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This paper summarizes the lessons learnt for the management of small pelagic fish from the case study of managing the international fishery on the Bay of Biscay anchovy. A constant catch regime ended up with a fishery crash and closure (2005–2009) after a series of recruitment failures. Precautionary advices had been disregarded due to their inability to predict the size of the population during the first half of the year when the major fishery takes place. The crash triggered the EU to develop a long-term management plan in 2008. In the absence of a recruitment indicator, biological risk was minimized through a close coupling between assessment, advice and management, changing the management year to start just after the spring surveys on adults. A major improvement arrived in 2014 by the incorporation of an early recruitment indicator from an autumn acoustic survey on juveniles. This allowed additional exploitation of the resource at similar risk levels. Accordingly, TACs are nowadays set after the recruit survey on a management calendar basis. The interactive collaboration between fishers, scientists, and managers allowed inclusion of the stakeholders’ preferences for a biomass-based catch bounded harvest strategy suitable for these valuable fisheries. This strategy allows catches between a minimum and maximum TAC level, to account for an economically viable minimum activity when approaching a minimum biomass threshold level, and for the limited market absorption capacity when exceeding an upper biomass threshold level, respectively. Such strategy was adopted by consensus and supposed a successful participatory process in fishery management., This work has been carried out with the financial support of the Basque Government (Agriculture and Fisheries Department) to the authors affiliated at AZTI, the European Commission through the STECF (Scientific, Technical and Economic Committee for Fisheries) meetings and the EU through the funding of several projects, as PRONE (Precautionary risk methodology in fisheries -- Contract No. 022589), CEVIS (Comparative Evaluations of Innovative Solutions in European fisheries management -- Contract No. 022686) and UNCOVER (Understanding the mechanisms of stock recovery -- Contract No. 022717). This is publication number 1149 from the Marine Research Division of AZTI.

Local fish markets are often saturated during periods of full production. Solar drying offers a suitable alternative to reduce losses of surpluses, and to preserve products for a longer period. In this respect, this work was carried out to study the effect of the air indirect solar convective drying process on the dehydration kinetics of anchovy. Experimental drying kinetics was measured at four air temperatures (50, 60, 70 and 80 °C) and for a constant air flow of 300 m3/h. The moisture desorption isotherms of the anchovy were determined at three temperatures (30, 40 and 50 °C), using the static gravimetric method to determine the optimum water activity for conservation of the nets anchovy. Experimental results showed that the drying kinetics of the anchovy was accelerated synchronously with the increase of the air temperature. The value of optimal water activity for conservation of anchovy is aw = 0.30 and the desorption isotherms suggest a non spontaneous process. Nine drying models were adapted to the drying data; the Logarithmic model allowed better adaptation than the other models. The effective diffusion coefficient value Deff determined by Fick’s second law varied from 3.84 10−9 to 5.60 10−9 m2/s and the activation energy value was Ea = 12.90 kJ/mol.

Anchovy oil was successfully encapsulated into multi-core microcapsule powder using a two-step microencapsulation method. The inner and outer shells of the microcapsules were created separately using gelatin-SHMP complex coacervates as shell materials. Fucoidan extract was used to crosslink these complex coacervates shells of microcapsules before spray drying. The spray dried microcapsules produced using the two-step method exhibited high encapsulation efficiency (99.83%), low surface oil content (0.10%), high oil payload (55.68%) and significantly improved oxidative stability. The formation of the outer shell during the second cooling step of two-step microencapsulation method significantly improved the oxidative stability of the anchovy oil by smoothing the surface of the microcapsules.

In many exploited marine fish species, older individuals within cohorts often have slower growth rates at age than their younger counterparts, a process generally attributed to fishing. However, environmental changes might also contribute to the selective disappearance of faster growing individuals because of the increasing constraints acting on growth in suboptimal environments. Using otoliths of anchovy and sardine collected each year in spring since 2000 in the Bay of Biscay, we measured individuals’ growth during age-0 and catch-up growth during age-1, and followed their changes in time from 2000 to 2018 to quantify the magnitude of selective mortality. We then determined whether the variations in growth and selective mortality were related to seasonal temperature, food quantity, stock biomass or stock harvest rate. In both species, there was a decline in growth during age 0 over time and a catch-up growth declined in anchovy. Density-dependence had a strong effect on growth in anchovy. In both species, there was a systematic selective disappearance of individuals with large growth at age-0 within each cohort and selection has changed over time to favour individuals with large catch-up growth in anchovy. Moreover, diversifying selection occurred for growth at age-0 in both species and catch-up growth in anchovy. In anchovy, years with high selective disappearance of large individuals, high catch-up growth and high diversifying selection were those in which the harvest rates were high (environmental variables having more limited effect). In sardine, the selective disappearance of large individuals was stronger in years with low food quantity and the magnitude of selection acting on growth was unrelated to this stock’s harvest rate. Though fishing exerted strong selection pressure in anchovy, selective mortality against large growth still occurred even at low harvest rates in both species, suggesting that this might be a natural process affecting these small pelagic forage fish species. Although anchovy and sardine have a similar trophic position, their selection regimes differed due to differences in their stock dynamics, environmental sensitivity, and fishing rate. It might therefore be hazardous to extrapolate the responses of single species to environmental and anthropogenic factors onto others.

A key factor in population models, the temporal scale, should both reflect intra-annual biological processes and avoid over-parameterization. We applied the separability assumption to model recruitment process error as additive effects of random annual deviates and quarterly fixed effects (QFEM) to improve our understanding of intra-annual recruitment patterns and, at the same time, minimize the impact of over-parameterization. We formulated a length-based model with a quarter-year temporal resolution and applied it to the anchovy (Engraulis ringens) fishery off northern Chile and southern Peru, using data from 1984 to 2015. Model performance was compared to that of a larger model in which the process error is treated as an interaction of quarter-year effects (QYIM). QFEM proved to be most adequate only when the variability of population processes and the fishery are determined by a clear seasonal pattern. In those cases, QFEM characterized recruitment seasonality as well as inter-annual trends. Under these conditions, the separability hypothesis of recruitment process error substantially reduced the number of parameters in the stock assessment model, the bias of estimated population variables, and uncertainty when the most recent data were incomplete or non-informative. QFEM provides an alternative way to improve assessments and fishery management for fast-growing and short-lived species such as small pelagic fish.

For small pelagic fish, recruitment success is mainly determined by the degree of survival over the early stages of life. In the case of European anchovy in the Bay of Biscay, major mortality events take place during spring and summer, and thus, the juvenile population in autumn is considered as an indicator of the next year recruitment. However, overwinter mortality could be an additional process regulating anchovy recruitment success in this area. Anchovy juveniles winter mortality was estimated over eleven years, between 2003 and 2013, using acoustic estimates of juvenile abundance (in autumn) and age-1 adults (the following spring) from two independent surveys. The results show that mortality is highly variable among years, with values ranging between 0.004 and 0.016 d−1. Size- and density-dependent mortality were also evaluated during the analysis. Observed size distributions of juveniles in autumn were projected to the following spring assuming different size specific growth rate distributions in the population. Thereafter, the projected size frequency distributions were compared with the observed ones. The results indicate that mortality is higher for small individuals in most of the years (7 of 11). The mortality rate is positively correlated with juvenile abundance in autumn but not with mean juvenile length. The results suggest that although a density-dependent effect could be one of the main factors regulating the survival of juveniles during winter, size-dependent mortality could also impact recruitment. Understanding the factors that trigger size-dependent mortality during winter could contribute to the management of this fishery.

This study aims at quantifying and characterising microplastics (MP) distribution in the water column of the NW Mediterranean Sea as well as MP ingestion by the 2 main planktivorous fish of the area, sardine and anchovy. Debris of similar sizes were found in all water column samples and in all but 2 fish guts (out of 169). MP were found in 93% of water column samples with an average concentration of 0.23 ± 0.20 MP·m−3, but in only 12% of sardines (0.20 ± 0.69 MP·ind−1) and 11% of anchovies (0.11 ± 0.31 MP·ind−1). Fibres were the only shape of MP encountered and polyethylene terephthalate was the main polymer identified in water columns (61%), sardines (71%) and anchovies (89%). This study confirms the ubiquity of MP in the Mediterranean Sea and imparts low occurrence in fish digestive tracts.

This study analyzed the spatial and temporal variation in the community composition of the pelagic species inhabiting the Atlantic Iberian waters using a multivariate approach. Trawl data (pelagic and bottom fishing) were collected during the spring acoustic surveys of pelagic fish from 1996 to 2015. There were significant effects of geographical area, periods, and type of trawls in terms of both, abundance and biomass. Sardine was typical throughout the study area whereas other species were typical of few areas, such as anchovy. The main difference between periods was the variation in typical pelagic species, diminishing the importance of sardine and increasing others, such as chub mackerel, bogue or anchovy. Depth also influenced the community structure with horse mackerel being the principally responsible for sample similarity in bottom trawls. Surface temperature and salinity showed significant relationship with the taxa-derived multivariate data cloud but only explained between 5 and 7% of the total variability.

Engraulis anchoita larvae were captured in 16 surveys carried out at a fixed sampling station (EPEA) in the Argentinean Sea between 2008 and 2017. Nutritional condition and growth of 214 anchovy larvae were estimated through RNA/DNA index and analysis of otolith microstructure. Standard length, developmental stage, age, weight, otolith radius, recent otolith growth rate (RGR), daily otolith growth rate (DGR), RNA/DNA index (sRD) and a derived index of growth performance were determined for each larva. Significant differences in nutritional condition and otolith growth rates were found among seasons and developmental stages, with slower RGR and lower sRD in larvae captured during winter and in the preflexion stage. On a long time scale, a similar seasonal pattern was observed with DGR. However, the amount of variability explained by ontogeny and seasonality was not equal in both RGR and sRD indexes. RGR was better explained with the analyzed variables, while future studies are required to improve the understanding of the nature of sRD. We observed signs that spring and autumn would be the most propitious season for larval survival in a short time scale, while winter would be the worst one, both in short and in long term scale.

The abundance and distribution of Northern anchovy (Engraulis mordax) and young of the year (YOY) rockfish (Sebastes spp.) are critical for the survival and reproduction of seabirds, mammals, and predatory fish within the California Current Ecosystem. Traditional detection and quantification of forage fish by trawling can be time consuming and expensive, and may not provide the spatio-temporal resolution needed to examine ecological relationships in quickly-changing marine environments. In an effort to accurately sample forage fish with less expense and higher resolution, this study combined seabird diet and acoustic descriptors to quantify anchovy schools and YOY rockfish in hydroacoustic surveys conducted between 2004 and 2015. Anchovy-like schools were selected from echograms assuming a volume backscattering strength (Sv) range of −47.6 to −42.9 dB. YOY rockfish-like single targets were selected considering a target strength (TS) range between −52.8 to −50.9 dB, calculated from lengths of fish consumed locally by three piscivorous seabirds. Acoustics indices of forage fish were significantly correlated with abundance catches from trawl data collected from an ecosystem assessment survey and relative abundance estimated from breeding seabird diet data. Inter-annual and seasonal indices of forage fish indicated strong anchovy occurrence during 2004–2008 and increased YOY rockfish from 2011 to 2015. These observations confirm previously described changes in upwelling and forage fish variability off central California. Importantly, these results provide new information on the spatio-temporal variability of the vertical and cross-shelf distribution of anchovy schools and will benefit the design of habitat preference models for anchovy and predators. To verify the acoustics, indices were compared to trawl data from an ecosystem assessment survey and relative abundance estimated from seabird diet data collected from locally-breeding piscivorous seabirds. Results add to the existing knowledge of how these species distribute in the water column, and with regards to anchovy provide insight on how they distribute across the shelf in opposing ocean phases. In addition, acoustic indices derived for both forage fish species showed a significant coherence with both the trawl surveys and seabird diets. Combining acoustic methodologies with trawl data and predator diet can be used to monitor distribution and temporal variability of forage fish species to benefit conservation of top marine predators.

Small pelagic fish species, such as sardine and anchovy, can exhibit dramatic decadal-scale shifts in abundance in response to climate variability. Understanding the mechanisms and the relationships among the different components of the food web through which environmental forcing can drive the observed fish variability remains a challenging problem. The modelling study described herein, focusing on the Canary Current System, implements and builds on earlier modelling efforts by Rose et al. (2015) and Fiechter et al. (2015) in the California Current System. This new application of the modelling framework to the Canary Current system provides an approach that bridges a comprehensive database with end-to-end (climate-to-fish) modelling, thereby enabling the investigation of the sources of variability of sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus). The aim of the modelling effort is to gain insights into the underlying mechanisms that drive the observed biological variability. Particular attention is given to the absence of regime shifts between sardine and anchovy in the Canary Current, which is a distinctive feature among the four major eastern boundary upwelling ecosystems. A model simulation for 1958–2007 was performed and analysed. The biological traits and behaviours prescribed for sardine and anchovy for the Canary Current give rise to different spatial distribution of their populations, and in contrast with other eastern boundary upwelling ecosystems, to synchronous (rather than asynchronous) variability of their abundance and biomass. Analyses of years with anomalously high increases and declines of the adult populations implicate food availability (instead of temperature or other environmental drivers) as the main factor determining recruitment for both sardine (via spawning and survival of feeding age-0 individuals) and anchovy (via survival of feeding age-0 individuals). The common dependence of sardine and anchovy on food, together with the domain-wide response of zooplankton to climate forcing generated in the model, provides a plausible explanation for the synchronization of the two populations. Our results also point at differences between sardine and anchovy; while the two species thrive under enhanced upwelling-favourable winds, anchovy larvae become particularly vulnerable to drift mortality, and thus do better than sardine under more moderate upwelling conditions.

Synchrony of species alternations in the northern Humboldt (NHCS) and Kuroshio (KCS) Current systems was examined by comparing time series data of landings and population statistics of major small pelagic fish species along with climate indices from 1960 to 2015. Target species were anchovy Engraulis ringens, sardine Sardinops sagax, jack mackerel Trachurus murphyi and chub mackerel Scomber japonicus in the NHCS, and anchovy E. japonicus, sardine S. melanostictus, jack mackerel T. japonicus and chub mackerel in the KCS. The time series of total biomass and spawning stock biomass (SSB) of anchovy and sardine for the NHCS and the KCS were well correlated, as were the landings data. Landings of small pelagic fish including jack mackerel and chub mackerel indicated that multi-species alternations may also be synchronous at a community level between the two current systems. Peak landings of jack mackerel and chub mackerel were observed between peaks of anchovy and sardine in both current systems, although the relationships between jack mackerel and chub mackerel differed between the current systems. The species alternations between anchovy and sardine are most reasonably attributable to environmentally-induced changes in the biomass as a major mechanism, although the effect of fishing activity cannot be excluded. Future studies will be required to compare biological characteristics of multiple small pelagic fish species in the pelagic food chain in each current system.

Many small pelagic fish species exhibit dramatic fluctuations in abundance accompanied by range expansions during periods of favorable environmental conditions. The location and extent of suitable habitats also shift in response to both short term variability and long term trends in climate. Near the margins of a contemporary range, trends in abundance may reflect a continuation of historical variability but may also foreshadow future changes in distribution. The Salish Sea (all inland marine waters of Washington State and southern British Columbia; made up of the Strait of Georgia, Strait of Juan de Fuca, and Puget Sound) is a highly productive estuarine system at the northern end of the distribution of Northern Anchovy (Engraulis mordax). An apparent recent (2014–2016) increase in Northern Anchovy abundance has generated interest in the dynamics of this species in the Salish Sea. We compiled recent and historical data to understand spatiotemporal patterns of distribution and fluctuations in abundance over the last century. Spatially-consistent occurrence of eggs, larvae, and juveniles, and year-round presence of multiple age classes, confirm that successful spawning and recruitment of Northern Anchovy occurs within the Salish Sea. Most periods of elevated Northern Anchovy abundance in the last century have corresponded to, or lagged, periods of elevated ocean temperatures. While a 2005 peak in abundance within the Salish Sea also corresponded to higher abundance of Northern Anchovy in adjacent regions of the coastal Pacific Ocean, it seems unlikely that Salish Sea abundance is controlled primarily by advection or migration from external populations. Persistence of elevated ocean temperatures like those observed from 2014 to 2016 could lead to consistently high abundance of Northern Anchovy within the Salish Sea, with implications for trophic relationships and ecosystem function.

Small pelagic fishes such as sardine and anchovy play an important role in marine ecosystem and are affected largely by environmental changes because of their character as r-strategists and their low trophic levels. Small pelagic fishes are crucial targets of Chinese fisheries, accounting for 26% of the total catch in 2014. Their catches show an increasing trend since the 1950s. However, there is still little information on small pelagic species inhabiting Chinese waters. Catch trends and impacts of climatic regime shifts for six typical commercially important small pelagic species, chub mackerel (Scomber japonicus), Japanese scad (Decapterus maruadsi), Pacific herring (Clupea pallasi), Japanese anchovy (Engraulis japonicus), Japanese sardine (Sardinops melanostictus) and horse mackerel (Trachurus japonicus), are analyzed using Chinese Fishery Statistics, FAO data, climatic indices and sea surface temperature (SST) data. The aim is to explore the interannual to decadal variability of their catches in China Seas and their responses to climatic regime shifts. Decadal variability is evident in the catches of the six small pelagic fishes with different variation patterns between warm- and cold-water species. Step changes in catches of the six species were observed in 1976/77, 1986/87, 1995/96, 2001/02 and 2005/06, while regime shifts in climatic/SST indices occurred around 1976/77, the late 1980s and the mid-1990s. This indicates that decadal variations in small pelagic fishes respond strongly to the climatic regime shifts, and the different response patterns of warm- and cold-water species reflect their different life strategies. Marine thermal variation patterns during the period 1981–2000 were well explained by different phase changes in the SSTs between summer and winter and were consistent with the step change in the catches of small pelagic fishes. The double-integration hypothesis, which indicates that cumulative integrations of atmospheric forcing can generate marine population responses, is useful both to understand the process from climate forcing to fish and the controlling mechanism of climate variability on small pelagic fishes in China Seas.

Future scenarios of fish stocks and the impacts of climate variability and change on fisheries are critical to anticipate and minimize potential economic losses in this sector. In this study, we assessed the impact of recent sea warming and future climate change on anchovy in the Bay of Biscay, where sea surface temperature has increased in the last three decades. We analyzed the historical evolution of the anchovy spawning and built species distribution models that are projected under the RCP8.5 climate change scenario. The historical analysis of anchovy spawning showed that spawning peak advanced at a rate of 5.5 days/decade from 1987 to 2015, and the gonadosomatic index (as proxy of spawning activity) generally increased, which might be associated to changes in phytoplankton abundance. In addition, the spawning area expanded and contracted depending on the total egg production. In the future, the overall anchovy egg abundance in the Bay of Biscay is expected to increase between 1.05 and 2.66-fold under the RCP8.5 climate change scenario by the mid and end-of-the-21st-century, respectively. Projected environmental changes are expected to induce an expansion of the spawning area (7.8% and 16.4% for mid- and end-of-the-century) and higher egg densities.

The change in species dominance between anchovy and sardine that took place during the 1980s in the southern Benguela has been investigated previously using an Ecopath with Ecosim (EwE) model. The results from that model indicated that fishing pressure was unlikely to have been the driver of change. Instead, the findings indicated that changes within low trophic level groups such as the zooplankton affected prey availability for anchovy and sardine, leading to the shift in dominance. This paper applies the donor-driven Ecotran model to these same data for the southern Benguela ecosystem in the 1980s. The consumption matrix from the Ecopath model was converted to a production matrix, apportioning the production of prey groups in a constant proportion to their predators, rather than assuming the consumption of predator groups is taken in fixed proportions from their prey. This configuration allows donor-control of model ecosystem dynamics, appropriate when low trophic level groups affect the outcomes. The trophic structure for the Ecotran model was further amended to exclude “cannibalism”, and dissolved nutrient groups were added to allow for recycling. To test whether the donor-driven modelling affected model results, the same set of scenarios was applied using Ecotran models as were tested using the EwE model in previous research. Qualitative methods were used to compare the results of the two model techniques, as Ecotran scenarios represented static, steady-state solutions for the ecosystem state, whereas EwE scenarios represented dynamic solutions for the ecosystem state. These results indicate that for the majority of groups and scenarios the Ecotran model predicts the same direction of change as the EwE model when the 1980s ecosystem is used as a starting point. However there is more uncertainty in the direction of change predicted by the Ecotran model when it is applied to the 1990s state in an attempt to recreate the 1980s state, and thus more disagreements between the models. The results of the Ecotran model supported the conclusion from prior EwE analysis that the driver of change in anchovy and sardine dominance was likely changes in prey availability. The underlying cause of this shift in prey availability remains a question for further research.

Seabirds are upper trophic level predators and as such reflect bottom-up changes in the conditions of their prey species through behavioural or demographic changes. This is especially useful in fisheries management where seabirds can act as biomonitors of commercially-important prey species, potentially providing an attractive, albeit coarse, supplementation to expensive and labour-intensive conventional stock surveys. The Cape gannet Morus capensis is an important predator of both sardine Sardinops sagax and anchovy Engraulis encrasicolus within the Benguela upwelling region, and has been shown to be a useful biomonitor of these fish stocks. A recently-developed automated monitoring system that measures foraging trip durations (a reflection of foraging effort and prey availability) in Cape gannets using VHF technology was used in this study to explore a range of intrinsic and extrinsic drivers of foraging effort that potentially need to be accounted for when relating foraging effort to availability of prey resources. Data from three seasons (2011/2012, 2012/2013 and 2013/2014) representing 5470 foraging trips from 50 chick-provisioning pairs were used for this purpose. Using a linear mixed-effects modelling approach, Cape gannet foraging trip behaviour was shown to be influenced by chick age, parent sex, meteorological conditions (barometric pressure, rainfall and wind) and ambient light conditions. These factors ideally need to be accounted for when foraging effort in seabirds is used as a proxy for prey availability.

Species - specific differences in the levels of 26 metals and elements in sardine and anchovy are investigated and the factors of proximate composition (proteins, lipids, ash) and body size (length, weight) that may affect the metal and elemental concentrations in fish are explored. Statistical analysis revealed that levels of metals and elements in fish seem to strongly depend on species. Significantly higher levels of most of the metals and elements studied have been observed in anchovy compared to sardine at each of six different sites. The observed species-specific differences in metal content could be attributed to different proximate composition and size among other factors. The significant (positive or negative) correlations found between lipids, proteins, ash, weight, length and metals or elements, suggest that higher levels of most of the metals and elements studied can be associated with lower lipid content, greater protein and ash content and smaller size.

The Peruvian anchovy is an important species from an ecological and economical perspective. Some important features to evaluate fisheries management are the relationship between the anchovy presence/abundance and covariates with spatial and temporal dependencies accounted for, the nature of the behaviour of anchovy throughout space and time, and available spatio-temporal predictions. With these challenges in mind, we propose to use flexible Bayesian hierarchical spatio-temporal models for zero-inflated positive continuous data. These models are able to capture the spatial and temporal distribution of the anchovies, to make spatial predictions within the temporal range of the data and predictions about the near future. To make our modelling computationally feasible we use the stochastic partial differential equations (SPDE) approach combined with the integrated nested Laplace approximation (INLA) method. After balancing goodness of fit, interpretations of spatial effects across years, prediction ability, and computational costs, we suggest to use a model with a spatio-temporal structure. Our model provides a novel method to investigate the Peruvian anchovy dynamics across years, giving solid statistical support to many descriptive ecological studies.

A prerequisite in fisheries management is to identify biological meaningful delineations of stocks, the fundamental exploited units. The European anchovy is one such species in need to better identify stock boundaries. Indeed, despite a spawning aggregation behaviour both in the southern Bay of Biscay and southern North Sea in spring and summer, it has a seemingly continuous distribution in autumn across a broad region ranging from the Bay of Biscay to the northern North Sea including the English Channel, thus with potential mixing of the spawning units. We therefore used genetic markers (single nucleotide polymorphisms) to quantify the degree of gene flow between the currently managed fish stock of the bay of Biscay and northern areas of European anchovy’s distribution. Our results confirm the clear distinction between the Bay of Biscay and northernmost populations, with assignment of all English Channel samples to the latter. We also found a clear overall pattern of isolation by distance that resulted primarily from an increasing differentiation with geographic distance in the Northern group magnified by the lack of gene flow with the anchovies of the Bay of Biscay. The small reduction in gene diversity towards northern latitudes may indicate partial isolation of the leading-edge component of the Northern population. Quotient plots relating anchovy’s distribution to environmental covariates showed that anchovies sampled in autumn in the English Channel originate from the summer spawning aggregation in the warm, low saline and plankton rich south-eastern North Sea. This change in the seasonal distribution of the northern population mimics, but in opposite direction, the one of the Bay of Biscay where anchovy spread towards the north from the spawning habitat in the south-eastern bay. The encounter, without mixing, of the two populations west of Brittany in autumn suggests strong spawning site fidelity. Finally, we identified for the first time anchovies belonging to the estuarine ecotype in the Loire estuary. Our results therefore support current management units, yet with some uncertainties for the catches in the transition zones between the Bay of Biscay and the English Channel, and within river plumes in the vicinity of estuaries hosting the estuarine ecotype.

10 pages, 6 figures, 1 table, supplementary data https://doi.org/10.1016/j.marpolbul.2020.111399, We quantified the incidence of microplastics in the gut contents of the European sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) in the Northwestern Mediterranean Sea and tested which variables influence this abundance, including the prevalence of parasites (i.e., trematoda larvae and nematodes). We detected a 58% occurrence of microplastics ingestion in sardines and a 60% in anchovies. With respect to sardines, the individuals with lower body conditions were found to have the highest microplastics ingestion probabilities, whereas in anchovies such probabilities were observed in individuals with higher gonadosomatic indices and smaller size. The areas with the highest microplastics ingestion probabilities were the Gulf of Alicante for sardines and the Gulf of Lion - Ebro Delta for anchovies. Both species showed a positive relationship between parasites and microplastics ingestion. These results highlight that both parasitism and ingestion of microplastics are concerns for the health of marine stocks and human consumers, This study was carried out within PELWEB (CTM2017-88939-R) and PELCAT (CAT 152CAT00013, TAIS ARP059/19/00005) projects. [...] MEDITS data collection has been co-funded by the EU through the European Maritime and Fisheries Fund (EMFF) within the National Program of collection, management and use of data in the fisheries sector and support for scientific advice regarding the Common Fisheries Policy, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

The effect of migration was investigated on the amino acid and fatty acid profiles and proximate composition of the anchovy caught from the coasts along the Black Sea. During migration, the percentage of lipid in anchovy decreased and varied from 8.23 to 12.2 %. The most abundant fatty acids were palmitic acid (among saturated fatty acids; SFAs), oleic acid (among monounsaturated fatty acids; MUFAs), and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (among polyunsaturated fatty acids; PUFAs). The ∑n3/n6 ratio, and the atherogenic and thrombogenic indices of the samples were within the limiting range reported by international organizations. The fish lipid quality index was found to be high in the feeding areas. The total essential (∑EAA) and nonessential (∑NEAA) amino acids differed among stations and ranged from 6602 to 8773 mg/100 g and from 7267 to 9612 mg/100 g, respectively. The most dominant EAA and NEAA were lysine and glutamic acid, respectively. In this study, some changes were detected in the fatty acid and amino acid profiles in the feeding and wintering areas during migration. Moreover, it was assumed that these changes did not cause a significant loss in the nutritional value and the meat quality of the anchovy.

Characterizing the structure and functioning of marine ecosystems requires a deep understanding of the dynamics of its populations and the biotic interactions among them. To this end, we developed a mass-balanced food-web model of a regional sea in the Northeast Atlantic, the Bay of Biscay (BoB), considering one of the most important anthropogenic disturbance in the area, the fishing pressure. The food-web model was performed for the whole BoB region for the first time. The model represents the ecosystems in the early 2000s, encompassing 120433 km2 between 0 and 1000 m depth. The model was composed of 52 functional groups, ranging from primary producers to top predators, and considering both Spanish and French fishing fleets. Input data included biomass obtained locally from bottom trawl and acoustic surveys, data from stock assessment, official fishery statistics, published and unpublished data on stomach content analyses and the use of empirical equations to estimate consumption and production rates. Our results highlight the importance of the pelagic domain, since the main trophic flows are determined by the interaction between phytoplankton, zooplankton and forage fishes. The role of the detritivore pathway was also relevant due to the relatively high abundance of detritivores organisms and the large percentage of primary production flowing to the detritus. Forage fish have resulted to be a key compartment fostering the connectivity between the benthic and pelagic domains. Pelagic sharks, dolphins, anglerfish, large hake and large demersal fishes were identified as potential keystone functional groups in the BoB model. The results also showed an intense exploitation by fisheries in early 2000s. Different strategies between Spanish and French fleets were also found. French fleets were mainly focussed on low trophic level forage fish (e.g., sardine and anchovy) and had larger impacts on higher trophic levels, while Spanish fleets mostly focussed on higher trophic level forage fishes (e.g., mackerel, horse mackerel and blue whiting) but also targeting sardine and anchovy; and displayed lower impacts on higher trophic levels. Overall, our model demonstrates the importance of combining data sources from different countries to regionally address the sought-after implementation of the ecosystem-based management approach.

The main goal of this study was to examine the nutritional condition of Engraulis anchoita larvae during the austral spring-summer seasons of 2010/2011 and 2012/2013 in highly productive waters in the southwestern Atlantic Ocean called El Rincón. RNA/DNA (RDs) index and derived index of Growth performance (Gpf) were used. Significant differences were observed in average RDs indices for 2010/2011 (5.27 ± 3.26) and 2012/2013 (0.81 ± 0.44). A difference in the years was also observed in Growth performance with higher values in 2010/2011 (2.45 ± 1.83) compared to 2012/2013 (−0.03 ± 0.25). Anchovy larvae captured in 2010/2011 were in good condition (Gpf > 1). During 2012/2013, extremely high larval densities were observed although Gpf values were very low indicating poor larval condition. Chlorophyll dynamics differed between sampled periods, with higher maximum values during spring 2012 as compared to 2010. Concerning chlorophyll concentrations showed a sharp decline in the values for the rest of the 2012/2013 season. We propose that the low larval growth and condition observed during 2012/2013 may have resulted from a decrease in chlorophyll concentrations together with very large larval densities which enhanced the competition for food within the larval population. Our results reinforce the idea that satellite ocean color products can be valuable tools for understanding variability in ecosystem dynamics and its effects on reproductive success in fish. Fil: Diaz, Marina Vera. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina Fil: Marrari, Marina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval. Departamento Oceanografía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Casa, Valeria. Universidad Nacional de San Martín. Instituto de Investigación en Ingeniería Ambiental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Gattás, Florencia María. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina Fil: Pajaro, Marcelo. Instituto Nacional de Investigaciones y Desarrollo Pesquero; Argentina Fil: Macchi, Gustavo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Subsede Instituto Nacional de Investigación y Desarrollo Pesquero; Argentina

Among multiple ways to ameliorate Alzheimer's disease, antioxidant and acetylcholinesterase (AChE) inhibition are considered as two primary approaches. Previous studies have indicated that anchovy protein hydrolysate (APH) exhibited strong antioxidant and AChE inhibitory capacities, and Maillard reaction could significantly (p

Fish habitat models based on remotely-sensed data may be limited by satellite coverage and availability. We compared the fit and predictive power of Random Forest habitat classifiers that were developed using predictors derived from a coupled biophysical model (i.e., modeled predictors) versus similar classifiers that used remotely-sensed satellite data for two data sets (eggs and adults) and four species that occur widely in the California Current system. When tested on independent data, classifiers of spawning habitat that used derived predictors (derived classifiers) had nearly identical accuracies (0–2% difference) to similar classifiers based on satellite data (satellite classifiers). Accuracies of derived classifiers of adult habitat were within −8% to +7% of comparable satellite classifiers. Accuracies of both types of classifiers on test data were much greater for Northern anchovy Engraulis mordax and Pacific hake Merluccius productus (0.75–0.97) than for jack mackerel Trachurus symmetricus and Pacific sardine Sardinops sagax (0.61–0.72), and generally were greater for classifiers of spawning habitat than for adult habitat. Specificity was very good for both types of classifiers, but sensitivity was poor, because classifiers identified potential habitat which was not fully occupied. Adults of all species used a broader range of habitat conditions during summer than during the spring spawning period. Derived classifiers have some advantages over satellite classifiers; they are not limited by cloud cover and they can make predictions in near real-time or the short-term future. However, there was no consistent improvement in the accuracy of derived predictors that included modeled zooplankton concentrations over comparable satellite classifiers that included reflectance/chlorophyll concentration.

Some top predators couple their migration with the migration of their main prey. Magellanic penguins, Spheniscus magellanicus, migrate north from their Patagonian colonies during their non-breeding period, supposedly following the Argentine anchovy, Engraulis anchoita, a keystone species and their main prey item in the southwestern Atlantic Ocean. However, previous studies based on stranded carcasses suggest that cephalopods are the main food item for the penguins at their Brazilian wintering grounds. Moreover, anchovy stocks are in the early stages of commercial exploitation in southern Brazil. This study aims to investigate the importance of the Argentine anchovy in the diet of Magellanic penguins, including penguins of different age classes, both healthy and debilitated individuals, and in different parts of their annual cycle, using stomach content analysis and stable isotope analysis of multiple tissues, representing different time windows. Juvenile and adult penguins were collected (n = 54), either stranded on the beach or incidentally killed during gillnet fishing in adjacent waters. Penguins collected at sea had higher body mass indexes compared to stranded, demonstrating that they were healthy individuals. Among adult penguins from both areas (n = 21), fish was the main food item in their stomachs (prey-specific index of relative importance, PSIRI = 86%), with high contribution of Argentine anchovy. Cephalopods were the main food item (PSIRI = 71%) for juveniles (n = 20), with a predominance of the squid Doryteuthis sanpaulensis. In liver, muscle and feathers of penguins, mixed models based on δ13C and δ15N values demonstrated large contribution of the Argentine anchovy in the diet of the juveniles (95% credibility interval = 46–98.6%) and adults (39.8–98.9%), despite the high importance of cephalopods in the juvenile diet as identified in the stomach content analysis. Adults and juveniles presented isotopic niche overlap for all the tissues analysed, despite the differences in isotopic niche areas (= niche width) among the age classes. In 29% of the stomach contents, plastic debris was also found. Our results highlight the importance of using complementary techniques to study trophic ecology, as stomach content analysis of individuals found dead on beaches may not provide reliable information on diet. The strong reliance of penguins on the Argentine anchovy as a key resource throughout its annual cycle suggests that the stocks of this small pelagic fish should be exploited sustainably, ensuring the minimal forage biomass needed not only for seabirds but also for other consumers.

This paper is a practical contribution to two important debates raised by the implementation of marine ecosystem based management: (i) which ecosystem data can be provided by a fisheries survey optimised for ecosystem monitoring; and (ii) how to combine/select potential indicators to derive useful information on marine ecosystem status and dynamics? A suite of 143 potential indicators, including spatial indices, representing small pelagic fish and their biotic and abiotic environments are presented. Indicators were routinely derived from the PELGAS integrated ecosystem survey conducted in spring in the Bay of Biscay (BoB). The general patterns over time in this suite of 5–16 years, non-stationary time series are characterised using a methodology based on min–max autocorrelation factors (MAF), to select the most continuous indicators within, and across, several ecosystem components: hydrology, phytoplankton, mesozooplankton, small pelagic fish and megafauna. Potential interactions between selected indicators and external forcing variables, including climate and fishing, were assessed. The results confirm the importance of river discharges, bottom temperature, chlorophyll-a and mesozooplankton biomass in the dynamics of the BoB pelagic ecosystem. Small pelagic fish species appear to have followed distinct trajectories during the last 15 years. A marked decrease in anchovy and sardine mean weights at ages 1 and 2 over the last 15 years was highlighted; potentially caused by density-dependent competition. The quasi-absence of significant correlation between selected survey indicators and climate and fishing pressure proxies suggests a moderate exploitation rate of small pelagic fish resources, and confirms the so far limited effects of large-scale climate forcing on the BoB pelagic ecosystem. Perspectives for the assessment of marine ecosystem status on the basis of suites of indicators derived from integrated ecosystem surveys are discussed.

Variations in the relative condition (Kn) of the Black Sea anchovy (Engraulis encrasicolus ponticus) have been evaluated over eleven overwintering seasons (2005–2016). During the study period, a linear decrease was observed in the condition each year. Difference in condition from the onset to end of winter varied between 10% and 20%. Overall however, condition displayed an increasing trend within the time frame studied. Considering the worsening state of the stock during the same period, this increasing trend indicates that condition may be dependent on the fish density. The negative relationship observed between body condition of anchovies and the spawning stock biomass supports the same view and points out that particularly in winter when food supply is limited, interspecies competition could be a considerable factor determining condition. The strong correlation between condition and eddy kinetic energy underlines that velocity of water movement might be an effective factor conserving energy use and consequently supporting maintenance of body condition. Finally, the positive correlation observed between condition loss during winter and number of recruits the following year indicates that how fish overwinter plays an important role in recruitment success rates.

Effective ecosystem-based fishery management involves assessment of foraging interactions among consumers, including upper level predators such as marine birds and humans. Of particular value is information on predator energetic and consumption demands and how they vary in response to the often volatile dynamics of forage populations, as well as the factors that affect forage availability and potential prey switching. We examined the prey requirements of common murre (Uria aalge), Brandt's cormorant (Phalacrocorax penicillatus), and rhinoceros auklet (Cerorhinca monocerata) in the central California Current over a 30-year period, 1986–2015. We developed a bioenergetics model that incorporates species-specific values for daily basic energy needs, diet composition, energy content of prey items and assimilation efficiency, and then projected results relative to stock size and levels of commercial take of several species. The most common forage species consumed were juvenile rockfish (Sebastes spp.), northern anchovy (Engraulis mordax), smelt (Osmeridae), and market squid (Doryteuthis opalescens). Total biomass of forage species consumed during the breeding season varied annually from 8500 to >60,000 metric ton (t). Predator population size and diet composition had the greatest influence on overall prey consumption. The most numerous forage species consumed in a given year was related to abundance estimates of forage species derived from an independent ecosystem assessment survey within the central place foraging range of breeding avian predators. The energy density of dominant prey consumed annually affected predator energy expenditure during chick rearing and whether prey switching was required. Increased forage species take by predators, as revealed by seabirds, may be adding consumptive pressure to key forage fish populations, regardless of the potential additional impacts of commercial fisheries. Improving estimates of consumption by predators and fisheries will promote more effective management from an ecosystem perspective.

International audience; To assess one of the dimensions of mesozooplankton functional diversity, this study quantifies energy density during the springtime in the Bay of Biscay considering both taxonomic and size-classes diversity. Energy density among copepods species (Centropages typicus, Anomalocera patersoni, Calanus helgolandicus, and Labidocera wollastoni), as well as anchovy eggs (Engraulis encrasicolus) ranges from 0.5 to 6.7 kJ/g on a taxonomic basis. Considering size-classes, energy density varies from 0.74 to 1.26 kJ/g. C. helgolandicus exhibits with average energy density estimates generally higher in the plume of the Gironde estuary. In contrast, no spatial coherence is found in the variability of mesozooplankton energy density by size-classes. Our results show that the mesozooplanktonic resource is not homogeneous in terms of quality in the Bay of Biscay. During spring, some species and some geographical areas seems thus to be more profitable to predators than others. We argue that the energy density is a key functional trait of mesozooplankton, but the assessment of mesozooplankton quality should be preferentially based on taxonomy rather than on size-classes. We conclude that interspecific and spatial variability of energy density among the mesozooplankton community can have important implications on fish population dynamics.

In Portugal mainland, the purse seine fishery is one of the most important fisheries, accounting for about 50% by weight of landings. At present, these fleets mainly target sardine (Sardina pilchardus) and chub mackerel (Scomber colias). This work aimed to study the Portuguese purse seine fleet activity (vessel length>16m) and catch composition using onboard observations from 2009 to 2013. Data were collected during 179 trips and 229 fishing sets. Short trips (mean 9.38 h) with one to two sets (duration time 1.39 h/set) were observed, where most of the trip was dedicated to searching (43.7% of total trip duration) and fishing (23.5%). Fishing time depended of the number of sets and search time, which increased due to the growing scarcity of fish and distance to and from fishing grounds to the homeport. S. colias was the main species captured followed by S. pilchardus, although there were an inverse trend in the two species landings. Other pelagic species such as horse mackerel (Trachurus trachurus), Atlantic mackerel (S. scombrus), blue jack mackerel (T. picturatus) and anchovy (Engraulis encrasicolus) were also caught but represented small volumes of the catch. The average capture and landings observed were 4.47 ( ± S.D. 7.64) and 3.19 ( ± S.D. 4.46) tons per set. Capture and landings were both higher in the North, intermediate in the South and lower in the Centre. Differences between fish captured and fish landed are due to slipping. Slipping was more frequent in the North, mainly because of the implementation of daily limit quotas. In the South, usually was the result of the mixture of S. pilchardus with non-commercial species that would decrease its landing price. Throughout the study period, S. pilchardus landings peaked of 64 000 ton in 2008, decreased 20% until 2011 and dropped sharply after 2012. Landing patterns of S. colias, the second most important species, have been inverse, increasing continuously since 2009. On the overall, the decline of S. pilchardus landings has been compensated by increasing capture and landings of S. colias along the country.

We studied the abundance, size and growth rates of Engraulis anchoita larvae during the end of the species’ spawning season in relation to environmental variables. Two sampling transects, one in Península Valdés (northern transect: NT) and the other in Isla Escondida (southern transect: ST), with four stations each, were established in late summer. Both locations are characterized by high concentrations of E. anchoita larvae in spring, strongly associated with the presence of frontal waters, at the beginning of the species’ spawning season. Zooplankton and ichthyoplankton were sampled, and temperature profiles and chlorophyll-a satellite images were analyzed for each sampling station. Zooplankton samples were divided in size fractions, and composition and abundances were estimated. Standard length (SL), ontogenetic stages, and abundance (including eggs) were estimated. Additionally, age and growth rates were determined by otolith analysis. Two different scenarios were observed in both transects. In the NT, a frontal structure was found, while at the ST, the water column was completely homogeneous. Total zooplankton abundance was maximum at frontal waters, with 22,195 ind. m−3, being the small size fraction (

This paper analysed cross correlations among multispecies and single species bio-economic diversity measures related to a local dynamic fisheries ecosystem along the period {1986:1–2014:12}. We focused on bio-economic Simpson, Shannon and multispecies Berger Parker indexes (our proposal of multispecies pure leadership indicator) and the percentage share of income of anchovy and mackerel. These two species were chosen because they showed the highest correlation with the multispecies diversity indices, and led, respectively the “antidiversity” and “prodiversity” groups of species within the ecosystem. Time series were subjected to a double treatment to avoid the potential for spurious and biased correlations. First, the long run and seasonal cycles were removed by means of a cyclical ARFIMA modelling approach. Second, the time series were pre-whitened using conventional ARMA modelling. Correlations between the multispecies indices were remarkably high and hardly changed with the pre-whitening procedure. Conversely, the correlations of the multispecies indicators with the income shares of the two leading species decreased to almost the half after pre-withening, but still remained significant. The concentration in our particular ecosystem is high (i.e. diversity low) and it is significantly correlated with the income shares of the leading species. Accordingly, the risk of collapse for the local fishing sector is high.

In the present study, we evaluated the changes in quality that can occur during the distribution of nonheated anchovy ( Engraulis japonicus) fish sauce after packaging. The pH values of all samples ranged from 5.5 to 5.8, and there were no significant differences ( P0.05) in pH among the samples during storage regardless of storage temperature or salt concentration. The initial total volatile base nitrogen concentration in all samples after bottling was 115 to 121 mg/100 mL, but this concentration increased gradually with storage time. After 1 year of storage, total volatile base nitrogen concentration had increased to approximately 170% of the initial concentration (166 to 194 mg/100 mL). Amino nitrogen increased slightly during storage but was significantly lower than the increase in amino nitrogen during general anchovy fish sauce fermentation with anchovy flesh. Most of the free amino acids increased slightly during the storage period regardless of storage temperature or salt concentration, but tyrosine and histidine increased and then decreased during the storage period. The histamine concentration of the anchovy fish sauce at a salt concentration of 20% was 43.3 mg/100 mL initially, but after 1 year the histamine concentration was 89.7 mg/100 mL in samples stored at 10°C, 102.6 mg/100 mL in samples stored at 25°C, and 116.8 mg/100 mL in samples stored at 35°C . Changes in putrescine and cadaverine concentrations were similar to those in histamine; concentrations increased about twofold from the initial concentrations after 1 year of storage. However, the rate of increase in putrescine from 4 months after storage was very high, and cadaverine slightly decreased by 12 months of storage. High scores for umami and aroma sensory characteristics were given to samples stored at 10°C, but samples stored 35°C were given high scores for rancid. Despite the overall low scores for aroma and umami for samples stored at 35°C, the quality of the anchovy fish sauce as a fermented food was considered acceptable.

10 pages, 2 tables, 2 figures, In recent years, scientific evidence from clinical case studies has been accumulated to suggest that consumption of homemade raw anchovies (Engraulis encrasicolus) in vinegar (referred to locally as “boquerones en vinagre”) represented the main potential risk source for anisakiasis and IgE sensitization to Anisakis in Spain. Conversely, most epidemiological surveys for this fish species in fishing grounds along the Spanish coast and in Spanish markets showed parasite-free fish lots or parasite prevalence below 10%. In order to update the anchovy infection data and to re-evaluate the importance of this species as a potential source of risk exposure to zoonotic and allergy diseases, 956 anchovies collected by Spanish commercial fishing vessels operating in NE Atlantic fishing grounds were analyzed, using a high performance methodology. Results revealed an overall mean prevalence for zoonotic nematodes (genera Anisakis and Hysterothylacium combined) of 64.33% (14.75% in the flesh). Infection values reached 87% in one of the lots. Prevalence in anchovy muscle was 28.65%, which represents the highest value of parasitization of the flesh ever reported for European stocks of this species. An enhanced risk communication plan focused on control measures, such as removal of anchovy viscera by retailers, and educational campaigns stressing the importance of freezing anchovies that are intended for raw consumption, may clearly contribute to avoid this emergent biohazard in seafood, The EU-granted PARASITE Project (GA312068) supported this work

The recruitment of anchovy Engraulis encrasicolus, the crucial forage fish in the Black Sea ecosystem, has drastically decreased in the last two decades, mainly due to overfishing. The wild-caught fertilized anchovy eggs were hatched and the larvae exposed to the different feeding levels to indicate the irreversible starvation criteria based on RNA/DNA, then the nutritional status of wild-caught larvae were evaluated. The newly hatched larvae had mean notochord length of 3.25 ± 0.04 mm and first feeding started on day 3 after hatching. The feeding levels applied to produce the irreversible starvation were fed control (FC), unfed control (UC), delayed first feeding for 1 (1DF), 2 (2DF) and 3 days (3DF). The whole body RNA/DNA ratio and the daily protein growth rate were individually analyzed. There were no survivors left in unfed group on day 6. Irreversible starvation (IS) occurred on the first day after first feeding which suggest the Black Sea anchovy larvae have a very low tolerance to starvation and the critical RNA/DNA ratio was 1.022 ± 0.20. The survival rate in the unfed control was similar to the other delayed groups. The highest daily protein growth rates were on day 6 with 43.45% for FC. Based on IS derived from RNA/DNA, 91% survival probability was detected in field-caught larvae. In future, irreversible RNA/DNA ratio can be used for monitoring and comparing of nutritional status and recruitment probability of different cohorts of the Black Sea anchovy larvae.

A number of ecologically and economically important species in the southern Benguela, including the forage fish sardine Sardinops sagax and anchovy Engraulis encrasicolus, have undergone southward/eastward shifts in their distribution in the 1990s/early 2000s. In addition to the effects of changes in prey availability to top predators, the spatially-distinct nature of the system means the location of a stock has implications for its productivity. The spatial dynamics of small pelagic fish are of particular importance because they are thought to exert wasp-waisted trophic control on the system. An objective-driven frame-based model was constructed to investigate the ability of the approach to represent spatial and population dynamics of sardine and anchovy, and to explore the implications of possible management strategies. Climate variability and fishing pressure were assumed as drivers. Sensitivity analyses were performed and a number of scenarios tested. A frame-based approach appears to be useful within this context. Results suggest that the productivity of the sardine resource within the model is highly dependent on the spatial characteristics of fishing pressure. The role of anchovy within the model system has not yet been fully developed. Increasing our understanding of the relative suitability of environmental conditions of different regions is also important if we are to increase our capacity to predict trends in abundance and distribution. This study shows support for continued careful consideration of spatialized management approaches to the South African sardine fishery.

The BP-contracted Deepwater Horizon Macondo well blowout occurred on 20 April 2010 and lasted nearly three months. The well released millions of barrels of crude oil into the northern Gulf of Mexico, causing extensive impacts on pelagic, benthic, and estuarine fish species. The bay anchovy (Anchoa mitchilli) is an important zooplanktivore in the Gulf, serving as an ecological link between lower trophic levels and pelagic predatory fish species. Bay anchovy spawn from May through November in shallow inshore and estuarine waters throughout the Gulf. Because their buoyant embryos are a dominant part of the inshore ichthyoplankton throughout the summer, it is likely bay anchovy embryos encountered oil in coastal estuaries during the summer and fall of 2010. Bay anchovy embryos were exposed to a range of concentrations of two field-collected Deepwater Horizon oils as high-energy and low-energy water accommodated fractions (HEWAFs and LEWAFs, respectively) for 48 h. The median lethal concentrations (LC50) were lower in exposures with the more weathered oil (HEWAF, 1.48 µg/L TPAH50; LEWAF, 1.58 µg/L TPAH50) compared to the less weathered oil (HEWAF, 3.87 µg/L TPAH50; LEWAF, 4.28 µg/L TPAH50). To measure delayed mortality and life stage sensitivity between embryos and larvae, an additional 24 h acute HEWAF exposure using the more weathered oil was run followed by a 24 h grow-out period. Here the LC50 was 9.71 µg/L TPAH50 after the grow-out phase, suggesting a toxic effect of oil at the embryonic or hatching stage. We also found that exposures prepared with the more weathered Slick B oil produced lower LC50 values compared to the exposures prepared with Slick A oil. Our results demonstrate that even relatively acute environmental exposure times can have a detrimental effect on bay anchovy embryos.

Special issue Vectors of change in the marine environment.-- 10 pages, 9 figures, 3 tables, Despite the large fluctuation in annual recordings of gelatinous plankton along the Catalan coast in the north western Mediterranean and the lack of long term data sets, there is a general perception that jellyfish abundances are increasing. Local authorities are concerned about the stranding events and arrivals of jellyfish to beaches and believe it could reduce the recreational appeal of the beaches – a valuable ecosystem service for the regional tourist industry. Previous studies also demonstrate the predation of jellyfish (Pelagia noctiluca ephyrae) upon some small pelagic fish larvae (Engraulis encrasicolus). Small pelagics are the principal source of revenue for the local fisheries. A social-ecological model was created in order to capture the effects of changes in abundance of P. noctiluca upon the local fisheries, the tourist industry and the wider economy. The following sub-models were constructed and connected following the systems approach framework methodology: an age-class based fisheries model; a jellyfish population matrix model; a jellyfish stranding model; a study on the impact of jellyfish strandings on beach users; and an economic input–output matrix. Various future scenarios for different abundances of jellyfish blooms were run. The “Expected blooms” scenario is similar to the quantity and size of blooms for 2000–2010. For a hypothetical “No blooms” scenario (standard background level of jellyfish but without any blooms) landings would increase by around 294 tonnes (5.1%) per year (averaged over 10 years) or approximately 0.19 M€ in profits per year (4.5%), and strandings would decrease by 49%. In a “Frequent blooms” scenario, landings would decrease by around 147 tonnes per year (2.5%) and decrease profits by 0.10 M€ per year (2.3%), and strandings would increase by 32%. Given the changes that these scenarios would cause on the regional gross domestic product and employment, this study concludes that the overall impact of either of these scenarios on the economy would not be significant at the regional scale, This research was made possible by funding made available through the European Commission's Seventh Framework Programme (FP7-KBBE, 2007-2013) for the project “Vectors of Change in Oceans and Seas Marine Life, Impact on Economic Sectors” (VECTORS) - project reference 266445; the European Union ENPI CBC Mediterranean Sea Basin Programme for the project MED-JELLYRISK – project reference I-A/1.3/098; and the Spanish project FISHJELLY (MAR-CTM2010-18875)

The habitat use and life history characteristics of the estuarine tapertail anchovy, Coilia nasus from Qiantang River were studied by examining the environmental signatures of Sr and Ca in otoliths using otolith microchemical analysis. The results indicate the C. nasus in the present study could be briefly divided into three types: Types 1/Type 2 of riverine origin and initial relative long-term/short-term freshwater residence, and Types 3 of estuarine origin and initial brackish early life history. The availability and fluctuation of certain levels of Sr:Ca ratios (i.e., Sr:Ca × 1000) between salinity scale of 3.00 and 7.00 reveal that the C. nasus analyzed in this study spent much more time in brackish habitat of the river’s estuary. This study has established that the C. nasus of Qiantang River Estuary has a diverse and complex pattern of life history and habitat use which makes their life history and migration pattern vary from those of the Yangtze River.

The effect of sunflower oil treated with varying proportions of rosemary and thyme essential oils (0.3%, 0.6%, 0.9%, and 1.2%) on the lipid quality of Mediterranean horse mackerel and anchovy during traditional pan-frying was assessed in this research. Concentrations of rosemary and thyme essential oils greater than 0.9% applied to sunflower oil tend to reduce the lipid content of horse mackerel, while anchovies fried in sunflower oil with only a few concentrations of rosemary essential oil seemed to avoid a rise in lipid content that leads to frying. The addition of thyme and rosemary essential oils with the different percentages in frying oil significantly caused a reduction in the peroxide and thiobarbituric acid values of all fish samples after pan-frying (p 0.05). According to our results, the amount of EPA and DHA in Mediterranean horse mackerel during traditional pan-frying was affected by the type of essential oils and their concentration in sunflower oil. Using EOs at different concentrations, on the other hand, has no noticeable impact on the retention of highly unsaturated fatty acids in anchovies. It shows that all of the essential oils used significantly reduce lipid oxidation and protect against EPA and DHA reduction as a result of frying in Mediterranean horse mackerel.

In the southwestern Atlantic Shelf, in northern Patagonia, the coastal-inner shelf area of El Rincon (38°-41°S) is relevant due to retention processes and the occurrence of a mid-shelf front (MSF), which provide favorable habitat for the anchovy Engraulis anchoita, from which other commercial species feed on. Here, we assess the protistan plankton (>5 μm) composition and biomass during spring and summer of different years to explore the community structure at the base of the food web and its potential relation with the heterogenic spatial distribution of the anchovy's life stages previously reported in the literature. Our in situ data together with analyses of surface circulation patterns and satellite chlorophyll a denote a marked zonation of phytoplankton. We find that diatoms are the largest carbon contributors in the coastal sector and dinoflagellates near the MSF, where large copepods and mainly juveniles and adults of E. anchoita are found. In turn, transient small-scale eddies develop in the low chlorophyll central area dominated by nanoflagellates and ciliates, where small copepods and eggs and larvae of the anchovy dominate. Our results provide insights of the potential link between plankton assemblages, hydrological settings and developing stages of a highly exploited fish. Moreover, we contribute to biodiversity records used in global assessments of possible shifts at the population and community levels that might have cascading effects on marine ecosystems' productivity.

The management of small pelagic fisheries is a complex task due to its large variability of both environmental and biological processes. This high variability can impact the reliability of stock assessment models and fishery management recommendations. When this occurs, management decisions should explore alternative control rules based on empirical abundance indices or pragmatic management procedures. In this paper, we examined the performance of a harvest control rule (HCR) for the Chilean fleet in the shared Chile-Peru anchovy (Engraulis ringens) fishery (16°S–24°S), which is one of the most important stocks in the Humboldt marine ecosystem in the Southeast Pacific. The HCR uses the annual changes in spawning biomass estimated by Daily Egg Production Method (DEPM) surveys in the waters off northern Chile. Analyzes are carried out through operating models simulating population regime shifts under different uncertainty sources. The results show that despite the latent risk of overfishing caused both by recruitment variability and the lack of fisheries management coordination between two jurisdictions, the control of one of the parties' fishing mortality can enable the sustainability of the entire stock, provided the fishing effort of the other jurisdiction be remained at similar levels as in the last decade. The use of an HCR would avoid increases in fishing mortality and would facilitate BMSY-based management goals. This research determined conditions under which the shared Chile-Peru anchovy fishery can be sustainable considering different sources of uncertainty of the biological-fishing system.

Paleorecords of pelagic fish abundance could better define the nature of fishery productivity dynamics and help understand responses of pelagic fish stocks to long-term climate changes. We report a high-resolution record of sardine and anchovy scale deposition rates (SDRs) from Beppu Bay, Southwest Japan, showing multidecadal and centennial variability in the abundance of Japanese sardine and Japanese anchovy during the last 2850 years. Variations in the sardine SDR showed periodicities at ∼50, ∼100, and ∼300 yr, while variations in the anchovy SDR showed periodicities at ∼30 and ∼260 yr. Comparisons between and correlation analyses of the time series of the sardine and anchovy SDRs demonstrate that there is not a consistent out-of-phase relationship during the last 2850 years. This indicates that the multidecadal alternations in the sardine and anchovy populations commonly seen in the 20th century did not necessarily occur during earlier periods. The Japanese sardine SDR record shows a long-term decreasing trend in the amplitudes of the multidecadal to centennial fluctuations. This decreasing trend may have resulted from an increasing trend in the winter sea surface temperature in the western North Pacific. The multicentennial variability in sardine abundance during the last millennium is consistent with the variabilities in the abnormal snow index in East Asia and the American tree ring-based Pacific Decadal Oscillation index, suggesting a basin-wide or regional climate–marine ecosystem linkage.

The aim of this study was to evaluate technological and antioxidant properties, including in vitro bioaccessibility of polyphenols, conferred on raw anchovy mince by the addition of polyphenol-rich grape pomace dietary fibre at different concentrations. For this purpose, headed and gutted anchovy was heat-flayed, deboned and mixed with 0%, 2%, 3%, 4% grape pomace dietary fibre. A significant increase (P < 0.05) in the concentration of polyphenols and associated antioxidant capacity was detected when grape pomace dietary fibre was incorporated in a proportion of at least 2% of the final mixture. In vitro digestion showed that the higher the grape pomace dietary fibre content, the higher was the proportion of polyphenols reaching the large intestine. Additionally, it was observed that the ABTS (2,2′-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) assay seems to be more suitable for evaluating antioxidant capacity in this kind of samples than FRAP (Ferric Reducing Antioxidant Power) assay. Technological properties such as mechanical and water holding, as well as sensory scores, indicated excellent qualities and acceptability of all samples. Hence, given the good acceptance of these samples, it should be feasible to make fish products based on mince anchovy as a means of increasing dietary intake of polyphenols with antioxidant capacity, especially considering the high concentration of polyphenols bioaccessible in the large intestine., This study was funded by FINCyT, Peru (No. 160-2013). J. P.-J. acknowledges the Spanish Ministry of Science and Innovation for a Juan de la Cierva postdoctoral contract.

Recruitment of sardine ( Sardina pilchardus Walbaum, 1792) and anchovy ( Engraulis encrasicolus Linnaeus, 1758) is thought to be regulated by predation of their eggs and larvae. Predators of sardine and anchovy can be identified by visual taxonomic identification of stomach contents, but this method is time consuming, tedious and may underestimate predation, especially in small predators such as fish larvae. Alternatively, genetic tools may offer a more cost-effective and accurate alternative. Here, we have developed a multiplex real-time polymerase chain reaction (RT-PCR) assay based on TaqMan probes to simultaneously detect sardine and anchovy remains in gut contents of potential predators. The assay combines previously described and newly generated species-specific primers and probes for anchovy and sardine detection respectively, and allows the detection of 0,001 ng of target DNA (which corresponds to about one hundredth of the total DNA present in a single egg). We applied the method to candidate anchovy and sardine egg predators in the Bay of Biscay, Atlantic Mackerel ( Scomber scombrus ) larvae. Egg predation observed was limited primarily to those stations where sardine and/or anchovy eggs were present. Our developed assay offers a suitable tool to understand the effects of predation on the survival of anchovy and sardine early life stages.