Applicability of the current stock assessment models to the priority azorean fishery resources

This work presents a guidance to conduct stock assessment based on ICES Maximum Sustainable Yield framework. A cross-analysis based on the models’ assumptions and inputs and data available for 22 Azorean priority stocks was performed to assess the applicability of each model to each stock. Information currently available for coastal and some demersal/deep-water stocks limits the use of most models validated by ICES. Only four demersal/deep-water stocks (Pagellus bogaraveo, Helicolenus dactylopterus, Phycis phycis, and Pontinus kuhlii) have data availability and quality enough to perform trend analysis, length-based and catch and survey-based methods. The next steps involve validating life-history parameters, evaluating model performances, and applying alternative tools for data-deficient stocks. Additional monitoring programs are of utmost importance, which must collect missing information and clarify stock delimitation to improve assessment quality. This study guides future stock assessment actions and highlights data gaps where future research should focus.This study is part of the PESCAz project (ref. MAR-01.03.02-FEAMP-0039) financed by the European Maritime and Fisheries Fund (EMFF) through the Regional Government of the Azores under the MAR2020 operational program.info:eu-repo/semantics/publishedVersio

Stock assessment prioritization in the Azores : procedures, current challenges and recommendations

To implement the Marine Strategy Framework Directive (MSFD) of the European Union (EU) in order to achieve the Sustainable Development Goals (SDGs) of the United Nations (UN) regarding the biological sustainability of marine fisheries, it is fundamental to apply a framework for prioritizing stocks. This process helps the regional managers to make the best use of data and resources for management. The present study describes and applies a standard framework for prioritization of stock assessment in the Azores. The current state of the selected stocks is identified and the main issues and gaps for assessment are presented and discussed. A total of 138 species were landed in the region during the period 2009-2019. Twenty-two (18 fishes, 2 molluscs and 2 crustaceans) were selected as priority stocks according to the Food and Agriculture Organization of the United Nations (FAO) and International Council for the Exploration of the Sea (ICES) criteria. Most of these showed a decreasing trend in their abundances. Only four stocks are currently assessed using data-limited approaches: Pagellus bogaraveo, Aphanopus carbo, Raja clavata, and Trachurus picturatus. No biological reference points are defined and stock and exploitation status relative to Maximum sustainable yield (MSY) are not assessed. The main issues identified were the lack of information regarding catches and population structure and validated analytical methods. Future studies should evaluate which methods for assessment may be suitable for each stock and identify what additional data are needed to improve the analyses.info:eu-repo/semantics/publishedVersio

Multidimensional Indicators to Assess the Sustainability of Demersal Small-Scale Fishery in the Azores

The Azorean demersal fishery sector is one of the most important in the archipelago. As a small-scale fishery, it plays an important role in the livelihood of the community, being a source of employment and income, and contributing to poverty alleviation. Because fisheries are a complex system, a multidisciplinary approach that includes socioeconomic indicators is required for a broader assessment of fishery sustainability. This study analyzes the Azorean bottom longline fishery using the Fishery Performance Indicators tool, regarding its ecology, economy, and community indicators. The findings indicated that the fishery is mostly sustainable, although there is still opportunity for improvement. Its ecological indicators had a good performance, mainly due to the effort and work of the scientific community that makes continuous studies to examine the state of its stocks. The economic indicators are in good condition as well, but some obstacles stopped the indicator from obtaining a better performance; mainly the landing volatility and the fishery's main source of capital (subsidies), which can make the fishery less competitive. Finally, its community indicator had a very good performance, which reflects the fishery's socioeconomic and cultural relevance for the Azores.info:eu-repo/semantics/publishedVersio

Estimates of biomass and potential yield for the deep-water red crab, Chaceon affinis and the toothed rock crab, Cancer bellianus (Decapoda: Brachyura) off the Azores (Mid-North Atlantic)

Available information on the deep-water red crab, Chaceon affinis and the toothed rock crab, Cancer bellianus, resulting from exploratory research surveys and commercial fishing experiments carried out in the Azorean Exclusive Economic Zone (EEZ), were summarized to estimate the biomass and potential yield (Maximum Sustainable Yield – MSY) for both fishery resources. The fishery potential was estimated through empirical methods usually applied when available information is scarce in line with the precautionary approach principle. Results suggest modest MSY values (considered as precautionary Total Allowable Catch – TAC), around 2,205 t for the deep-water red crab (2,159 t year-1 at seamounts and 46 t year-1 at coastal areas), and 471 t for the toothed rock crab (281 t year-1 at offshore seamounts and 189 t year-1 at coastal areas). Considering the limited available data and high uncertainty associated with these estimations, it is suggested that only a reduced number of vessels should be allowed to fish in the aggregated areas, namely coastal and seamount areas. The exploitation of these resources should be started in a very limited way followed by an ad hoc observer programme, aiming to collect reliable data that will allow, if it is the case, to raise in the future the exploitation level in a gradual and sustainable way.Régis Santos was supported by the IMAR Institute of Marine Research, through a post-doc fellowship (ref. IMAR/DEMERSAIS/001-2018). Wendell Silva was funded by the IMAR Instituto do Mar, through a scholarship (ref. IMAR/UNI/MAR/04292/2013 MARE/001-2018). Ana Novoa-Pabon was funded by an FCT Ph.D. fellowship (ref. SFRH/BD/124720/2016).info:eu-repo/semantics/publishedVersio

Estimates of biomass and potential yield for the deep-water red crab, Chaceon affinis and the toothed rock crab, Cancer bellianus (Decapoda: Brachyura) off the Azores (Mid-North Atlantic)

Available information on the deep-water red crab, Chaceon affinis and the toothed rock crab, Cancer bellianus, resulting from exploratory research surveys and commercial fishing experiments carried out in the Azorean Exclusive Economic Zone (EEZ), were summarized to estimate the biomass and potential yield (Maximum Sustainable Yield – MSY) for both fishery resources. The fishery potential was estimated through empirical methods usually applied when available information is scarce in line with the precautionary approach principle. Results suggest modest MSY values (considered as precautionary Total Allowable Catch – TAC), around 2,205 t for the deep-water red crab (2,159 t year-1 at seamounts and 46 t year-1 at coastal areas), and 471 t for the toothed rock crab (281 t year-1 at offshore seamounts and 189 t year-1 at coastal areas). Considering the limited available data and high uncertainty associated with these estimations, it is suggested that only a reduced number of vessels should be allowed to fish in the aggregated areas, namely coastal and seamount areas. The exploitation of these resources should be started in a very limited way followed by an ad hoc observer programme, aiming to collect reliable data that will allow, if it is the case, to raise in the future the exploitation level in a gradual and sustainable way.Régis Santos was supported by the IMAR Institute of Marine Research, through a post-doc fellowship (ref. IMAR/DEMERSAIS/001-2018). Wendell Silva was funded by the IMAR Instituto do Mar, through a scholarship (ref. IMAR/UNI/MAR/04292/2013 MARE/001-2018). Ana Novoa-Pabon was funded by an FCT Ph.D. fellowship (ref. SFRH/BD/124720/2016).info:eu-repo/semantics/publishedVersio

ESTRUTURA POPULACIONAL E CONDIÇÃO FISIOLÓGICA DE Hoplias malabaricus (BLOCH, 1794) NO BAIXO RIO CAPIBARIBE

This research aimed to determine population structure and physiological condition of Hoplias malabaricus in the Capibaribe river (PE), northeastern Brazil. Monthly sampling were carried out between September/2013 and August/2014, using gill nets. The sex was identified by macroscopic and microscopic viewing of gonads, following the classification proposed by Vazzoler (1996). The specimens were distributed in length classes, being applied Kolmogorov-Smirnov test to evaluate the presence of sexual dimorphism. The length-weight relationship was calculated assessing differences through Kruskal Wallis test and physiological condition was calculated through allometric condition factor (K) between sexes, being applied the Spearman correlation test. Was collected 30 males and 42 females. No sexual dimorphism was observed relative to the size. Was observed positive allometric growth for females and negative for males. Was evidenced physiological condition variations along the year regarding seasonality. Population structure and physiological condition of the Hoplias malabaricus differed from that found in other environments, being this research, an important tool support the development of future management plans and conservation of Hoplias malabaricus, especially in this region.Keywords: population dynamics; fishing; reproduction.Esta pesquisa objetivou determinar a estrutura populacional e condição fisiológica de Hoplias malabaricus no rio Capibaribe (PE), nordeste brasileiro. Foram realizadas coletas mensais entre setembro/2013 e agosto/2014, utilizando redes de espera. O sexo foi identificado pela visualização macroscópica e microscópica das gônadas, seguindo a classificação proposta por Vazzoler (1996). Os indivíduos foram distribuídos entre classes de comprimento, sendo aplicado teste de Kolmogorov-Smirnov para verificar a presença de dimorfismo sexual. A relação peso-comprimento entre sexos foi calculada, avaliando diferenças pelo teste Kruskal-Wallis e a condição fisiológica foi avaliada pelo fator de condição alométrico (K) entre sexos, sendo aplicado teste de correlação de Spearman. Foram coletados 30 machos e 42 fêmeas, não sendo observado dimorfismo sexual relativo ao tamanho. Além disto, verificou-se um crescimento alométrico positivo para as fêmeas e negativo para os machos. Também foram evidenciadas variações na condição fisiológica ao longo do ano em relação à sazonalidade. A estrutura populacional e condição fisiológica de Hoplias malabaricus diferiram do encontrado em outros ambientes, sendo este estudo uma importante ferramenta para embasar o desenvolvimento de futuros planos de manejo e conservação de Hoplias malabaricus, especialmente nesta região.Palavras-chave: dinâmica populacional, pesca, manejo de recursos pesqueiros

Synopsis of biological, ecological and fisheries-related information on priority marine species in the Azores region

Studies on life history and stock structure of marine species have evolved in the Azores region during the last 40 years. This information is essential to feed fishery stock assessment models that fit available data to determine current stock status and provide advice on the optimum (sustainable) exploitation. However, most of these data are only available in a fragmented manner in several scientific papers, books, theses and reports. In some cases, these sources of information are difficult to access. The present document aims to gather and summarize biological, ecological and fisheries-related information for the main commercially exploited species in the Azores. The species treated here have previously been selected as priority stocks for assessment and monitoring at regional level by applying a standard framework aligned with the ICES and FAO recommendations. They are: the blackspot seabream Pagellus bogaraveo, veined squid Loligo forbesii, blue jack mackerel Trachurus picturatus, blackbelly rosefish Helicolenus dactylopterus, red porgy Pagrus pagrus, forkbeard Phycis phycis, European conger Conger conger, alfonsino Beryx decadactylus, splendid alfonsino B. splendens, parrotfish Sparisoma cretense, silver scabbardfish Lepidopus caudatus, red scorpionfish Scorpaena scrofa, Atlantic chub mackerel Scomber colias, blacktail comber Serranus atricauda, offshore rockfish Pontinus kuhlii, amberjacks nei Seriola spp., common mora Mora moro, common spiny lobster Palinurus elephas, black scabbardfish Aphanopus carbo, rough limpet Patella aspera, thornback ray Raja clavata, and Mediterranean slipper lobster Scyllarides latus. The document is presented as concisely and effectively as possible. An overview table of the current data available is presented by stock.This document is part of the PESCAz project (ref. MAR-01.03.02-FEAMP-0039) financed by the European Maritime and Fisheries Fund (EMFF) through the Regional Government of the Azores under the MAR2020 operational programme.info:eu-repo/semantics/publishedVersio

Complementary Role of Fishers’ Experiential Knowledge to Conventional Science in Terms of Species-Specific Biological Traits and Population Changes in Azorean Waters

Combining scientific information with fishers’ perceptions may be a robust approach for directing decision-makers working with marine ecosystems. This is particularly the case when baseline data on a vulnerable stock are poor, as the integration of fishers’ experiential knowledge can help fill data gaps, as well as inform legitimate management actions, and empower fishing communities in resource management. This study aimed to analyze fishers’ knowledge regarding the biology (reproduction, growth, and maximum size) and temporal changes in the abundance and size of six commercially important marine species (red porgy Pagrus pagrus, veined squid Loligo forbesii, blue jack mackerel Trachurus picturatus, blackspot seabream Pagellus bogaraveo, blackbelly rosefish Helicolenus dactylopterus, and European conger Conger conger) in the Azores small-scale communities. Additionally, a comparison between fishers’ knowledge and available scientific information was performed to determine the former’s value and its possible complementarity with the latter. A total of 105 fishers were surveyed in the nine islands of the archipelago. The results demonstrated a reasonable level of agreement between the information from fishers and scientific literature on the species-specific spawning seasons and growth rates. The median values of size at maturity and maximum length were not statistically different between data sources. Most participants indicated size and abundance trends that were consistent with the literature. This study highlights the usefulness of fishers’ perceptions in improving knowledge about species characteristics and temporal changes in commercially exploited stocks, especially when scientific research is limited, but further research should be encouraged to improve the reliability and consistency of these results

Complementary Role of Fishers’ Experiential Knowledge to Conventional Science in Terms of Species-Specific Biological Traits and Population Changes in Azorean Waters

Combining scientific information with fishers’ perceptions may be a robust approach for directing decision-makers working with marine ecosystems. This is particularly the case when baseline data on a vulnerable stock are poor, as the integration of fishers’ experiential knowledge can help fill data gaps, as well as inform legitimate management actions, and empower fishing communities in resource management. This study aimed to analyze fishers’ knowledge regarding the biology (reproduction, growth, and maximum size) and temporal changes in the abundance and size of six commercially important marine species (red porgy Pagrus pagrus, veined squid Loligo forbesii, blue jack mackerel Trachurus picturatus, blackspot seabream Pagellus bogaraveo, blackbelly rosefish Helicolenus dactylopterus, and European conger Conger conger) in the Azores small-scale communities. Additionally, a comparison between fishers’ knowledge and available scientific information was performed to determine the former’s value and its possible complementarity with the latter. A total of 105 fishers were surveyed in the nine islands of the archipelago. The results demonstrated a reasonable level of agreement between the information from fishers and scientific literature on the species-specific spawning seasons and growth rates. The median values of size at maturity and maximum length were not statistically different between data sources. Most participants indicated size and abundance trends that were consistent with the literature. This study highlights the usefulness of fishers’ perceptions in improving knowledge about species characteristics and temporal changes in commercially exploited stocks, especially when scientific research is limited, but further research should be encouraged to improve the reliability and consistency of these results

Biological Knowledge of Thornback Ray (Raja clavata) from the Azores: Improving Scientific Information for the Effectiveness of Species-Specific Management Measures

Elasmobranchs are globally recognized as vulnerable due to their life-history characteristics, fishing pressure, and habitat degradation. Among the skates and rays caught by commercial fisheries, the thornback ray Raja clavata is one of the most economically important in Northwest European seas. However, the scarcity of biological knowledge about this species in Azorean waters has limited the stock assessment types that can be conducted. To improve information on its habitat preferences, spatial distribution and movement pattern, growth, sex ratio, mortality, and reproduction, as well as to investigate long-term changes in abundance and size, this study analyzed approximately 25 years of fishery-dependent and independent data from the Azores. Raja clavata was mainly caught at depths up to 250 m. Most of the tagged fish were recaptured near the release point. A larger–deeper trend was found, and females were larger and more abundant than males. Life-history parameters showed that R. clavata has a long lifespan, large size, slow growth, and low natural mortality. The sustainability of its population is of concern to fisheries management and, while our findings suggested a relatively healthy stock in the Azores, a thorough increase in data quality is required to better understand the stock condition and prevent overexploitation