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In this paper, a sustainability framework with a case application for UK's Scottish fisheries has been developed which integrates aspects related to economic growth, social development, governance, biology, environment, and logistics. Scotland is the centre of UK's commercial fishery sector however it faces challenges such as overexploitation, and changes in the governance structure following Brexit. The contributions of this study are threefold including (i) collecting and analysing primary data gathered from a diverse group of stakeholders in the Scottish fishery sector and scientific community, (ii) prioritising a diverse range of criteria in terms of importance in decision making from industry and scientific community perspectives, (iii) elaboration of the key management objectives in this region within the context of sustainable management of fisheries in the UK.The results of this stakeholders' survey show that the key management objectives are reductions in overexploitation of stocks, inclusive governance, increase in transparency and simplicity of policy measures, reduction in marine litter, and increase in the efficiency of vessels. The analysis also shows that the industry group places a higher importance on socio-economic objectives such as increase in profit and employment compared to the scientific group. On the other hand, the scientific group prioritised the objectives such as reducing discards, bycatch, and impact on seafloor compared to the industry group. This study provides insight for the UK's fisheries sector, and scientific advisory groups for the enhanced implementation of sustainable fisheries management policies.

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The three grouper species most heavily fished for the live reef fish trade (LRFT) in Indonesia are Plectopomus leopardus (greatest catch volume), and two species classified as Vulnerable on the International Union for Conservation of Nature (IUCN) Red List: Plectropomus areolatus and Epinephelus polyphekadion. Understanding the reproductive biology of these fishes is essential for sustainable management, but relevant data are limited. This study aimed to determine reproductive dynamics, so as to inform management measures to maintain the reproductive capacity of these groupers. Grouper gonad samples collected from fish caught for the LRFT were analyzed histologically. Data were also collected from participatory mapping and interviews with fishermen, and underwater monitoring of three known spawning aggregation sites in the Wakatobi National Park, Eastern Indonesia. Based on observed gonad development, the respective lengths and weights at first maturity were: 37.7 cm and 759 g (P. leopardus); 36.65 cm and 771.2 g (P. areolatus); 36.95 cm and 889.9 g (E. polyphekadion). The mean weight of the groupers market-based sampled was higher than the size at first sexual maturity. Sex transition was observed in P. leopardus; sex reversal was not observed in E. polyphekadion, and the sex pattern of P. areolatus was unresolved. Based on the fisher surveys and spawning aggregation monitoring, spawning occurs around the new moon from September to April, with reproductive peaks in November and December. Fisheries management measures that are suggested to sustain grouper stocks include enforcing appropriate size limits, temporal spatial closures (spawning aggregation sites), and a trading ban during the peak spawning season (November-December).

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Connectivity between fish stocks is fundamental to the understanding of population dynamics and the implementation of sustainable fisheries management. Otolith microchemistry is a promising tool as it can provide information on the continuous growth of otoliths and the environmental effects on otolith composition. Such elemental fingerprints can help distinguish different stocks or life history stages, identify the origins or nursery areas of fish, and assess population structure. In this study, we examined the stock discrimination and spatial connectivity of cage-cultured and wild stocks of yellowfin seabream (Acanthopagrus latus) from the coastal waters of Shantou, Yangjiang, and Zhanjiang in China southern province Guangdong during 2012-2014, based on otolith trace-elemental signatures using multivariate statistical analysis and machine learning approaches. The concentrations of 13 elements (7Li, 23Na, 24Mg, 40Ca, 55Mn, 56Fe, 59Co, 59Ni, 64Cu, 65Zn, 88Sr, 122Sb, and 137Ba) in the natal spot of fish otoliths, representing the embryonic and paralarval stages of fish, were analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Stepwise discriminant analysis and random forests were used to distinguish the cultured and wild stocks of yellowfin seabream, and non-metric multidimensional scaling (NMDS) and cluster analysis were used to determine the spatial variation and connectivity of yellowfin seabream stocks. Overall, the cultured and wild stocks of yellowfin seabream could be identified with classification accuracy of 80.7% and 99.2% by using stepwise discriminant analysis and random forests respectively. When we compared site difference between cultured and wild stocks (site × stock interactions), the classification success was 60.4% for stepwise discriminant analysis and 85.7% for random forests. The misclassification of cultured and wild stocks within the three sites suggested the spatial connectivity between stocks and among sampling locations. Our findings suggested that the three wild stocks of yellowfin seabream from Guangdong coastal waters could be considered as one unit for management, and the difference between cultured and wild stocks was significant for yellowfin seabream from Shantou and Yangjiang, but less significant for yellowfin seabream from Zhanjiang. This study demonstrated that otolith elemental fingerprints can help improve our knowledge on the spatial connectivity, population structure, and life history of fish stocks, and random forests can be a useful tool for identifying cultured and wild stocks compared to the traditional stepwise discriminant analysis.

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The global European eel (Anguilla anguilla) stock is critically endangered according to the IUCN, and the European Commission has urged the development of conservation plans aimed to ensure its viability. However, the complex life cycle of this panmictic species, which reproduces in the open ocean but spends most of its prereproductive life in continental waters (thus embracing a huge geographic range and a variety of habitat types), makes it difficult to assess the long-term effectiveness of conservation measures. The interplay between local and global stressors raises intriguing cross-scale conservation challenges that require a comprehensive modelling approach to be addressed. We developed a full life cycle model of the global European eel stock, encompassing both the oceanic and the continental phases of eel's life, and explicitly allowing for spatial heterogeneity in vital rates, availability of suitable habitat and settlement potential via a metapopulation approach. We calibrated the model against a long-term time series of global European eel catches and used it to hindcast the dynamics of the stock in the past and project it over the 21st century under different management scenarios. Although our analysis relies on a number of inevitable simplifying assumptions and on data that may not embrace the whole range of variation in population dynamics at the small spatiotemporal scale, our hindcast is consistent with the general pattern of decline of the stock over recent decades. The results of our projections suggest that (i) habitat loss played a major role in the European eel decline; (ii) the viability of the global stock is at risk if appropriate protection measures are not implemented; (iii) the recovery of spawner escapement requires that fishing mortality is significantly reduced; and (iv) the recovery of recruitment might not be feasible if reproductive output is not enhanced.

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Artisanal diving fisheries are a source of income, employment and food security of coastal areas in many countries. Understanding the dynamics of these fisheries, including the spatial and temporal dynamics of fishing effort, gears and species can help to address the challenges involved in fisheries management. We aimed to analyze the differences in fishing strategies under- taken by fishers that use two different diving methods (hookah and free diving), the conditions and their potential impacts on catches when adjustments to those strategies are applied over time. For this, detailed information of fishing operations from artisanal boats in the North Pacific coast of Costa Rica was analyzed in two fishing seasons (2007-2008 and 2011-2012). Data were collected by onboard observers (fishing site, fishing time, species composition, depth and visibility). Additionally, interviews with divers were applied to obtain information of price per species, species volume and fishing operations. From the total number of trips during both seasons, hookah diving was represented by a sample size of 69.3%, while free diving, with a sample of 41.9%. More than 15 species were identified in each fishing season. Nevertheless, three categories had substantial contributions in both seasons with differences in the proportions for each case: green lobster (Panulirus gracilis), octopus (Octopus sp.) and parrotfish (Scarus perrico and S. ghobban). It is worth noting that an important proportion of catch was retained by fishers for personal consumption purposes, including species of high commercial value. Additional night diving activity, increased the number of dives from one season to another. Besides, cooperation processes in free diving fishing operations, and changes in fishing effort between seasons, defined important changes in fishing strategies. Potential causes of changes in fishing strategies and the implications for manage- ment to ensure the sustainability of these fisheries in the long term are discussed.

Las pesquerías artesanales asociadas a métodos de buceo son fuente de ingreso, empleo y seguridad alimentaria de zonas costeras en muchos países. Los altos precios y la poca movilidad de especies bénticas capturadas por buceo enfrentan retos cada vez mayores en su aprovechamiento y manejo, esto demanda un entendimiento integral de estas pesquerías en diferentes contextos, incluyendo la dinámica espacial y temporal del esfuerzo pesquero, las artes y las especies. En el presente estudio se busca elucidar si existen diferencias en las estrategias de pesca desarrolla- das por pescadores que emplean buceo en dos modalidades (hookah y buceo libre). También se busca conocer si se desarrollan adaptaciones de estas estrategias en el tiempo, bajo qué condiciones y el posible efecto de las estrategias sobre las capturas. Para ese fin se analizó información detallada de las operaciones de pesca de embarcaciones artesanales que operan en la costa del océano Pacífico de Costa Rica durante dos temporadas de pesca. Se analizó información obtenida a bordo de embarcaciones como: sitio de pesca, composición de especies, tiempo de pesca, número de inmersiones por viaje, entre otros; y se aplicaron entrevistas a buzos al momento de las descargas para obtener información de precios, el volumen de las especies capturadas y forma de operación de los pescadores. Para el buceo con hookah se obtuvo una muestra del 69.3% del total de viajes en las dos temporadas de pesca y en el caso del buceo libre se obtuvo una muestra del 41.9% del total de viajes en las dos temporadas de pesca estudiadas (2007-2008 y 2011-2012). Se identificaron más de 15 especies en cada temporada de pesca, dominaron tres categorías en ambas temporadas pero con diferencias en las proporciones obtenidas en cada caso: langosta (Panulirus gracilis), pulpo (Octopus sp) y pez loro (Scarus perrico y S. Ghobban). Resalta un componente importante de captura retenida por los pescadores para consumo personal, incluyendo especies de alto valor comercial. Se identificaron cambios en las estrategias de pesca asociadas a cambios en las capturas y cambios en la asignación espacial del esfuerzo pesquero de una temporada de pesca a otra, definidas por la adición de buceo nocturno, aumento en el número de inmersiones de una temporada a otra y procesos de cooperación en las faenas de pesca de buzos que usan buceo libre. Se discute las potenciales causas de los cambios en las estrategias de pesca observadas y se derivan implicaciones para el manejo que permiten la sostenibilidad de estas pesquerías a largo plazo.

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