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The crisis in small-scale fisheries (SSFs) is worsened by weak governance structures, requiring urgent transformation. Participatory arrangements like co-management offer potential to enhance resilience in these social-ecological systems. However, the performance of collaborative governance modes must be evaluated to support institutional learning, refine governance structures, and ensure the legitimacy of transformative changes. In Uruguay, Local Fishery Councils (LFCs) were institutionalized a decade ago to involve fishers in managing and governing SSFs. This study assesses the LFC for the yellow clam SSF using three approaches: analysis of LFC meeting minutes, compilation of stakeholder perceptions, and analysis of social networks. The study found a decline in session frequency due to limited resources caused by the termination of an externally funded project. Performance indicators from the minutes identified recurring concerns on assessment, governance, and management, and issues related to monitoring, control, and surveillance. The influence of markets and the impact of red tides on fisheries performance were also brought up. Stakeholders perceived successful management solutions achieved through collaborative efforts, supporting co-management and resource recovery progress. However, social network analysis revealed communication patterns marked by core-periphery structure, showing partial disconnection and reluctance of the coastal marine authority to engage in inter-institutional collaboration. Despite challenges from climate change and markets, the LFC played a crucial role in co-creating solutions, empowering fishers with new skills and knowledge. Findings stress the importance of collaborative governance in promoting sustainable management and supporting institutional learning for transformative change in SSFs. • Governance transformation into co-management is assessed in a small-scale fishery. • Mixed methods using content analysis of minutes and structured interviews. • Participatory management led to success, optimism, and support for co-management. • Challenges in sustaining governance infrastructure hinder effective management. • Social network analysis suggests that engaging peripheral actors enhances governance. [ABSTRACT FROM AUTHOR]

In 2000, longline fishing was banned inside the Galapagos Marine Reserve to prevent illegal fishing of sharks and bycatch of endangered, threatened, and protected (ETP) species. Despite local management institutions possess one of the most sophisticated control and surveillance systems in the Eastern Tropical Central Pacific, statistical and anecdotic evidence suggest the longline ban has been ineffective in eradicating illegal, unreported and unregulated (IUU) fishing for the last two decades. This short communication examines the legal, institutional, and socio-economic factors that have prevented the effective implementation of the longline ban and proposes an ecosystem approach to fisheries to maintain bycatch mortality rates below biologically based limits, facilitating the recovery of ETP species while safeguarding a sustainable development of the Galapagos small-scale tuna fishery. Significant investments in science, technology, and innovation are necessary to encourage gradual and adaptive improvements in fishing practices to reduce IUU fishing and bycatch. [ABSTRACT FROM AUTHOR]

Spawning aggregations are critical for the resilience of some coral reef fish populations and for the sustainability of many coastal fisheries. However, overexploitation of these aggregations is leading to a rapid decline of fish stocks. The fish aggregation site (FAS) associated with the San Felipe Keys National Park (in southwestern Cuba) is of great importance for the conservation of northern Caribbean snapper. An assessment of the pressure which fishing is placing on these populations, however, has not to date been conducted. To characterize the fishing use of San Felipe Keys FAS, data pertaining to five snapper species were evaluated in 2014. Samples consisted of 3879 individuals collected from 80 catch samples from commercial and sport fishing modalities. Catch assessment was performed using indicators based on length-frequency data (minimum legal size, length at first maturity, optimal length and average size of catch) and on fisheries effort data (seasonal and spatial yield by different modalities). To identify whether individuals were caught before or after spawning, the stage of gonads was analyzed. Individuals with sizes below the maturity length and with mature gonads before spawning prevailed in the five species, with Lutjanus analis and L. cyanopterus being the most affected. The government commercial fishing fleet had the highest volume of catches and the largest impact. The indicators suggest that the current use of this FAS may impede the effective preservation of reproductive capacity of the population. Therefore, management and conservation initiatives of this FAS are urgently needed to maintain the sustainability and resilience of the coralline social-ecological system. [ABSTRACT FROM AUTHOR]

Structural and functional changes in a sandy beach ecosystem in the southwestern Atlantic (Barra del Chuy, Uruguay) were assessed by contrasting four Ecopath trophic models and performing temporal dynamic simulations using Ecosim. Each model (1982, 1989, 1996 and 2012) represents a historical period of a clam fishery in which regulatory structure, management tools and resource status varied substantially. The results showed that this land-ocean interface experienced significant changes reflected at the population and ecosystem levels, owing to a combined effect of fishing and climate variability. Most system biomass (excluding phytoplankton and detritus) consisted of benthic invertebrates. Phytoplankton increased significantly over time, whereas the biomass of benthic macrofaunal components varied among the periods due to bottom-up processes, mass mortalities of the harvested clams and fishing intensity. Major fishing impacts on the targeted clam and mass mortalities occurred concurrently with low phytoplankton biomass, and clam recovery occurred in the absence of harvesting and increasing primary production. Ecosystem-level attributes (e.g., Total System Throughput, Ascendency) showed considerable temporal fluctuations, which were primarily related to changes in system productivity associated with a climatic shift from a cold phase to a warm phase and increasing onshore winds. An analysis of robustness and order showed an ecosystem state lacking the flexibility to adapt to new perturbations. Dynamic simulations showed the prominent bottom-up role of environmental variability on ecosystem function and structure. Temporal dynamics is conducted by changes in primary production forced mainly by temperature patterns. The concurrent role of climate variations and fishing explained the long-term dynamics of this ecosystem, suggesting that sandy beaches are fragile social-ecological systems whose services are increasingly threatened by long-lasting stressors. [ABSTRACT FROM AUTHOR]

The systematic dwindling over time of many commercially important fish stocks in developed countries and the increasing demand of international markets provided a window of opportunity for fishery sector development in many developing countries. Science-based assessments of how market forces impact on fisheries trends are particularly limited in developing countries. This study assessed long-term trends (1960–2013) of the Uruguayan industrial fishery sector, including: (i) landings discriminated by species and resource type; (ii) variations in nominal effort and fleet capacity; (iii) bioeconomic patterns for most important species; and (iv) export and import volumes at the Uruguayan seafood market. Results indicate the sector underwent four phases that depict long-term patterns: development, expansion, stabilization-diversification and declining yields and market contraction. The development of the sector was mainly due to the Argentine hake fishery, which was characterized by a sustained increase in landings, nominal effort and fleet capacity during the initial decades, but showed a decreasing trend afterwards. In response, a fishery diversification policy based on more valuable target species but with lower trophic levels was developed. Uruguay adopted a seafood net exporter role since the very beginning, with exports increasing linearly through time. More recently, seafood imports, with more competitive prices than locally caught seafood, have been gaining ground in the domestic market, reaching a third of all seafood currently consumed. Nowadays, the Uruguayan fishery sector is facing a crisis that is clearly reflected in the decreasing yields of the main species targeted, exports dwindling and increasing seafood imports. These results highlight the pressing need of the industrial sector to shift its model of fisheries exploitation. This study also provides evidence of the need to consider additional bioeconomic analysis to fully understand the behavior of the fishery sector as a dynamic social-ecological system operating in a globalized seafood trade scenario. [ABSTRACT FROM AUTHOR]

The deep-sea crab Chaceon notialis is distributed along the continental shelf and slope of the SW Atlantic Ocean, mainly in Uruguayan waters, supporting a male-only fishery of high commercial value since 1993. A long-term study of catch per unit of effort (CPUE), population structure and individual weight was carried out before and after the onset of exploitation. Some 23,000 individuals were collected at 300–900 m depth and between latitudes 35°00′ and 36°40′S during seven fishery-independent trap surveys. Additional data on weight and individuals with signs of molting were gathered from 1000 to 1600 m south to 37°00′S after the start of the fishery. Individual weight decreased markedly over time, particularly after the start of the fishery, and decreased with depth for both sexes, with opposite patterns with latitude. CPUE peaked at 900 m and 35°40′S and remained stable over time, suggesting that it does not reflect the condition of the stock. Ovigerous females were found between 300 and 500 m and in the northernmost edge of the distribution range (35°00′S–35°40′S). The number of females decreased exponentially with depth and linearly with latitude. Molting males and females followed opposite latitudinal patterns, with highest percentages of molting individuals found between 600 and 900 m depth. A spatial management framework is proposed, which includes closing areas to fishing where ovigerous females, juvenile crabs and largest males are concentrated. [ABSTRACT FROM AUTHOR]

Ecosystem engineers can modify the environment, affecting the associated community. Studies of mussels as ecosystem engineers have been conducted mostly in the rocky intertidal zone, while those in sedimentary intertidals have been relatively scarce. The present study assessed the effect of varying densities of Brachidontes rodriguezii on local environmental variables (substrate weight, water content, organic matter, weight of sediments adhering to mussel byssus) and ecological attributes of the associated community (richness, abundance, diversity, evenness, and assemblage structure) at different intertidal levels, sites, and seasons, in a mixed-sediment intertidal region in San Antonio Bay (Patagonia, Argentina). We performed two independent manipulative field experiments at low and mid intertidal levels at two sites -Punta Verde (PV), with relatively higher current velocities and coarser grain sizes than Punta Delgado (PD)- in both winter and summer. Manipulative experiments consisted in reducing mussel density to 50% in the low intertidal and increasing that density to up to 100% in the mid zone. We hypothesized that local environmental variables and ecological attributes associated with B. rodriguezii depended on mussel density. The reduction in B. rodriguezii density increased the evenness and reduced the abundance at PD plus reduced the richness at PV. Also, when reducing mussel density, the assemblage structure differed in water content and organic matter at both sites between treatments and seasons. The sediment weight adhering to mussel byssus in PD and substrate weight in PV were the best descriptors of the assemblages. The increase in mussel density, however, produced a weak effect on the ecological attributes of the community, and the assemblage structure did not correlate with the environmental variables considered. Our results demonstrated a stronger engineering effect of B. rodriguezii at reduced, but not increased, mussel density. This study revealed that the ecological attributes associated with B. rodriguezii both were density-dependent and varied with sites along the year in mixed-sediment intertidal zones. • Manipulative experiments showed an engineering effect of the mussel B. rodriguezii. • Increasing and reducing the mussel-density modified the local environmental variables. • Manipulation of the mussel density affected the evenness, abundance and richness. • This effect was stronger in the low than in the mid-intertidal level in both sites. • The assemblage structure was explained by some environmental variables. [ABSTRACT FROM AUTHOR]

To assess how sandy beach biodiversity is influenced by the effects of environmental features and urbanization, we sampled the macrofauna in the whole across-shore gradient of 90 beach sites in Southeast Brazil. We found that morphodynamic features were the main drivers of macrobenthos, but urbanization-related variables, such as number of beachgoers and number of constructions on the upper shore, decreased species richness and biomass. We also found that submerged zones sustained the highest number of species and biomass in the across-shore gradient, but were the most impacted by human activities. By demonstrating the ecological importance of submerged zones, our results show that beach management practices, which are mainly focused on the upper shore, are missing important components of beach biodiversity. To secure the sustainability of beach ecosystems, management initiatives should include both their social and ecological components and consider the entire Littoral Active Zone as the proper management unit. • We unravel the effects of urbanization and environment on sandy beach biodiversity. • Morphodynamic variables were the primary drivers of beach macrobenthos. • Submerged zones had the highest biodiversity and were mostly affected by humans. • Number of visitors, buildings and grooming were critical indicators of impact. • The entire littoral active zone should be considered as the management unit. [ABSTRACT FROM AUTHOR]

Sandy beaches are part of an integral social-ecological system whose management has to encompass the natural and societal features of the catchment and the adjacent marine area, as well as the beach itself. Using a multi-use and complex beach system in Uruguay, the La Coronilla and Barra del Chuy resort, we interrogate those natural and societal features by employing the DAPSI(W)R(M) cause-consequence-response cycle and pathways. This identifies the Drivers, Activities, Pressures, State change on the natural system, Impacts (on the Welfare of the human system), and the Responses (requiring management Measures). We contend that this approach is needed for the sustainable development and use of this ecosystem and its biodiversity protection. This also indicates the importance of a holistic and systems approach, which is necessary, valid and valuable for sandy beaches worldwide. [Display omitted] • Managing beaches at the appropriate scale is a pressing, short-term need, worldwide. • Managing these open social-ecological systems must include ecosystem interlinkages. • As narrow interfaces, beach management must be linked to the land and the sea. • The DAPSI(W)R(M) framework addresses major management concerns of sandy beaches. • Despite being an open beach, the framework is exemplified in a catchment-to-coast system. [ABSTRACT FROM AUTHOR]

The Ecosystem Approach to Fisheries (EAF) has been proposed as a holistic approach for managing fisheries. Although EAF is a widely accepted concept, many challenges remain in its practical implementation, particularly in small-scale fisheries (SSFs) in developing countries. Long-term evaluations of EAF performance in SSFs are scarce and even fewer when considering co-management (Co-M) as the institutionalized governance mode implemented under an EAF scheme (EAF/Co-M). This paper addresses the implementation, development process and performance of an EAF/Co-M in the yellow clam SSF of Uruguay through multiple fishery indicators for the period 2007–2015. EAF/Co-M showed a highly positive response in abundance and biomass of the harvestable stock through time, stabilization in individual sizes above the minimum landing size limit, and a fairly constant exploitation rate at low levels that did not exceed 25%, accompanied by relatively constant CPUE values through time. Temporal variations in unit price and revenues per unit of effort showed higher values after EAF/Co-M implementation. These indicators, taken together, suggest that the enhanced production capacity of the fishery during the EAF/Co-M implementation did not have a negative impact on the stock. The number of fishers involved in the activity has not changed markedly through time, but two remarkable positive changes occurred in the composition of the group: (i) an increasing number of licenses allocated twice in a row through time, which suggests the consolidation of a stable group of fishers; and (ii) a significant increase in the number of women directly involved in the fishing activity. This study provides solid empirical evidences to the idea that EAF, coupled with Co-M as a formal governance mode, could be helpful to address management tasks and to improve social–ecological conditions of SSFs. [ABSTRACT FROM AUTHOR]

Plastics and other marine debris affect wildlife through entanglement and by ingestion. We assessed the ingestion of marine debris by seven albatross species in the southwest Atlantic by analyzing stomach contents of birds killed in fisheries. Of the 128 specimens examined, including four Diomedea species ( n = 78) and three Thalassarche species ( n = 50), 21 (16.4%) contained 1–4 debris items, mainly in the ventriculus. The most common type was plastic fragments. Debris was most frequent in Diomedea species (25.6%) and, particularly, Diomedea sanfordi (38.9%) and very rare in Thalassarche species (2.0%), presumably reflecting differences in foraging behavior or distribution. Frequency of occurrence was significantly higher in male than female Diomedea albatrosses (39.3% vs. 18.0%). Although levels of accumulated debris were relatively low overall, and unlikely to result in gut blockage, associated toxins might nevertheless represent a health risk for Diomedea albatrosses, compounding the negative impact of other human activities on these threatened species. [ABSTRACT FROM AUTHOR]

Small-scale fisheries (SSF) are critical to food systems and livelihoods. However, the relation between fisheries resilience, outcomes of proximate and distal drivers and the potential space for transformative changes have been largely unexplored. Such knowledge is key to understanding how fishery resources, institutions and actors respond to, and learn from, diverse drivers of change and social-ecological crises, as well as to design policies aimed at building resilience in SSF. This paper provides a new heuristic model to analyze the factors that combined lead SSF to trajectories towards shifts, traps and collapses, including the opportunity to navigate sustainable transformations. We illustrate the proposed Heuristic with three case studies with different biophysical and socio-cultural contexts and final outcomes: the Galician shellfisheries on foot (Spain), the Chilean king crab small-scale fishery (Chile), and the Galapagos sea cucumber small-scale fishery (Ecuador). The application of the Heuristic and a detailed description of model key elements for each case study provide practical examples and a valuable guide for fisheries scientists, practitioners and decision-makers to learn and/or respond in a flexible way to SSF social-ecological crises in the pursuit of fisheries sustainability and equity. Scholars are welcome to adopt our Heuristic to classify and bound SSF, order events, suggest hypotheses of linked drivers, pathways of change, potential trajectories, and outcomes, and envision potential space for transformative changes. [ABSTRACT FROM AUTHOR]

Small-scale fisheries (SSFs) provide food security, livelihood, and employment to millions of people around the world. Whereas the urgency of securing sustainable SSFs is widely recognized, the governance characteristics that promote sustainability are poorly understood. This study evaluates the performance and governance of SSFs in 20 countries in the Americas and Europe, with the aim of finding the most likely paths to improve SSFs outcomes. Fisheries performance was assessed through ecological and socio-economic indicators derived from stakeholders' perceptions. The relative importance of 15 governance attributes associated with the perceived performance was identified using random forest regression models. The perceived status of many SSFs analyzed here is of great concern. Trends in reported landings, landings per unit effort, and revenues have decreased between 3% and 10% on average in the last 5 years, and these declines were steeper in Latin American and southern European fisheries than in North American or northern European fisheries. Perceived social cohesion was also poor, as reflected by conflicts outweighing cooperation. Adaptability, communication, transparency, and the involvement of highly skilled fishers and community leaders were the most relevant factors associated with reversing the perceived declines in SSFs. Strengthening human capital should be a priority in the reform of SSFs, and the following actions are strongly recommended to support sustainable SSFs: 1) adopting flexible approaches in responding to changes; 2) fostering dialog by using diverse communication channels or involving neutral mediators; 3) identifying and training community leaders; and 4) empowering fishers to participate actively in governance. • This is the largest study linking SSF performance to governance characteristics. • Many SSFs are perceived to be in a poor state socio-economically and ecologically. • Performance tracked human development; was poorer in southern than northern regions. • Transparency, adaptability, and empowerment of communities are key to reform SSFs. [ABSTRACT FROM AUTHOR]

Abstract: Global patterns in species richness in sandy beach ecosystems have been poorly understood until comparatively recently, because of the difficulty of compiling high-resolution databases at continental scales. We analyze information from more than 200 sandy beaches around the world, which harbor hundreds of macrofauna species, and explore latitudinal trends in species richness, abundance and biomass. Species richness increases from temperate to tropical sites. Abundance follows contrasting trends depending on the slope of the beach: in gentle slope beaches, it is higher at temperate sites, whereas in steep-slope beaches it is higher at the tropics. Biomass follows identical negative trends for both climatic regions at the whole range of beach slopes, suggesting decreasing rates in carrying capacity of the environment towards reflective beaches. Various morphodynamic variables determine global trends in beach macrofauna. Species richness, abundance and biomass are higher at dissipative than at reflective beaches, whereas a body size follows the reverse pattern. A generalized linear model showed that large tidal range (which determines the vertical dimension of the intertidal habitat), small size of sand particles and flat beach slope (a product of the interaction among wave energy, tidal range and grain size) are correlated with high species richness, suggesting that these parameters represent the most parsimonious variables for modelling patterns in sandy beach macrofauna. Large-scale patterns indicate a scaling of abundance to a body size, suggesting that dissipative beaches harbor communities with highest abundance and species with the smallest body sizes. Additional information for tropical and northern hemisphere sandy beaches (underrepresented in our compilation) is required to decipher more conclusive trends, particularly in abundance, biomass and body size. Further research should integrate meaningful oceanographic variables, such as temperature and primary production, in deciphering latitudinal trends. [Copyright &y& Elsevier]

As sites of floating marine material deposition, sandy beaches accumulate marine litter. While research and assessment on beach litter is increasing and involves various actors (scientists, society and NGOs), there is the need to assess current and future dominant trends, directions and priorities in that research. As such, a textural co-occurrence analysis was applied to published scientific literature. Words were considered both singly and as part of compound terms related to concepts relevant to sandy beach ecology: morphodynamic state; Littoral Active Zone; indicator fauna. Litter as a compound term was also included. The main co-occurrences were found within compounds, with scarce interaction of "morphodynamic state" with the others, indicating the need for further integration of beach ecology paradigms into beached plastics studies. Three approaches are proposed to overcome the research limits highlighted: the unequivocation of terms, the consideration of adequate scales, and the attention to dynamics rather than just patterns. • Keywords related to sandy beach ecology and plastics litter studies were selected. • Co-occurrence analysis was applied to literature on beach ecology and plastics litter. • All keywords were found in use, though with co-occurrence across compounds still low. • To overcome limits highlighted, approaches were suggested for forthcoming research. • Unequivocation of terms, focus on different scales and on dynamics were recommended. [ABSTRACT FROM AUTHOR]

All clam fisheries in the western Mediterranean Sea have dramatically declined in the last few decades. Recently, most have collapsed in Spain, resulting in job loss for hundreds of small-scale fishers. However, insufficient attention has been given to the profound significance of this socio-ecological crisis. We evaluated the historical, social, and ecological context of the striped venus clam (Chamelea gallina) fisheries in the western Mediterranean Sea, focusing on one of the main productive areas of this region (the Ebro Delta, Catalonia, NE Spain) to detect possible causes of the decline in clam landings. Different governance systems (self-governance, centralized governance, and de facto co-governance) had been successful in maintaining striped clam fisheries since they were established in the 1940s. However, since the industrialization of fishing fleets in the mid-1970s, a lack of reliable management (e.g. , free access; conflicts between different interested parties) and a progressive increase in fishing capacity, fishing effort, and technological enhancements across the small fishing grounds have increased the vulnerability of the exploited stocks and set them on a collapse trajectory. We recommend the following management measures to promote the recovery of the striped venus clam stock and mitigate the loss of its ecological, social, and economic value: (1) the closure of the fishery in the Ebro Delta; (2) the preparation and implementation of a Spanish Management Fishery Plan to restore the striped clam fishing grounds; (3) the establishment of a supra-regional Management Plan for the striped venus clam on the Mediterranean coast of Spain. • Clam fisheries in western Mediterranean Sea declined dramatically in the last decades. • Most small-scale clam fisheries collapsed in Mediterranean coast of Spain. • Long-term trends in the striped venus clam fishery in the Ebro Delta are assessed. • Weak management and increase in fishing capacity set stocks on a collapse trajectory. • Local and supra-regional Management Plans and co-governance are encouraged. [ABSTRACT FROM AUTHOR]

Abstract: This paper addresses the need for a simple model for managers to employ when planning strategies for management of sandy beaches. It is based on the premise that in the overwhelming majority of cases beaches are suitable for recreation or for conservation or a combination of the two, whereas other uses are rare. The broad range of physical, ecological and socio-economic factors relevant to beaches, are reviewed briefly. Then three key factors are selected to develop each of two simple indices, an index of conservation value, CI, based on dune state of health, the presence of iconic species and macrobenthic species richness; and an index of recreation potential, RI, based on the extent of infrastructure, the level of safety/health of the beach and its physical carrying capacity. By combining these two indices, a beach can be simply classified as suitable for intensive recreation, or primarily for conservation, or for mixed use. Ten principles are outlined for consideration and potential application to beach management strategies. Finally, 23 beaches from three continents are classified, with detailed descriptions of a beach typical of each major use type. [Copyright &y& Elsevier]

Abstract: The global fisheries crisis has critical socioeconomic impacts on small-scale fisheries. In addition, the crisis also exacerbates the conflicts and technological interdependencies between artisanal and industrial fisheries. In the coastal zone of Uruguay, both the artisanal and the industrial fleet target the whitemouth croaker Micropogonias furnieri (Desmarest, 1823). In this paper, we assess the spatial dynamics of the artisanal fleet and evaluate technological interdependencies with the industrial fleet. To this end, information gathered from logbooks, vessel monitoring systems and monthly landing reports for five consecutive years was analyzed using a Geographic Information System (GIS). An Index of Fisheries Interdependencies (IFI) was developed to identify and measure the intensity of spatial overlap between the fleets. A strong intra-annual displacement of the artisanal fleet was observed along the coast, as the fleet followed the migrations of the stock to the coastal spawning areas. The catches increased from April to July for both fleets, whereas an inverse trend was observed from October to January. This finding indicated the negative effects of the activities of the industrial fleet on the artisanal catches. Declining Catch per Unit Effort (CPUE) trends and high IFI scores were detected at nursery and spawning areas and suggest early warning signals of stock overexploitation. Artisanal exclusive-use zones and spatio-temporal management windows are recommended to decrease the potential interdependencies between fleets. [Copyright &y& Elsevier]

Abstract: Ecosystem-based management (EBM) has recently received considerable attention. However, examples of empirical approaches to marine EBM are scarce. Therefore, empirical information on the presence of EBM elements within existing policies and the way they may provide settings and lessons for EBM implementation is timely. This study analyses stakeholders’ perceptions on the existence of EBM principles in current marine management practices and policies, and how they determine perceptions for success and satisfaction regarding coastal management within selected case studies drawn from four developing countries in the Southern Cone of South America. Patterns of response across study sites show that although EBM principles as such are not explicitly included in management/conservation plans, there are policies (mainly local), which generate conditions for more explicit inclusion of them. These are based on participatory bottom-up planning, place-based management and consensus reaching: all elements included within the theoretical literature on EBM implementation. [Copyright &y& Elsevier]

The Rio de la Plata and the adjacent Atlantic Ocean are covered by the most significant amount of environmental cooperation in the Southwest Atlantic. There are joint agreements between Uruguay and Argentina and their institutions, and there is a long history of bi-national fisheries management and maritime traffic organizations. However, these agreements do not cover many other activity sectors that come under different jurisdictions and regulatory instruments. Documentary sources spanning 30 years have been used to describe the spatial extent and evolution of more than 30 activities (grouped into main clusters), as well overlaps and conflicts between them. The higher number and diversity of activities were found in the coastal zone, while fisheries and spatially-defined management measures were dominant in common waters and on the continental shelf. Transport/navigation and communication cables were the most common clusters along surface and sub-bottom linear routes, respectively. The different and overlapping use of the water column and across multiple jurisdictions were the cause of sectoral conflicts, such as between fisheries-transport or fisheries-submarine cables. Under a sector-by-sector analysis, and in the absence of a comprehensive planning environment, many of these conflicts are resolved, at best, by legal proceedings. There have been significant advances in the governance and spatial organisation of fisheries and transport, while progress in conservation and infrastructure has not occurred at the same speed or by considering a broader vision of the system. Addressing the existing and increasing interferences or unresolved conflicts emphasises the need to consolidate multilevel governance frameworks and opportunities in order to advance in marine spatial planning in the Southwest Atlantic Ocean. [Display omitted] • Long-term and spatial changes in the use of marine space are assessed in Uruguayan waters. • 34 activities were mapped, with higher number and diversity in the coastal zone than offshore. • Interferences and conflicts between activities were assessed by combining maps, conflict scores and regulations. • Overlaps and interferences were found in clusters Transport, Fisheries and Cables and pipelines. • Suggestions are made to develop multilevel marine spatial planning, including shared waters with Argentina. [ABSTRACT FROM AUTHOR]

Despite the global occurrence of microplastic contamination on sandy beaches, evidence of microplastic distribution within beaches remains contradictory. When conflicting evidence is used to inform sampling surveys, it increases uncertainty in resulting data. Moreover, it hampers spatially explicit risk characterization of microplastic pollution to intertidal fauna. We aimed to guide sampling designs for microplastic monitoring on beaches, and to quantify macroinfauna exposure to microplastics. Microplastic abundance, quantified between 5 mm–66 μm, lacked a significant zonation across the top sediment layer of sub-terrestrial, upper and lower midlittoral, and swash zones at two sites with varying anthropogenic influence on a microtidal dissipative beach in Uruguay. Microplastic abundance decreased exponentially with increasing grain size, as revealed by Bayesian Poisson regression, although the decrease was less steep compared to prior knowledge regarding sediment – plastic interactions obtained for large (millimeter-sized) industrial pellets. Significant differences in microplastic contamination between the two sites with varying anthropogenic influence likely related to their proximity to a freshwater canal. Corresponding field measurements of body burdens of fibers and irregular particles were significantly lower for the polychaete Euzonus (Thoracophelia) furcifera , despite its preference for finer sediments with higher microplastic loads, compared to the isopods Excirolana braziliensis and Excirolana armata. Results provide critical insights toward representative sampling of microplastics within beach sites. Specifically, we caution against sampling limited to the drift line, and instead recommend: 1) reporting beach morphodynamic characteristics; 2) using clearly defined, ecologically-informed zonation schemes; and 3) accounting for sediment grain size as a covariate to normalize among reported contamination levels. The results contribute valuable baseline data toward realistic exposure landscapes relative to the sediment grain size preferences of macroinfauna, needed to inform laboratory experiments. [Display omitted] • Microplastic abundance decreases exponentially with sediment grain size. • Absence of microplastic zonation cautions against sampling at the drift line only. • Habitat preferences are not reflected in species-specific body burdens. • Sediment grain size and beach morphodynamics affect macroinfauna exposure. Our results suggest species-specific body burdens relating to exposure landscapes where microplastic abundance decreases exponentially with grain size but lacks a clear across-shore zonation. [ABSTRACT FROM AUTHOR]

This paper develops a precautionary bioeconomic approach for the red grouper (Epinephelus morio) multi-fleet fishery in the Campeche Bank, Gulf of Mexico, based on a long-term analysis covering the years 1980–2000. Population structure was estimated through commercial sampling of the three fishing fleets participating in the fishery: two Mexican (one artisanal and the other industrial) and one Cuban (industrial). Length frequency distributions (LFDs) did not show significant differences between the Mexican industrial and the Cuban fleets, but differed from those of the artisanal fishery, which targets smaller individuals. The lack of differences in the LFDs between years suggests that the population structure was stable during the last two decades. However, the instantaneous coefficient of total mortality Z, estimated through length-converted catch curves, significantly increased during the 21-year period of analysis, being in average 1.22 times higher in 2000 than in 1980. Annual estimates of yield and Z, together with unit costs of effort and ex-vessel prices, were used as inputs to build a bioeconomic yield–mortality model. A sensitivity analysis was performed under three scenarios of natural mortality M (0.16, 0.25 and 0.35 per year). The yield at maximum economic yield (YMEY) and the associated mortality levels ZMEY and FMEY were always the most conservative bioeconomic reference points (BRPs). The yield at maximum biological production (YMBP), YMEY and mortality-related BRPs were substantially lower than those based on maximum sustainable yield (MSY), thus constituting useful target BRPs for precautionary management. The bootstrap method used for determining the uncertainty associated at BRPs, shows that the best targets BRPs were YMEY and YMBP, whereas MSY is confirmed as a risky and limit BRP. A simple approach to the formulation of risk-averse management strategies was explored using the percentiles of cumulative distributions of MSY, YMBP and YMEY estimates generated from bootstrap against Z. We conclude that the red grouper fishery at Campeche Bank is overexploited and that immediate management actions are needed to prevent stock collapse. [Copyright &y& Elsevier]

The spatial structure and seasonal changes of estuarine fish assemblages in the Cie´naga Grande de Santa Marta (CGSM) were analysed based on four seasonal comprehensive surveys conducted in 1993–1994 and 1997. Geostatistical and multivariate techniques were used to: (a) determine seasonal changes in spatial distribution of the species richness, and (b) identify assemblages of estuarine fish and their relation to abiotic factors. Potential biotic interactions affecting the assemblage structure were also explored. A total of 11075 individuals representing 39 species were collected, with Eugerres plumieri, Diapterus rhombeus, Micropogonias furnieri, Mugil incilis, Cathorops spixii, Elops saurus and Anchovia clupeoides as dominant species between seasons. Spatial distribution of fish richness differed between rainy and dry seasons in each year, whereas species mapping showed spatial patchiness in 1993–1994 and gradients during 1997. Strong evidence of species saturation was found in all seasons, suggesting biotic interactions limiting species richness at a threshold density of ca. 50 ind./5000 m2. Marine, marine-estuarine and freshwater species were classified in each season according to their capability to cope with salinity fluctuations. Associations defined by functional feeding guilds were also identified. Empirical and statistic evidence showed that fish assemblages differed between seasons within each year, and each assemblage was always dominated by a small number of species, notably E. plumieri in both years 1993–1994 and 1997. Between-season differences in fish assemblage structure in the CGSM seem to be driven by abiotic factors; however, evidence of species saturation could suggest the existence of density-dependent factors operating together. [Copyright &y& Elsevier]

We demonstrated through a 2-year field study that mortality rates of juvenile shrimps Farfantepenaeus duorarum in a coastal lagoon from the Gulf of Mexico decrease as the individual size increases. The size-dependent mortality was successfully modeled by a reciprocal function of length as well as by the conventional exponential decay model. The reciprocal model appears to provide a more reasonable prediction from a biological point of view, because the exponential model could underestimate mortality at smaller sizes. [Copyright &y& Elsevier]

A quantitative fishing survey of the scallop Zygochlamys patagonica was conducted in Uruguayan waters of the southwestern Atlantic Ocean in July 2001. The area surveyed extends between latitudes 35°50′S and 36°50′S, water depth ranging from 75 to 135 m. Stations were located systematically on parallel transects along the latitudinal gradient at 10-miles intervals and tows were set at every 5 m water depth interval. Stock estimates were obtained using geostatistics (kriging). This model-based approach showed a persistent spatial structure of the scallop population, as denoted by the spherical model fitted to both the whole population and the harvestable stock (individual height>55 mm). The structure of spatial dependence suggests a latitudinal structured process close to 48 km (total population) and 61 km (harvestable stock). Mean kriged density for the most likely value of gear efficiency (e=0.35) was 0.0122 and 0.0089 kg m−2 respectively, whereas global biomass estimated by block kriging were 48 039 and 35 246 t. Further analysis conducted at the bed of highest scallop densities provided additional support to the spatially structured process observed at a macroscale. Sensitivity analysis conducted with gear efficiency (e), revealed consistency of estimates with accepted theory, i.e., density and biomass estimates increased with decreasing e. Most of the life history traits of Z. patagonica showed clear large scale patterns: (1) concerning latitude, the highest density patch was found at the middle (36°20′S: mean=0.0279 kg m−2) of the surveyed area, whereas the southern border (36°50′S: mean=0.0204 kg m−2) had densities 16 times higher than the northern one (35°50′S: 0.0013 kg m−2). Muscle weight also increased linearly towards higher latitudes, whereas the harvestable stock, mean individual height and maximum height increased asymptotically in the NE–SW direction. Only muscle yield, either as global mean or discriminated by scallop size, significantly increased at the northern end of species distribution. (2) Bathymetric analysis showed a clear maximum density at depths close to 100 m, coinciding with the minimum proportion of harvestable stock, and a consistent inverse relationship between depth and (a) individual height and (b) muscle weight. Guidelines are suggested for fishery planning and development, taking special emphasis on the applicability of spatially explicit management tools. [Copyright &y& Elsevier]

This paper analyses the spatial and temporal effects of a freshwater discharge (Canal Andreoni) on the macroinfauna community and its habitat in a sandy beach of Uruguay. Bimonthly, we examined 17 environmental variables plus macroinfauna abundance, biomass, richness, evenness and diversity of three sites: Andreoni, at the canal mouth, Coronilla, at 1 km, and Barra, at 13 km from the mouth. Both univariate and multivariate techniques showed an increasing degree of perturbation towards the canal. This was reflected by abiotic and biotic differences between sites and by a consistent two-dimensional ordination of the samples. A clear seasonal pattern was found, specially accentuated at Coronilla, where the effects of the canal were stronger in winter and weaker in summer. Multivariate linking between macroinfauna and its habitat highlighted the role of salinity as explanatory variable of the observed trends. [Copyright &y& Elsevier]

We analyze intra and inter-annual harvesting patterns of the black escolar Lepidocybium flavobrunneum (Gempylidae), an important component of the incidental catch of the Uruguayan tuna fleet (UTF) at the southwestern Atlantic Ocean (SAO), based on daily information of catch, fishing effort and individual weight of all the specimens caught during 16 years (1981–1996). The analysis also compares the activities of two fishing fleets that operated in two different periods of fishery development: category A, which comprises Japanese vessels that operated between 1981 and 1991, and category B, consisting of American and Spanish vessels that operated between 1992 and 1996. The relative representation of the total incidental catch significantly increased during the 16-year period of activity of the UTF, reaching 43% of the total catch in 1995. A recurrent seasonal pattern in fishing effort, catch and catch per unit of effort (CPUE) was observed, peaking in austral winter and spring. The daily number of hooks and total catch were significantly higher for category A, which exerted 2.7 times higher number of hooks and obtained catches 3.33 times higher than category B. Differing with the above trends, mean daily CPUE of a category B vessel was 16% higher than category A, which can be attributed to the increase of fishing power. The mean individual weight decreased almost 40% in 15 years, i.e., from 23.2 kg in 1982 to 14.1 kg in 1996, suggesting overexploitation risks of this incidental species. The effect of increasing fishing power and the effectiveness of management measures for large pelagics at the SAO are discussed. [Copyright &y& Elsevier]

• We assessed changes in a warming hotspot and their impacts on a small-scale fishery. • Climate-related stressors affected biophysical and social components of the SES. • Autonomous and government-led adaptations were essential to face climate change. • Co-management fostered climate-responsive policy actions. • 40 yr of scientific and local knowledge provided a unique learning platform. Small-scale fisheries in developing regions are particularly vulnerable to climate change, but the assessment of climate-induced changes and impacts are often hampered by the data poor-situation of these social-ecological systems. Based on 40 years of scientific and local ecological knowledge, we provide a coherent narrative about the effects of a marine hotspot of climate change on a small-scale fishery across different geographical and temporal scales. We applied a mixed-methods approach to assess biophysical changes, social-ecological impacts, and the incremental spectrum of actions implemented at multiple levels to increase the adaptive capacity of a small-scale clam fishery. The warming hotspot here analyzed was the fastest-warming region in the South Atlantic Ocean. Long-term changes in wind intensity and direction were also noticeable at a regional scale. Both sea surface temperature and winds showed a clear shifting pattern in the late 1990 s. These climate-related stressors determined ecosystem and targeted population changes (e.g. clam mass mortalities, slow stock recovery rates after ecological shocks, habitat narrowing), and favored harmful algal bloom-forming organisms. Climate-induced drivers also affected the human component of the social-ecological system, preventing fishers from securing a fulltime livelihood and limiting the fishery economic potential. Adaptive responses at multiple levels provided some capacity to address climate change effects, and transformative pathways are being taken to adapt to climate-induced changes over the long-term. Transformative changes were fostered by the local perception of environmental change, shared narratives, sustained scientific monitoring programs, and the interaction between knowledge systems, facilitated by a bridging organization within a broader process of governance transformation. The combination of autonomous adaptations (based on linking social capital and fishery leaders agency) and government-led adaptations were essential to face the challenges imposed by climate change. Our results serve as a learning platform to anticipate threats and envision solutions to a wide range of small-scale fisheries in fast-warming regions worldwide. [ABSTRACT FROM AUTHOR]

Since the beginning of the fishing industry in Uruguay, a variety of fishing activities began, evolved, and expanded into the deeper waters of the Uruguayan marine territory. The purpose of this study was to identify and map the Uruguayan higher intensity fishing areas over a 58-year time span. The concept of métier was used, which allows the grouping of fishing modalities according to target species, fishing units, gear and operation areas as descriptors for each activity. Information sources included published articles, reports, records in official publications, direct observations and research surveys conducted between 1960 and 2018 in the Río de la Plata and the Argentine-Uruguayan Common Fishing Zone. An overlapping model using a geographic information system was deployed in order to identify area use and intensity weighted by the number of fishing units. A total of 60 métiers were listed in two fleet segments, 25 artisanal métiers and 35 industrial métiers, throughout the analysed period. Currently, most métiers are inactive, and of those that are operational, most are the oldest métiers that are considered to be traditional fisheries. The overlap model showed higher activity spatially concentrated on the continental slope, in the eastern coastal zone and along the area near Montevideo, separated by fleet segment. Industrial activity showed an expansion of the area according to the number of métiers between 1995 and 2010. This analysis allowed us to quantify the geographical extent of fisheries in the long term, providing critical information for fisheries management and marine spatial planning. • The "Métier" concept was applied to fisheries between 1960 and 2018. • Sixty métiers were identified, including active and inactive, in two fleet segments. • The use of marine areas was different in small-scale and industrial fleet segments. • The area used by the industrial fleet expanded when the number of métiers reached the maximum. [ABSTRACT FROM AUTHOR]

Highlights • Short-term fishery dynamics assessed by a community-based data collection program. • GLMMs used to model the contribution of environmental, socio-economic, and cultural factors. • Winds and red tides play a critical role in fishery dynamics. • CPUE of each fishing event affected by fisher attributes such as gender and age. • Adaptation strategies needed to counteract the increasing effects of external drivers. Abstract We assessed the relative contribution of a set of predictors on the short-term dynamics of the yellow clam intertidal fishery in Uruguay based on a community-based data collection program for five consecutive fishing seasons. Results of generalized linear mixed models showed that the occurrence of fishable days depends on the absence of red tide events and prevailing wind conditions, but also was related to the timing of each fishing event throughout the fishing season. Furthermore, higher fishing yields were coincident with the prevalence of northerly offshore winds. Catch per unit of effort levels of each fishing event were mostly related to interannual characteristics of each fishing season and, to a lesser extent, with fisher attributes (gender and age) and the timing of each fishing event. The adverse effect of red tides and unfavorable environmental conditions impose a high degree of uncertainty in this social-ecological system, leading to economic inefficiency. A key challenge for successful management of the yellow clam fishery and other similar small-scale fisheries relies in considering not only the resource and the governance subsystems, but also the dynamics of the resource users, together with relevant external drivers affecting them. [ABSTRACT FROM AUTHOR]

We model and compare for the first time the ecosystem structure and trophic networks of two sandy beaches with contrasting morphodynamics (i.e. dissipative and reflective). To this end, an Ecopath model was implemented to represent the macroscopic food web on each sandy beach ecosystem. The dissipative beach model comprised 20 compartments and the reflective nine, including detritus, phytoplankton, zooplankton, benthic invertebrates, fishes and seabirds. Input data mainly came from direct surveys, whereas additional information was gathered from published and unpublished sources. Results revealed a major number of top predators and higher trophic levels (TLs) in the dissipative beach (seabirds, fishes, gastropods and the polychaete Hemipodus olivieri) than in the reflective one (fishes and Hemipodus olivieri). Detritivorous and filter feeding benthic invertebrates constituted intermediate trophic levels on both beaches. Exportation of most primary production and detritus was a common feature, with a detritivory:herbivory ratio of 0.42 in the dissipative beach and 0.51 in the reflective, indicating a higher utilization of the primary production in the former. The aggregation analysis showed five TLs in the dissipative beach and four in the reflective. Lower transfer efficiencies in the reflective beach could be attributed to a lower diversity of predators when compared to the dissipative system. Comparison of global ecosystem properties showed that the dissipative system had higher values for total system throughput, total biomass, net production, Ascendency and total number of pathways. We concluded that the greater diversity and biomass in the dissipative beach are reflected in a higher dimension and ecosystem organization than in the reflective beach, thus providing new evidences at the ecosystem level about well-established differences in biological descriptors between beach types. Finally, we stressed the need for acquiring experimentally-based information on benthic invertebrate's consumption rates and the inclusion of the surf zone microbial loop and the interstitial compartment to test for differences in structure and functioning of these coastal ecosystems. [Copyright &y& Elsevier]

Abstract: This paper analyzes the spatial and temporal effects of a freshwater discharge (Andreoni Canal) on polychaete assemblages and the corresponding habitat in a sandy beach of Uruguay. Bimonthly, we examined 17 environmental variables plus polychaete abundance, richness, and diversity of three sites: ‘Andreoni’ (highly disturbed) at the canal mouth, ‘Coronilla’ (moderately disturbed), 1km far away, and ‘Barra del Chuy’ (less disturbed), 13km north from Andreoni Canal. The highly disturbed site showed significantly lower values of salinity, beach width, swash width, slope, chlorophyll a, and significantly higher values of sediment organic matter. Polychaete abundance and diversity significantly decreased towards the canal and were positively correlated with spatial variations in salinity, which was the most important factor structuring polychaete assemblages. The results highlighted the negative effects of this artificial freshwater discharge on the sandy beach environment and stress the usefulness of polychaetes as effective and reliable ecological indicators for these ecosystems. [Copyright &y& Elsevier]

Abstract: Quantitative surveys of penaeoid shrimps (Farfantepenaeus duorarum, F. aztecus, Litopenaeus setiferus, Xiphopenaeus kroyeri, Sicyonia brevirostris and Trachypenaeus similis) were conducted in Campeche Sound, southwestern Gulf of Mexico, in October and November 2002. A total of 20 stations were located along a bathymetric gradient ranging from 8 to 50m. Spatial patterns in density and individual size were evaluated by geostatistics and linear/nonlinear models, respectively. Variographic analysis revealed that the isotropic spherical model successfully explained the spatial population structure of F. duorarum, F. aztecus, L. setiferus and X. kroyeri. Density maps obtained by punctual kriging clearly showed a species-specific spatial segregation in high-density patches, with a differential bathymetric distribution for these four species. Spatial structure was not evident for both S. brevirostris and T. similis. Clear bathymetric patterns in individual size were observed, increasing linearly (F. duorarum, F. aztecus and L. setiferus) and asymptotically (T. similis) with depth. These patterns are in agreement with the life cycle characteristics of these species. Geostatistical methods were useful to display the spatial structure of penaeoid shrimps, both for target and incidental species. [Copyright &y& Elsevier]

Highlights • The effect of a man-made freshwater discharge is assessed in a sandy beach ecosystem. • Spatial and long-term changes in ecosystem structure and functioning were detected. • A more complex trophic structure was found in the undisturbed site. • Biodiversity loss affected the functioning of the sandy beach ecosystem. • Ecosystem indicators reflected a low resilience of the system. Abstract Sandy shores comprise one of the coastal ecosystems most vulnerable to human impacts, and they are increasingly affected by a variety of stressors. Local-scale drivers such as man-made freshwater discharges have changed the salinity, temperature and nutrient regimes, leading to the degradation of sandy beaches. However, there is still little understanding about the effects of salinity changes on the structure and functioning of sandy shores at the ecosystem level of ecological organization. This study seeks to identify the main spatial and long-term variations in a sandy beach ecosystem due to salinity changes induced by a freshwater discharge using a trophic network approach and thus linking anthropogenic pressures with functional and structural ecosystem changes. The trophic networks of nine scenarios involving three sampling sites representing different salinity stress regimes and three study phases established between 1987 and 2015 were modelled and compared. The results showed important space-time variations that were reflected at the community and ecosystem levels. A more complex trophic structure was developed with longer distances to the freshwater inflow, with higher biomass, species richness and number of predators. The highly disturbed and undisturbed sites occupied discrete, contrasting and clearly distinguishable states over time, whereas the moderately disturbed site showed a variable pattern over time. Recent trends in ecosystem indicators reflected a more fragile state, characterized by a greater organization (Ascendency) and a lower adaptive potential (Overhead) to address unexpected disturbances. Ecosystem indicators were sensitive enough to distinguish among sites and long-term phases in the ecosystem, where different organization states can persist over time. Future studies aimed at assessing press disturbances on sandy beach ecosystems should emphasize a longer time scale in order to assess the recovery capacity of these systems that are increasingly threatened by long-lasting stressors. [ABSTRACT FROM AUTHOR]

• First regional habitat classifications of the South Atlantic Ocean. • Comparing two broad-scale clusterings of benthic environmental variables. • Areas of agreement include some abyssal basins, topography and front systems. • Areas of divergence around Mid-Atlantic Ridge, shelf and slope habitats. • Further sampling is required to understand if these are biologically meaningful. Marine Spatial Planning (MSP) has become a priority for many states wanting to develop national blue economy plans and meet international obligations in response to the increasing cumulative impacts of human activities and climate change. In areas beyond national jurisdiction (ABNJ), MSP is proposed as part of a package of solutions for multi-sectoral management at the ocean basin scale. To facilitate planning, maps showing the spatial distribution of marine biological diversity are required. In areas lacking data, like the South Atlantic, environmental proxies can be used to predict these distributions. We undertook broad-scale benthic habitat classification of the South Atlantic, employing two top-down approaches spanning from national waters to ABNJ. The first was non-hierarchical and clustered groups of environmental variables prior to combination; the second was hierarchical and clustered Principal Components of environmental variables. Areas of agreement between the two approaches were identified and results compared with existing national and global classifications and published biodiversity patterns. We highlight several habitat classes we can be cautiously confident represent variation in biological diversity, such as topographic features, frontal systems and some abyssal basins. We also identify critical gaps in our knowledge of regional biogeography and advocate for collaborative effort to compile benthic species records and promote further exploration of the region to address these gaps. These insights into the distribution of habitats have the potential to support sustainable use and conservation of biodiversity beyond national jurisdiction, enable transboundary and ocean basin scale management, and empower nations to make progress towards achieving Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

The Marine Stewardship Council (MSC) certification program is a market-based instrument aimed at recognizing sustainable fishing practices. Although there are 10 MSC-certified fisheries in Latin American and the Caribbean (LAC), this proportion is low (4%) compared to the total number of certified fisheries globally. Therefore, implementation of MSC certification in LAC fisheries is examined by considering: (1) fishing industry drivers for certification and (2) certified fisheries performance against the MSC standard. The MSC certification was suitable for large multi-national enterprises with export-oriented markets and for small-scale fisheries with exclusive access rights harvesting high-value resources. Maintaining or increasing market-share was a main motivation to pursue certification. Most LAC certified fisheries showed high performance in terms of stock status, governance and management systems. However, the expansion of the MSC certification in LAC remains limited by: (1) intrinsic weaknesses of fisheries in the region (shortage of information and instability in governance systems); and (2) high costs associated to certification and extrinsic market conditions (price shocks and demand retractions). Innovative strategies to encourage the development of domestic certified seafood markets, and a major inclusiveness of small-scale fisheries with traditional management arrangements at the local level, could constitute significant steps toward a more sustainable pathway on a regional scale. [ABSTRACT FROM AUTHOR]

Tagging studies are a fundamental tool for understanding fish population dynamics. Choosing the right tag type, however, is of major importance, as properties such as shedding rate can affect estimates of mortality, abundance, and movement rates. Here, we provide tag-specific recapture rates for blue sharks (Prionace glauca) and assess the retention performance of plastic and stainless-steel dart tags based on shedding rates from a double-tagging experiment. In total, 4648 sharks were tagged, of which 67 were recaptured. Single-barb (SB) and double-barb (DB) plastic tags yielded similar recapture rates, which were almost eight times lower compared to stainless-steel dart tags (M). Shedding rates from recaptured double-tagged sharks were 54%, 8% and 0% for SB, DB and M tags, respectively, with the shedding probability of SB tags positively correlated with time. Double-tagging results provided critical insight into the potential loss of information through tag shedding: the overall recapture rate from this study would drop from 1.4% to 1.0%, and above half of all long-term (≥ 1 year) and large-scale (≥ 1000 km) recaptures would have been lost through shedding of SB tags. This study showcases the utility of double-tagging experiments to assess the performance of different tag types. We conclude that M tags outperform SB tags in retention performance and ease of application, and recommend that future conventional tagging studies focused on large pelagic sharks implement the use of this tag type, as they minimize tag loss through shedding and maximize the probability of obtaining long-term and large-scale recaptures. • 2821 blue sharks single-tagged and 32 recaptured; 1827 double-tagged and 35 recaptured. • Single-barb plastic tags had the worst retention performance, decreasing with time. • Critical loss of information due to shedding of single-barb plastic tags is revealed. • Stainless-steel dart tags maximize long-term and large-scale recapture probability. • Stainless-steel dart tags are recommended for tagging large pelagic sharks. [ABSTRACT FROM AUTHOR]

The yellow clam Mesodesma mactroides is a cool-water species that typifies sandy beaches of the Southwestern Atlantic Ocean (SAO), which embraces one of the strongest ocean warming hotspots. The region is influenced by the Rio de la Plata (RdlP), which represents a zoogeographic barrier that restricts its larval exchange. We investigated yellow clam larval connectivity patterns using an individual based model (IBM). The IBM combined outputs from a 3D hydrodynamic model with a clam submodel that considered salinity- and temperature-dependent mortality for the planktonic larvae. Connectivity across the RdlP estuary occurred only for larvae released in spring during a strong La Niña event. Mortality due to freshwater precluded larval transport across the RdlP, whereas larval mortality induced by warmer waters reduced connectivity, leading to self-recruitment in most areas. Warming acceleration in this hotspot could further restrict larval connectivity between populations in the SAO, with conservation implications for this threatened species. • Mesodesma mactroides larval connectivity was studied through individual-based model. • 12-year ROMS outputs were used to address connectivity along Atlantic sandy beaches. • Connectivity across Rio de la Plata estuary occurred during a strong La Niña event. • Larval mortality due to warm water temperature reduced larval connectivity. • Warming acceleration could further restrict connectivity in this threatened species. [ABSTRACT FROM AUTHOR]

Highlights: [•] We examined the bycatch of great albatrosses in pelagic longline fisheries of the southwest Atlantic. [•] We determined the areas and seasons where the interaction is most intense. [•] We identified key vessel operational practices and habitat variables affecting bycatch. [•] Results are useful for developing or improving conservation measures. [Copyright &y& Elsevier]

Abstract: Spatial heterogeneity is a conspicuous feature in life history traits of the deep sea red crab Chaceon notialis in the Southwestern Atlantic Ocean. However, a quantitative assessment of its spatial distribution in Uruguayan waters is lacking. A fishing survey was conducted in 2005 between latitudes 35°00′S and 37°00′S, water depth ranging from 300 to 1600m. A likelihood-based geostatistical approach showed a persistent spatial structure of the red crab for both the whole population and the harvestable stock, with global biomass estimates of 55,054t and 34,870t respectively. Similar estimates were provided by the “effective fishing area” technique (53,800t and 36,400t, respectively). C. notialis showed clear large-scale patterns: (1) concerning latitude, the highest density and CPUE were found between 35°40′S and 36°20′S. Males were mainly concentrated between 35°20′S and 36°00′S, whereas the relative representation of both ovigerous and non-ovigerous females increased at the northern end of the study area. Male individual weight increased asymptotically towards higher latitudes, while females followed the reverse pattern. (2) Bathymetric analysis showed the highest density and CPUE at depths close to 900–1100m, coinciding with the highest representation of males. By contrast, females mainly occurred in shallower waters (300–500m), and ovigerous females only between 300 and 400m. Individual weight of males and females consistently decreased from 300 to 1600m. Proportion of molting males increased with latitude and depth, whereas molting females followed the reverse trend. Spatially explicit management tools are suggested, including fishing closures between 300 and 500m depth and between latitudes 35°00′S and 35°40′S (main spawning area with the highest proportion of females) and at depths>1200m (recruitment area). [Copyright &y& Elsevier]

Abstract: Environmental water chemistry analysis and microcosm toxicity bioassays (MTB) were performed to assess lethality of herbicides on the mole crab Emerita brasiliensis in a sandy beach affected by a freshwater discharge (Andreoni canal) from rice crops. A 5-yr macrocosm field sampling (MFS) was conducted to evaluate freshwater effects on population abundance. Propanil was only detected at the inner portion of the Andreoni canal (IAC), whereas quinclorac and clomazone were found at the IAC and at the canal mouth (CM). A major propanil metabolite was detected at the CM. Herbicides were undetectable at 13km from the CM. MTB showed an increased susceptibility to propanil with decreasing crab sizes. The MFS showed a drastic decrease in abundance towards the freshwater discharge, concurrently with decreasing salinities. The triad approach that included water analyses, toxicological experiments and long-term field sampling allowed rejecting relationships between herbicide exposure and mole crab lethal effects. [ABSTRACT FROM AUTHOR]

Abstract: We evaluated spatio-temporal effects of fishing gear selectivity on the ichthyofauna discarded by the artisanal shrimp fishery in Celestun Lagoon (Mexico). Selectivity experiments, based on the covered codend method, were carried out in different zones (seaward, middle, inner) and climatic seasons (Nortes, Dry, Rainy) using two bottom nets with different mesh size codends: 13mm (MS13: currently used in the fishery) and 25mm (MS25). The number of fish species retained with MS13 was higher than with MS25, and the abundance, biomass and proportion retained of fish discards were significantly higher with MS13 for all seasons and zones. Additionally, community indices (species richness, diversity and evenness) calculated for the ichthyofauna retained by the MS13 codend were significantly the highest. The length of 50% retention was at least 2 times larger with MS25 than with MS13 for the 5 most abundant fish species in the catches. We conclude that an increase in mesh size would reduce substantially the impact on the ichthyofauna discarded by the artisanal shrimp fishery in this coastal lagoon. [Copyright &y& Elsevier]

Abstract: For decades beach nourishment and groyne building have been used to combat sandy beach erosion, but their effects on sandy beach macrofauna are often neglected. Here, we analysed the effects of beach nourishment and groyne building on a sandy beach within the San Rossore-Migliarino-Massaciuccoli Regional Park (a natural park in Tuscany, Italy) on two different levels of organization: the abundance of the crustacean amphipod Talitrus saltator (population level) and community descriptors of the sandy beach arthropod fauna (community level), with emphasis on supralittoral species. Samples were taken bimonthly from September 2004 to January 2006 using pitfall traps. T. saltator abundance was described by generalized linear models (GLMs) and arthropodofauna community descriptors were estimated by species number, diversity indexes and ordered with multivariate ordination methods. The abundance of T. saltator in different seasons was influenced by the month of sampling during the autumn–winter season and by beach width, substrate penetrability and the “species number” biotic factor during the spring–summer season. The abundance models revealed no direct effects of beach nourishment. T. saltator was shown to be both a typifying and discriminating species, confirming its key role in the community of sandy beaches. The arthropodofauna community showed sensitivity to the substrate grain size and quality changes generated by beach nourishment, as the community composition changed at the nourished sites in line with seasonal dynamics. Human actions to stabilise the shoreline therefore emerged as a driving environmental feature, altering the beach''s physical characteristics and consequently its fauna on different organizational levels: it was shown to have a direct effect on the arthropodofauna community structure and on sandhopper population abundance by determining habitat availability. [Copyright &y& Elsevier]

Abstract: The worldwide increasing trend in fishing catches together with the impact of fishing on ecosystems and inefficient fishery management have led to overfishing and frequent collapse of traditional fish stocks. In this context, the assessment of fishery-induced impacts and the implementation of ecosystem-based fisheries management programs are urgently required. In this study, the mean trophic level (TLm) and the fishing-in-balance (FIB)-index of Uruguayan landings during 1990 and 2001 were estimated using the trophic level of 60 fishery resources. A decline in total landings (Y) is observed, which is explained by the lower fishing yield in major fishery resources (especially demersal). Moreover, a marked decreasing trend in TLm at a rate of approximately 0.28 trophic levels per decade, and a decreasing trend in FIB-index since 1997 were observed. The present situation of fishery resources in Uruguay (fully exploited or overexploited) and the drop in Y, FIB and TLm can be considered as indirect indicators of the fishing impacts on the trophic structure of Uruguayan marine communities. We suggest that a more holistic ecosystem-based fisheries management could help to alleviate the critical situation of fish stocks in Uruguayan waters. [Copyright &y& Elsevier]