Search

This Collective Article presents information about 27 taxa belonging to five Phyla (one Ochrophyta, one Cnidaria, three Arthropoda, two Mollusca and twenty Chordata) and extending from the Western Mediterranean Sea to the Levantine Sea and the Black Sea (Sea of Marmara). The new records were reported from 11 countries as follows: Algeria: occurrence of the African striped grunt Parapristipoma octolineatum; Spain: new records of eight uncommon fish species (Gadella maraldi, Hypleurochilus bananensis, Lobotes surinamensis, Parapristipoma octolineatum, Selene dorsalis, Sphoeroides marmoratus, Tetragonurus cuvieri, and Trachyrincus scabrus) from the Spanish Mediterranean; Italy: new record of the football octopus Ocythoe tuberculata from the Southern Tyrrhenian Sea; a rare sighting of a juvenile phase of a moray eel of the genus Gymnothorax, tentatively identified as Gymnothorax cf. unicolor in the Ligurian Sea; first record of adult Facciola’s sorcerer Facciolella oxyrhynchus in the Adriatic Sea; occurrence of the tope shark Galeorhinus galeus in the Northern Adriatic Sea; Libya: first confirmed record of the pen shell Pinna rudis; first documented record of the palaemonid shrimp Brachycarpus biunguiculatus; first record of the fish Sudis hyalina; Malta: new records of Grant’s rockling, Gaidropsarus granti; multiple concomitant reports of the rare hydro-medusan species Aequorea forskalea; Croatia: a record of the skipjack tuna Katsuwonus pelamis in the Southern Adriatic Sea; Albania: new record of the bigeye thresher shark Alopias superciliosus; Greece: confirmation of the rare brown alga Sargassum flavifolium occurrence in the Eastern Mediterranean Sea; first record of the scaleless dragonfish Bathophilus nigerrimus; Turkey: first occurrence of the calanoid copepod Pteriacartia josephinae in the Aegean Sea; first documented record of the Cremona’s sea slug Placida cremoniana for the easternmost Mediterranean Sea; new record of the yellow-headed goby Gobius xanthocephalus in the Sea of Marmara; Cyprus: first record of the Liechtenstein’s goby Corcyrogobius liechtensteini; an individual of the Yellow-fin tuna Thunnus albacares captured with handline by an artisanal fisher; Lebanon: an individual of the Black marlin Istiompax indica captured in a gill net., peer-reviewed

15 pages, 6 figures, 4 tables, supplementary data https://doi.org/10.1016/j.fishres.2020.105714, Discards is an important issue in fisheries around the world. The spatial management of discards has attracted interest as a potential tool for minimizing the unwanted catch. The aim of the present work was to identify areas with high quantities of bottom trawl discarded catch regarding species subjected to MCRS, in six areas of southern European waters (southern Portuguese waters, Catalan Sea, Ligurian and northern Tyrrhenian Seas, Strait of Sicily, eastern Ionian Sea, and Aegean Sea). Analyses were based on two types of data: (a) the undersized catch of species subjected to MCRS from bottom trawl surveys and (b) the actual discarded catch (including undersized and non-undersized individuals) of species subjected to MCRS from commercial bottom trawling. Geostatistical analysis techniques were applied to the first type of data and Generalized Additive Models using environmental variables were applied to the second one. Subsequently, areas that persistently presented high quantities of discarded catch (i.e., “iDC grounds”) or undersized catch (i.e., “iUC grounds”) were identified and mapped. The “iDC grounds”/“iUC grounds” were located either over the slope or within the continental shelf and over marine plateaus, largely depending on the main target species of each fishery. Next, the overlap of “iDC grounds”/“iUC grounds” with the existing Fisheries Restricted Areas (FRAs) and the proposed Marine Protected Areas (MPAs) was estimated aiming to explore how spatial closures could contribute to the reduction of bottom trawl discarded catch/undersized catch. Certain spatial closures were more effective in the Central Mediterranean and others to the Eastern Mediterranean. The overlapping of existing FRAs with “iDC grounds”/“iUC grounds” did not exceed 24 % in any study area, whereas proposed MPAs, like the CIESM Marine Peace Parks, reached up to 90 % for the same study area, This work was funded by the European Commission’s Horizon 2020 Research and Innovation Program under Grant Agreement No. 634495 for the project Science, Technology, and Society Initiative to minimize Unwanted Catches in European Fisheries (MINOUW). We thank people involved in the MEDISEH project (MAREA PROJECT MEDISEH: Mediterranean Sensitive Habitats, Specific Contract No 2, SI2.600741) for data provision regarding FRAs and MPAs, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Ecosystem modelling constitutes a useful tool for the ecosystem approach to fisheries management, which demands a shift to more complex models that include multi-species trophic interactions, environmental and anthropogenic forcing. The Thermaikos Gulf is a shallow gulf in the northwestern Aegean Sea (Greece) and one of the major fishing grounds of the northeastern Mediterranean concentrating high fishing effort of trawlers and purse-seiners and producing more than 20% of the total Greek catches. In the present work, we developed an Ecopath base model and ran Ecosim simulations for 26 years (2000–2025), including the calibration period (2000–2016), aiming to describe the food web structure and function of the Thermaikos Gulf, identify main components and interactions among the 33 functional groups, assess the ecosystem impacts of fishing over time and compare ecosystem properties with other Mediterranean areas. Overall ecosystem degradation with biomass and catch decline was observed at the end of the calibration period due to the impact of environmental factors and fishing activities. The ecosystem seemed to stabilize in an intermediate state by the end of the projection years, but with an overall biomass and catch decline. Fishing effort reduction after 2016 resulted in higher biomass and catches compared to 2014–2015, that could not however reach the 2000 levels in most cases. The examined fishing effort reduction scenarios clearly showed that the more the fishing effort is reduced, the higher the biomass in the ecosystem and the lower the catches obtained compared to the baseline scenario. In a nutshell, since environmental drivers may be harder to predict or control, lowering the exploitation levels is an important step towards the rebuilding of overfished marine resources and more resilient ecosystems.

The mitigation and incorporation of fisheries discards into the spatial management perspective call for a well-planned approach considering their high spatiotemporal variability. This study describes an approach to map the spatiotemporal distribution of bottom trawl discards taking into account on-board observer data, environmental information and high-resolution estimates of fishing effort derived from Vessel Monitoring System data. Two were the main objectives: i) mapping the Discards Per Unit Effort (DPUE: kg/h) and ii) mapping the total discards quantities (in kg) in a predefined spatial unit (grid cell of 5 × 5 km). For this purpose, discards data from commercial bottom trawlers (seasonal basis, period 2003–2006, 2008) operating on the continental shelf of the eastern Ionian Sea were analyzed. The DPUE for a) all species with Minimum Landing Size (MLS), b) all species without MLS and c) all fish species, were modeled by means of Generalized Additive Models (GAMs) using satellite environmental parameters, bathymetry and season as independent covariates. Mapping discards quantities in a predefined spatial unit was based on the spatial overlapping between GAM estimates for the year 2010 and fishing effort distribution for the same year. Spatial clusters of high discard quantities (hot spots) and their spatiotemporal persistence were also investigated. Results revealed how the environmental and temporal factors influence the DPUE distribution of each discard group and indicated increased discards quantities in areas of high fishing effort. The potential implications of the resulting DPUE maps for advancing discards spatial mitigation are further discussed. Mapping discards quantities using both the DPUE and the fishing effort distribution provide valuable insights that can be useful to investigate the broader ecosystem consequences of the EU landing obligation and other potential fishery management policies.

Τhe ecosystem structure of a Mediterranean lentic system (Lake Volvi, Northern Greece) was assessed and quantified for the first time, using the Ecopath with Ecosim model. Biological and fisheries-related data were collected during 2014–2015 from field surveys; moreover, operational and other data concerning fisheries exploitation were assessed by interviews. The model will (a) describe the ecological structure of the lake in terms of trophic flows (b) disaggregate the impacts imposed by fishing and other factors on the food web and (c) investigate the ecosystem’s functional changes by testing the introduction of a new fish species. Lake Volvi constitutes a mature system whose food web is characterized by “bottom-up” processes, exhibiting a “good” systemic resistance to unexpected perturbations and a rather low intensity of fisheries exploitation. Simulations from 2015 to 2025 revealed that an increase in fishing effort and/or stocking with the new species will have negligible impact on the food web and will not affect negatively the fisheries resources and top megafauna. The model presented provides key ecosystem information that is lacking for most European freshwaters systems, which can be useful in assessing their ecosystem structure and in simulating the pressure of fisheries exploitation on their food web.

The study of small pelagic fish by hydroacoustic methods in the Mediterranean Sea began in the Adriatic in the 1950’s. Since 2009, internationally coordinated, extensive, regular surveys have been conducted in the framework of the MEDIAS - Mediterranean International Acoustic Surveys – action, under the EU Data Collection Framework, to provide inputs for the management of small pelagics, particularly European anchovy (Engraulis encrasicolus) and European sardine (Sardina pilchardus). The surveys cover EU Mediterranean waters and monitor the distribution and abundance of small pelagic species using a common protocol. The hydroacoustic surveys, historically conducted by each Country separately, have since been standardized and harmonized. This is a review of the evolution of the surveys from the beginning up to the present and discusses the future prospects. It reports the historical time series of anchovy, sardine and other small pelagics in different areas and describes the spatial and temporal distribution of small pelagic species in decadal maps of the major areas of their distribution in the European Mediterranean Sea. Furthermore, it discusses the use of MEDIAS data for stock assessment purposes, the collection of auxiliary information for an ecosystem-based management approach, the need for further standardization and future challenges.

Mediterranean coastal ecosystems provide various valuable ecosystem goods and services; however, they are vulnerable to ecological degradation due to a dramatic increase in resource use and environmental stress. Disentangling the effects of multiple human interventions on coastal ecosystems requires whole description of food web interactions using quantitative tools. A mass balance Ecopath model has been developed here for Saronikos Gulf, a naturally oligotrophic Mediterranean coastal ecosystem with a long history of human interventions. Our main focus was to describe the structure and functioning of the ecosystem, investigate the trophic interplay among the various compartments of the food web under the impact of mixed multi-gear fisheries, and to quantify resilience related emergent ecosystem properties. To this end, we reviewed a large amount of local and regional biological information which was integrated in 40 functional groups covering all trophic levels, while fishing activities were described with 7 fleets. The model shared characteristics of both productive (e.g., high amount of flows) and oligotrophic systems (e.g., low biomass accumulation) and presented typical features of Mediterranean ecosystem functioning, such as the importance of detritus as an energy source, strong benthic-pelagic coupling and the dominance of the pelagic compartment in terms of total production and consumption. Trophic forcing in the ecosystem of Saronikos Gulf was complex with both top-down and bottom-up drivers being important. Zooplankton was the central nexus between basal resources and higher trophic levels, while top predators such as hake, squids and anglerfish were identified as keystone species presenting a significant overall effect on the food web via direct and indirect trophic interactions. Ecological indicators depicted a moderately complex food-web of a large and immature ecosystem with its strengths in reserve being affected by environmental degradation. Additionally, exploitation indices classified fishing activities in Saronikos Gulf as unsustainable, affecting several target groups, including high trophic level species. Despite the cumulative anthropogenic stress, the morphological and bathymetric complexity of Saronikos Gulf seems to function as a natural ecological reserve for the ecosystem by providing nursery grounds to various species (e.g., hake, small pelagic fishes) and supporting important fish stocks for local fisheries.

The multi-species/multi-gear nature of the Mediterranean fisheries, the high number and dispersion of landing points, and the varying motivations for discarding make regulation enforcement in the basin challenging. In this study, reasons for explaining discarding are initially explored and then the main focus is on identifying potential incentive mechanisms and other measures that could reduce unwanted catches in Mediterranean trawl fisheries, in the face of the recent landing obligation. Both literature review and stakeholder engagement are employed, while special emphasis is put on the role of socio-economic tools to influence fishers’ behavior. Results show that although discarding is mainly driven by market demand, a number of factors have a synergistic effect which is sometimes difficult to disentangle and capture. Regarding measures, evidence from involved stakeholders (marine scientists and fishers) shows that economic incentives but also “social measures” such as more involvement of the industry and raising awareness are offering common ground. However, specific concerns have been also expressed on measures applicability. Overall, reducing discards is a complex issue and solutions should involve a combination of management measures designed for specific fleets and regions. However, irrespective of the synthesis of the management options, it is important to create a framework of action that takes into account human behavior as a source of variability. In this context, actions that for example encourage, engage, and enable can incentivize behavioral change in order to achieve specific outcomes.

Spatial management of discards has attracted increasing interest as a potential mitigation measure. However, most studies are restricted to commercial species. The aim of the present work was to fill this gap by identifying and mapping the spatial distribution of five non-commercial species with high frequency of occurrence in the discarded catch of bottom trawl fishery in the Aegean Sea, i.e., Brown comber Serranus hepatus, Mediterranean scaldfish Arnoglossus laterna, Red bandfish Cepola macrophthalma, Argentine Argentina sphyraena, and Boarfish Capros aper. For this purpose, Generalized Additive Models were used to account for catch dependency on environmental parameters in order to explore the spatial distribution of species. Modeling results revealed that the spatial distribution of species was driven by environmental variables. Depth was the most informative variable explaining most catch variation in all species. For A. laterna, C. macrophthalma, and S. hepatus the highest estimated values of catch were located over the continental shelf and at shallower waters inside gulfs, whereas C. aper and A. sphyraena catch were more broadly distributed across the study area and at greater depths. Seasonal variations in species catch were also observed, probably related in most cases to species reproduction period. Mapping species distribution is essential for the identification of priority areas of protection in future marine spatial plans.

The aim of this work is to assess potential effects on dolphins caused by fishing Small Pelagic Fish (SPF) in the North Aegean Sea (Eastern Mediterranean, Greece) ecosystem due to competition for food. To this end, an existing Ecopath ecosystem model was updated with dolphins' abundance estimates derived from a recent dedicated aerial survey. The approach included the quantification of trophic impacts and the estimation of the fraction of production of SPF that is consumed by dolphins and their main competitor, the purse seine (PS) fishery. Overall, competition for resources (i.e., SPF) between purse seines and dolphins was at relatively low levels as revealed by the analyses of flows in the "small pelagic fish - dolphins - fisheries" triangle, despite the relatively high abundance of dolphins in the NAS compared to adjacent areas. Specifically, the consumption of anchovy's production by dolphins was very low (3.6%) while consumption by the PS fleet was almost four times higher (13.1%). A much larger fraction (71.8%) of consumption of anchovy's production was attributed to other predators. The competition for sardine was at slightly higher levels than for anchovy (4.6% consumption by dolphins and 20.4% removals by the PS fleet). Even when different SPF abundance estimates were assumed to take into account uncertainty and historical records from acoustic surveys, food competition didn't seem to be an important issue. Nevertheless, as anchovy (and to a lower extent sardine) was found to be a key forage species in the North Aegean Sea ecosystem according to two food web indices (SURF and Connectance indices) estimated, special attention should be placed to ensure that the dolphins' populations are not threatened by food depletion in the future.

The Greek economic crisis has attracted much attention during recent years, as its depth and duration have been far greater than in crises experienced elsewhere. Structural similarities and peculiarities between the Greek economy and fishery sector are identified in terms of the large number of small enterprises and artisanal vessels, as well as inefficiencies in data collection and tax compliance (unreported income or landings). These highly differentiate Greece from most of the rest of the developed world. In the absence of domestic reforms geared to the specific case of Greece, policy solutions applied elsewhere are being imported into the country, with little success so far. We argue that structural characteristics should be taken into account in order to facilitate economic recovery and improve the efficiency of fisheries.

The mass-balance-trophic-model Ecopath and its extension Ecopath with Ecosim is very popular for modelling marine ecosystems. In this work, a model of the marine ecosystem of the North Aegean Sea (eastern Mediterranean) was created, incorporating the use of biological traits in both building and explaining the model. For the former, data regarding a total of 19 biological traits concerning the biology, distribution, ecology and behavior were used for the definition of fish functional groups. Regarding model interpretation, the results were not only analyzed in the functional groups level but also regarding the composition of the resulting biological traits. In total, 41 functional groups were created for this model. Landings data and discards estimations of the year 1993 were used for the Ecopath component. Six different fisheries management scenaria, one retaining a business-as-usual (maintenance of the status quo) approach and the others investigating changes in fishing effort for the period 2018–2033 were simulated with Ecosim. The simulation results indicated a reduction of pelagic species as well as of biological characteristics associated with them. Concurrently, an increase in the biomass of deep-living species and of relevant biological traits was observed. In general, no strong differences were documented among the various simulation scenarios with the exception of the species targeted by the individual fisheries whose fishing effort changed in each scenario and the associated traits. Significant findings pertain to the decrease of thermophilic traits like high optimal temperature and summer spawning in all fisheries management scenaria simulated. These could mitigate the opposite trend expected to be favored by climate change and the decrease of characteristics associated with the r-life strategy, possibly resulting in less resilient future fish communities. In addition, the negative trends of the biological traits that are anyway rare (e.g. low trophic level and small lifespan) may impact ecosystem functioning. The modelling approach used on this work could be adopted to model other marine communities (possibly also using traits for other ecosystem components) to provide interesting insights regarding anthropogenic effects on marine ecosystem functioning.

Discards are of primary target for the European Union policy and concerns have been expressed on the consequances that the landing obligation may have on the fisheries resources and other ecosystem components. In this context, we used an ecosystem modelling approach based on a previously constructed food web model for the Greek Ionian Sea to explore changes in food web components and fisheries due to the application of the landing obligation. Time series were also used to tune the trophic relationships during a hindcast period (1998–2014) and six scenarios were explored after 2015 simulating the current policy; a partial and a total discard ban (implemented after 2017) under both constant and decreasing fishing effort. Results indicated that, under constant fishing effort, changes in the management of unwanted catches (from discarding to landing them) had a significant consequences on certain functional groups, especially on marine birds which were even more adverse in the scenario tuned for the total discard ban. However, the new management practices seem pointless for the sustainability for most of the stocks, because there were no changes in the main commercial fish species apart from few exceptions (e.g. flatfish, deep water shrimps, continental shrimps) in which biomass changes were generally low. In contrast, simulations of declining fishing effort affected to higher extent more groups, whereas additionally representing changes in discarding policies had little effect. The model presented here is intended to shed light in the importance of discards in the food-web structure and subsequently to incentivize the practices to avoid producing discards in the first place.

Reliable biomass estimates by means of hydroacoustics largely depend on the correct identification of acoustic targets. Data collected during five summer acoustic surveys (2004-2008) in the North Aegean Sea (Greece) were analyzed to explore effective discrimination of small pelagic fish schools according to the species they belong. Discriminant Function Analyses (DFA) using bathymetric, energetic and morphometric school descriptors as explanatory variables were applied per research cruise as well as to pooled data from all surveys. Results revealed that the schools can be successfully classified into the five species considered (anchovy Engraulis encrasicolus, sardine Sardina pilchardus, round sardinella Sardinella aurita, blue whiting Micromessistius poutassou, and Atlantic mackerel Scomber scombrus). The percentage of correct classifications in terms of number of schools was higher in the analyses of the annual cruises (75.6%-95.36%) than in the analysis of pooled data (≈72%). This is because of (i) the lower number of species, as well as (ii) the reduced intraspecific variability, occurring in each separate cruise. Significant differences were detected among school descriptors for the different species, revealing discrete aspects of schooling behaviour for each species. The benefit of the specific approach is that the classification functions of the DFAs can be used to classify a larger set of schools, which has not been possible to assign to specific species. Overall the approach constitutes an objective, more automated and less time consuming procedure for the analysis of acoustic data and can contribute to the improvement of biomass estimates in the area.

Discarding is considered globally among the most important issues for fisheries management. The recent reform of the Common Fisheries Policy establishes a landing obligation for the species which are subject to catch limits and, in the Mediterranean, for species which are subject to Minimum Conservation Reference Size (MCRS) as defined in Annex III to Regulation (EC) No 1967/2006. Additionally, several other initiatives aim to reduce unwanted catches of target and bycatch species, including species of conservation concern. This raises the need to study discarding patterns of (mainly) these species. In this work we collated a considerable amount of historical published information on discard ratios and lengths at discarding for species caught in EU Mediterranean bottom trawl fisheries. The main aim was to summarize the available historical records and make them more accessible for scientific and managerial needs, as well as to try identifying patterns in discarding. We show discard ratios and lengths at which 50% of the individuals were discarded (L50) for 15 species (9 bony fishes, three crustacean decapods, and three elasmobranchs). Discard ratios were usually low for target species such as hake, red mullets and highly commercial shrimps and exemptions from the landing obligation under the de minimis rules could be sought in several cases. Discard ratios were usually higher for commercial bycatch species. Discarding is affected by a combination of factors and for a given species, especially for non-target ones, discards are likely to fluctuate within a fishery, across seasons, years, and regions. For most species considered, L50s were lower than the MCRS (when in place) and length at first maturity. L50s of target species, such as hake, were very small due to the existence of market demands for small sized individuals. However, for species of low demand, like horse mackerels, a higher retention size was observed, often exceeding MCRS. Lengths at discarding are affected by legal provisions, market demands but also by biological, population, and ecological traits. Understanding the factors that affect discarding constitutes the starting point for designing mitigation measures and management plans to reduce discards and improve the sustainability of the stocks, SI

Bundy, Alida ... et al.-- 28 pages, 6 figures, 8 tables, supporting information https://dx.doi.org/10.1111/faf.12184, Fisheries have had major negative impacts on marine ecosystems, and effective fisheries management and governance are needed to achieve sustainable fisheries, biodiversity conservation goals and thus good ecosystem status. To date, the IndiSeas programme (Indicators for the Seas) has focussed on assessing the ecological impacts of fishing at the ecosystem scale using ecological indicators. Here, we explore fisheries ‘Management Effectiveness’ and ‘Governance Quality’ and relate this to ecosystem health and status. We developed a dedicated expert survey, focused at the ecosystem level, with a series of questions addressing aspects of management and governance, from an ecosystem-based perspective, using objective and evidence-based criteria. The survey was completed by ecosystem experts (managers and scientists) and results analysed using ranking and multivariate methods. Results were further examined for selected ecosystems, using expert knowledge, to explore the overall findings in greater depth. Higher scores for ‘Management Effectiveness’ and ‘Governance Quality’ were significantly and positively related to ecosystems with better ecological status. Key factors that point to success in delivering fisheries and conservation objectives were as follows: the use of reference points for management, frequent review of stock assessments, whether Illegal, Unreported and Unregulated (IUU) catches were being accounted for and addressed, and the inclusion of stakeholders. Additionally, we found that the implementation of a long-term management plan, including economic and social dimensions of fisheries in exploited ecosystems, was a key factor in successful, sustainable fisheries management. Our results support the thesis that good ecosystem-based management and governance, sustainable fisheries and healthy ecosystems go together, This is a contribution to the IndiSeas Working Group, which, by the time of the study, was cofunded by IOC-UNESCO (www.ioc-unesco.org), EuroMarine (http://www.euromarinenetwork.eu), the European FP7 MEECE research project, the European Network of Excellence Eur-Oceans and the FRB EMIBIOS project (contract n°212085)

Spatial distribution and life history aspects of Pagellus bogaraveo in the eastern Ionian Sea were investigated using the data from 13 different studies carried out in the area from 1983 to 2010. The spatial patterns of the abundance, biomass and mean size showed that the species inhabits the shallow waters of the shelf ( 250 mm LT , (4) the presence of hermaphrodites between 200 and 370 mm, (5) a long reproduction period from June to March, (6) a size at first maturity around 300 mm and (7) a diet composition of adults based mainly on fishes, and also on opportunistic behaviour in the food scarce environment of deep waters. The results suggest that the species' distribution and feeding strategies are the most appropriate for the oligotrophic eastern Ionian waters and that these conditions result in smaller sizes of the species in the east Mediterranean Sea compared to the west basin and the east Atlantic Ocean, with implications for the growth and reproductive biology of the species.

Data from the MEDITS bottom trawl surveys in the Eastern Ionian Sea, covering a depth range of 28 to 845 m were analysed for the period 1998-2008. For each trawling location, environmental and geographical pa- rameters were recorded, while biomass, abundance, biodiversity and size-based metrics were estimated for the total megafaunal community, as well as for four taxonomic sub-communities (Osteichthyes, Chondrichthyes, Crustacea and Cephalopoda) which were expected to respond differently to environmental changes and fishing. In addition, biomass and abundance of ten species selected based on commercial interest, depth range and life history traits were explored, with particular emphasis on deep-sea species. Fishing effort data collected during the study period were analysed and showed a decreasing trend, mainly due to a decrease in the activity of static nets. The relation between the estimated parameters and environmental and spatial factors, as well as temporal (interannual) effects and the effect of fishing effort were explored using generalized additive models (GAMs). Results of GAMs showed that depth and location explained much of the variation in community metrics, probably reflecting mesoscale spatial features and species/communities requirements. Even though the different communities and species exhibited variant patterns in bathymetric and spatial distribution, some common aggregation patterns in productive areas were identified. Despite the relatively short time series, GAMs were effective in detecting increasing trends for several metrics; taking into account spatial factors fur- ther contributed to attributing the remaining deviance to temporal effects. These trends were partly explained by the observed decline of fishing effort, which is further supported by the fact that negative relations between several metrics and fishing effort were identified, for some of the selected communities and populations. Abundance, species richness and maximum length proved the most informative metrics concerning the effect of fishing. The current decline in fishing effort in the area seems to be a move in the right direction and should be complemented by additional measures aiming to prevent allocation of effort towards the deep sea.

A considerable amount of the existing knowledge of discards in the Mediterranean Sea is presented. Discarding highly varies along the basin both geographically and among the different fishing gears with bottom trawls being responsible for the bulk of discards, since they are characterized by high discards ratios. Midwater trawls, purse-seines, and small-scale fisheries, despite their less proportion of discards per se, produce overall high discards quantities, since they are responsible for the majority of the landings. Based on the collected information, a rough Mediterranean-wide estimate of discards around 230 000 t or 18.6% (13.3–26.8%) of the catch is produced. Discarding in the Mediterranean is regulated by market demands rather than by legal constraints, and marketable bycatch may constitute an important supplemental source of income. A pattern in resource use related to socio-cultural characteristics is apparent, with welfare communities discarding more in terms of percentages. Natural conditions (e.g. environmental gradients) and fishers' strategies also substantially affect discarding. Mitigation tools mainly comprise selectivity improvement and spatio-temporal closures. Despite the progress in studying discards, needs are evident to expand monitoring schemes, apply analytical techniques, and establish objectives of the discards issue under the framework of ecosystem approach to fisheries.

Coll, Marta ... et al.-- 16 pages, 6 figures, 6 tables, IndiSeas (>Indicators for the Seas>) is a collaborative international working group that was established in 2005 to evaluate the status of exploited marine ecosystems using a suite of indicators in a comparative framework. An initial shortlist of seven ecological indicators was selected to quantify the effects of fishing on the broader ecosystem using several criteria (i.e., ecological meaning, sensitivity to fishing, data availability, management objectives and public awareness). The suite comprised: (i) the inverse coefficient of variation of total biomass of surveyed species, (ii) mean fish length in the surveyed community, (iii) mean maximum life span of surveyed fish species, (iv) proportion of predatory fish in the surveyed community, (v) proportion of under and moderately exploited stocks, (vi) total biomass of surveyed species, and (vii) mean trophic level of the landed catch. In line with the Nagoya Strategic Plan of the Convention on Biological Diversity (2011-2020), we extended this suite to emphasize the broader biodiversity and conservation risks in exploited marine ecosystems. We selected a subset of indicators from a list of empirically based candidate biodiversity indicators initially established based on ecological significance to complement the original IndiSeas indicators. The additional selected indicators were: (viii) mean intrinsic vulnerability index of the fish landed catch, (ix) proportion of non-declining exploited species in the surveyed community, (x) catch-based marine trophic index, and (xi) mean trophic level of the surveyed community. Despite the lack of data in some ecosystems, we also selected (xii) mean trophic level of the modelled community, and (xiii) proportion of discards in the fishery as extra indicators. These additional indicators were examined, along with the initial set of IndiSeas ecological indicators, to evaluate whether adding new biodiversity indicators provided useful additional information to refine our understanding of the status evaluation of 29 exploited marine ecosystems. We used state and trend analyses, and we performed correlation, redundancy and multivariate tests. Existing developments in ecosystem-based fisheries management have largely focused on exploited species. Our study, using mostly fisheries independent survey-based indicators, highlights that biodiversity and conservation-based indicators are complementary to ecological indicators of fishing pressure. Thus, they should be used to provide additional information to evaluate the overall impact of fishing on exploited marine ecosystems. © 2015 Elsevier Ltd. All rights reserved, We thank the Euroceans IndiSeas Working Group funded by the European Network of Excellence EUR-OCEANS (FP6, Contract N° 511106), the European collaborative project MEECE – Marine Ecosystem Evolution in a Changing Environment (FP7, Contract N° 212085) and IRD (Institute of Research for Development) and IOC/UNESCO. [...] MC was partially funded by the European Commission through the Marie Curie Career Integration Grant Fellowships – PCIG10-GA-2011-303534 – to the BIOWEB project and by the Spanish National Program Ramon y Cajal. LJS was supported through the South African Research Chair Initiative, funded through the South African Department of Science and Technology (DST) and administered by the South African National Research Foundation (NRF). LJS and YS were also funded by the European collaborative project MEECE – Marine Ecosystem Evolution in a Changing Environment – (FP7, Contract N° 212085). KMK was supported by the Northeast Fisheries Science Center and the Nature Conservancy through a grant from the Gordon and Betty Moore Foundation. MJJJ was supported by an EU Marie Curie International Outgoing Fellowship – PIOF-GA-2013-628116. MFB was supported by the Portuguese Oceanic and Atmospheric Institute and the trawl survey data collected under Biological Sampling (PNAB) Program. LJG would like to thank the Joint Research Centre of the European Commission for support. HO was financed by the Estonian Ministry of Education and Research (Grant SF0180005s10). JJH was supported by the Natural Environment Research Council and Department for Environment, Food and Rural Affairs [Grant Number NE/L003279/1, Marine Ecosystems Research Programme]. GIvdM was supported by the Institute of Marine Research, Norway. KT was partially funded by the project PERSEUS (Policy-oriented marine Environmental Research in the Southern EUropean Seas; FP7 Contract N° 287600). MAT was funded by the Spanish Institute of Oceanography (IEO) through a Predoctoral FPI fellowship. KNM was supported by a National Research Council fellowship at the Northwest Fishery Science Center. YJS and MTT were partially supported by the French project EMIBIOS (FRB, Contract No. APP-SCEN-2010-II). Chatham Rise trawl survey data were provided by the Ministry for Primary Industries. CL acknowledges DEVOTES – Development of innovative tools for understanding marine biodiversity and assessing good Environmental Status – EC project (FP7 Grant Agreement 308392)

Identification of the potential habitat of European anchovy (Engraulis encrasicolus) at different life stages in relation to environmental conditions is an interesting subject from both ecological and management points of view. For this purpose, acoustic data from different seasons and different parts of the Mediterranean Sea along with satellite environmental and bathymetry data were modelled using generalized additive models. Similarly, egg distribution data from summer ichthyoplankton surveys were used to model potential spawning habitat. Selected models were used to produce maps presenting the probability of anchovy presence (adults, juveniles and eggs) in the entire Mediterranean basin, as a measure of habitat adequacy. Bottom depth and sea surface chlorophyll concentration were the variables found important in all models. Potential anchovy habitats were located over the continental shelf for all life stages examined. An expansion of the potential habitat from the peak spawning (early summer) to the late spawning season (early autumn) was observed. However, the most suitable areas for the presence of anchovy spawners seem to maintain the same size between seasons. Potential juvenile habitats were associated with highly productive inshore waters, being less extended and closer to coast during winter than late autumn. Potential spawning habitat in June and July based on ichthyoplankton surveys overlapped but were wider in extent compared with adult potential habitat from acoustics in the same season. Similarities and dissimilarities between the anchovy habitats as well as comparisons with sardine habitats in the oligotrophic Mediterranean Sea and other ecosystems with higher productivity are discussed.

We analysed data collected on board commercial purse seine vessels in the Aegean and Ionian Seas (eastern Mediterranean Sea, Greece) in 13 seasonal sampling periods from 2003 to 2008 in order to describe the composition of the retained and discarded catch and shed light on discarding practices. In each area, five species constituted the majority of the marketable catch (> 97%): sardine (Sardina pilchardus), anchovy (Engraulis encrasicolus), round sardinella (Sardinella aurita), bogue (Boops boops) (in both areas), mackerel (Scomber japonicus; in the Aegean Sea) and picarel (Spicara smaris; in the Ionian Sea). Discarded quantities were on average 4.6% and 2.2% of the total catch in terms of weight in the Aegean and Ionian Seas respectively. Discards on the marketable ratio fluctuated over years and seasons without showing any particular trend. At the species level, sardine and mackerel were seldom discarded while large amounts of anchovy were discarded only during its recruitment period (autumn), when juvenile fish dominate the population. The discarding ratio for bogue, picarel and round sardinella ranged from zero to total discarding because they constitute a supplementary source of income for the fishers. Discarded fish comprised mainly small individuals for all species considered with the exception of round sardinella. However, the lengths at which 50% of the individuals were discarded were generally small, often smaller than the species minimum landing sizes. Geographical coordinates and marketable catch explained part of the variability of the discarded quantities, as revealed by generalized additive models. Discarding practices and implications for management of purse seine fisheries are also discussed. Analizamos datos recogidos a bordo de pesqueros comerciales de cerco en el mar Egeo y el mar Jónico (Mediterráneo Oriental, Grecia) durante 13 estacionales de muestreo desde 2003 hasta 2008, con el objetivo de describir la composición de las capturas conservadas y de las descartadas con el fin de arrojar luz sobre la práctica del descarte. En cada zona, la mayor parte de la captura comercial (> 97%) consistía en cinco especies, a saber: la sardina (Sardina pilchardus), el boquerón (Engraulis encrasicolus), la alacha (Sardinella aurita), la boga (Boops boops) (en ambas zonas), la caballa (Scomber japonicus; en el mar Egeo) y el caramel (Spicara smaris; en el mar Jónico). Las cantidades descartadas representaban un promedio del 4.6% y 2.2% de la captura total en términos de peso, en el mar Egeo y en el Jónico respectivamente. La proporción de la captura descartada sobre la captura comercializable fluctuó mucho en todos los años y estaciones sin mostrar ninguna tendencia particular. Con respecto a las especies, en el caso de la sardina y de la caballa, los descartes ocurrieron raramente e incluso los individuos más pequeños se conservaron, mientras que grandes cantidades de boquerón fueron descartadas solamente durante su temporada de reclutamiento (otoño), cuando la población está dominada por peces jóvenes. La proporción descartada en el caso de la boga, del caramel y de la alacha fluctuó mucho, desde un descarte de cero hasta un descarte total, ya que estas especies representan una fuente de ingresos complementaria para los pescadores. Las coordenadas geográficas y la captura comercial explicaban parte de la variabilidad de las cantidades descartadas, como se demuestra con modelos aditivos generalistas. Asimismo, presentamos una discusión sobre la práctica del descarte así como de las consecuencias sobre la gestión de la pesca de cerco.

Intraspecific variability in the characteristics of fish schools is often affected by the size of individuals. In this study, juvenile and adult sardine schools detected in five hydroacoustic surveys (2004–2008) in the North Aegean Sea (eastern Mediterranean) were analysed in an effort to identify differences in a suite of school descriptors (i.e. positional, energetic, morphometric) and define the size at which schooling behaviour changed from juvenile to adult. Juveniles exhibited discrete schooling characteristics and microhabitat preferences compared to adult fish. Specifically, schools of juvenile sardines were smaller, more elongated and irregular than those of adults, they backscattered less energy and were located higher in the water column. Based on the length frequency distributions of experimental pelagic trawl catches, the length at which 50% of sardines shifted behaviour from juvenile school structure to the more typical adult school form was estimated at 10.7 cm. This length almost coincides with several ontogenetic changes in biology (i.e. first maturity, allometric change in the length–weight relationship and onset of phytoplankton consumption). Several size-dependent school features observed in this study are partly attributed to the higher feeding demands of juvenile fish and the need to avoid intraspecific competition and predation.

Acoustic data from summer echo-surveys in the Aegean Sea (Eastern Mediter- ranean) were analysed in an effort to better understand the mechanisms related to diel vertical migration and the schooling behaviour of European anchovy Engraulis encrasicolus in relation to the time of day. Cosine, quadratic and generalized additive models (GAMs) were used to describe the diurnal patterns in the vertical position and the energetic and morphometric characteristics of anchovy schools. The effect of environmental variables on a suite of school descriptors was addi- tionally examined using GAMs. Disruption of schooling at night was followed by school formation just before dawn at shallow layers, usually above the base of thermocline. Schools moved to deeper depths, close to the seabed during daytime and returned close to the surface to disperse after dusk. Surface light intensity and bottom depth explained a significant amount of variability in the vertical position of schools. Higher light intensities urged schools to deeper depths but max- imum downward displacement was constrained by sea bottom in coastal waters (

Identification of potential juvenile grounds of short-lived species such as European sardine (Sardina pilchardus) in relation to the environment is a crucial issue for effective management. In the current work, habitat suitability modelling was applied to acoustic data derived from both the western and eastern part of the Mediterranean Sea. Early summer acoustic data of sardine juveniles were modelled using generalized additive models along with satellite environmental and bathymetry data. Selected models were used to construct maps that exhibit the probability of presence in the study areas, as well as throughout the entire Mediterranean basin, as a measure of habitat adequacy. Areas with high probability of supporting sardine juvenile presence persistently within the study period were identified throughout the Mediterranean Sea. Furthermore, within the study period, a positive relationship was found between suitable habitat extent and the changes in abundance of sardine juveniles in each study area.

18 pages, 12 figures, 3 tables, Since the first introduction of the landing obligation (a.k.a. Discard ban) in 2015, the EU Mediterranean fisheries are facing some unforeseen challenges. The demersal bottom trawl fisheries, being the most significant contributors to the so-called 'discard problem', are confronted with the greatest challenges. Data from the Italian and the Greek fleet, spanning over two decades (1995-2015), were analysed with the intention of revealing the diversity and heterogeneity of the discard problem, especially for regulated species. Species composition of discards, as well as discarding rates, were shown to be irregular, fluctuating among areas, depth strata, seasons and years. Although fish dominated the discarded gross catch in weight, benthic invertebrates (other than commercial cephalopods and crustaceans) were the taxa discarded almost exclusively. The established minimum conservation reference size was largely ignored by fishers. From a management point of view, the present investigation suggests that the recently established Discard Management Plans lack scientific evidence (given the high intrinsic variability of the parameters and confusion regarding the rules) and provide exemptions from the landing obligation that will in practice allow the average Mediterranean bottom trawl vessel to continue business as usual. Moreover, detecting if these rules are actually respected is an almost impossible task for the Mediterranean control and enforcement authorities. Incentivizing the adoption of fishing technologies and practices that reduce pre-harvest mortality and post-harvest discards, while avoiding damage to sensitive marine species and habitats, seems the only way to move forward, rather than dealing with the problem after it has occurred., This research was funded by the European Commission’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 634495 for the project Science, Technology and Society Initiative to minimize Unwanted Catches in European Fisheries (MINOUW)

16 pages, 8 figures, 4 tables, 1 appendix supplementary data https://doi.org/10.1016/j.ecss.2010.04.007, A mass-balance trophic model was built to describe the food-web traits of the North Aegean Sea (Strymonikos Gulf and Thracian Sea, Greece, Eastern Mediterranean) during the mid 2000s and to explore the impacts of fishing. This is the first food-web model representing the Aegean Sea, and results were presented and discussed in comparison to other previous ecosystems modelled from the western and the central areas of the basin (South Catalan and North-Central Adriatic Seas). Forty functional groups were defined, covering the entire trophic spectrum from lower to higher trophic levels. Emphasis was placed on commercial invertebrates and fish. The potential ecological role of the invasive ctenophore, Mnemiopsis leidyi , and several vulnerable groups (e.g., dolphins) was also explored. Results confirmed the spatial productivity patterns known for the Mediterranean Sea showing, for example, that the total biomass is highest in N.C. Adriatic and lowest in N. Aegean Sea. Accordingly, food web flows and several ecosystem indicators like the mean transfer efficiency were influenced by these patterns. Nevertheless, all three systems shared some common features evidencing similarities of Mediterranean Sea ecosystems such as dominance of the pelagic fraction in terms of flows and strong benthic-pelagic coupling of zooplankton and benthic invertebrates through detritus. The importance of detritus highlighted the role of the microbial food web, which was indirectly considered through detritus dynamics. Ciliates, mesozooplankton and several benthic invertebrate groups were shown as important elements of the ecosystem linking primary producers and detritus with higher trophic levels in the N. Aegean Sea. Adult anchovy was shown as the most important fish group in terms of production, consumption and overall effect on the rest of the ecological groups in the model, in line with results from the Western Mediterranean Sea. The five fishing fleets considered (both artisanal and industrial) had high impacts on vulnerable species and numerous targeted groups given the multispecies nature of the fisheries in the N. Aegean Sea. Several exploitation indices highlighted that the N. Aegean Sea ecosystem was highly exploited and unlikely to be sustainably fished, similarly to other Mediterranean marine ecosystems, Marta Coll was supported financially by the European Commsission Marie Curie Post-doctoral Fellowship through the International Outgoing Fellowships (Call FP7-PEOPLE-2007-4-1-IOF) for the ECOFUN project

Despite the importance of the recruitment process for small pelagic fish and the high economic importance of European sardine (Sardina pilchardus, Walbaum 1792) in the Mediterranean Sea, knowledge on the distribution and environmental characteristics of its nursery grounds is very limited. In the present study, we used pelagic trawl data collected during 1995–2006 to explore the spatial distribution of sardine juveniles in the Aegean Sea in early summer. Based on sardine abundance per length class, a cluster analysis was initially used to define hauls dominated by juveniles. In a subsequent step, Discriminant Function Analysis (DFA) was applied to discriminate stations with high relative abundance of juveniles using satellite environmental data and bottom depth. The parameters contributing mostly to the discrimination of juvenile grounds were sea level anomaly, photosynthetically active radiation, sea surface temperature, chlorophyll-a and bottom depth. The classification functions of DFA were finally used to post classify unsampled areas in the Greek Seas and the Mediterranean Sea in order to map grounds that meet characteristic environmental conditions for young sardine. Such areas were mostly located inshore, in semi-closed productive areas and often in proximity to river mouths, a pattern that is generally supported by existing information.

Acoustic and satellite environmental data as well as bathymetry data were used to model the presence of anchovy, Engraulis encrasicolus during early summer in the northern Aegean Sea (Eastern Mediterranean). Generalized Additive Models (GAMs) were used for modelling and subsequently applied in a predictive mode to identify those areas in the Greek Seas and the entire Mediterranean basin that could support species’ presence. Model results were evaluated with the estimation of Receiver Operating Characteristic (ROC)-plots as well as qualitatively, based on (a) acoustic data from concurrent studies in certain areas of the northern Aegean Sea that were not included in the estimation of the GAM model and (b) historical acoustic data from the central Aegean and Ionian Seas. Mapping the estimated environmental conditions in the Mediterranean basin indicated areas that generally agree with the known distribution grounds of anchovy, such as the straits of Sicily and coastal waters of Tunisia, areas in the Tyrrhenian Sea, the Adriatic Sea, the Gulf of Lions and the Catalan Sea.

Tsagarakis, K., Machias, A., Giannoulaki, M., Somarakis, S., and Karakassis, I. 2008. Seasonal and temporal trends in metrics of fish community for otter-trawl discards in a Mediterranean ecosystem. – ICES Journal of Marine Science, 65: 539–550. Trends in discard to marketed ratios, size spectra, diversities, and trophic levels of the demersal fish community were examined using data from a seasonally closed commercial trawl fishery in the eastern Mediterranean Sea (Ionian Sea), over a period of about 10 years. Trends were also examined for the artificial fractions derived from the discarding process (the marketed, the discarded, and the non-marketed clusters of the catch), as well as for the “big” and “small” fractions (defined by the size at which 50% of all specimens were discarded). The ratio of the discarded/marketed catch fluctuated greatly. Two commercial (Merluccius merluccius, and Mullus barbatus) and two non-marketed species (Lepidotrigla cavillone, and Argentina sphyraena) were the characteristic species of the fractions. A declining trend with time was observed for the examined time-series for species richness (S), Margalef’s d, and average taxonomic distinctness (Δ+), whereas the variation in taxonomic distinctness (Λ+) increased. The composition and/or trophic level of discards in relation to the marketed catch seemed to be indicative of the exploitation state of the demersal community: differences between the discarded and marketed fractions were high at the beginning of the fishing season (autumn), but the values of the indices converged at the end of the fishing season (spring). These changes could be attributed to alternative discarding strategies for certain species in response to increased cumulative fishing mortality towards the end of the period.

We would like to thank the IndiSeas Working Group, endorsed by IOC-UNESCO (www.ioc-unesco.org) and the European Network of Excellence Euroceans (www.eur-oceans.eu). KMK was supported by Conservation International and the Sea Around Us project, a collaboration between The University of British Columbia and The Pew Charitable Trusts. MC was partially supported by the EC Marie Curie CIG grant to BIOWEB and the Spanish Research Program Ramon y Cajal. LJS was supported through the South African Research Chair Initiative, funded through the South African Department of Science and Technology (DST) and administered by the South African National Research Foundation (NRF). YJS and MIT were supported by the French project EMIBIOS (FRB, contract no. APP-SCEN-2010-11). US and YS were also funded by the European collaborative project MEECE - Marine Ecosystem Evolution in a Changing Environment - (FP7, Contract no. 212085). CPL was supported by Defra project MF1228 (From Physics to Fisheries) and DEVOTES (DEVelopment of innovative Tools for understanding marine biodiversity and assessing good Environmental Status) funded by EU FP7 (grant Agreement no. 308392), www.devotes-project.eu. GIvdM was partially supported by the Norwegian Nature Index programme and the Institute of Marine Research, Norway. HO was funded was funded by the Estonian Ministry of Education and Research (grant SF0180005s10). MAT was funded by a predoctoral FPI fellowship from the Spanish Institute of Oceanography (IEO). MJJJ was supported by the EC Marie Curie IOF Grant, PIOF-GA-2013-628116. We acknowledge all those who conducted surveys to collect the data used in this study.; Fisheries provide critical provisioning services, especially given increasing human population. Understanding where marine communities are declining provides an indication of ecosystems of concern and highlights potential conflicts between seafood provisioning from wild fisheries and other ecosystem services. Here we use the nonparametric statistic, Kendall's tau, to assess trends in biomass of exploited marine species across a range of ecosystems. The proportion of 'Non-Declining Exploited Species' (NDES) is compared among ecosystems and to three community-level indicators that provide a gauge of the ability of a marine ecosystem to function both in provisioning and as a regulating service: survey-based mean trophic level, proportion of predatory fish, and mean life span. In some ecosystems, NDES corresponds to states and temporal trajectories of the community indicators, indicating deteriorating conditions in both the exploited community and in the overall community. However differences illustrate the necessity of using multiple ecological indicators to reflect the state of the ecosystem. For each ecosystem, we discuss patterns in NDES with respect to the community-level indicators and present results in the context of ecosystem-specific drivers. We conclude that using NDES requires context-specific supporting information in order to provide guidance within a management framework. (C) 2015 Elsevier B.V. All rights reserved.

Crise, A. ... et. al.-- 12 pages, 1 figure, 5 tables, PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also independently performed. The comparison between meta-analysis results and IAs shows similarities for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification of additional research themes targeting research topics that are requested to the achievement of GES. © 2015 The Authors, This work has been partially funded by the EC FP7 PERSEUS Project (Grant. Agr. 287600)

In this third Collective Article, with fisheries-related data from the Mediterranean Sea, we present the historical length distribution of Lophius budegassa in the catch of commercial trawlers in the Greek seas; length-weight and length-length relationships of five flatfish species ( Lepidorhombus boscii, L. whiffiagonis , Platichthys flesus , Pegusa lascaris and Solea solea ) from different coastal areas of Turkey (Black Sea and Eastern Mediterranean Sea); growth of settled Polyprion americanus and length-weight relationships of this species and of Deltentosteus quadrimaculatus , Capros aper and three commercially important groupers in the Eastern Mediterranean Sea; the age, growth and mortality of Zosterisessor ophiocephalus in the Eastern Adriatic Sea; the length-weight relationship and condition factor of Atherina boyeri in a Central Mediterranean semi-isolated lagoon, and also the length-weight and length-length relationships of three Alburnus species from different inland waters in Turkey.

12 pages, 8 figures, 1 table, 1 appendix, The EcoTroph modeling approach was applied to five Mediterranean marine ecosystems to characterize their food webs and investigate their responses to several simulated fishing scenarios. First, EcoTroph was used to synthesize the outputs of five pre-existing heterogeneous Ecopath models in a common framework, and thus to compare different ecosystems through their trophic spectra of biomass, catch, and fishing mortalities. This approach contributes to our understanding of ecosystem functioning, from both ecological and fisheries perspectives. Then, we assessed the sensitivity of each ecosystem to fishery, using EcoTroph simulations. For the five ecosystems considered, we simulated the effects of increasing or decreasing fishing mortalities on both the biomass and the catch per trophic class. Our results emphasize that the Mediterranean Sea is strongly affected by the depletion of high trophic level organisms. Results also show that fisheries impacts, at the trophic level scale, differ between ecosystems according to their trophic structure and exploitation patterns. A top-down compensation effect is observed in some simulations where a fishing-induced decrease in the biomass of predators impacts their prey, leading to an increase in the biomass at lower trophic levels. The results of this comparative analysis highlight that ecosystems where top-down controls are observed are less sensitive to variations in fishing mortality in terms of total ecosystem biomass. This suggests that the magnitude of top-down control present in a system can affect its stability. © 2015 Elsevier B.V., This publication has been produced with the financial support of the DPF PhD fellowships program of the Institut de Recherche pour le Développement (IRD) for GH and TH. It was also partly funded by the projects BISTROMED (ENVI-Med - MISTRALS) and CHARMMED (Fondation TOTAL). MC was partially supported by a Marie Curie CIG grant (PCIG10 GA-2011-303534) to the BIOWEB project and the Spanish Research Program Ramón y Cajal. KT was partially supported by the FP7 project PERSEUS (FP7 Theme “Oceans of Tomorrow” OCEAN.2011-3 Grant Agreement No. 287600)

Spatial distribution and life history aspects of Pagellus bogaraveo in the eastern Ionian Sea were investigated using the data from 13 different studies carried out in the area from 1983 to 2010. The spatial patterns of the abundance, biomass and mean size showed that the species inhabits the shallow waters of the shelf (170 m depth) as juveniles up to a certain size (180 mm total length, LT ), moving to deeper waters of the slope (mainly 400-500 m depth) as adults. The spatial pattern of abundance indicated a continuous distribution of the species in deep waters, with hot-spot areas of high values, whereas in shallow waters distribution was more discontinuous, with higher concentrations of juveniles in estuaries and brackish waters. The study of biological aspects of the species revealed (1) a difference in the increase in mass between males and females, (2) protandrous hermaphroditism, accompanied by the presence of primary females and males that do not change sex, (3) a sex ratio in favour of females250 mm LT , (4) the presence of hermaphrodites between 200 and 370 mm, (5) a long reproduction period from June to March, (6) a size at first maturity around 300 mm and (7) a diet composition of adults based mainly on fishes, and also on opportunistic behaviour in the food scarce environment of deep waters. The results suggest that the species' distribution and feeding strategies are the most appropriate for the oligotrophic eastern Ionian waters and that these conditions result in smaller sizes of the species in the east Mediterranean Sea compared to the west basin and the east Atlantic Ocean, with implications for the growth and reproductive biology of the species.

Information integrated from different parts of the Mediterranean was used in order to model the spatial and temporal variability of the distribution grounds of anchovy at different life stages. Acoustic data from the Aegean Sea (Eastern Mediterranean), the Adriatic Sea and the Sicily Channel (Central Mediterranean), the Spanish waters and the Gulf of Lions (Western Mediterranean) have been analyzed along with satellite environmental and bathymetry data to model the spatial distribution of adult anchovy during summer and early autumn and the spatial distribution of juvenile anchovy during late autumn and winter. Similarly, egg distribution data from summer surveys were used to model the potential spawning habitat of anchovy in June and July. Generalized Additive Models were applied in a presence/absence approach. Selected models were used to produce potential habitat maps for the entire Mediterranean basin for each year and period, indicating areas presenting the highest probability of supporting the presence of anchovy adults, juveniles and spawning grounds. The temporal stability of these areas was examined. Bottom depth and productivity were 1 the most important parameters found in all models. An expansion of anchovy adult habitat area was observed from summer to early autumn in all study regions. Potential juvenile grounds were identified within the continental shelf in association to high productivity waters, presenting a more extended distribution towards deeper waters in late autumn and moving to more inshore waters in winter. Potential spawning grounds presented a high degree of overlapping between June and July, being more extended compared to the adult grounds in summer.

Integrated information from different parts of the Mediterranean Sea was used to model the spatial and temporal variability of the distribution grounds of the sardine population. Acoustic data from the North Aegean Sea (Eastern Mediterranean), the Adriatic Sea (Central Mediterranean), the Sicily Channel (Central Mediterranean) and Spanish Mediterranean waters (Western Mediterranean) were analysed along with satellite environmental and bathymetric data to model the potential habitat of sardine during summer, autumn and early winter. Generalized additive models were applied in a presence−absence approach. Models were validated in terms of their predictive ability and used to construct maps exhibiting the probability of sardine presence throughout the entire Mediterranean basin as a measure of habitat adequacy for sardine. Bottom depth and sea surface temperature were the environmental variables that explained most of the data variability. Several areas along the Mediterranean coastline were indicated as suitable habitat for sardine in different seasons. An expansion of these areas over the continental shelf, up to 100 m depth, was consistently noticed from summer to winter. This was attributed to the horizontal movements of sardine related to spawning (i.e. winter period) and the peculiarities of the Mediterranean Sea where areas favouring growth, feeding and spawning processes tend to be localised and prevent a long range, offshore migration as opposed to large upwelling ecosystems. Moreover, within the study period, a positive relationship between the extent of sardine preferred habitat and landings was revealed for both summer and winter seasons throughout the entire Mediterranean Sea, Sí