of Aterno River (Italy) disturbed by ASD. Leaf litter breakdown of Phragmites australis and macroinvertebrate assemblages were studied. Discharge was monitored since 2006. The experiment was performed during summer 2010 using the litterbag technique, and was replicated four times. The disturbed site was affected by drought in the three previous summers while the control was always flowing. Taxonomic diversity indices, abundance and structure of macroinvertebrate assemblages varied significantly between sites. Instead, leaf litter breakdown wasn’t influenced by ASD. Therefore ASD events seem to affect the structure of macroinvertebrate assemblages, confirming the role of drying memory of the systems. The resilience of leaf litter breakdown in reach affected by ASD seems to be high, probably depending on the activity of selected microbial communities and macroinvertebrate features like metabolism and biomass.
The effectiveness and accuracy of biomonitoring programs, based on benthic macroinvertebrates, is strictly related to the sampling design and effort, whereas the feasibility depends on the economic sustainability of sample collection and processing methodologies. In the last decade, how to improve the Rapid Bioassessment Protocols (RBPs) maintaining the accuracy of the results has been a topic recurrently debated among researchers. It is well know that the sample unit size (i.e., surface of the sampled area; SUS) and the sieve mesh size (SMS), selected to collect and to retain benthic macroinvertebrates from soft-bottom samples, may affect the evaluation of the aquatic ecosystem ecological status; however, studies analyzing the combined influence of SUS and SMS on assessment tools are lacking, in particular for transitional water ecosystems. Even if the Water Framework Directive (WFD) suggests rapid and cost-effectiveness sampling effort and procedures, the identification of optimal SUS and SMS is a basic step to improve the RBPs and to meet WFD suggestions. Therefore, this research analyzes the effects of four soft-bottom sample unit sizes (0.0225 m2, 0.0450 m2, 0.0675 m2, 0.0900 m2), and three sieve mesh sizes (4 mm2, 1 mm2, 0.25 mm2) on the selection of benthic macroinvertebrates and, thus, on assessment tools, in a Mediterranean lagoon. A sampling survey was performed in September 2009 at a perturbed and an unperturbed study site in the Lesina lagoon (SE Italian coastline); three replicates were taken for each SUS and SMS using an Ekman-Birge grab (15 cm x 15 cm). The samples were sieved on a column of three sieves, with decreasing mesh size. Benthic macroinvertebrates were sorted, identified, measured, weighted and included in twelve datasets (4 SUS x 3 SMS). Sampling effort (SE) was calculated for each SUS and SMS combination as: SE = [SUS m2 x (1/SMS mm2)] x 100. Four simple community descriptors (numerical density, taxonomic richness, biomass density, individual body-size) and four ecological indicators (AMBI, BENTIX, BITS, M-AMBI) were compared for each combination of SUS and SMS in both study sites. Simple community descriptors and ecological indicators varied significantly between perturbed and unperturbed study site. The results showed that SMS had significant effects on simple community descriptors and ecological indicators, except for BITS index. Conversely, no significant differences were observed for different SUS analyzing simple community descriptors and ecological indicators, except for taxonomic richness and M-AMBI index. The response of the ecological indicators was only slightly affected by the SMS, whereas SUS choice did not influence the ecological status assessment. Anyway, using the larger SMS (4 mm2), all ecological indicators showed either the same ecological quality status as the 1 mm2 and 0.25 mm2 SMS or, in some cases, one class higher, except for the AMBI index.
Lagoons are ecotone ecosystems, naturally exposed to immigration from their freshwater and marine input environments; strictly lagoonal species are rare, if ever occurring, and lagoon community are likely to be organised through loItery competition processes. These evidences suggest the study of lagoons as models address ecosystem fragility to alien species. Here, we present an analysis of lagoon guild fragility to alien species carried out using the e-Science facilities of LifeWatch, the European Research Infrastructure on biodiversity and ecosystem research. The analysis has been performed on two EUNIS habitat (X02 and X03) using data existing on 18 Italian lagoons. The analysis has been carried out taking into account that rarity, redundancy and singularity are key properties of different guilds in lagoon ecosystems at every geographical area, affecting B (Beta) and y (Gamma) diversity. At every area an high regional biodiversity is determined by a large number of rare species and a high dissimilarity among lagoons. Life cycle traits and the behaviour of larval stages, at the species level, as well as lagoon openness and vigour, at the ecosystem level, seem to have a major role to explain the difference in patterns of biodiversity between study areas at a biogeographical scale. The same species and ecosystem level properties, together with spatial patchiness, seem also to be key factors downscaling biodiversity analysis at the landscape level.
Coastal habitats worldwide are threatened by invasive alien species (IAS) that can alter community and ecosystem processes. Invasions are of particular concern for the Mediterranean Sea, and IAS-related descriptors of good ecological status have been recently proposed in European reference regulations. Here, the occurrence of the Atlantic blue crab Callinectes sapidus was analysed in two Mediterranean coastal habitats, the Acquatina lagoon and Torre Colimena basin (SE Italy). The blue crab is to date recognized as an IAS; however, quantitative information on abundance patterns of the species are scant, and its functional role in European waters is virtually unexplored. Blue crabs were sampled seasonally using crab traps. Specimens were enumerated, sexed, and measured. In addition, in both habitats the carbon and nitrogen isotopic signatures of C. sapidus were determined at its maximum seasonal abundance, and compared against those of other representatives of the benthic food web. In the Acquatina lagoon, C. sapidus was collected only in spring and summer, while other autochthonous crab species were predominantly captured in winter and autumn. In contrast, in the Torre Colimena basin the blue crab was the only captured brachyuran; it was collected during the whole sampling period, and showed summer abundances more than twice as higher than those observed in the Acquatina lagoon. In both environments, juveniles and ovigerous females were sampled, and males dominated over females. Condition factors calculated using individual widtheweight data showed that blue crabs from the Torre Colimena basin had higher condition factors compared to those from the Acquatina lagoon. Independently from the environment, Callinectes sapidus d13C values in summer were consistent with those characterizing autochthonous crabs and other representatives of the macrozoobenthos. Its d15N signature, however, varied significantly, suggesting that in the Acquatina lagoon the species may have more predatory trophic habits. Our study indicates the occurrence of established populations of Callinectes sapidus in both study sites, yet characterized by different biological characteristics and roles within the local benthic food web. The results are compared to information on blue crab populations in their native habitats, while their ecological implications are discussed in the context of the effort currently made to clarify the concomitant effects of invasions and climate change on marine ecosystems.
In Italy, dredging in marine coastal areas are authorized after the risk evaluation which includes physical-chemical and microbiological analyses of sediments. Exception made for harbours settled inside high polluted areas ruled by a specific Decree (D.M. November 7th, 2008), sampling procedures and variables of interest are defined by a specific Decree Law (January 24th, 1996). This DL does not include references for data evaluations and results are compared to: i) quality standards for sediments (DL 152/2006, Tab. 2/A); ii) standard concentration limits for soils (DL 152/2006, Tab. 2, Col. A/B, title V); iii) Sediment Quality Guideline defined by the Italian Environmental Research Institute (ISPRA, Istituto superiore per la protezione e la ricerca ambientale, ex ICRAM). Compared to DL January 24th, 1996, ISPRA Guideline proposes a different sampling strategy and integrates some physico-chemical analysis (i.e. TBT, mycetes) including ecotoxicological tests but, mainly, proposes a rationale criteria of evaluation of results. Sediment quality is evaluated by a multi-step process taking into account results obtained both by chemical analysis and ecotoxicological tests. Sediments could be classified into six different quality classes (from A1 – good quality, low attention to C2 – bad quality, high attention) and associated different management possibilities ranging from beach nourishment to authorized waste disposal. Results from chemical analysis are classified on the basis of a comparison with three different reference ranges of values defined by the natural concentration limit (LCB) and by the critical concentration limit (LCL). Furthermore, concerning trace elements, ISPRA Guideline proposes two different LCBs depending on the sediment grain-size structure to taking into account the accumulation properties of silts. In spite of described advantages, ISPRA Guideline evidences some applicative problems to be solved. Sampling strategy (i.e. grid size, number of cores per each grid unit, thickness and levels of samples along the core) and analyses that have to be performed on collected samples are quite different compared to the prescriptive Decree Law (January 24th, 1996). Furthermore, ISPRA Guideline could be integrated including reference criteria for microbiological data evaluation and a sediment classification process which includes microbiological results. In case of dredged sediments destined to beach nourishment, ISPRA Guideline does not consider how to define mineralogy and colour compatibility of sediments that are parameters of great importance for the release of authorization. In conclusion, even if ISPRA Guideline proposes for the first time objective criteria well-sized for sediment classification in harbours areas that are easy to apply and clear to understand also by not specialized operators, nevertheless, with the exception of some Region which recognized to the ISPRA Guideline a legal value (DGR 255/09), its application is not prescriptive. Furthermore, some applicative problems remain jet to be solved as previously described. In itinere and post operam monitoring approaches proposed in ISPRA Guidelines are not ruled by Italian law and are rarely applied due to the costs. Monitoring the effects on biota during and after dredging procedures could better focuses the occurrence of significant impacts. The application of several biological indicators of stress known as biomarkers from molecular to population and community levels will assure a complete picture of biological responses exert by an organism exposed to stress including classical (ruled) and emerging contaminants (not jet ruled). The integration of biological responses analysis with the residue analysis of highly toxic and persistent contaminants including endocrine disruptors will make possible to address cause and effects in terms of biological responses in exposed
1 - Mediterranean lagoons are naturally exposed, during the dry season, to dystrophic and hypoxic events determining dis-equilibrium conditions along temporal and spatial scales, which are linked to metabolism and life cycle of the biotic components. 2 - In summer 2008, Lesina lagoon (SE Italian coastline) was interested by a geographically localized dystrophic crisis which affected up to 8% of the total lagoon surface. 3 - Temporal dynamics of principal descriptors of abiotic (water, sediment) and biotic (phytoplankton, benthic macroinvertebrate) compartments have been followed during the 2008 by collecting data inside stressed and control lagoon areas before a dystrophic event and in the six months after the dystrophic event. 4 - The aim of the study was to analyse the pathways of ecosystem responses to dystrophic stress, searching for the characteristic scales of ecosystem compartment resistance and resilience. 5 - The characteristic time-scale of abiotic and biotic component time responses varied from days, for the selected markers of the water column, to year, for the benthic ones. Short-term biotic and abiotic responses in the water column were strongly coupled while biotic and abiotic responses at the sediment level were remarkably un-coupled. Dynamics and recovery time of water column and benthic components do not match in Lesina following the dystrophic crisis, highlighting an intrinsic individualistic behavior within the lagoon community driving ecosystem processes and ecosystem level responses. 6 - Taxonomic and non-taxonomic descriptors of both phytoplankton and benthic macroinvertebrates showed different response patterns as early warning signals and overall resilience. The emphasized differences in the stability components, i.e., resistance and resilience, of water column and sediment abiotic and biotic characteristics as well as of taxonomic and non-taxonomic descriptors has key implication in planning monitoring strategies and programs for transitional waters in the Mediterranean and Black Sea EcoRegions.
1 - Mediterranean lagoons are naturally exposed, during the dry season, to dystrophic and hypoxic events determining dis-equilibrium conditions along temporal and spatial scales, which are linked to metabolism and life cycle of the biotic components. 2 - In summer 2008, Lesina lagoon (SE Italian coastline) was interested by a geographically localized dystrophic crisis which affected up to 8% of the total lagoon surface. 3 - Temporal dynamics of principal descriptors of abiotic (water, sediment) and biotic (phytoplankton, benthic macroinvertebrate) compartments have been followed during the 2008 by collecting data inside stressed and control lagoon areas before a dystrophic event and in the six months after the dystrophic event. 4 - The aim of the study was to analyse the pathways of ecosystem responses to dystrophic stress, searching for the characteristic scales of ecosystem compartment resistance and resilience. 5 - The characteristic time-scale of abiotic and biotic component time responses varied from days, for the selected markers of the water column, to year, for the benthic ones. Short-term biotic and abiotic responses in the water column were strongly coupled while biotic and abiotic responses at the sediment level were remarkably un-coupled. Dynamics and recovery time of water column and benthic components do not match in Lesina following the dystrophic crisis, highlighting an intrinsic individualistic behavior within the lagoon community driving ecosystem processes and ecosystem level responses. 6 - Taxonomic and non-taxonomic descriptors of both phytoplankton and benthic macroinvertebrates showed different response patterns as early warning signals and overall resilience. The emphasized differences in the stability components, i.e., resistance and resilience, of water column and sediment abiotic and biotic characteristics as well as of taxonomic and non-taxonomic descriptors has key implication in planning monitoring strategies and programs for transitional waters in the Mediterranean and Black Sea EcoRegions.
Macroinvertebrates are commonly applied for ecological investigations and as ecological indicators. However, the role of the sampling technique, effort and habitat on macroinvertebrate descriptors, diversity indices and ecological indicators in transitional water ecosystems is little known yet. This research aims to evaluate the influence of sampling techniques on macroinvertebrate assemblages and ecological indicators comparing box-corer and litterbag techniques, in prairie and unvegetated habitats. The experiment was conducted in a protected Mediterranean shallow lagoon dominated by marine water input. Three types of litterbags were prepared with: i. Phragmites australis dry leaves (terrestrial input); ii. Posidonia oceanica dry leaves (marine input), and iii. an equal mixture of both leaves. Three replicates of box-corer samples were collected in two sites per habitat, litterbags were submerged and retrieved after 30 days. Macroinvertebrate abundance, species richness, diversity indices and ecological indicators were measured and compared among sampling techniques and between habitats. Macroinvertebrate data was then pooled, analysed and compared to each single technique. Twenty-seven species were sampled overall, 4 species overlapped between box-corer and litterbags, 6 species (26%) were exclusive to the box-corer and 16 species (59%) were caught using only litterbags. Species diversity in litterbags was always higher than in box-corer, but macroinvertebrate assemblages were described better when using data pooled. In prairie, the ecological indicators varied significantly between the data pooled and separate sampling technique. Finally, this research highlights the relevance of using more than one sampling technique to obtain a better description of macroinvertebrate assemblages and the ecological status of Mediterranean lagoons.
The Marine Framework Strategy Directive (MFSD, 2008/56/EC) aims for clean, healthy and productive marine ecosystems within all the EU Members states. The MFSD promotes an holistic, ecosystem based approach to marine conservation and monitoring (Art. 13) Monitoring strategies should: 1) focus on the potential of scale dependence in the observed dynamics and 2) be able to integrate the effect of mediating factors operating at different scale levels. However, present knowledge on spatial and temporal fluctuations in marine ecosystems is scarce. The boundaries of natural variation of several important marine ecosystem processes are still undefined. A major source of complexity is the fact that ecosystem processes are occurred across different spatial as well as temporal scales. The present knowledge gap results in uncertainty on the selection of measured parameters and the definition of sampling frequency and sites. Hereby, we discuss theoretical and applied issues related to definition of optimal cross-scale monitoring strategies. Literature data and existing databases were analyzed, to define the connectivity across nested scales of principal D1 (Biodiversity), D5 (Eutrophication), D6 (Seabed habitat integrity) MFSD descriptors. We conclude that present monitoring strategy does not completely fulfil the scaling issues due to lack of theoretical knowledge on cross-scale processes and poor coordination across monitoring operators. A stronger cooperation among member states and regional environmental agencies is needed to implement efficient cross-scale environmental monitoring. This research was developed by partners of the Integrated Regional monitoring Implementation Strategy in the South European Seas (IRIS-SES, http://iris-ses.eu) Project, a pilot project on new knowledge for an integrated management of human activities in the sea (PP/ENV D2/SEA 2012), funded by the European Union.
Information on both structure and functions is essential to evaluate the ecological integrity of streamecosystems and their response to natural and anthropogenic disturbance. Leaf-bags have been widelyemployed to assess stream ecosystem processes and the degree of leaf mass consumption has been pro-posed as one of the most useful functional descriptor in aquatic environments. However, the breakdownrate of leaves has been compared with structural indicators of macroinvertebrate assemblages derivedfrom leaf-bags or from benthic samples, without any direct comparison on the characteristics of com-munities sampled with the two methods. The main objective of the paper is to conduct a comparativeanalysis of the structure, functional organization and biological traits of macroinvertebrate assemblagesfrom artificial leaf packs and from benthic samples of a third-order stream in the Central Apennines(Italy).Of the 43 macroinvertebrate taxa globally found in our survey, 9 showed low ability or scarce attitudeto colonize leaf-bags, while 6 rare taxa were exclusively sampled in artificial leaf packs. Both assemblageswere characterized by the dominance of Chironomidae, though they were more abundant in leaf-bags(71% of total individuals collected) than in benthic samples (44%). Conversely, the mayfly Baetis sp. com-prised more than 17% of total individuals collected with Surber nets and only 5% of leaf-bag assemblages.We found that compared to benthic assemblages, leaf-bag communities were less diversified with alower richness and a lower number of Ephemeroptera, Trichoptera and Plecoptera (EPT) taxa; significantdifferences also emerged in assemblage composition.Contrary to what expected, artificial leaf packs resulted not particularly attractive for shredder orga-nisms and were mainly colonized by collectors. Also the biological trait profiles of the leaf-bag communitywere significantly different from those shared by resident benthic taxa.Our findings could have profound implications in the assessment of the structural and functionalintegrity of stream ecosystems and in studies on freshwater biodiversity and ecosystem functioning.In these studies, the two methods (leaf-bags and Surber nets) should be regarded as complementary andnot alternative.
1 - Coastal marine and transitional water ecosystems are threatened world-wide by invasions of nonindigenous invertebrate species, altering community structure and ecosystem functioning. 2 - Here, we report on the occurrence of the Atlantic blue crab Callinectes sapidus in transitional water ecosystems of the Apulia coastline (Salento peninsula, SE Italy). 3 - Blue crabs were sampled seasonally, every three months over a whole-year period in the Torre Colimena basin (Ionian Sea) and Acquatina lagoon (Adriatic Sea). Specimens were identified and enumerated. In addition, their hemolymph was screened for parasite infections using histological techniques. 4 - Callinectes sapidus was sampled in the Torre Colimena basin, where no other crab species were collected during the whole experimental period. In contrast, in the Acquatina Lagoon four crab species were sampled, including C. sapidus. 5 - The parasitic dinoflagellate Hematodinium sp., known to determine in C. sapidus the degenerative “bitter crab syndrome” in its native habitats, was ubiquitously detected in the hemolymph of blue crabs from both habitats and in autochthonous brachyurans collected in the Acquatina Lagoon. 6 - An assessment of the diverse spectrum of potential ecological effects triggered by the Callinectes-Hematodinium interaction on autochthonous brachyuran species is presented, together with a preliminary evaluation of the molecular approaches to be implemented in order to verify the species-specificity of the host-parasite interaction.
In the Island of Corfu there are seven lagoons which have different biological and chemical characteristics and also different impacts and human interventions. In this research, a preliminary description of the lagoons is reported using available data from the literature. The lagoons of Corfu have been poorly studied from the point of view of ecological functuins and biodiversity. Specifically the lagoons are: 1.Lagoon Korission, it is the largest lagoon of Corfu. Located in the southwest of the island has an area of 600hectares approximately. Works like a fish farm and is protected area Natura 2000. The main intervention of the lagoon is the increasing of the human activities in the area of the lagoon; 2. Lagoon Chalkiopoulou, the second largest lagoon of Corfu, it has a total size of 180 hectares. There was a fish farm fifteen years ago. It is estimated that the last seventy years the lagoon has lost about 1/3 of its extent. This lagoon has received the most and the major intervention is the reduction in the area in order to create the Airport of Corfu; 3.Lagoon Antinioti, it is located northeast of Corfu and it has a total size of 100 hectares with the marshland Kounoufadi which is part of the lagoon. Works like a fish farm and is included in the protected areas Natura 2000. The main interference of the area has been done on the part of the marshland Kounoufadi where twenty years ago have been put polders by the municipality of Corfu in order to build a Municipal Stadium; 4. Lagoon Alykes Lefkimmis, it is a small lagoon of about 30 hectares in the southeast of Corfu. Along with former Alykes Lefkimmis is included in the protected areas Natura 2000. There is not significant human intervention in the lagoon in addition with the former Saline of Lefkimmi (which forms a single ecosystem) for which the area has decreased due to residential use. Three small lagoons in the area of Erimitis which is in the northeast part of Corfu, there are 3 small lagoon ecosystems (Akoli, Vromolimni and Avlaki) located on the northeast coast of Corfu. Each of these has a size of 2-4hectares. The most remarkable is that the lagoon Akoli in the past served as a fish farm and had an artificial orifice communicating with the sea. Such abandonment of this orifice it is noticed a decrease in the depth of the lagoon.
Of the total number of species of animals inhabiting our planet 2/3 are insects with at least 1 million species. Diptera are bloodsucking insects. This review article considers medical significance of bloodsucking dipterous insects – mosquitoes (fam. Culicidae). It is important for understanding the entomological risk of bloodsucking dipterous insects-borne disease transmission. At present, it has been registered that mosquitoes (fam. Culicidae) transfer more than 50 viral and parasitic diseases. Control measures are personal, protection against mosquito bites and destruction of larval forms and places of fertility.
Coastal marine ecosystems world-wide are threatened by invasions of non-indigenous invertebrate species, altering population, community and ecosystem processes. Here, we report on the occurrence of the Atlantic blue crab Callinectes sapidus in coastal habitats of the Salento peninsula (South-East of Italy). Blue crabs and other indigenous crab species were sampled monthly in Acquatina and Torre Colimena basins (Adriatic and Ionian Sea, respectively). Specimens were enumerated, and sexed. In addition, their hemolymph was collected and analyzed using histological techniques. C. sapidus occurred episodically in the Acquatina basin, whereas it was collected during the whole sampling period in the Torre Colimena basin. Immature and mature individuals of both sexes were sampled; in addition, the ubiquitous occurrence in the hemolymph of both C. sapidus and indigenous crab species of the parasite Hematodinium sp. suggested the occurrence of an established population in the basin. A preliminary evaluation of the molecular approaches to be implemented on C. sapidus and its parasites from Torre Colimena to assess the relationship with other established populations in Croatian and Albanian waters is presented. In particular, the transmission of parasites between invasive and indigenous species is generally poorly investigated, and molecular techniques may provide a rapid and effective screening methodology.
Regulation of metabolism is a common strategy used by individuals to respond to a changing environment. The mechanisms underlying the variability of metabolic rates in macroinvertebrates are of primary importance in studying benthicepelagic energy transfer in transitional water ecosystems. Lekanesphaera monodi is an isopod endemic to transitional water ecosystems that can modify its metabolic rate in response to environmental changes. Therefore it is a useful model in studying the influence of environmental factors on metabolism. This study focused on the interpopulation variability of standard metabolic rates (SMR) in L. monodi populations sampled in three transitional water ecosystems differing in their trophic status. The standard metabolic rates of L. monodi individuals across the same range of body size spectra were inferred from oxygen consumption measurements in a flow-through respirometer in the three populations and a body condition index was assessed for each population. Habitat trophic status was evaluated by monthly measurement of the basic physicalechemical parameters of the water column in the ecosystems for one year. Standard metabolic rates showed high variability, ranging from 0.27 to 10.14 J d^-1. Body size accounted for more than 38% of total variability. In terms of trophic status, individuals from the eutrophic ecosystem had significantly higher standard metabolic rates than individuals from the other ecosystems (SMR ¼ 2.3 J d^-1 in Spunderati Sud vs. 1.36 J d^-1 in Alimini and 0.69 J d^-1 in Acquatina). The body conditions index was also higher in the population from the eutrophic ecosystem. Results show that standard metabolic rates and growth rates are directly related to habitat productivity in accordance with the expectations of the food habits hypothesis. A possible extension of this hypothesis to benthic invertebrates is proposed
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