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In the Mediterranean, one of the most prized small pelagic species is the European anchovy (Engraulis encrasicolus). This species has long been targeted by fishermen in the southern Alboran Sea and the Mediterranean Sea. The objective of this research was to identify any linkages that may exist between environmental changes in the southern Alboran Sea and the reported drop in anchovy landings between 1983 and 2020. The method of forward stepwise regression was used, taking into account environmental indicators, such as sea surface salinity (SSS), sea surface temperature (SST), surface chlorophyll a (Chl-a), U and V wind components, NAO index, and Atlantic jet velocity. To select the best prediction models, generalized linear models (GLMs) were created and organized based on their corrected akaike information criteria (AICc) values. Trended time data were used to create six top models, which explained 60 to 79% of the variation in anchovy landings. Temperature, salinity, and the U wind component all displayed a negative association with anchovy landings. On the other hand, the Atlantic jets' velocity as they traveled through the Strait of Gibraltar was positively correlated with anchovy landings. When the trend component was taken out; however, none of the environmental variables could explain the variations in anchovy landings. This may imply that while environmental influences have an effect over the long term, they have little effect on the inter-annual time scale. Hence, the decline in landings of this species may be due to factors other than environmental change. Overfishing may have played a substantial role in the long-term decline in landings since this species was the most targeted of the small pelagic species in the study area.

Morphometric indices of body condition are assumed to reflect an animal’s health and ultimately its fitness, but their physiological significance remains a matter of debate. These indices are indeed usually considered as proxies of energy reserves, ignoring other physiological processes involved in animal health such as nutritional, immune and hormonal states. Given the wide variety of ecological processes investigated through morphometric body condition indices in marine sciences, there is a clear need to determine whether morphometric indices reflect primarily individuals’ energy reserves or their broader integrated physiological status. To address this issue, we used morphometric and physiological data (cortisol level, oxidative stress, digestive enzymes activity, and both fatty acids percentage and total amount) collected in three stocks of the European sardine (Sardina pilchardus) presenting contrasted patterns of growth and body condition. We found that morphometric body condition indices are indeed mainly and consistently linked to a proxy of the amount of lipid reserves (i.e., fatty acids amount), but also significantly to quality of lipid reserves (i.e., fatty acids percentage) and fish chronic stress (scale cortisol levels). We found no significant relationship between morphometric indices of body condition and both oxidative stress proxies and variables measuring digestive enzymes activity. Our study confirmed that morphometric body condition indices primarily reflect the variance in individuals’ lipid reserves and to a lesser extent the actual composition of these reserves (linked to differences in fish diet) and scale cortisol levels (indicating fish metabolism and/or their chronic stress levels). Therefore, some non-energetic aspects should be considered when studying individuals’ responses to environmental changes and other key physiological processes (oxidative stress proxies, activity of digestive enzymes) should be investigated directly to support

Morphometric indices of body condition are assumed to reflect an animal’s health and ultimately its fitness, but their physiological significance remains a matter of debate. These indices are indeed usually considered as proxies of energy reserves, ignoring other physiological processes involved in animal health such as nutritional, immune and hormonal states. Given the wide variety of ecological processes investigated through morphometric body condition indices in marine sciences, there is a clear need to determine whether morphometric indices reflect primarily individuals’ energy reserves or their broader integrated physiological status. To address this issue, we used morphometric and physiological data (cortisol level, oxidative stress, digestive enzymes activity, and both fatty acids percentage and total amount) collected in three stocks of the European sardine (Sardina pilchardus) presenting contrasted patterns of growth and body condition. We found that morphometric body condition indices are indeed mainly and consistently linked to a proxy of the amount of lipid reserves (i.e., fatty acids amount), but also significantly to quality of lipid reserves (i.e., fatty acids percentage) and fish chronic stress (scale cortisol levels). We found no significant relationship between morphometric indices of body condition and both oxidative stress proxies and variables measuring digestive enzymes activity. Our study confirmed that morphometric body condition indices primarily reflect the variance in individuals’ lipid reserves and to a lesser extent the actual composition of these reserves (linked to differences in fish diet) and scale cortisol levels (indicating fish metabolism and/or their chronic stress levels). Therefore, some non-energetic aspects should be considered when studying individuals’ responses to environmental changes and other key physiological processes (oxidative stress proxies, activity of digestive enzymes) should be investigated directly to support

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

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

In the Canary Islands waters, small pelagic fish are targeted by the artisanal purse seine fleet, whose activity is monitored by the Canary Centre of the Spanish Institute of Oceanography (IEO) since 2013, including the study of the most caught species (i.e. Scomber colias, Trachurus spp, Sardinella spp and Sardina pilchardus). In 2015, the status assessment of these species (which in absence of ad hoc studies are considered as single stocks) was included in the FAO Working Group on the Assessment of Small Pelagic Fish off Northwest Africa (FAO, 2016). However, the short time series and the limited knowledge of their life history traits in the Archipelago had been considered too limited to perform any assessment exercise. In this context, a multi-model approach has been attempted to assess the status of these species for the first time in the area, using both length- and catch-based methods.

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

We examined growth rates and reproductive characteristics of Sardinella aurita off Senegal and other coastal areas over a 20 year period (1995-2014) to determine how they relate to variations in environmental characteristics of coastal waters. Based on fish length-frequency data and a coastal upwelling index, we found that S. aurita recruitment tends to occur during the periods of most intensive upwelling (March-April off Senegal). Peak reproduction corresponds to periods of low sea-surface temperature (in February or March). The sex ratio was remarkably consistent during the 30 year study period and so was not affected by environmental changes. We hypothesise that S. aurita takes advantage of the higher zooplankton productivity that occurs in coastal waters when upwelling brings nutrient-rich water to the surface (i.e., it increases its growth rate and accumulates energy reserves for spawning). Growth performance appears to be strongly dependent on environmental conditions. The timing of spawning seems to occur when food (zooplankton) is most available for supplying the energy requirements needed by adults for spawning and early development of larvae. Environmental changes seem to have a significant effect on S. aurita growth and reproduction, which endorses their high phenotypic plasticity.

We examined growth rates and reproductive characteristics of Sardinella aurita off Senegal and other coastal areas over a 20 year period (1995-2014) to determine how they relate to variations in environmental characteristics of coastal waters. Based on fish length-frequency data and a coastal upwelling index, we found that S. aurita recruitment tends to occur during the periods of most intensive upwelling (March-April off Senegal). Peak reproduction corresponds to periods of low sea-surface temperature (in February or March). The sex ratio was remarkably consistent during the 30 year study period and so was not affected by environmental changes. We hypothesise that S. aurita takes advantage of the higher zooplankton productivity that occurs in coastal waters when upwelling brings nutrient-rich water to the surface (i.e., it increases its growth rate and accumulates energy reserves for spawning). Growth performance appears to be strongly dependent on environmental conditions. The timing of spawning seems to occur when food (zooplankton) is most available for supplying the energy requirements needed by adults for spawning and early development of larvae. Environmental changes seem to have a significant effect on S. aurita growth and reproduction, which endorses their high phenotypic plasticity.

We examined growth rates and reproductive characteristics of Sardinella aurita off Senegal and other coastal areas over a 20 year period (1995-2014) to determine how they relate to variations in environmental characteristics of coastal waters. Based on fish length-frequency data and a coastal upwelling index, we found that S. aurita recruitment tends to occur during the periods of most intensive upwelling (March-April off Senegal). Peak reproduction corresponds to periods of low sea-surface temperature (in February or March). The sex ratio was remarkably consistent during the 30 year study period and so was not affected by environmental changes. We hypothesise that S. aurita takes advantage of the higher zooplankton productivity that occurs in coastal waters when upwelling brings nutrient-rich water to the surface (i.e., it increases its growth rate and accumulates energy reserves for spawning). Growth performance appears to be strongly dependent on environmental conditions. The timing of spawning seems to occur when food (zooplankton) is most available for supplying the energy requirements needed by adults for spawning and early development of larvae. Environmental changes seem to have a significant effect on S. aurita growth and reproduction, which endorses their high phenotypic plasticity.

The Fisheries Management Area of Indonesia-711 (WPPNRI-711) is the fishing ground of small pelagic which is vulnerable to illegal fishing activities. The research aimed (1) to estimate the economic values of small pelagic catch fishery and the economic loss caused by illegal fishing, (2) to formulate the model of marine control in order to improve fishermen welfare and GDP. The primary data were collected by interviewing the fishermen, the ocean guard inspector and the expert using questionnaire from July to November 2016. The secondary data were obtained from the Catch Fisheries of Indonesian Statistics Data. The illegal fishing ship data were obtained from the marine resources and fisheries station, Indonesian Navy, and the Marine Security Guard (Bakamla). The data series of 2005 to 2016 were then analyzed using Bio-economic analysis model (Gordon Schaefer) and Surplus Production Model (Fox) to analyze the economic benefits.The optimum economic exploitation of small pelagic is 5,040 fishing ships efforts, 13,560.30 tons per year productions, and Rp 225,501.54 million economic rent per year. Meanwhile, the value of fishing 3,284.76 tons and Rp 53,798.26 million due to illegal fishing per year. The exploitation rate carried out in small pelagic catch fishery still must be improved to the optimum rate. The result of Importance and Productivity Analysis (IPA) and SWOT Analysis describes that the marine control model which is effective, efficient and sustainable is indispensable, to combat illegal fishing in WPPNRI-711.

The Fisheries Management Area of Indonesia-711 (WPPNRI-711) is the fishing ground of small pelagic which is vulnerable to illegal fishing activities. The research aimed (1) to estimate the economic values of small pelagic catch fishery and the economic loss caused by illegal fishing, (2) to formulate the model of marine control in order to improve fishermen welfare and GDP. The primary data were collected by interviewing the fishermen, the ocean guard inspector and the expert using questionnaire from July to November 2016. The secondary data were obtained from the Catch Fisheries of Indonesian Statistics Data. The illegal fishing ship data were obtained from the marine resources and fisheries station, Indonesian Navy, and the Marine Security Guard (Bakamla). The data series of 2005 to 2016 were then analyzed using Bio-economic analysis model (Gordon Schaefer) and Surplus Production Model (Fox) to analyze the economic benefits.The optimum economic exploitation of small pelagic is 5,040 fishing ships efforts, 13,560.30 tons per year productions, and Rp 225,501.54 million economic rent per year. Meanwhile, the value of fishing 3,284.76 tons and Rp 53,798.26 million due to illegal fishing per year. The exploitation rate carried out in small pelagic catch fishery still must be improved to the optimum rate. The result of Importance and Productivity Analysis (IPA) and SWOT Analysis describes that the marine control model which is effective, efficient and sustainable is indispensable, to combat illegal fishing in WPPNRI-711.

The Fisheries Management Area of Indonesia-711 (WPPNRI-711) is the fishing ground of small pelagic which is vulnerable to illegal fishing activities. The research aimed (1) to estimate the economic values of small pelagic catch fishery and the economic loss caused by illegal fishing, (2) to formulate the model of marine control in order to improve fishermen welfare and GDP. The primary data were collected by interviewing the fishermen, the ocean guard inspector and the expert using questionnaire from July to November 2016. The secondary data were obtained from the Catch Fisheries of Indonesian Statistics Data. The illegal fishing ship data were obtained from the marine resources and fisheries station, Indonesian Navy, and the Marine Security Guard (Bakamla). The data series of 2005 to 2016 were then analyzed using Bio-economic analysis model (Gordon Schaefer) and Surplus Production Model (Fox) to analyze the economic benefits.The optimum economic exploitation of small pelagic is 5,040 fishing ships efforts, 13,560.30 tons per year productions, and Rp 225,501.54 million economic rent per year. Meanwhile, the value of fishing 3,284.76 tons and Rp 53,798.26 million due to illegal fishing per year. The exploitation rate carried out in small pelagic catch fishery still must be improved to the optimum rate. The result of Importance and Productivity Analysis (IPA) and SWOT Analysis describes that the marine control model which is effective, efficient and sustainable is indispensable, to combat illegal fishing in WPPNRI-711.

The objective of this study was to assess the effect of environmental variations on the abundance of Sardinella aurita and Sardinella maderensis in Senegalese waters in the upwelling system. Monthly data indicating the abundance of sardinella were first estimated from commercial statistics, using Generalized Linear Model from 1966 to 2011. Abundance indices (AIs) were then compared with environmental indices, at the local scale, a Coastal Upwelling Index (CUI) and a coastal Sea Surface Temperature (SST) index, and on a large scale, the North Atlantic Oscillation (NAO), the Atlantic Multidecadal Oscillation (AMO) and the Multivariate El Nino Southern Oscillation Index (MEI), using correlations and times series analyses. The results showed that the abundance of sardinella is determined by a strong seasonal pattern and inter-annual fluctuations. The abundance of S.aurita peaked in spring and in autumn, whereas that of S.maderensis peaked in the warm season (July-September). The trend of the sardinella abundance was significantly correlated with the CUI, especially in autumn and spring. Interannual fluctuations of S.maderensis and S.aurita abundance are, respectively, driven by the precocity and the duration of the upwelling season that is attributed to distinct migration patterns. Both sardinella species also respond with a delay of around 4years to the winter NAO index and the autumn CUI, and the AMO index, respectively, both related to migration patterns. The wide variations in sardinella biomass are caused by variations in environmental conditions, which should be considered in the implementation of an ecosystem-based approach in sardinella stocks management.

The objective of this study was to assess the effect of environmental variations on the abundance of Sardinella aurita and Sardinella maderensis in Senegalese waters in the upwelling system. Monthly data indicating the abundance of sardinella were first estimated from commercial statistics, using Generalized Linear Model from 1966 to 2011. Abundance indices (AIs) were then compared with environmental indices, at the local scale, a Coastal Upwelling Index (CUI) and a coastal Sea Surface Temperature (SST) index, and on a large scale, the North Atlantic Oscillation (NAO), the Atlantic Multidecadal Oscillation (AMO) and the Multivariate El Nino Southern Oscillation Index (MEI), using correlations and times series analyses. The results showed that the abundance of sardinella is determined by a strong seasonal pattern and inter-annual fluctuations. The abundance of S.aurita peaked in spring and in autumn, whereas that of S.maderensis peaked in the warm season (July-September). The trend of the sardinella abundance was significantly correlated with the CUI, especially in autumn and spring. Interannual fluctuations of S.maderensis and S.aurita abundance are, respectively, driven by the precocity and the duration of the upwelling season that is attributed to distinct migration patterns. Both sardinella species also respond with a delay of around 4years to the winter NAO index and the autumn CUI, and the AMO index, respectively, both related to migration patterns. The wide variations in sardinella biomass are caused by variations in environmental conditions, which should be considered in the implementation of an ecosystem-based approach in sardinella stocks management.

The objective of this study was to assess the effect of environmental variations on the abundance of Sardinella aurita and Sardinella maderensis in Senegalese waters in the upwelling system. Monthly data indicating the abundance of sardinella were first estimated from commercial statistics, using Generalized Linear Model from 1966 to 2011. Abundance indices (AIs) were then compared with environmental indices, at the local scale, a Coastal Upwelling Index (CUI) and a coastal Sea Surface Temperature (SST) index, and on a large scale, the North Atlantic Oscillation (NAO), the Atlantic Multidecadal Oscillation (AMO) and the Multivariate El Nino Southern Oscillation Index (MEI), using correlations and times series analyses. The results showed that the abundance of sardinella is determined by a strong seasonal pattern and inter-annual fluctuations. The abundance of S.aurita peaked in spring and in autumn, whereas that of S.maderensis peaked in the warm season (July-September). The trend of the sardinella abundance was significantly correlated with the CUI, especially in autumn and spring. Interannual fluctuations of S.maderensis and S.aurita abundance are, respectively, driven by the precocity and the duration of the upwelling season that is attributed to distinct migration patterns. Both sardinella species also respond with a delay of around 4years to the winter NAO index and the autumn CUI, and the AMO index, respectively, both related to migration patterns. The wide variations in sardinella biomass are caused by variations in environmental conditions, which should be considered in the implementation of an ecosystem-based approach in sardinella stocks management.

The objective of this study was to assess the effect of environmental variations on the abundance of Sardinella aurita and Sardinella maderensis in Senegalese waters in the upwelling system. Monthly data indicating the abundance of sardinella were first estimated from commercial statistics, using Generalized Linear Model from 1966 to 2011. Abundance indices (AIs) were then compared with environmental indices, at the local scale, a Coastal Upwelling Index (CUI) and a coastal Sea Surface Temperature (SST) index, and on a large scale, the North Atlantic Oscillation (NAO), the Atlantic Multidecadal Oscillation (AMO) and the Multivariate El Nino Southern Oscillation Index (MEI), using correlations and times series analyses. The results showed that the abundance of sardinella is determined by a strong seasonal pattern and inter-annual fluctuations. The abundance of S.aurita peaked in spring and in autumn, whereas that of S.maderensis peaked in the warm season (July-September). The trend of the sardinella abundance was significantly correlated with the CUI, especially in autumn and spring. Interannual fluctuations of S.maderensis and S.aurita abundance are, respectively, driven by the precocity and the duration of the upwelling season that is attributed to distinct migration patterns. Both sardinella species also respond with a delay of around 4years to the winter NAO index and the autumn CUI, and the AMO index, respectively, both related to migration patterns. The wide variations in sardinella biomass are caused by variations in environmental conditions, which should be considered in the implementation of an ecosystem-based approach in sardinella stocks management.

A review on small pelagic fisheries of anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) in the Northern Alboran Sea (Western Mediterranean Sea) was carried out. The study was focused on a very extense historical serie of landings (from 40’s to the present), as well as the number of fishery vessels and fishery effort during the last decade, and the assessment in 2001

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