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In coastal habitats, physical disturbances of benthic organisms can be caused by natural events like wave-born objects and human activity like trampling, and these disturbances can be sub-lethal (e.g., resulting in the organism's displacement). We know little of how sessile organisms respond to physical disturbances such as displacements. Using Mytilaster minimus , a mussel that is native to the Mediterranean Sea, we tested how byssus production and oxygen uptake rates changed in response to different frequencies of disturbance events (10–60 events h−1). Mussels increased oxygen uptake rates but not byssus production with increasing disturbance frequencies (50–60 events h−1). Our results show that sub-lethal, physical disturbances can cause increased physiological rates in mussels if disturbances repeat rapidly. Therefore, sub-lethal, physical disturbances can have negative consequences for benthic organisms even if they do not cause immediate damage or mortality. • Waves and trampling can cause sub-lethal disturbances of benthic organisms. • Mussels showed large increase in oxygen uptake after rapidly repeated disturbances. • Mussels did not consistently alter byssus production in response to disturbances. [ABSTRACT FROM AUTHOR]

Abstract Organisms can mitigate the effects of long term variation in environmental conditions through acclimation, which involves changes in various physiological responses. To elucidate the possible effects of temperature and food concentrations on acclimation capacity, physiological responses of the mussel, Perna viridis , were measured after individuals were held for six weeks under varying temperatures and food availability. Warm-acclimated mussels experiencing higher food levels had significantly greater upper thermal limits than those maintained on lower food levels. In contrast, the upper thermal limits of cold-acclimated mussels were not affected by food levels. For warm-acclimated mussels, differences in upper thermal limits were likely due to rapid depletion of energy storage as predicted by Dynamic Energy Budget model simulations for P. viridis exposed to lower food levels. Clearance rates of cold-acclimated mussels were significantly lower than warm-acclimated mussels, regardless of food availability. The impacts of lower food acquisition on energy storage, however, could be compensated by lower metabolic rates of the cold-acclimated mussels. The availability and the ability to acquire food are not, therefore, the main drivers differentiating between the upper thermal tolerances of cold- and warm-acclimated mussels, but these differences are driven by the past thermal history the mussels experienced. The temperature tolerance range of P. viridis showed a positive shift to tolerate higher temperatures after acclimation. Such flexibility in thermal tolerance implies P. viridis has high capacity to acclimate to novel environments, which will enhance its future success given its commercial importance as an aquaculture species. Highlights • Perna viridis has a strong acclimation capacity to temperature stress. • Temperature and food supply have an interactive effect on thermal tolerance. • Energetic status of P. viridis played a crucial role during acclimation. • Thermal optimum of P. viridis shifts with increased optimal heart rates. [ABSTRACT FROM AUTHOR]

Abstract: Defining sustainability goals is a crucial but difficult task because it often involves the quantification of multiple interrelated and sometimes conflicting components. This complexity may be exacerbated by climate change, which will increase environmental vulnerability in aquaculture and potentially compromise the ability to meet the needs of a growing human population. Here, we developed an approach to inform sustainable aquaculture by quantifying spatio‐temporal shifts in critical trade‐offs between environmental costs and benefits using the time to reach the commercial size as a possible proxy of economic implications of aquaculture under climate change. Our results indicate that optimizing aquaculture practices by minimizing impact (this study considers as impact a benthic carbon deposition ≥ 1 g C m−2 day−1) will become increasingly difficult under climate change. Moreover, an increasing temperature will produce a poleward shift in sustainability trade‐offs. These findings suggest that future sustainable management strategies and plans will need to account for the effects of climate change across scales. Overall, our results highlight the importance of integrating environmental factors in order to sustainably manage critical natural resources under shifting climatic conditions. [ABSTRACT FROM AUTHOR]

Abstract: Changing environments have the potential to alter the fitness of organisms through effects on components of fitness such as energy acquisition, metabolic cost, growth rate, survivorship, and reproductive output. Organisms, on the other hand, can alter aspects of their physiology and life histories through phenotypic plasticity as well as through genetic change in populations (selection). Researchers examining the effects of environmental variables frequently concentrate on individual components of fitness, although methods exist to combine these into a population level estimate of average fitness, as the per capita rate of population growth for a set of identical individuals with a particular set of traits. Recent advances in energetic modeling have provided excellent data on energy intake and costs leading to growth, reproduction, and other life‐history parameters; these in turn have consequences for survivorship at all life‐history stages, and thus for fitness. Components of fitness alone (performance measures) are useful in determining organism response to changing conditions, but are often not good predictors of fitness; they can differ in both form and magnitude, as demonstrated in our model. Here, we combine an energetics model for growth and allocation with a matrix model that calculates population growth rate for a group of individuals with a particular set of traits. We use intertidal mussels as an example, because data exist for some of the important energetic and life‐history parameters, and because there is a hypothesized energetic trade‐off between byssus production (affecting survivorship), and energy used for growth and reproduction. The model shows exactly how strong this trade‐off is in terms of overall fitness, and it illustrates conditions where fitness components are good predictors of actual fitness, and cases where they are not. In addition, the model is used to examine the effects of environmental change on this trade‐off and on both fitness and on individual fitness components. [ABSTRACT FROM AUTHOR]

Abstract: Aim: The introduction of non‐indigenous species (NIS) via man‐made corridors connecting previously disparate oceanic regions is increasing globally. However, the environmental and anthropogenic factors facilitating invasion dynamics and their interactions are still largely unknown. This study compiles and inputs available data for the NIS bivalve Brachidontes pharaonis across the invaded biogeographic range in the Mediterranean basin into a species distribution model to predict future spread under a range of marine scenarios. Location: Mediterranean Sea. Methods: A systematic review produced the largest presence database ever assembled to inform the selection of biological, chemical and physical factors linked to the spread of B. pharaonis through the Suez Canal. We carried out a sensitivity analysis to simulate current and future trophic and salinity scenarios. A species distribution model was run to determine key drivers of invasion, quantify interactive impacts arising from a range of trophic states, salinity conditions and climatic scenarios and forecast future trajectories for the spread of NIS into new regions under multiple‐parameter scenarios (based on the main factors identified from the systematic review). Results: Impacts on invasion trajectory arising from climate change and interactions with increasing salinity from the new opening of the canal were the primary drivers of expansion across the basin, the effects of which were further enhanced by eutrophication. Predictions of the current distribution were most accurate when multiple stressors were used to drive the model. A habitat suitability index developed at a subcontinental scale from model outputs identified novel favourable conditions for future colonization at specific locations under 2030 and 2050 climatic scenarios. Main conclusions: Future expansion of B. pharaonis will be enhanced by climate‐facilitated increased sea temperature, interacting with increasing pressures from salinity and eutrophication. The spatially explicit risk output maps of invasions represent a powerful visual product for use in communication of the spread of NIS and decision‐support tools for scientists and policymakers. The suggested approach, the observed distribution pattern and driving processes can be applied to other NIS species and regions by providing novel forecasts of species occurrences under future multiple stressor scenarios and the location of suitable recipient habitats with respect to anthropogenic and environmental parameters. [ABSTRACT FROM AUTHOR]

Fisheries currently represent the main source of animal protein intake worldwide, although catches of most commercial species are at or beyond maximum sustainable yields. Increasing production would require an excess of exploitation levels and aquaculture is expected to become crucial in sustaining a growing seafood demand. Nonetheless, many threats are expected to affect aquaculture and the increased production must evolve in a way that minimizes environmental and socio-economic impacts. The claimed sustainable development of human activities at sea (blue growth and economy) seeks for new joint analyses and solutions at (trans-)national systemic level should be planned and applied. To meet a sustainable development, both production and management approaches should evolve. Here we propose a conceptual framework to integrate a “downscaling approach” based on functional features of cultivated organisms to accommodate multiple stressors in setting sustainable development standards to design adaptive solutions fitting with the management of marine space. [ABSTRACT FROM AUTHOR]

This study investigated the influence of physical and chemical conditions and biotic factors on the distribution and diversity of meiofauna in intertidal zone along a geographical gradient. At 11 sites along the Italian coast, we studied the concurring role of environmental variables, trophic resources and the presence of habitat-forming species (macroalgae vs. mussels) in controlling the meiofaunal communities. The increase of water temperature combined with local thermal conditions was associated with a decrease in nematodes and copepods, with a consequent decrease in meiofaunal abundance towards the south. However, the increase in salinity, as geographical gradient decreases, and local thermal conditions favoured the settlement of a greater number of taxa, influencing communities' composition. The presence of macroalgae or mussels differently influenced the community structure of meiofauna on intertidal substrates and their response to environmental factors. From our results, the presence of macroalgae coverage appeared to reduce the impact of thermal stress on meiofauna and was associated with higher levels of meiofaunal diversity with respect to mussels. This work highlighted the importance of considering the interplay among biotic and abiotic factors, resulting in local combinations of environmental conditions, in order to understand the pattern of diversity and distributions of marine organisms. [ABSTRACT FROM AUTHOR]

Biomagnification (increase in contaminant concentrations at successively higher levels of trophic web), is a process that can transversally impair biodiversity and human health. Most research shows that biomagnification should be higher at poles with northern sites having a major tendency to biomagnify Persistent Organic Pollutants (POPs) through their marine food webs. We investigated the biomagnification degree into two marine trophic webs combining carbon and nitrogen stable isotopes and POP analyses. We showed that the Antarctic trophic web was more depleted than the sub-Arctic one and the differences highlighted for the basal part could explain the difference in length between them. Concentrations of polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), and p,p’ -DDE were of the same order of magnitude in the two polar trophic webs, with some values surprisingly higher in the Antarctic than sub-arctic organisms: PCBs ranged (average ± standard deviation) 1.10 ± 0.39–12.93 ± 7.62, HCB <0.10–7.28 ± 5.32, and p,p’ -DDE 0.52 ± 0.18–11.36 ± 5.3 ng/g wet weight (wt) in the Antarctic organisms, and 0.53–5.08, <0.10–1.48, and 0.27 ± 0.35–5.46 ± 1.73 ng/g wet wt, respectively, in the sub-Arctic ones. The contribution of tetra- and penta-CBs to the ∑PCBs was 10–65% in the Antarctic species and 15–45% in the Arctic species. The relationships between POPs and trophic levels, and the information obtained by the Trophic Magnification Factor revealed that the Antarctic trophic web had a greater tendency to biomagnify PCBs and p,p’ -DDE than its sub-Arctic counterpart. POP availability in the environment and specific ecological features may play an important role in the bioaccumulation, and biomagnification is apparently less important than bioconcentration. [ABSTRACT FROM AUTHOR]

Biodiversity is crucial in preservation of ecosystems, and bacterial communities play an indispensable role for the functioning of marine ecosystems. The Mediterranean marine protected area (MPA) 'Capo Gallo-Isola delle Femmine' was instituted to preserve marine biodiversity. The bacterial diversity associated with MPA sediment was compared with that from sediment of an adjacent harbour exposed to intense nautical traffic. The MPA sediment showed higher diversity with respect to the impacted site. A 16S rDNA clone library of the MPA sediment allowed the identification of 7 phyla: Proteobacteria (78%), Firmicutes (11%), Acidobacteria (3%), Actinobacteria (3%), Bacteroidetes (2%), Planctomycetes (2%), and Cyanobacteria (1%). Analysis of the hydrocarbon (HC)-degrading bacteria was performed using enrichment cultures. Most of the MPA sediment isolates were affiliated with Gram-positive G+C rich bacteria, whereas the majority of taxa in the harbour sediment clustered with Alpha- and Gammaproteobacteria; no Gram-positive HC degraders were isolated from the harbour sediment. Our results show that protection probably has an influence on bacterial diversity, and suggest the importance of monitoring the effects of protection at microbial level as well. This study creates a baseline of data that can be used to assess changes over time in bacterial communities associated with a Mediterranean MPA. [ABSTRACT FROM AUTHOR]

Persistent organic pollutants (POPs) are widespread compounds that accumulating in polar regions canalise through trophic webs. Although several dozens of studies have been carried out in the last decades, the information is generally scattered across a large number of literature sources. This does not allow an efficient synthesis and constraints our understanding on how address future monitoring plans and environmental conservation strategies on the Polar Regions with respect to POPs. Thus, here, we present the outcome of a systematic map (SM) to scope, screen and chart evidences from literature dealing with POPs in Polar regions. The SMs strive to produce rigorous guidelines and have recently been proposed as useful and effective tools to summarise growing bodies of research that seek to reduce bias and increase reliability, particularly in the case of high priority and controversial topics. Our SM was based on 125 polar studies, focussing on the most studied target species among those listed in the International Union for Conservation of Nature's Red List (IUCN Red List). To facilitate analysis of evidence, the studies were classified into Accumulation Monitoring (accounting for POP monitoring through sub-organismal, functional and population levels) and Food Web Monitoring approaches (accounting for contaminants monitoring through food webs). Our SM allowed us to assess and visualise, a set of both knowledge gaps and gluts and lastly a list was provided to address future research on POPs in Polar Regions. [ABSTRACT FROM AUTHOR]

We investigated the functional trait responses to 5 nm metallic silver nanoparticle (AgNPs) exposure in the Lessepsian-entry bivalve B. pharaonis. Respiration rate (oxygen consumption), heartbeat rate, and absorption efficiency were evaluated across an 8-day exposure period in mesocosmal conditions. Basal reference values from not-exposed specimens were statistically compared with those obtained from animals treated with three sublethal nanoparticle concentrations (2 μg L−1, 20 μg L−1, and 40 μg L−1). Our data showed statistically significant effects on the average respiration rate of B. pharaonis. Moreover, complex nonlinear dynamics were observed as a function of the concentration level and time. Heartbeat rates largely increased with no acclimation in animals exposed to the two highest levels with similar temporal dynamics. Eventually, a decreasing trend for absorption efficiency might indicate energetic constraints. In general, these data support the possible impact of engineered nanomaterials in marine environments and support the relevance of functional trait assessment in present and future ecotoxicological studies. [ABSTRACT FROM AUTHOR]

The blue crab Callinectes sapidus (Rathbun, 1896) is one of the most invasive species in the Mediterranean Sea. Understand how the populations are maintained and how the environment is driving the populations in the areas invaded is the key to an effective future management. This current study is presenting a monthly long-term monitoring of the blue crabs' population structure, body size, sexual maturity, reproduction periods and fecundity, and their relationships with environmental factors in a saltmarshes system in Italy. During winter, high densities (15 ± 8 ind m-2) of early juveniles (< 2 cm) were observed, and their numbers decreased due the population growth until summer. The size-spectra showed that across different temperature (18–26°C) and salinity (24–40 psu) gradients, the growth period for males is faster than for females. Based on abdominal analysis, sexual maturity was defined at ∼12 cm for males and females but the population was in favor of males that were more than 66% of the time mature throughout the year. Copulations periods were identified between spring and autumn when more than 50% of females were matures, and ovigerous females' migrations were observed in late summer. Our study expand our understanding of how the environment interacts to effect physiological and biological processes of alien species and improve our ability to make predictions of how environmental change the distribution of the alien species in the future. Based on our results, we also discuss which population control strategy would be most effective based on the data available in the literature. [ABSTRACT FROM AUTHOR]

The functional trait-based bioenergetic approach is emergent in many ecological spectra, from the conservation of natural resources to mitigation and adaptation strategies in a global climate change context. Such an approach relies on being able to exploit mechanistic rules to connect environmental human-induced variability to functional traits ( i.e. all those specific traits defining species in terms of their ecological roles) and use these to provide estimates of species life history traits ( LH; e.g. body size, fecundity per life span, number of reproductive events). LHs are species-specific and proximate determinants of population characteristics in a certain habitat. They represent the most valuable quantitative information to investigate how broad potential distributional boundaries of a species are, and to feed predictive population models. There is much to be found in the current literature that describes mechanistic functional trait-based bioenergetics models, using them to test ecological hypotheses, but a mathematical framework often renders interpretation and use complicated. Here, we wanted to present a simpler interpretation and description of one of the most important recent mechanistic bioenergetic theories: the dynamic energy budget theory by Kooijman (Dynamic Energy Budget Theory for Metabolic Organisation, 2010, Cambridge University Press, Cambridge). Our main aim was to disentangle those aspects that at first reading may seem too mathematically challenging to many marine biologists, ecologists and environmental scientists, and present them for use in mechanistic applications. [ABSTRACT FROM AUTHOR]

Cardiac activity (Arrhenius breakpoint temperatures and Q10 relationships) and heat shock response (hsp70 expression) were measured in the congeneric limpets Patella rustica, P. caerulea and P. ulyssiponensis in order to test the relationship between their vertical distribution and physiological thermal tolerance. These species exhibit different vertical distributions along Mediterranean shores and despite the narrow tidal range in the Mediterranean, they experience different environmental conditions and consequently had specific thermal windows. Cardiac activity of the upper zoned P. rustica was maintained at higher temperatures than its mid- or low shore counterparts, P. caerulea and P. ulyssiponensis. P. rustica had the highest Arrhenius breakpoint temperature (37.9±2.1°C, mean±SD), followed by P. caerulea (35.9±2.6°C), and finally the low-zoned P. ulyssiponensis (32.2±2.3°C). The same pattern was found for Q10 relationships. Expression of hsp70 increased at 34°C and kept increasing with temperature in P. rustica. In P. caerulea, expression reached a maximum at 36°C and decreased at 38°C, suggesting that hsp70 expression in P. rustica provides a more efficient defence against thermal stress than in P. caerulea. As summer environmental temperatures in the Mediterranean regularly reach 35 to 38°C, performances of these limpets suggest that they are already living at the edges of their thermal window, and further temperature changes may have large-scale consequences for these keystone species. [ABSTRACT FROM AUTHOR]

Highlights: [•] We used a Dynamic Energy Budget (DEB) model with data from buoys and from IPCC A1B climatic hindcasts and forecasts. [•] Models provided estimates of growth and reproductive output of the mussel Mytilus galloprovincialis. [•] We ran models using five different temporal resolutions of weather data around the Italian peninsula. [•] Model skill can diverge when outputs of climate models are applied to biological issues if temporal resolution is not considered. [•] Mismatches of scale between physical drivers and biological responses can significantly decrease confidence in model skill. [Copyright &y& Elsevier]

Captive-induced behavioural deviations may involve many aspects of fish behaviour such as swimming activity and enhancement of individual aggressiveness. We studied seabass (Dicentrarchus labrax) behaviour as a function of manual and automatic feeding distribution modes. Under manual mode, the food is distributed over an extended area for a longer period, and its precise location is not always predictable, while with pneumatic automatic feeders, fish receive the same amount of resource, which is concentrated in the same surface area over a shorter period. We compared seabass behaviour under automatic and manual conditions collecting video image recordings before, during, and after feeding distribution, in the morning and in afternoon, on two different days, and analysing data within independent sessions of measurements. Feeding modes significantly affected swimming behaviour: automatically- fed fish were characterised by vertical movements through the water column (towards the surface and bottom) and by horizontal swimming. Manually-fed fish were instead characterised by sharp direction changes during their swimming, mostly towards the surface. Feeding distribution induced changes in collision frequency and elicited aggressive behaviour. In particular, agonistic behaviour (i.e. a fish attacks another fish) was almost exclusively recorded during the feeding under automatic distribution, whereas it was constantly expressed during all the distribution phases under manual mode. [ABSTRACT FROM AUTHOR]

The ‘scope for growth’ (SFG) tool was used to study the growth performance of cultivated populations of Mytilus galloprovincialis (Lmk., 1819) in an oligotrophic area of the Southern Mediterranean Sea. The study was carried out between 1993 and 1996 by using data from four seasonal oceanographic cruises and from growth experiments. Water samples were collected and analysed for total suspended matter (TSM), particulate organic carbon (POC) and nitrogen (PON), particulate lipids, proteins and carbohydrates and chloropigments. The sum of the carbon equivalents of carbohydrates, proteins and lipids is indicated as the total biopolymeric particulate organic carbon (BPC) and was converted into a unit of energy in order to calculate the SFG of a theoretical mussel of 5 cm length. In order to test the performance of mussel growth at two depths (5 and 15 m water depth), mussel body size [as ash free dry weight (AFDW)] and the actual concentrations of BPC were used to calculate the monthly SFG using the physiological energetic relationships suggested in the current literature. Data from the field cruises led us to characterise the study site as ultra-oligotrophic (annual average of chloropigment concentration approximately 0.5 μg L−1). SFG calculations allowed us to identify a site where mussels grown successively were found to reach a commercial size in approximately 12 months. The good agreement obtained between energetic response and subsequent production response suggests that the available energy from particulate food could be fully available for organic production for maintaining “proportionate” growth trajectories, even in a ultra-oligotrophic system. [ABSTRACT FROM AUTHOR]

The effects of aquaculture on the ecology of the water column have been extensively studied in the last two decades. However, to date, it has not been possible to extrapolate homogeneous information from the peer-reviewed literature. In the present study, 68 peer-reviewed articles were analysed and about 1087 study cases were used to test whether worldwide cultivations of aquatic organisms (shrimps, fish, bivalves and polyculture) have a differential effect on living and non-living fractions of the water column (suspended matter, chlorophyll-a, particulate organic carbon, nitrogen and phosphorus, bacteria and plankton). Meta-analysis feasibility depends on obtaining an estimate of the effect size from every study, and the most common measure of effect size (Hedges’d) is the difference between means of controls and impacts standardised by dividing by the pooled standard deviation. Shrimp, fish and bivalve cultivation differentially affected water column dynamics, with a general major impact on bacteria and phytoplankton. In addition, results showed that the water column dynamics are probably affected by organic aquaculture loading but, due to the substantial heterogeneity across studies, the information available on the effects can be considered partially flawed and therefore not sufficient to either support or exclude the notion that different forms of aquaculture affect ecological processes of the water column. [Copyright &y& Elsevier]

The bluefin tuna, Thunnus thynnus (Linnaeus 1758), is biologically and economically important in the Atlantic—Mediterranean ecosystems. Bluefin tuna feed on diverse food items depending on their age, thus they occupy different trophic levels during their lifespan. Hexachlorobenzene (HCB), p,p′-DDE and polychlorinated biphenyls (PCBs) are well-known persistent organic pollutants (POPs) in the Mediterranean basin. The relationship between stable isotopes of nitrogen (N) and the POP residue levels in tissues has recently increased knowledge on the link between the trophic levels and the contaminant accumulation. Trophic levels were estimated by using 15N/14N ratio (δ15N) and HCB, p,p′-DDE, and forty-three PCBs were quantified in bluefin tuna from the southern Tyrrhenian Sea. Results showed that changes in PCB and p,p′-DDE concentrations were a function of size and trophic level, while no correlations were observed for HCB. Apart from HCB and PCB nos. 101, 207, 95, 158, and 60 + 56, which did not show any significant increase per trophic level, the other PCBs and the p,p′-DDE increased significantly. The ontogenetic magnification factor of PCBs was 6.6 ± 0.5, which was significantly (12 times) higher (p < 0.05) than the values found for p,p′-DDE (1.4) and HCB (1.4). [ABSTRACT FROM AUTHOR]

More than 30 peer-reviewed articles (1980-2005) were analysed using meta-analytical reviewing techniques, and about 340 study cases were used to test whether aquaculture facilities had any effects on physical and chemical variables. The analysis tested differences between experimental conditions vs. chosen-by-author controls. Across all study cases, cultivated organisms (fish, shrimps and bivalves) did not have any clear effects on the water temperature and salinity. Dissolved oxygen also was found to be unaffected by aquaculture practices. On the other hand, crowding led to significant pH variations, which was more accentuated in shrimp (d+=0.66; P<0.05) than in fish farming plants (d+=-0.15; P>0.05). Water transparency and turbidity were significantly affected by shrimps and fish farming. [ABSTRACT FROM AUTHOR]

Fouling species richness, abundance and composition and biomass were chosen as the descriptors of effect of fish farm organic enrichment. The study was carried out in September 2004 in the Gulf of Castellammare (South Tyrrhenian, Mediterranean). The fouling species were sampled from plastic buoys spaced throughout the study area both up- [UP] and down-stream [DOWN]. The results showed that fouling community responded to the chronic input of allochthonous organic matter experiencing local changes more or less significantly with regard to abundance, species composition and general community diversity. Upper fouling would work as a first filter naturally opposed by environment resistance assimilating and facilitating the accommodation of most organic surplus. In highly hydrodynamic and sufficiently deep systems, the transport of organic particles produced from farms would have an effect along the horizontal axis rather than along the vertical axis, involving upper located benthic organisms rather than sedimentary benthic organisms. [ABSTRACT FROM AUTHOR]

Relationships among chemical–physical features, total gross suspended organic matter, coverage of the seagrass Ruppia cirrhosa and its associated algal community in eight ponds of a saltworks system of western Sicily (Mediterranean Sea) were investigated in spring and summer 2004. All biological features varied both at different levels of seagrass coverage and between seasons. A low algal diversity (46 taxa, 14.75 ± 1.41 on average) was highlighted; algal coverage and species richness showed to be negatively correlated. Ruppia cirrhosa coverage was negatively correlated with algal coverage, but positively correlated with species richness. Moreover, a significant correlation among R. cirrhosa coverage, the availability of suspended matter in the water column and the chlorophyll a concentration was detected. [ABSTRACT FROM AUTHOR]

The carbon and nitrogen isotopic compositions of fractions of the seagrass Posidonia oceanica (L.) Delile in a Mediterranean shallow environment (Stagnone di Marsala, western Sicily) were investigated seasonally throughout 1998. The stable isotope ratios of seagrass leaves (intermediate and adult), rhizomes, leaf litter and aegagropiles were compared over 1 year in order to distinguish between seasonal and plant part variability. Significant differences in the isotopic composition tested using ANOVA were observed as a function of both plant fraction and season. There was an overall trend towards less discrimination against 13C in summer (average δ13C ∼ −10‰) than in winter (average δ13C ∼ −13‰). In contrast, greater δ15N enrichment was observed in winter (average ∼ 5‰) than in summer (average ∼ 3‰). The possibility of a link between δ13C and δ15N seasonal variability and seagrass physiology such as plant carbon balance and reserve dynamics is proposed to explain the observed patterns. The demonstration of seasonal and plant fraction variability in P. oceanica isotopic composition provides a broader perspective to seagrass ecological and physiological studies. Overall, the observed variability can be up to 4 and 5‰ for δ13C and δ15N, respectively, a range that largely exceeds that associated with the transition between consecutive trophic levels (1 and 3.5‰ for δ13C and δ15N, respectively).Our results corroborate the need for, at least, seasonal sampling designs to obtain a good understanding of organic matter fluxes into food webs and highlight the limitations in drawing general conclusions about food webs where a low seasonal sampling effort has been applied. They also suggest that stable carbon and nitrogen isotope ratios deserve attention as a possible valuable approach in seagrass ecophysiological studies. [Copyright &y& Elsevier]

. ω13C and ω15N of organic matter sources and consumers were employed to analyse trophic differentiation between a benthic consumer, Gobius niger (L., 1758) (Pisces, Osteichthyes), and a pelagic consumer, Atherina boyeri (Risso, 1810) (Pisces, Osteichthyes) in a Mediterranean coastal lagoon (Lake of Sabaudia) in winter and summer 1999. Trophic differences between the two species throughout the two sampling periods were related to the environmental trophic condition (i. e. nutrient and phytopigment concentrations). Although these two fish have different habitats, they both exploited benthic organisms, above all in summer. When the nutrient and phytopigment concentrations were higher (summer), the most abundant benthic organisms were the main food sources for both species. In winter A. boyeri apparently shifted its feeding preferences to include zooplankton, confirming its opportunistic feeding strategy. Par-ticulate organic matter and algae seemed to play the main trophic role in the food web structure. Benthic invertebrates used both sources, while zooplankton seemed to rely exclusively on the particulate fraction. The overlapping and very depleted signatures of sedimentary and particulate organic matter highlights a strong link between sediments and water column, rarely observed in other aquatic ecosystems using stable isotopes. Such a finding further substantiates the importance of particulate organic matter as a food source in the study area. [ABSTRACT FROM AUTHOR]

Reef restoration has gained attention as it has strategic actions and powerful means in sustaining and maintaining coastal ecosystem services. This scientometric study systematically analyzes the current trends and research hotspot in coral restoration across the last five decades (1971–2022). The metadata (12,667 articles with 652,860 cited references) were obtained from the Clarivate Web of Science platform through the Core Collection database, associated with the CiteSpace and R‐software for further analysis. The results indicated that the trend of coral restoration is increasing in paper/year, with the United States, Australia, and China as major contributors to the related research. Furthermore, James Cook University, Australia had the largest number of articles, and the Consortium of Research Libraries of the United Kingdom was the most influential institution on coral restoration. The highly cited keywords are "Great Barrier Reef," "climate change," and "coral reef," while the most influential keywords are "coral," "model," and "Atlantic." A total of 23 clusters in the field with "coral reef," "phase shift," "bacterial communities," "coral restoration," "symbiotic dinoflagellate," "stony coral tissue loss disease," "bleaching event," "ocean acidification," "oyster reef," and "quantitative reconstruction" are among the top cluster size labeled. Early‐stage researcher may use both keywords and cluster analysis to find topics attractive to their future research projects. In addition, this study contributes toward evaluating recent scientific productivity about coral restoration as well as informing researchers and policymakers regarding funding, future strategic planning, and potential collaboration opportunities. [ABSTRACT FROM AUTHOR]

The studies on the bioinvasion phenomenon focus mainly on the biological and ecological traits of a species, while scattered literature is addressed to a correct systematic assessment and an updated geographical distribution on the whole. It is noteworthy that non-indigenous species should be monitored on both sides of their range, i.e., towards the front of dispersal and beyond the original range. The backside range boundaries are not often monitored or well delimited; thus, the novel global distribution of an invasive taxon is not often accurately delimitated. A model species for highlighting criticisms about the scarce knowledge on the novel range was chosen. Brachidontes pharaonis is a mussel that has successfully colonised the Mediterranean Sea, following an immigration pathway through the Suez Canal from the Red Sea, presumably from a wider Indo-Pacific area. In this case, the Indo-Pacific boundaries have been overlooked and are still misunderstood due to diverse causes, principally as the synonymy with the congeneric B. variabilis has created confusion in the taxonomic identification. The present review demonstrates that the borders of the B. pharaonis range are still unclear and that the species should be analysed in a wider geographical area. Records of B. pharaonis from Southeast Asia should be treated with caution as this area is out of its range. The Indian and Pacific Oceans host the taxon B. variabilis, composed of two potential cryptic species. Data from the literature highlight the importance of the integrative taxonomic approach to solving various issues concerning the species group complex, morphological variations and cosmopolitan claims of species. [ABSTRACT FROM AUTHOR]

The freshwater jellyfish Craspedacusta sowerbii is one of the most widespread invasive species, but its global distribution remains uncertain due to ephemeral appearances and general lack of information in various aquatic environments. The aim of this study was to map current and future distributions (2050 and 2100) using Species Distribution Models allowing to visualize the habitat suitability and make projections of its changes under potential climate change scenarios. Except in Oceania where the range decreased, an expansion of C. sowerbii was projected during the next century under modeled future scenarios being most intensive during the first half of the century. The present study shows that the expansion of C. sowerbii worldwide would be facilitated mainly by precipitation, vapor pressure, and temperature. The predictions showed that this species over the eighty years will invade high-latitude regions in both hemispheres with ecological consequences in already threatened freshwater ecosystems. [ABSTRACT FROM AUTHOR]

The studies on the variation of acoustic communication in different species have provided insight that genetics, geographic isolation, and adaptation to ecological and social conditions play important roles in the variability of acoustic signals. The dolphin whistles are communication signals that can vary significantly among and within populations. Although it is known that they are influenced by different environmental and social variables, the factors influencing the variation between populations have received scant attention. In the present study, we investigated the factors associated with the acoustic variability in the whistles of common bottlenose dolphin (Tursiops truncatus), inhabiting two Mediterranean areas (Sardinia and Croatia). We explored which factors, among (a) geographical isolation of populations, (b) different environments in terms of noise and boat presence, and (c) social factors (including group size, behavior, and presence of calves), were associated with whistle characteristics. We first applied a principal component analysis to reduce the number of collinear whistle frequency and temporal characteristics and then generalized linear mixed models on the first two principal components. The study revealed that both geographic distance/isolation and local environment are associated with whistle variations between localities. The prominent differences in the acoustic environments between the two areas, which contributed to the acoustic variability in the first principal component (PC1), were found. The calf's presence and foraging and social behavior were also found to be associated with dolphin whistle variation. The second principal component (PC2) was associated only with locality and group size, showing that longer and more complex tonal sound may facilitate individual recognition and cohesion in social groups. Thus, both social and behavioral context influenced significantly the structure of whistles, and they should be considered when investigating acoustic variability among distant dolphin populations to avoid confounding factors. [ABSTRACT FROM AUTHOR]

Simple Summary: Climate change is significantly impacting the structure and functioning of marine communities through temperature rise and the repeated occurrence of temperature spikes and marine heat waves. The present study investigated the metabolic responses of the sponge Chondrilla nucula, an important component of benthic ecosystems in the Mediterranean Sea, to temperature. Organisms were exposed to six different temperatures ranging from 15 to 32 °C, and respiration and clearance rates were measured. The results revealed temperature-dependent effects on both traits. Higher temperatures correlated with increased respiration rates, peaking at 26 °C. In contrast, clearance rates declined beyond 26 °C, signifying reduced food intake not mirrored by respiration rates. This response at high temperatures implied a potential negative energy balance, suggesting vulnerability to chronic or repeated thermal stress. Consequently, this study predicted the susceptibility of C. nucula to climate change conditions, with potential repercussions for its metabolic performance, ecological role, and the associated ecosystem services it provides. As a result of climate change, the Mediterranean Sea has been exposed to an increase in the frequency and intensity of marine heat waves in the last decades, some of which caused mass mortality events of benthic invertebrates, including sponges. Sponges are an important component of benthic ecosystems and can be the dominant group in some rocky shallow-water areas in the Mediterranean Sea. In this study, we exposed the common shallow-water Mediterranean sponge Chondrilla nucula (Demospongiae: Chondrillidae) to six different temperatures for 24 h, ranging from temperatures experienced in the field during the year (15, 19, 22, 26, and 28 °C) to above normal temperatures (32 °C) and metabolic traits (respiration and clearance rate) were measured. Both respiration and clearance rates were affected by temperature. Respiration rates increased at higher temperatures but were similar between the 26 and 32 °C treatments. Clearance rates decreased at temperatures >26 °C, indicating a drop in food intake that was not reflected by respiration rates. This decline in feeding, while maintaining high respiration rates, may indicate a negative energy balance that could affect this species under chronic or repeated thermal stress exposure. C. nucula will probably be a vulnerable species under climate change conditions, affecting its metabolic performance, ecological functioning and the ecosystem services it provides. [ABSTRACT FROM AUTHOR]

Abstract The on-going climate change threats are rapidly growing at both global and local scales, affecting ecosystems, societies and economies by altering natural distribution and productivity of key commercial species. Although the ecosystem based management (EBM) focuses on ecosystem equilibria, to provide realistic management measures for important activities at sea such as fisheries and aquaculture, there is a need of quantities; mechanistic approaches are suggested as reliable solutions. Here, a Dynamic Energetic Budget (DEB) application studies the link between environmental change (temperature forecasted increasing scenario in a context of COP 21 [Paris climate conference Agreement] and food density increase) and life-history traits of some Mediterranean fishery and aquaculture target species (Engraulis encrasicolus , Dicentrarchus labrax , Mytilus galloprovincialis , Crassostrea gigas). A sensitivity analysis was applied to simulate the effects of future environmental change on the time needed to reach the commercial size and the length at first maturity. We also explored the efficiency of Integrated Multitrophic Aquaculture (IMTA) as a potential management solution in a context of an adaptive EBM. The worst scenario of rising temperatures (+2 °C) seems to reduce the time needed to reach the commercial size in most species and IMTA potentiates the thermal effect on it. A spatial contextualisation of model outcomes allowed disentangling potential conflicts among human activities at sea. The DEB based life history traits approach can provides quantities to inform the management of marine activities at local scale additionally allowing translating complex results into useful figurative representations for stakeholders. Highlights • DEB shows that fishery and aquaculture will be affected by increasing temperature • IMTA trophic enrichment seems to accelerate the time to reach the commercial size • Spatial mapping facilitates the stakeholders dialogue and the design of measures [ABSTRACT FROM AUTHOR]

In this work the influence of habitat complexity on fish assemblages associated with extractive platforms in the Mediterranean Sea was investigated. More specifically, at large spatial scale we tested the differences in fish assemblage between 4-legs vs 8-legs platforms, whereas at medium scale we evaluated, within each platform, the differences between internal structures with increasing complexity degrees (respectively: the water volume without any pillar - complexity "0"; the junction of two pillars - "1"; the junction of four pillars - "2"). Both univariate and multivariate analyses showed highly significant differences for each of the tested factors, as well as for their interaction. In general, at both medium and large spatial scales, mean species richness and abundance were positively correlated with the increasing habitat complexity with the highest values associated with 8-legs platforms and with the most complex internal structures within each platform. According to our findings, a more complex structure is able to attract more fish species and specimens than a less complex one, supporting previous studies carried out on different man-made structures outside the Mediterranean Sea. The study will integrate the still poor available knowledge baseline on the attractive potential of extractive platforms with strong implications for the environmental management under the incoming light of decommission in the basin. [ABSTRACT FROM AUTHOR]

Eutrophication affects coastal oceans worldwide, modifies primary production and sediment biogeochemistry and, overall, is progressively compromising marine ecosystems' integrity. Because of their known bioturbation ability, sea cucumbers are supposed to be candidates for mitigating benthic eutrophication. To provide insights on this, we investigated differences in organic matter quantity and biochemical composition (as proxies of benthic trophic status) of sediments and feces of the sea cucumber Holothuria tubulosa acclimated in mesocosms at temperatures comprised between natural conditions (14–26 °C) and an extreme of 29 °C (representing the highest anomaly under heat waves in the Mediterrranean Sea). Organic matter features differed significantly between sediments characterized by different trophic statuses and the holothuroid's feces, though with some exceptions. Feces resulted almost always organically enriched when compared with the ambient sediments, though with variable differences in composition in sediments characterized by different initial trophic status. Our results point out that sea cucumbers maintain their bioreactor capacity at all experimental temperatures including the (anomalous) highest one, irrespectively of the available food, suggesting that they could be profitably utilized to mitigate benthic eutrophication also in a warmer Mediterranean Sea. [ABSTRACT FROM AUTHOR]

SECTION C: RELATING BIODIVERSITY, FUNCTIONAL TRAITS, AND ECOSYSTEM FUNCTIONING The functional diversity of communities provides an additional dimension of biodiversity that complements more traditional taxonomic measures such as species richness and evenness. Aquatic ecosystems (both marine and freshwater) have long served as model systems for exploring the role of environmental stressors on organismal performance and survival, the biogeographic distributions of populations and species, and ultimately the diversity, functioning, and stability of ecosystems (Adams, 2002; Forbes, 1887; MacArthur & Wilson, 2001; Paine, 1969; Somero et al., 2017). In this special issue, Jamwal et al. (2022) use the Climate Niche Factor Analysis (CNFA) framework (Rinnan & Lawler, 2019) combined with species distribution models to evaluate the vulnerability of three species of Himalayan Otter ( I Lutra i spp.) to the combined exposure to future climate and land use changes in the Himalayan region. Climate change, alien species invasions, land use change, urbanization, and other anthropogenic impacts have all been demonstrated to impair aquatic ecosystems at multiple levels of biological organization within aquatic ecosystems (Karr, 1991; Doney et al., 2012; Harley et al., 2006; Poloczanska et al., 2013). [Extracted from the article]

Management of fish populations and ecosystems suffers from data and knowledge gaps, particularly with respect to how humans and nature affect dynamics at multi‐decadal and longer time scales. However, collection of new data which indicates population or ecosystem status is slow and expensive. Here we analyse c. 110 years of neglected fishery data for an overexploited top predator, swordfish, in the Mediterranean Sea. These data are available at scales of high time–space–biological resolution (i.e., sub‐weekly, sub‐regional sea; individual weights) and allow different ecological questions to be addressed than is possible with coarsely scaled data (e.g., annually resolved total catches aggregated over large sea areas). We constructed regional indicators of population status (relative abundance, mean individual size and its variability, migration phenology) covering most of the 20th century, and pre‐dating other population datasets by 50–70 years. The length and duration of these new time series allowed detection of significant multi‐annual/decadal variations in abundance and mean weight not detectable in shorter, more recent time series. These new data and evidence of multi‐annual variability in population variables improve knowledge of Mediterranean swordfish ecology. The findings provide a new basis on which further historical data recovery and analysis of contemporary data can provide new perspectives and opportunities for quantifying vulnerability of populations to exploitation and climate change. [ABSTRACT FROM AUTHOR]

The mechanistic approach and the potential predictive power of Dynamic Energy Budget (DEB) models are making this modelling framework increasingly popular in aquaculture management. The potential to mechanistically simulate life-history traits of a species in a changing environment has already been applied to many commercial species, including the New Zealand Greenshell™ mussel Perna canaliculus. However, the previous P. canaliculus model parameterisation, available in the Add-my-Pet (AmP) collection, has been carried out on a limited data set. We used data obtained through targeted laboratory experiments and combined it with literature data, to derive a new version of the model which included information on additional processes – such as feeding, respiration, and reproduction – and life stages: larvae and adults. We compared the performance of the previous version of the model, termed AmP-2018 with the revised model (AmP-2024), to predict the whole life-cycle of the mussel and life-history traits of interest in the context of aquaculture. The entry completeness score (0−10), which provides an indication of data quality and variety as well as model comprehensiveness and applicability, increased dramatically from 2.5 to 5.5, suggesting P. canaliculus is now the most comprehensively DEB-parameterised bivalve, while the model increased in accuracy of the predictions. The endeavour highlights several conclusions: (i) reliable temperature response data are required to establish the thermal response curve; the presence/absence of this type of data should be taken into account when assessing the completeness of a model and its applicability to predict thermal responses of a species; (ii) species-specific parameter values are preferred over general (higher taxonomic level) specific values, e.g. for tissue organics and water content, as they increase the accuracy of predictions; (iii) data pertaining to laboratory trials and to wild populations both need to be taken into account when calibrating a mechanistic model at a species level; and (iv) calculating energy requirements of any organism, including bivalves, requires data on characteristics and products often overlooked in an experimental setting. We discuss the new version of the model in the context of the knowledge and predictive power potentially gained by adding more information and data during model calibration. The obtained results and conclusions are especially relevant in aquaculture, whether for commercial rearing of mussels, or their potential application in multitrophic aquaculture systems. [Display omitted] • A DEB model for Perna canaliculus was reparameterised with targeted experimental and literature data. • The model can realistically predict the growth, development (including larval stage), and reproduction of the mussel. • Quality thermal response data is crucial for assessing thermal response curves in DEB models. • Both ex-situ and in-situ data should be considered for species-level calibration in DEB models. • We discuss calculations for closing an energy and/or mass budget in an experimental setting. [ABSTRACT FROM AUTHOR]

This commentary describes a gap in the qualitative and quantitative knowledge of the provision of benefits to humans from the intertidal ecosystems of the Mediterranean and offers a framework for quantification of the benefits provided by these systems. The identification of such benefits, understanding their spatial distribution and their subsequent quantification will be critical to the design of policy responses to future climate change, sea level rise and seawater acidification. A baseline understanding of the current state of ecosystem functions, as well as of the provision of related ecosystem services, is therefore needed. Further, researchers must strive to generate forecasts of the changes in these functions and services conditional on policy responses and the range of expectations for climate change. [ABSTRACT FROM AUTHOR]

There is some evidence that the presence of Tursiops truncatus in fishing areas represents a real economic threat to fishermen due the dolphin feeding on the entangled fish, damaging the nets and reducing the fish catch. We have carried out experiments to assess the efficiency of a pinger in decreasing the interaction between the dolphins and fishing nets, in a fishing area off the coast of southern Italy, where Tursiops truncatus is frequently observed to interact with bottom gill nets. Two identical monofilament bottom gill nets (900 m long), one equipped with pingers and the other without, were used to measure the effect of these pingers on the abundance of the catch and net damage. For each haul (58 in total), data on dolphin sightings near the nets, damage judged to have been done by dolphins, weight and species composition of the catch were collected. All damage to the nets were recorded at the end of each haul. Dolphins in the fishing area were sighted 11 times out of 29 fishing activities (38%). The net equipped with pingers contained 28% more fish (biomass) than the net without pingers ( t test, P < 0.04) and was less damaged (−31%, t test, P < 0.01). To assess whether the efficacy of these pingers remain constant over long period, long-term experiments should be carried out. [ABSTRACT FROM AUTHOR]

MAP: Figure 1 Panels (a-c) Maps showing locations of bluefin tuna traps whose swordfish bycatch data were retrieved from historical fishing reports and accounts and geographic features mentioned in the text. The size data from the traps can be used to derive ages from growth relationships in the literature (Abid and Idrissi, 2006; Tserpes and Tsimenedes, 1995), and, when compared with the known size- or age-at-maturity schedules for Mediterranean Sea swordfish (Abid and Idrissi, 2006; ICCAT, 2020), indicate the likelihood that the traps capture adults or juveniles. Some reports also mention bycatches of swordfish (Ambrosio and Xandri, 2015; ICCAT, 2020; Rodríguez-Roda, 1964), but the quantities and sizes have so far not been compiled or analysed; consequently the potential value of the traps for generating new insights into the long-term dynamics of swordfish ecology is unknown. Furthermore, historical trap data could be combined with more contemporary catch data (e.g., from longlines or harpoons; Perzia et al., 2016; Tserpes et al., 2008) including other Mediterranean swordfish fisheries to investigate spatial aspects of swordfish reproductive and migratory behaviour. [Extracted from the article]

Over the years, concern about the effects of microplastics has grown. Here, we answered the main question "What are the impacts of microplastics on the functional traits of fish species?" through a meta‐analysis. The general impact of microplastic exposure on the functional traits of fishes and specifically on eight variables, namely, behaviour, development, fecundity, feeding, growth, health, hatching and survival was explored. Subgroup analyses were performed to detect correlations between the impact of microplastics and the following factors: species, life stage, habitat, water column habitat, day of exposure to microplastics and microplastic size, type and shape. A meta‐regression analysis allowed understanding the correlation between the impact of microplastics and the size of organisms. Generally, microplastics have a negative effect on the functional traits of fishes. Feeding and behaviour, followed by growth showed the greatest impact. Among the subgroup analysis, four of the eight variables considered showed a significant difference between groups: species, life stage, microplastic shape and days of exposure to microplastics. Depending on their life stage, organisms may be more sensitive to microplastic pollution. Changes in growth rates, development of early life stage and behavioural patterns in fishes may have a negative effect on the structure and functions of aquatic ecosystem in the long term and consequently affect the ability of aquatic ecosystems to provide ecosystem services and sustain human communities. [ABSTRACT FROM AUTHOR]

Management of marine fisheries and ecosystems is constrained by knowledge based on datasets with limited temporal coverage. Many populations and ecosystems have been perturbed long before scientific investigations have begun. This situation is particularly acute for the largest and commercially most valuable species. We hypothesized that historical trap fishery records for bluefin tuna, Thunnus thynnus, could contain catch data and information for other, bycatch species, such as swordfish, Xiphias gladius. This species has a long history of exploitation and is presently overexploited, yet indicators of its status (biomass) used in fishery management only start in 1950. Here we examine historical fishery records and logbooks from some of these traps and recovered ca. 110 years of bycatch data (1896-2010). These previously-neglected, but now recovered, data include catch dates and amounts in numbers and/or weights (including individual weights) for the time period before and after major expansion of swordfish fisheries in the Mediterranean Sea. New historical datasets such as these could help understand how human activities and natural variability interact to affect long-term dynamics of this species. [ABSTRACT FROM AUTHOR]

A responsible approach to marine stock enhancement is an effective approach to restore fishery resources. While the release strategy of target species has been well investigated, the impacts on local ecological equilibrium and habitat qualities have only been poorly considered. In the present study, we evaluated how the macro-benthic food web in Daya Bay was affected by purple sea urchin (Heliocidaris crassispina (Agassiz, 1864) stock enhancement using stable isotope analyses (δ13C and δ15N). Our results indicated that the distribution of local species and trophic diversity were influenced to a certain degree by release of purple sea urchins and changes in the feeding habit of the urchins were observed in line with food abundance, which seasonally varied. When food is abundant, the main food source of sea urchins was microphytobenthos and no significant differences were observed among sites; significant differences in the diet of purple sea urchins were detected when food is less abundant. These results suggested that optimization of the release strategy should include information on seasonal productivity of local recipient sites, food web structure and feeding habits of released species. Such information is essential for building a responsible release approach to maximize production enhancement. • The study estimated the success of purple sea urchin stock enhancement at Chinese coastal benthic food web. • Stable isotopes allowed to investigate whether stock enhancement caused changes of the purple sea urchin's feeding habit. • Stock enhancement actions was absorbed by the recipient communities with no significant shocks of recipient trophic dynamics. • Optimization of the release strategy should include information on food web structure and feeding habits of released species. [ABSTRACT FROM AUTHOR]

Aim: Understanding and quantifying the seasonal patterns in biodiversity of phytobenthos, macro‐zoobenthos and fishes in Mediterranean coastal lagoons, and the species dependence upon environmental factors. Location: The study was carried out in the "Stagnone di Marsala e Saline di Trapani e Paceco," the largest coastal lagoon system in the central Mediterranean Sea (Sicily, Italy), a Special Protection Area located along one of the central ecological corridors joining Africa and Europe. Methods: The coastal lagoon system was selected as a model ecosystem to investigate the seasonal variations in biodiversity indices and dominance–diversity relationships in phytobenthos, macro‐zoobenthos and fishes, and how seasonal variations in temperature, salinity, depth, inorganic and organic suspended matter affect the abundance of the species constituting these communities. Models of ecosystem structure, describing the interactions among functional groups and environmental variables, were also developed using confirmatory path analysis and artificial neural networks to exemplify their application in predicting temperature‐driven alterations. Results: Wide seasonal variations in biodiversity indices and dominance–diversity relationships across the communities of the coastal lagoon system were observed, driven by the dynamics in climate and resource availability. The effects of the environmental variables on taxon abundances varied in relation to the community, with the widest responses elicited in phytobenthos and fishes. Temperature was the main variable affecting taxon abundances in macro‐zoobenthos and was also the major driver of shallow water ecosystem structure. Main conclusions: This research shed light on the seasonal variations in biodiversity of Mediterranean coastal lagoons, elucidating also the tight dependence of phytobenthos, macro‐zoobenthos and fish diversity upon environmental factors. The findings and the methodological approach proposed may be crucial in developing models able to predict future climate‐driven alterations in communities inhabiting these important and threatened ecosystems. [ABSTRACT FROM AUTHOR]

Fish farm deposition, resulting in organic matter accumulation on bottom sediments, has been identified as among the main phenomena causing negative environmental impacts in aquaculture. An in situ bioremediation treatment was carried out in order to reduce the organic matter accumulation in the fish farm sediments by promoting the natural microbial biodegradation processes. To assess the effect of the treatment, the concentration of organic matter in the sediment and its microbial degradation, as well as the response of the benthic prokaryotic community, were investigated. The results showed a significant effect of the treatment in stimulating microbial degradation rates, and the consequent decrease in the concentration of biochemical components beneath the cages during the treatment. During the bioremediation process, the prokaryotic community in the fish farm sediment responded to the overall improvement of the sediment conditions by showing the decrease of certain anaerobic taxa (e.g. Clostridiales, Acidaminobacteraceae and Caldilinaceae). This suggested that the bioactivator was effective in promoting a shift from an anaerobic to an aerobic metabolism in the prokaryotic community. However, the larger importance of Lachnospiraceae (members of the gut and faecal microbiota of the farmed fishes) in treated compared to non-treated sediments suggested that the bioactivator was not efficient in reducing the accumulation of faecal bacteria from the farmed fishes. Our results indicate that bioremediation is a promising tool to mitigate the aquaculture impact in fish farm sediments, and that further research needs to be oriented to identifying more successful interventions able to specifically target also fish-faeces related microbes. Image 1 • Bioremediation reduces the accumulation of organic matter in fish farm sediments. • The bioactivator stimulates in situ microbial degradation processes. • Bioremediation induces shifts in prokaryotic community composition. • A shift from anaerobic to aerobic prokaryotic metabolism is promoted. • The treatment is ineffective on the fecal bacteria from farmed fishes. [ABSTRACT FROM AUTHOR]

Extreme climate events are increasingly challenging the growth of the marine aquaculture sector, causing local influences on species performance and affecting production and yield - impacting where to locate cage aquaculture facilities. Here we produced scenario-based quantitative maps using modelled species-specific performance combined with predicted high-resolution future IPCC temperature scenarios. We ran a species-specific Dynamic Energy Budget mechanistic model for four model species, up to 2050, and mapped functional trait-based outcomes as: i) time to reach the commercial size, ii) feces produced and iii) uneaten food. A high spatial resolution suitability index allowed the sustainability of farming strategies for single- and multi-species to be identified across a 159.696 km2 surface extension (Italian Exclusive Economic Zone; 6% of the Mediterranean basin surface). Providing a good case study to shed light on difficult questions facing aquaculture planning around the world. Good future performance under both representative concentration pathway (RCP) scenarios were modelled for Sea bream and European seabass in inshore waters. Performance of Mediterranean mussels and Japanese oysters was found to decrease slightly when compared to the 2007–2010 time interval. Scenario-based quantitative maps represent a heterogeneous species-specific knowledge layer that is critical to better inform aquaculture management and development strategies. Yet this knowledge layer is missing from the process to develop climate-resilient risk maps and associated adaptation measures, as well as when informing stakeholders on potential site expansion and/or the establishment of nascent aquaculture industry sites. • The siting of aquaculture facilities is threatened by climatic extremes events • Species performance is influenced by climatic extreme events • Scenario-based quantitative maps are based on species-specific modelled performance • Our modelled performance incorporates high-resolution future temperature predictions • We produced a high spatial resolution suitability index across a 159.696 km2 extension [ABSTRACT FROM AUTHOR]

The green lipped mussel, Perna viridis , is an important aquaculture species throughout the Indo-Pacific region where production is often impacted by environmental degradation. To predict the impacts and mitigate against environmental problems due to various kinds of anthropogenic pollution, such as heavy metals and eutrophication, on P. viridis aquaculture a Dynamic Energy Budget (DEB) model was constructed. By integrating species-specific parameters and regional-specific environmental data the DEB model determined how the life history traits of P. viridis respond to changing environmental conditions. Using various levels of basal maintenance costs and food availability to elucidate the energetic costs due to environmental pollution, the DEB model predicted that a 20% increase in basal maintenance cost due to environmental pollution such as heavy metals will result in a subsequent decrease in both lifetime reproductive output and ultimate body size of P. viridis by ~18% and ~8%, respectively. Increasing food availability can, however, mitigate the energetic constraints due to increased basal maintenance cost. The time to reach commercial size, for example, will be longer by 13% and 3% under lower and higher food availability conditions, respectively when there is a 20% increase in maintenance cost due to environmentally induced stress, which would significantly increase the operational cost of an aquaculture facility. In light of the increased importance of P. viridis as an aquaculture species, the P. viridis DEB model can, therefore, be used to illustrate the effects of varying environmental conditions on P. viridis life history traits which are relevant to the success of aquaculture facilities, and contribute towards better management of this species. [ABSTRACT FROM AUTHOR]

Chlorophyll- a ( CHL-a ) and sea surface temperature ( SST ) are generally accepted as proxies for water quality. They can be easily retrieved in a quasi-near real time mode through satellite remote sensing and, as such, they provide an overview of the water quality on a synoptic scale in open waters. Their distributions evolve in space and time in response to local and remote forcing, such as winds and currents, which however have much finer temporal and spatial scales than those resolvable by satellites in spite of recent advances in satellite remote-sensing techniques. Satellite data are often characterized by a moderate temporal resolution to adequately catch the actual sub-grid physical processes. Conventional pointwise measurements can resolve high-frequency motions such as tides or high-frequency wind-driven currents, however they are inadequate to resolve their spatial variability over wide areas. We show in this paper that a combined use of near-surface currents, available through High-Frequency (HF) radars, and satellite data ( e.g. , TERRA and AQUA/MODIS), can properly resolve the main oceanographic features in both coastal and open-sea regions, particularly at the coastal boundaries where satellite imageries fail, and are complementary tools to interpret ocean productivity and resource management in the Sicily Channel. [ABSTRACT FROM AUTHOR]

Shellfish aquaculture represents a worldwide valuable segment of the aquaculture market, spreading along the Mediterranean coasts, and is sensitive to the still unforeseen, poorly-known effects of climate change. Threats due to temperature rise can threaten the deployment and development of this sector, up until now recognised as the best candidate to mitigate the effects of fishery overexploitation. Here, we investigate the effects of temperature increase on the model species, Mytilus galloprovincialis , measuring outcomes from valve fragility (thickness) and condition index. Evidence of a reduction in the thickness of valves and the modulation condition of the mussels along with temperature increase have been gathered from simulations of a natural temperature gradient changing along latitude (the Italian Peninsula) and temperature risen (mesocosm trial). The obtained results offer a baseline to help the next generation of managers and stakeholders when assessing the reliability and feasibility of shellfish culture in a changing sea that can generate undetected and underestimated impacts on the sector. [ABSTRACT FROM AUTHOR]