Leveraging deep learning and computer vision technologies to enhance management of coastal fisheries in the Pacific region.

This paper presents the design and development of a coastal fisheries monitoring system that harnesses artificial intelligence technologies. Application of the system across the Pacific region promises to revolutionize coastal fisheries management. The program is built on a centralized, cloud-based monitoring system to automate data extraction and analysis processes. The system leverages YoloV4, OpenCV, and ResNet101 to extract information from images of fish and invertebrates collected as part of in-country monitoring programs overseen by national fisheries authorities. As of December 2023, the system has facilitated automated identification of over six hundred nearshore finfish species, and automated length and weight measurements of more than 80,000 specimens across the Pacific. The system integrates other key fisheries monitoring data such as catch rates, fishing locations and habitats, volumes, pricing, and market characteristics. The collection of these metrics supports much needed rapid fishery assessments. The system's co-development with national fisheries authorities and the geographic extent of its application enables capacity development and broader local inclusion of fishing communities in fisheries management. In doing so, the system empowers fishers to work with fisheries authorities to enable data-informed decision-making for more effective adaptive fisheries management. The system overcomes historically entrenched technical and financial barriers in fisheries management in many Pacific island communities.

Characterization of a Peruvian coastal fishery targeting the Pacific guitarfish Pseudobatos planiceps.

From December 2012 to June 2014, 796 Pacific guitarfish were caught in 183 fishing sets in northern Peru. Catch occurred in 86.3% of sets. Most individuals caught were mature with a bias toward males. The mean total length for females and males was 83.4 cm, and 91.1 cm, respectively. The capture per unit effort (CPUE) was 12.6 ± 3.4 guitarfish (km.12 h)-1. The length-weight relationships showed that this species presents a sexual dimorphism in growth. These results support the importance of Sechura Bay as a key area for this species. This study represents the first species-specific fishery data for the Pacific guitarfish.

A synthesis of women's participation in small-scale fisheries management: why women's voices matter.

While women globally make up nearly half of the fisheries workforce, their contribution to the sector has long been overlooked with implications for fisheries management. To assess women's participation in small-scale fisheries (SSF) management and related socio-cultural, environmental, and economic impacts, we conducted a systematic review of peer-reviewed literature (n = 124 case studies). Women had no or limited participation in more than 80% of the examined case studies reporting their participation level in SSF management. Women's exclusion from SSF management resulted in negative outcomes, whereas their active participation was associated with various positive impacts at multiple scales. Most of the documented impacts were socio-cultural, suggesting a gap in documenting environmental impacts stemmed from women's participation in SSF management. Importantly, most impacts reported affected the social-ecological system scale, suggesting that gender inclusion may contribute to improving the management of SSF social-ecological systems. We conclude by highlighting the need to foster gender perspectives in data collection methods used in fisheries research, in SSF management, and in ecological research on SSF social-ecological systems. Supplementary Information: The online version contains supplementary material available at 10.1007/s11160-023-09806-2.

Impact of Hermodice carunculata (Pallas, 1766) (Polychaeta: Amphinomidae) on artisanal fishery: A case study from the Mediterranean sea.

Invasive species can cause severe economic damages, ecosystem alterations, and can even threat human health. In the global warming scenario, which can act as a driving force for the expansion of thermophilic species, we investigated for the first time the economic damage caused by the invasive bearded fireworm, Hermodice carunculata, to artisanal longline fishery in the Mediterranean Sea. We focused on bottom longline fishery targeting the highly prized white seabream Diplodus sargus, investigating catch composition of the fishing gear and Catch Per Unit Effort (CPUE) of species caught, with particular emphasis on the economic damage caused by the bearded fireworm, H. carunculata, in relation to water temperature. Our results clearly indicated direct and indirect economic damage to fishing activities practiced in the southeastern coast of Sicily (Ionian Sea). Type and extent of the damage caused by the invasive worm (H. carunculata) were discussed in relation to temporal scale and overall yields obtained by this traditional artisanal fishery, and some solutions are proposed. However, the actual situation requires special attention because it is expected to worsen in the context of the global warming future scenarios, such that further studies are urgently needed.

Social wellbeing, values, and identity among Caiçara small-scale fishers in southeastern Brazil.

Although much in the lives of members of the Caiçara small-scale fishing communities of Lázaro and Saco da Ribeira in Ubatuba, southeastern Brazil would suggest hardship, that population expresses a surprising degree of satisfaction with life. In this paper, we use a social wellbeing lens as applied through an ethnographic, mixed methods approach to reflect on this overall sense that lives rooted in small-scale fishing are well worth living despite their many challenges. We see the classic maritime anthropology theme of identity at the heart of meaning and life satisfaction. Identity provides core aspects of how people engage with their realities and anchors values that are reference points in work and social relations. With reference to the relational nuances revealed by the social wellbeing perspective, however, we show that Caiçara and small-scale fishing identities are not monolithic, but reflect gender and other social positions, and personal and familial experiences. These experiences include grappling with the complex effects of economic, social, political, and environmental changes. We conclude by arguing that fisheries policy that seeks to prioritize human wellbeing would benefit by adopting a social wellbeing perspective. Fisheries policy could thereby take into account identity, values, and relational elements of social life that give meaning and a sense of belonging to small-scale fishers, while also recognizing the cross-cutting and often contradictory variations in human experience that arise from social and economic differences. This social fabric of small-scale fishers' lives shapes their intentions and actions and is thus a necessary complication to the practice of fisheries management that its proponents need to consider.

Merging two eDNA metabarcoding approaches and citizen-science-based sampling to facilitate fish community monitoring along vast Sub-Saharan coastlines.

The coastline of Sub-Saharan Africa hosts highly diverse fish communities of great conservation value, which are also key resources for local livelihoods. However, many costal ecosystems are threatened by overexploitation and their conservation state is frequently unknown due to their vast spatial extent and limited monitoring budgets. Here, we evaluated the potential of citizen science-based eDNA surveys to alleviate such chronic data deficiencies and assessed fish communities in Mozambique using two 12S metabarcoding primer sets. Samples were either collected by scientific personnel or trained community members and results from the two metabarcoding primers were combined using a new data merging approach. Irrespective of the background of sampling personnel, a high average fish species richness was recorded (38 ± 20 OTUs per sample). Individual sections of the coastline largely differed in the occurrence of threatened and commercially important species, highlighting the need for regionally differentiated management strategies. A detailed comparison of the two applied primer sets revealed an important trade-off in primer choice with MiFish primers amplifying a higher number of species but Riaz primers performing better in the detection of threatened fish species. This trade-off could be partly resolved by applying our new data-merging approach, which was especially designed to increase the robustness of multiprimer assessments in regions with poor reference libraries. Overall, our study provides encouraging results but also highlights that eDNA-based monitoring will require further improvements of, for example, reference databases and local analytical infrastructure to facilitate routine applications in Sub-Saharan Africa.

Hidden demographic impacts of fishing and environmental drivers of fecundity in a sea turtle population.

Fisheries bycatch is a critical threat to sea turtle populations worldwide, particularly because turtles are vulnerable to multiple gear types. The Canary Current is an intensely fished region, yet there has been no demographic assessment integrating bycatch and population management information of the globally significant Cabo Verde loggerhead turtle (Caretta caretta) population. Using Boa Vista island (Eastern Cabo Verde) subpopulation data from capture-recapture and nest monitoring (2013-2019), we evaluated population viability and estimated regional bycatch rates (2016-2020) in longline, trawl, purse-seine, and artisanal fisheries. We further evaluated current nesting trends in the context of bycatch estimates, existing hatchery conservation measures, and environmental (net primary productivity) variability in turtle foraging grounds. We projected that current bycatch mortality rates would lead to the near extinction of the Boa Vista subpopulation. Bycatch reduction in longline fisheries and all fisheries combined would increase finite population growth rate by 1.76% and 1.95%, respectively. Hatchery conservation increased hatchling production and reduced extinction risk, but alone it could not achieve population growth. Short-term increases in nest counts (2013-2021), putatively driven by temporary increases in net primary productivity, may be masking ongoing long-term population declines. When fecundity was linked to net primary productivity, our hindcast models simultaneously predicted these opposing long-term and short-term trends. Consequently, our results showed conservation management must diversify from land-based management. The masking effect we found has broad-reaching implications for monitoring sea turtle populations worldwide, demonstrating the importance of directly estimating adult survival and that nest counts might inadequately reflect underlying population trends.

Impactos demográficos ocultos de la pesca y determinantes ambientales de la fecundidad en una población de tortugas marinas Resumen La captura accidental de las pesquerías es una amenaza importante para la población mundial de tortugas marinas pues estos reptiles son vulnerables a muchos tipos de artes de pesca. Aunque la Corriente de Canarias es una zona de pesca intensa, no se han realizado análisis demográficos que integren información de la captura accidental y el manejo poblacional de la tortuga caguama de Cabo Verde (Caretta caretta), una población de importancia mundial. Usamos datos de captura-recaptura y monitoreo de nidos (2013-2019) de la subpoblación de la isla Boa Vista (Cabo Verde occidental) para evaluar la viabilidad poblacional y además estimamos el volumen de captura accidental a nivel regional (2016-2020) de las pesquerías de palangre, arrastre, red de cerco y artesanal. También analizamos las tendencias de la anidación en el contexto de las estimas actuales de captura accidental, del posible impacto del traslado de las puestas a viveros y de la variabilidad ambiental (productividad primaria neta) en la zona donde se alimentan las tortugas. Proyectamos que, de persistir, la tasa actual de mortalidad por captura accidental llevaría a la subpoblación de Boa Vista al borde de la extinción. La reducción de la captura accidental en la flota de palangre incrementaría la tasa finita de crecimiento poblacional en un 1.76% y la reducción en todas las flotas un 1.95%. El traslado de las puestas a viveros incrementó la producción de crías y redujo el riesgo de extinción, pero no logra el crecimiento poblacional por sí solo. Los incrementos a corto plazo en el conteo de nidos (2013-2021), causados posiblemente por los incrementos temporales en la productividad primaria neta, pueden estar ocultando un declive poblacional. Cuando relacionamos la fecundidad con la productividad primaria neta, nuestros modelos retrospectivos pronosticaron correctamente ambas tendencias, a corto y largo plazo. Como consecuencia, nuestros resultados mostraron que la gestión de la conservación debe diversificarse más allá de las medidas aplicadas durante la fase terrestre. Los efectos ocultos que descubrimos tienen implicaciones generales para el monitoreo de las poblaciones de tortugas marinas en otras partes del mundo, lo que demuestra la importancia de la estimación directa de la supervivencia de adultos y que el conteo de nidos podría no refleja correctamente las tendencias poblacionales subyacentes.

A tragedy of the commons case study: modeling the fishers king crab system in Southern Chile.

Illegal fishing in small-scale fisheries is a contentious issue and resists a straightforward interpretation. Particularly, there is little knowledge regarding cooperative interactions between legal and illegal fishers and the potential effects on fisheries arising from these interactions. Taking the Chilean king crab (Lithodes santolla; common name centolla) fishery as a case study, our goal is twofold: (i) to model the effect of illegal-legal fishers' interactions on the fishery and (ii) analyze how management and social behavior affect fishery's outcomes. We framed the analysis of this problem within game theory combined with network theory to represent the architecture of competitive interactions. The fishers' system was set to include registered (legal) fishers and unregistered (illegal) fishers. In the presence of unregistered fishers, legal fishers may decide to cooperate (ignoring the presence of illegal fishers) or defect, which involves becoming a "super fisher" and whitewashing the captures of illegal fishers for a gain. The utility of both players, standard fisher and super fisher depend on the strategy chosen by each of them, as well as on the presence of illegal fishers. The nodes of the network represent the legal fishers (both standard and super fishers) and the links between nodes indicate that these fishers compete for the resource, assumed to be finite and evenly distributed across space. The decision to change (or not) the adopted strategy is modeled considering that fishers are subjected to variable levels of temptation to whitewash the illegal capture and to social pressure to stop doing so. To represent the vital dynamics of the king crab, we propose a model that includes the Allee effect and a term accounting for the crab extraction. We found that the super fisher strategy leads to the decrease of the king crab population under a critical threshold as postulated in the tragedy of the commons hypothesis when there are: (i) high net extraction rates of the network composed of non-competing standard fishers, (ii) high values of the extent of the fishing season, and (iii) high density of illegal fishers. The results suggest that even in the presence of super fishers and illegal fishers, the choice of properly distributed fishing/closure cycles or setting an extraction limit per vessel can prevent the king crab population from falling below a critical threshold. This finding, although controversial, reflects the reality of this fishery that, for decades, has operated under a dynamic in which whitewashing and super fishers have become well established within the system.

Macroalgal blooms affect the food web of tropical coastal ecosystems impacted by fisheries.

Macroalgal bloom events have been frequent in recent years. Eutrophication and overexploitation fishing may favor blooms through nutrient availability and capturing top predators. We aim to investigate the drivers of the macroalgae blooms and their consequences on the food web of the two tropical coastal ecosystems: Porto do Mangue (with high macroalgae production) and Baía Formosa (control environment, without macroalgae), both exploited by artisanal fisheries in northeastern Brazil. The food webs are modeled using the Ecopath with Ecosim (EwE) approach. Our results suggest that fishing did not favor macroalgae blooms but rather the high concentration of nutrients added to the semi-arid conditions. Furthermore, the macroalgae bloom showed low trophic impact, so much of their biomass is transferred into detritus. However, when it decomposes, this accumulation of matter alters the structure and functioning of the ecosystem, affecting its main fish resources: shrimp and piscivorous fish. Investigating blooms is key to management.

Global Fisheries Science Documents Human Impacts on Oceans: The Sea Around Us Serves Civil Society in the Twenty-First Century.

Fishing provides the world with an important component of its food supply, but it also negatively impacts the biodiversity of marine and freshwater ecosystems, especially when industrial fishing is involved. To mitigate these impacts, civil society needs access to fisheries data (i.e., catches and catch-derived indicators of these impacts). Such data, however, must be more comprehensive than the official fisheries statistics supplied to the Food and Agriculture Organization of the United Nations (FAO) by its member countries, which shape public policy in spite of their deficiencies, notably underestimating small-scale fisheries. This article documents the creation, based on the geographically coarse FAO data, of a database and website (https://www.seaaroundus.org) that provides free reconstructed (i.e., corrected) catch data by ecosystem, country, species, gear type, commercial value, etc., to any interested person, along with catch-derived indicators from 1950 to the near present for the entire world.

Differential effect of fisheries to the COVID-19 pandemic in the region of Andalusia (Spain).

Fishing is one of the most widespread and important human activities in coastal ecosystems and it plays a fundamental role in employment and the economy of coastal communities. However, in the period 2020-2021, the global outbreak of COVID-19 negatively affected fishing economic activity. Against this background, Andalusia (South of Spain) is an important region in which the resilience of different fishing exploitation systems can be studied, but within the same social and economic framework. Therefore, the main study aim was to investigate the resilience of fishing activity to the COVID-19 pandemic in two Andalusian fishing grounds (i.e. Atlantic and Mediterranean). We analysed daily landings and the first-sale prices of fresh fish of the most caught species in both fishing grounds, while taking into account the different seasonal behaviour of the fisheries. Generalised Linear Models were used to compare the data, which were obtained during periods in which the COVID-19 severity levels differed. These levels were implemented according to political measures. The final objective was to understand how the degree of industrialisation in the fleets can hinder or help maintain the economic activity of fisheries during major crises.

Fishers' knowledge on a large floodplain river in South America. Contributions for sustainable management of inland fisheries.

This study presents a comparison between fishers' knowledge and fiscal records about the structure of inland fisheries in the Paraná River (Argentina). First of all, we characterized the fishing population according to the main demographic and economic indicators, identifying two different fishing areas: the northern and southern sections in the lower La Plata basin. Secondly, we carried out a comparative analysis of fiscal fishery records (from two commercial sets: 1930-1984 and 2011-2019) and local fishers' knowledge on inland commercial fisheries (frequency of occurrence and abundance). Finally, we contrasted current fishing regulations (allowed meshes and boats, fishing prohibitions, exports) to fishers' effective practices. The study area included 52 sites located along the floodplain of the middle and lower sections of the Paraná River, in the province of Santa Fe. Socioeconomic analyses identified two different groups of fishers throughout the river corridor. Results showed that fishers have detailed knowledge on nomenclature, ecology, reproductive strategy, habitat distribution, and usefulness of commercial fish species. By contrasting fishers' knowledge with fiscal records, we found similar and complementary information about the changes in abundance and frequency of occurrence in fisheries. These results highlight the need of including local knowledge as an outstanding source of information for well-planned management of fishing programs and sustainable policies. Supplementary Information: The online version contains supplementary material available at 10.1007/s11160-022-09722-x.

SELECTIVIDAD DE RED DE ENMALLE PARA CAPTURA DE BOCACHICO (Prochilodus magdalenae, Prochilodontidae) EN LA CIÉNAGA DE ZÁRATE / Gillnet selectivity for catching bocachico (Prochilodus magdalenae, Prochilodontidae) In Zarate Swamp

RESUMEN La estimación precisa de curvas de selectividad de redes de enmalle en una población de peces es un requisito importante para la sostenibilidad de los stocks explotados. Sin embargo, los trabajos de selectividad para artes de pesca que operan en ecosistemas continentales de Colombia son muy escasos. Este estudio determinó los parámetros de selectividad de redes de enmalle utilizadas en la captura del bocachico (Prochilodus magdalenae). El diseño experimental evaluó tres tamaños de malla (5,72; 6,35 y 8,89 cm) y las capturas se realizaron en diferentes sitios de pesca de la ciénaga de Zárate. Con la utilización del método SELECT se estimaron los parámetros de selectividad y mediante un análisis de Kruskall Wallis se determinaron las diferencias en la captura por unidad de esfuerzo. Además, el tamaño de malla óptimo fue calculado a partir del principio de similaridad geométrica de Baranov. Los resultados muestran que el modelo normal con varianza proporcional al tamaño de malla es el que mejor ajuste presentó para la captura de bocachico. Las longitudes modales calculadas con el modelo normal con varianza proporcional al tamaño de malla fueron 22,90, 25,45 y 35,63 cm para tamaños de malla de 5,72, 6,35 y 8,89 cm, respectivamente. El tamaño de malla óptimo calculado fue 6,99 cm. Los resultados indican que las redes con tamaños de malla de 5,72 cm e inferiores tienen un efecto sobre la estructura de tamaños del bocachico. Estas redes requieren ser priorizadas en la formulación de medidas de manejo basadas en la ordenación de este arte de pesca, lo que permitirá la sostenibilidad de la pesquería.

ABSTRACT Accurate estimation of gillnet selectivity curves in a fish population is an important requirement for the sustainability of exploited stocks. However, selectivity studies for fishing gear operating in Colombia's inland ecosystems is very rare. This study determined the gillnet selectivity parameters used in the catch of the bocachico (Prochilodus magdalenae). The experimental design evaluated three mesh sizes (5.72, 6.35 and 8.89 cm) and the catches were made in different fishing sites at the Zárate swamp. With the use of the SELECT method, the selectivity parameters were estimated and the Kruskall Wallis test determined the differences in the catch per unit effort. Furthermore, the optimal mesh size was calculated from Baranov's principle of geometric similarity. The results show that the normal model (scale) presented the best fit for the catch of bocachico. The modal lengths calculated with the normal scale model were 22.90, 25.45, and 35.63 cm for mesh sizes of 5.72, 6.35, and 8.89 cm, respectively. The calculated optimal mesh size was 6.99 cm. The results indicate that nets with mesh sizes of 5.72 cm and lower influences the size structure of the bocachico. These nets need to be prioritized in the formulation of management measures based on the regulation of this fishing gear, which will allow the sustainability of the fishery.

The life history of longnose emperors (Lethrinus olivaceus) and a data-limited assessment of their stock to support fisheries management at Rangiroa Atoll, French Polynesia.

The spawning aggregations of coral reef species support artisanal fisheries throughout the Pacific Islands, but they are vulnerable to overexploitation and need improved fisheries management. To this aim, the authors employed a combination of fishery methods including life-history studies to estimate the age, growth and reproductive parameters of longnose emperor (Lethrinus olivaceus), and a length-based stock assessment to provide the community of Rangiroa Atoll with an assessment of their longnose emperor spawning aggregation fishery. The von Bertalanffy growth parameters of this species were estimated to be L∞  = 80 (75-87) cm TL, K = 0.18 (0.15-0.24), t0  = -0.82 (-1.43-0.27) with a mean natural mortality rate of 0.309 ± 0.038. The sex ratios observed in this study support the belief that this species exhibits functional protogyny with females reaching sexual maturity at 38 cm TL and approximately 3 years of age, and sex change occurring at approximately 45 cm TL and 4 years of age. The spawning potential ratio (SPR) of the longnose emperor stock was estimated to be between 19% and 28% across the years of this study, and simulations of SPR and yield per-recruit indicate that if the community wanted to conserve >30% of the stock's SPR, the ideal minimum size limit for this species is 50 cm TL. The results provide the baseline life-history information required to evaluate the fisheries for this species in the South Pacific region and support community-led management actions for this spawning aggregation fishery on Rangiroa Atoll.

Eco-Efficiency of the Fisheries Value Chains in the Gambia and Mali.

The Gambian and Malian fisheries and fish processing value chains are predominantly artisanal and represent a key source of protein and livelihoods, yet their eco-efficiency has not been studied to date. A Life Cycle Assessment was used to estimate the associated environmental impacts of those value chains and provide information on the eco-efficiency indicators, which relate technical efficiencies to environmental impacts. The results showed that industrial Gambian fleets' fuel use efficiency is rather low as compared with the global mean fuel use intensity (landed fish/consumed fuel) for both small pelagics and demersal fish. In Mali, the fuel use intensity of motorised artisanal fisheries is lower than the mean values for artisanal inland fisheries in developing countries, but the important increase of frozen imported fish from fish farming multiplies the estimated impacts by four. The least energy-intensive fisheries (cast nets and stow nets in Gambia and opportunistic fishers in Mali) feature better eco-efficiency scores. Based on the identified sources of inefficiencies, we suggest improvements in the landing/processing infrastructure and fishing units' engines, coupled with technical and business training and improved processing methods, to ameliorate seafood eco-efficiency and a stronger recognition of the importance of the artisanal fisheries subsector to overcome challenges and improving resource management.

Habitat use and nursery evaluation for the longnose stingray Hypanus guttatus (Bloch & Schneider, 1801) using vertebral microchemistry.

Here, we use vertebral microchemistry to investigate the habitat use patterns of the longnose stingray Hypanus guttatus in the northern and northeastern regions of Brazil, and to evaluate the existence of potential nurseries of the species. Samples were collected in Maranhão, Rio Grande do Norte and Pernambuco states between 2008 and 2019. Trace element concentrations of Ba:Ca, Mg:Ca, Mn:Ca and Sr:Ca in vertebrae were determined through laser ablation inductively coupled plasma mass spectrometry. We used one-step permutational ANOVAs to evaluate multi and single-element differences in element:Ca ratios among life stages and sexes across and within sites. Element signatures differed among all sites for both single and multi-element settings. However, there were few differences among life stages within sites, except for Mn:Ca between life stages for Maranhão state, and between sexes for Sr:Ca for both Pernambuco and Rio Grande do Norte, and Ba:Ca for Rio Grande do Norte. Furthermore, all multi and single-element analyses across locations were significant and highlight the strong differences by sites. We also performed a nonmetric multidimensional scaling analysis, which demonstrated the strong differences for samples from Rio Grande do Norte and the other two sites. By analysing the lifetime transects of each sample, we observed that there was little variation in all element:Ca ratios within sites. Therefore, we argue that the longnose stingray likely does not display extensive habitat use shifts and fulfils much of its life cycle within each area. Finally, we obtained no evidence of nurseries for any site and suggest this is likely a pattern across the species distribution. Future studies investigating habitat use with samples from larger specimens (disc width > 90 cm, >15 years) are needed to better understand the species habitat use patterns across all size ranges.

Predicting potential compliance of small-scale fishers in Brazil: The need to increase trust to achieve fisheries management goals.

Many global management and conservation initiatives fail to prevent overfishing either because they do not plan for local engagement, surveillance, and enforcement, and/or because they fail to include alternatives for short-term losses. Thus, these initiatives do not gain support among fishers. In this study, we interviewed fishers to investigate their stated behavior toward fisheries regulations. We assessed possible (non)compliant behavior under scenarios where fishers would face a moratorium on some of their target species. Additionally, we investigated the consequences of such a moratorium on the food web if it were to lead to fishing alternative species. Using data from two Brazilian coastal sites, we found that younger fishers and those who demonstrated a trustworthy relationship with stakeholders were inclined to comply with the rules. The level of potential compliance also varied between the studied places, probably due to unidentified local idiosyncrasies. Fishers tended to trust community actors (e.g., the leader or head of the fishing community) more than institutional actors (e.g., environmental agencies). When fishers were asked why they would choose specific replacement species in the event of a moratorium, they most often cited expected profitability and ease of capture as reasons. Fishers also tended to say that they would replace endangered species with species in the same and/or lower trophic categories. We suggest working toward stronger stakeholder engagement, given that an overall sense of trust in a community appears to be an important asset toward successful management. Higher levels of trust could promote more transparency in the decision-making process, which could facilitate information dissemination, awareness, and the need for compliance. The mixed methods approach used here could help predict responses to new and existing management policies and support adaptive fisheries management.

Growth Modeling of the Giant Electric Ray Narcine entemedor in the Southern Gulf of California: Analyzing the Uncertainty of Three Data Sets.

The age and growth rate of the giant electric ray, Narcine entemedor, was estimated using growth bands deposited in the vertebral centra of 245 specimens. Differences in size and age distribution were found between the sexes, a pattern that suggests the annual deposition of band pairs, possibly occurring in April. Multimodel inference and back-calculation were performed to three age data sets of females considering their reproductive cycle and time of capture, among which the von Bertalanffy growth function was found to be the most appropriate (L∞ = 81.87 cm TL, k = 0.17 year-1). Our research supports the idea that age can be determined via biological features such as birth date and growth band periodicity. We concluded that N. entemedor is of a moderate body size, moderate longevity and is a fast-growing elasmobranch species.

Consequences of calamities and their management: The case of COVID-19 pandemic and flooding on inland capture fisheries in Kenya.

During the period February to June 2020, heavy rainfall caused increases in levels and flooding in many lakes in East Africa. This coincided with the COVID-19 pandemic. These calamities affected ecosystems and livelihoods, especially of fishers who depend on fisheries as their only source of livelihood. This study examined the effects of COVID-19 and flooding on the major inland capture fisheries in Kenya to illustrate the effect of such calamities on vulnerable communities to guide interventions. Socioeconomic data were collected across the fish value chains during the peak of COVID-19 pandemic and flooding in Kenya from May to early June 2020. The measures put in place to contain COVID-19 pandemic notably dusk to dawn curfew (66%) and lock-downs (28%) in major cities that act as main fish markets were cited as the main factors that influenced fishing and fishing trade. Negative consequences reported included livelihood losses from the COVID-19 pandemic. Reduced fishing time and trips as well as a decline in consumables such as boat fuel resulted in low fish catches. Although COVID-19 pandemic affected livelihoods, the fish stocks benefited from reduction in fishing effort. Similarly flooding led to livelihood and material losses but positively impacted on stocks through expansion of fish breeding and nursery areas. The respondents recommended that governments should have disaster preparedness programs in place to address such calamities. There is also need for more detailed research on calamities that are increasing in frequency to provide information and data to guide policy and interventions.

Mercury dynamics in macroinvertebrates in relation to environmental factors in a highly impacted tropical estuary: Buenaventura Bay, Colombian Pacific.

The environmental health of Buenaventura Bay, a highly impacted tropical estuary, is influenced by numerous human activities, including mining upstream. Large- and small-scale fishing plays an important role in the local economy, so we investigated the dynamic processes of bioaccumulation of mercury at basal trophic levels. Four samples were taken at each of the four locations in Buenaventura Bay during each of the four seasons of 2015. We measured the total mercury content (T-Hg, dry weight) in sediments and in muscle tissue across 17 macroinvertebrate species. The most abundant were the blue crab (C. arcuatus) and the mantis shrimp (S. aculeata aculeata). Blue crab showed an average muscle T-Hg value ​​exceeding the limit of 0.2 g·g-1, which is the maximum T-Hg level suggested for food consumption by vulnerable humans and populations: pregnant women, children, and the community that feeds from this source of protein on a daily basis. It was found that, 6.22% of individuals exceeded the 0.5 g·g-1 level, which is the maximum T-Hg level suggested for food consumption by the general population: the population that consumes it sporadically. Significantly high values ​​of T-Hg in blue crab and mantis shrimp occurred during low salinity conditions in the estuary, suggesting that Hg mainly originates from river runoff during the rainy season. Nevertheless, the biota-sediment accumulation factor (BSAF) was favored in high salinity, which could mean greater availability of Hg for higher levels of the estuarine food web in the dry season and in marine waters. In general, the T-Hg levels in some samples exceeded 0.2 g·g-1. Therefore this pollutant must be monitored due to its biomagnification potential and as a threat to human health, especially that for the local population of fishermen and their families.