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.

Individual resource ingestion rates depend on both individual body size and resource supply. A component of the latter, namely resource availability, is also body-size dependent. This raises the question of the adequacy of simple scaling laws to describe the body-size dependency of resource ingestion. Here we propose a model which integrates resource ingestion drivers by merging a scaling law for feeding metabolism and Holling’s functional responses into a single mathematical framework. At any fixed level of resource supply, the model predicts a log-log concave-down relationship between resource ingestion rates and body size, rather than a simple scaling law. Deviations from the latter are accounted for by the body size dependency of resource limitations. Experimental and literature data describing patterns of perceived resource availability and individual intake rates under limiting conditions with increasing individual body size are used to validate the model’s assumptions nd predictions. The model incorporates and extends well-established theoretical approaches and is intended as a step towards the integration of metabolic theory with behavioral ecology and population dynamics.

Estuaries, rias, fjords and lagoons (collectively called transitional waters, TW) are highly important ecosystems both for their high productivity but also as sites of urban and industrial development, supporting many major cities and ports. Increasingly they are accepted as transitional environments and in Europe this term has been given legal and management importance; indeed, in some cases this has led to decisions with high economic repercussions. We have thus revisited the fundamental properties and paradigms of these systems in the light of recent ecological theory. The analysis has produced a unifying approach to transitional waters, by adopting and expanding the concept of ecotone to whole ecosystems, rather than ecosystem boundaries. Furthermore we have addressed the paradoxes related to (1) the gradients concerning variability and stability in the system, (2) the biodiversity and ecosystem functioning, as well as (3) the response and resilience of the system to anthropogenic stressors. We conclude that the term Transitional Waters is not merely a legal convenience or that the TW are merely an interface, with positive and negative characteristics, but ecological systems in their own right.

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.

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.

FishBase, a relational database freely available on the Internet, is to date widely used as a source of quantitative information on the trophic position of marine fish species. Here, we compared FishBase estimates for an assemblage of 30 fish species sampled in a Mediterranean lagoon (Acquatina lagoon, SE Italy) with their trophic positions calculated using nitrogen stable isotopes. To assess the influence of the trophic level used to compute the baseline indicator on the robustness of isotopic estimations, we compared the trophic position of fish calculated using the average delta N-15 signature of either basal resource or primary consumer taxa measured at three stations located in the lagoon in July and November 2007. In general, basal resources showed negligible among-station and inter-season variations in their delta N-15 values; however, they were characterized by a high inter-specific heterogeneity, with signatures varying by approximately 10 per mil units. In contrast, whereas primary consumer signatures showed significant spatial and temporal variations, they were characterized by a lower inter-specific variability. Fish trophic positions estimated using primary consumers as the isotopic baseline were highly correlated with values provided by FishBase, independently from whether the latter were calculated on either diet data or individual prey items. Conversely, estimations using a basal resources as the baseline indicator were significantly less correlated with FishBase estimates. The present study emphasized the crucial importance played by inter-specific variability in baseline taxa signatures for a robust assessment of fish trophic position, and confirmed primary consumers as the best candidate for baseline estimation. In addition, our results indicate that, notwithstanding the limitations characterizing the data provided in FishBase, they represent an adequate source of information on the trophic ecology of fish

Understanding the mechanisms of phytoplankton community assembly is a fundamental issue of aquatic ecology. Here, we use field data from transitional (e.g. coastal lagoons) and coastal water environments to decode patterns of phytoplankton size distribution into organization and adaptive mechanisms. Transitional waters are characterized by higher resource availability and shallower well-mixed water column than coastal marine environments. Differences in physico-chemical regime between the two environments have been hypothesized to exert contrasting selective pressures on phytoplankton cell morphology (size and shape). We tested the hypothesis focusing on resource availability (nutrients and light) and mixed layer depth as ecological axes that define ecological niches of phytoplankton. We report fundamental differences in size distributions of marine and freshwater diatoms, with transitional water phytoplankton significantly smaller and with higher surface to volume ratio than marine species. Here, we hypothesize that mixing condition affecting size-dependent sinking may drive phytoplankton size and shape distributions. The interplay between shallow mixed layer depth and frequent and complete mixing of transitional waters may likely increase the competitive advantage of small phytoplankton limiting large cell fitness. The nutrient regime appears to explain the size distribution within both marine and transitional water environments, while it seem does not explain the pattern observed across the two environments. In addition, difference in light availability across the two environments appear do not explain the occurrence of asymmetric size distribution at each hierarchical level. We hypothesize that such competitive equilibria and adaptive strategies in resource exploitation may drive by organism's behavior which exploring patch resources in transitional and marine phytoplankton communities.

Biovolume is commonly used as a size descriptor in the study of phytoplankton ecology. Usually, biovolume is not measured directly but is obtained from a standardized set of geometric models based on linear dimensions measured by light microscopy. This commonly used method allows visualization and measurement in two dimensions (2D) yielding no information at all on the third dimension of phytoplankton cells. Inaccurate biovolume assessment resulting from geometric approximation leads to erroneous interpretation of eco-physiological processes and morpho-functional traits. Here, we use confocal microscopy coupled with an image analysis system (NIS Elements AR software, Nikon) to determine directly shape and biovolume by means a 3D reconstruction of Coscinodiscus cf. granii specimens. We evaluate the accuracy of current methods by comparing the results obtained using geometric models with direct biovolume and shape. We find that calculation of biovolume by approximation to geometric models (cylindrical and complex shapes) leads to a significant overestimation with respect to direct volume. We also propose a data-driven formula for calculating the biovolume of Coscinodiscus cf. granii specimens based on diameter or other linear measurements.

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.

Phaeodactylum tricornutum was exposed to various toxic substances (zinc, copper or dodecylbenzenesulfonic acid sodium salt) in accordance with the AlgalToxkit(®) protocol based on the UNI EN ISO 10253 method in order to quantitatively compare the responses obtained by traditional growth-rate inhibition tests with morphological (biovolume) and physiological (chlorophyll-a, phaeophytin ratio) endpoints. A novel approach is proposed for detecting early and sub-lethal effects based on biovolume quantification using confocal microscopy coupled with an image analysis system. The results showed that effects on both biovolume and the photosynthetic complex are sensitive and powerful early warning tools for evaluating sub-lethal effects of exposure. Specifically, biovolume showed significant sensitive and early responses for the tested surfactant. Qualitatively, we also observed structural anomalies and effects on natural auto-fluorescence in exposed cells that also represent potentially useful tools for ecotoxicological studies.

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.

The metabolism of benthic aquatic invertebrates, populating transitional water ecosystems, is influenced by both physiological and environmental factors, thus involving an adjustment of physiological processes which has a metabolic cost. In order to discover changes in metabolic pathways in response to specific factors, it's firstly necessary characterizing the principal cellular metabolic activities of the small benthic aquatic organisms. We approach here the bioenergetic state issue of two benthic organisms, i.e. Lekanesphaera monodi and Gammarus insensibilis, evidencing that no apparent and statistically significative differences between them in aerobic as well in glycolytic capacities are detected, except for COX activity.

Although habitat size is known to influence both structural and functional properties of ecosystems, there have been few attempts to assess the influence of habitat size on ecosystem processes. Here we investigated the relationships between leaf litter decomposition and ecosystem surface area, macroinvertebrates and physico-chemical factors in five freshwater springs located in Huntingdon County (Pennsylvania, U.S.A.). Leaves of Ulmus americana L. were used to study leaf litter breakdown with the litter-bag technique. Field work was carried out at one sampling station per spring, each with eight replicates per sampling time (3, 20, 40 days), from April to May 2004. American elm leaves decomposed at different rates in the different springs, varying inversely with the spring area. The leaf bags were colonized by 16 taxa of benthic macrofauna, amongst which scrapers and shredders were the most common guild. Macroinvertebrate species richness co-varied with spring area, but not with other physico-chemical variables. Moreover, a significant inverse relationship was observed between American elm leaf decay rate and taxonomic richness. In the studied springs, habitat area was an ecosystem feature indirectly affecting detritus processing by influencing the structure of the detrital food web within the systems

Lagoons are habitat islands in the coastal landscapes characterised by heterogeneity among ecosystems, due to the different terrestrial-freshwater- marine interfaces, as well as by heterogeneity within an ecosystem, due to an intrinsic patchy spatial distribution of abiotic and biotic components. Here, we investigated the influence of nine hydrological forcing factors of the patchiness of a lagoon benthic macroinvertebrates, described through macroinvertebrate diversity. This study is based on the analysis of two databases built, respectively, upon (1) a literature survey (ITA-DB) carried out considering a 25-year period and (2) a series of sampling campaigns during 2004-2005 in ten Mediterranean and Black sea lagoons (CaD-DB). Both databases showed a patchy distribution of macroinvertebrate taxa among lagoons with most taxa found in one or two lagoons only. Average similarity in taxa composition among lagoons revealed to be low for both ITA-DB (10%) and CaD-DB (11%), showing that macroinvertebrate taxonomic diversity is strictly linked to large-scale phenomena. Regression trees models indicate that 60.0% (ITA-DB) and 42.3% (CaD-DB), respectively, of total deviance of the macroinvertebrates diversity are explained by physiographical and hydrological factors, being openness and tidal range the two most relevant components. Therefore, hydrological constraints in the connection between lagoon and marine ecosystems seem to have a relevant role in the organisation and maintenance of benthic macroinvertebrate fauna of coastal lagoons. In order to design strategies of biodiversity conservation in Mediterranean transitional waters one suggested direction is a coordinated, inter-country governance, rather than a purely local management. © 2010 Springer-Verlag.

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.

A key step of European Water Framework Directive (WFD) implementation is the ecological status classification and the achievement of 'good water status' for all waters, by 2015. Macroinvertebrates are key quality elements, and many metrics have so far been proposed for ecological status classification with benthic invertebrates. In transitional waters, the changing environmental niche induces responses in the macroinvertebrate guilds and macroinvertebrate responses induce uncertainty in the metrics. In this case, the sources of uncertainty in the ecological classification with benthic macroinvertebrates, is addressed by focusing on two major potential sources: Spatial heterogeneity and temporal heterogeneity. To this aim, we have studied relative pristine lagoons within protected areas - Le Cesine (Italy) and Sinoe (Romania) - that are characterized by a different degree of component of transitional water internal heterogeneity, i.e. habitat patchiness. Benthic macroinvertebrates were sampled with the same methodology at the two stations, with two sites per station and five replicates, in different seasonal periods and at tree different habitats. On the collected data different metrics were computed and compared. The variability between ecosystems, seasons, habitat types and replicates, was quantified and compared among metrics. Taxonomically based metrics showed a higher variability than non-taxonomic ones, highlighting that the latter better fulfill the requirement of low uncertainty.

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.

The assessment of human impacts on aquatic ecosystems requires separate quantification of natural and anthropogenic sources of environmental variability. This statement is very challenging in some categories of water bodies such as transitional waters, because they are naturally stressed ecosystems in which natural variability occur on different spatial scales (gradients versus patchiness) and temporal scales (regular versus pulse events). Among transitional water quality elements, benthic macroinvertebrates are the most exposed to natural variability patterns due to their life cycles and space-use behavior. In this article, we have evaluated the relevance of different potential sources of natural variability of benthic macroinvertebrate guilds on the temporal and spatial scales and we have quantified their effects on simple and multimetric descriptors of macroinvertebrate guilds; the latter included biomass and numerical densities, taxonomic diversity as well as M-AMBI and index of size spectra, ISS. The study was carried out using the TWReferenceNET database of 14 Eastern Mediterranean and Black Sea lagoons. Synoptic sampling of benthic macroinvertebrates was performed seasonally in different habitats within each lagoon in accordance with a nested design. All considered metrics showed a relatively high degree of variability among different reference stations and ecosystems, with the coefficient of variation ranging from 20% (log numerical density) to 45% (M-AMBI). The average values of every metric were significantly affected by the considered natural sources of variation: lagoon typology, seasonal period and habitat patchiness. Among components of lagoon typology, water salinity influenced the most the variation for both simple and multimetric descriptors. Seasonal period also had a strong influence, with higher values for all metrics before the summer season compared to the one after summer. Benthic habitat patchiness had a considerable influence only on the simple metrics, while continuous habitat variables significantly affected both M-AMBI and ISS. A general mixed model approach, used to quantify the relative influence of the different sources of variation on the considered metrics, allowed calculating type-specific boundaries for M-AMBI and ISS. The new boundaries significantly improved the accuracy of both multimetric indices in the classification of studied reference condition sites, with more than 75% of stations classified as good or high status. Nonetheless, results show that there is an intrinsic uncertainty in the classification of ecological status of lagoon ecosystem due to the degree of variability under reference conditions.

Confocal laser scanner microscopy coupled with an image analysis system was used to directly determine the shape and calculate the biovolume of phytoplankton organisms by constructing 3D models of cells. The study was performed on Biceratium furca (Ehrenberg) Vanhoeffen, which is one of the most complex-shaped phytoplankton. Traditionally, biovolume is obtained from a standardized set of geometric models based on linear dimensions measured by light microscopy. However, especially in the case of complex-shaped cells, biovolume is affected by very large errors associated with the numerous manual measurements that this entails. We evaluate the accuracy of these traditional methods by comparing the results obtained using geometric models with direct biovolume measurement by image analysis. Our results show cell biovolume measurement based on decomposition into simple geometrical shapes can be highly inaccurate. Although we assume that the most accurate cell shape is obtained by 3D direct biovolume measurement, which is based on voxel counting, the intrinsic uncertainty of this method is explored and assessed. Finally, we implement a data-driven formula-based approach to the calculation of biovolume of this complex-shaped organism. On one hand, the model is obtained from 3D direct calculation. On the other hand, it is based on just two linear dimensions which can easily be measured by hand. This approach has already been used for investigating the complexities of morphology and for determining the 3D structure of cells. It could also represent a novel way to generalize scaling laws for biovolume calculation.

Most estuarine ecology textbooks have included the so-called Remane diagram which is derived from German studies in the Baltic Sea region during the early part of the 20th Century. The model shows how aquatic species diversity changes from freshwater to more marine areas. In essence it aims to show the relative proportions of each component of the fauna (freshwater, brackish and marine) and how these change along a salinity gradient. These combined components decrease in diversity with a progression from both the freshwater and marine ends of the spectrum, with the 5e7 salinity area being dominated by a small number of true brackish/estuarine species. The way in which the Remane diagram has been interpreted (and misinterpreted) and used (and misused) in the literature is discussed here.We primarily investigate whether the model needs to be modified to help provide an understanding of current biotic distribution patterns within estuaries and how these patterns might be influenced by climate change. Using global estuarine examples for a variety of taxa we discuss the appropriateness of the Remane model beyond the zoobenthos (on which the model was originally based) and provide a revised model that is more suited to estuaries worldwide. Comment is also provided on the way in which a more appropriate estuarine biodiversity model can influence future estuarine ecotone and ecocline studies.

A first synoptic and trans-domain overviewof plankton dynamics was conducted across the aquatic sites belonging to the Italian Long-Term Ecological Research Network (LTER-Italy). Based on published studies, checked and complemented with unpublished information, we investigated phytoplankton and zooplankton annual dynamics and long-term changes across domains: from the large subalpine lakes to mountain lakes and artificial lakes, from lagoons to marine coastal ecosystems. This study permitted identifying common and unique environmental drivers and ecological functional processes controlling seasonal and long-termtemporal course. The most relevant patterns of plankton seasonal succession were revealed, showing that the driving factors were nutrient availability, stratification regime, and freshwater inflow. Phytoplankton and mesozooplankton displayed a wide interannual variability at most sites. Unidirectional or linear long-term trends were rarely detected but all sites were impacted across the years by at least one, but in many case several major stressor(s): nutrient inputs, meteo-climatic variability at the local and regional scale, and direct human activities at specific sites. Different climatic and anthropic forcings frequently co-occurred, whereby the responses of plankton communities were the result of this environmental complexity. Overall, the LTER investigations are providing an unparalleled framework of knowledge to evaluate changes in the aquatic pelagic systems and management options.

When investigating complex ecological dynamics at the population or community level, we necessarily need to abstract and aggregate ecological information. The way in which information is aggregated may be crucial for the outcome of the study. In this paper, we suggest that in addition to the traditional spatial, temporal and organizational levels, we need a more flexible framework linking ecological processes, study objects and types of aggregation. We develop such a framework and exemplify the most commonly used types of aggregation and their potential influence on identifiable drivers of community dynamics. We also illustrate strategies to narrow down the range of possible aggregation types for a particular study. With this approach, we hope (i) to clarify the function of aggregation types as related to traditional ecological levels and (ii) to raise the awareness of how important a deliberate way of aggregating ecological information is for a sound and reliable outcome of any empirical or theoretical ecological study.

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

This contribution describes ‘Research Game’, a game produced in a Lifelong Learning Programme-Comenius Project (The European Scientific Research Game) which aims at motivating secondary school students through the experience of the excitement of scientific research. The project proposes practical and didactic works which combine theoretical activities with ICT in order to introduce students to the scientific research. Students collaborated internationally across Europe, to build hypotheses, carry out research, test the validity of their hypothesis and finalize a theory based on their findings. On the project platform (www.researchgame.eu/platform) teachers and students registered, created a team, interacted on a forum space, played and learned science in a new innovative way. Here, the students shared their research findings with other groups of all Europe; finally competed online playing a serious game and showing to be able to apply the scientific method.

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.

In recent times many benthic indices have been proposed to assess the ecological quality of marine waters worldwide. In this study we compared single metrics and multi-metric methods to assess coastal and transitional benthic status along human pressure gradients in five distinct environments across Europe: Varna bay and lake (Bulgaria), Lesina lagoon (Italy), Mondego estuary (Portugal), Basque coast (Spain) and Oslofjord (Norway). Hence, 13 single metrics (abundance, number of taxa, and several diversity and sensitivity indices) and eight of the most common indices used within the European Water Framework Directive (WFD) for benthic assessment were selected: index of size spectra (ISS), Benthic assessment tool (BAT), Norwegian quality index (NQI), Multivariate AMBI (M-AMBI), Benthic quality index (BQI), (Benthic ecosystem quality index (BEQI), Benthic index based on taxonomic sufficiency (BITS), and infaunal quality index (IQI). Within each system, sampling sites were ordered in an increasing pressure gradient according to a preliminary classification based on professional judgement. The different indices are largely consistent in their response to pressure gradient, except in some particular cases (i.e. BITS, in all cases, or ISS when a low number of individuals is present). Inconsistencies between indicator responses were most pronounced in transitional waters (i.e. IQI, BEQI), highlighting the difficulties of the generic application of indicators to all marine, estuarine and lagoonal environments. However, some of the single (i.e. ecological groups approach, diversity, richness) and multi-metric methods (i.e. BAT, M-AMBI, NQI) were able to detect such gradients both in transitional and coastal environments, being these multi-metric methods more consistent in the detection than single indices. This study highlights the importance of survey design and good reference conditions for some indicators. The agreement observed between different methodologies and their ability to detect quality trends across distinct environments constitutes a promising result for the implementation of the WFD's monitoring plans. Moreover, these results have management implications, regarding the dangers of misclassification, uncertainty in the assessment, use of conflicting indices, and testing and validation of indices. © 2010 Elsevier Ltd.

An understanding of risks to biodiversity is needed for planning action to slow current rates of decline and secure ecosystem services for future human use. Although the IUCN Red List criteria provide an effective assessment protocol for species, a standard global assessment of risks to higher levels of biodiversity is currently limited. In 2008, IUCN initiated development of risk assessment criteria to support a global Red List of ecosystems. We present a new conceptual model for ecosystem risk assessment founded on a synthesis of relevant ecological theories. To support the model, we review key elements of ecosystem definition and introduce the concept of ecosystem collapse, an analogue of species extinction. The model identifies four distributional and functional symptoms of ecosystem risk as a basis for assessment criteria: A) rates of decline in ecosystem distribution; B) restricted distributions with continuing declines or threats; C) rates of environmental (abiotic) degradation; and D) rates of disruption to biotic processes. A fifth criterion, E) quantitative estimates of the risk of ecosystem collapse, enables integrated assessment of multiple processes and provides a conceptual anchor for the other criteria. We present the theoretical rationale for the construction and interpretation of each criterion. The assessment protocol and threat categories mirror those of the IUCN Red List of species. A trial of the protocol on terrestrial, subterranean, freshwater and marine ecosystems from around the world shows that its concepts are workable and its outcomes are robust, that required data are available, and that results are consistent with assessments carried out by local experts and authorities. The new protocol provides a consistent, practical and theoretically grounded framework for establishing a systematic Red List of the world's ecosystems. This will complement the Red List of species and strengthen global capacity to report on and monitor the status of biodiversity.

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.

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.

A growing number of studies suggest that ecological quality status assessment in transitional waters should rely upon functional indicators rather than structural indices. The experimental study of decomposition rates using leaf-bags are among the former. A recent example was conducted in Ria de Aveiro, Western Portugal, and the decomposition rates of Phragmites australis obtained through the registration of the biomass decrease in leaf samples left in the estuary for fixed periods of time (7, 15, 30 and 60 days). The leaf-bags were recollected from the field and the accompanying fauna retained, for comparison to that obtained in sediment samples taken with a hand-held corer. The study was conducted in five areas covering the full salinity gradient, in three sites per area and four replicates per site. A total of 89 taxa were registered, 70 in the leaf-bags and 50 in the sediment samples. 39 taxa were sampled only in the leaf-bags, 19 only in the corers and 31 were common. From marine to freshwater areas, average abundance increased in both types of samples, and species richness and diversity diminished, except in freshwater and in the leaf-bags. Both samplers portrayed the succession from the marine to the freshwater areas, and the benthic community was found significantly different between all areas except between the two located closer to the estuarine entrance, equally by both samplers. Despite these similarities, the benthic communities sampled by the two methods were significantly different, either dominated by annelids (corers), or by arthropods (leaf-bags), amphipods in the estuary and insects in freshwater. These differences were not significant neither in the freshwater, due to paucity of the endofauna in freshwater, nor in the fully marine area, possibly due to the high variability of samples within the area. These results indicate that the estuarine benthic invertebrates upon which the taxonomic indices are calculated and those which contribute to the functional aspects based in the study of decomposition rates, are essentially very distinct.

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