Search Results (117)

Small pelagic fish, including sardines, are essential to global fisheries and aquaculture feed production. However, these species are increasingly exposed to intense exploitation. In Chile, the common sardine (Strangomera bentincki), endemic to the Humboldt Current System, supports major industrial and artisanal fisheries. Landings are expected to reach 300,000 tons by 2025, mostly for fishmeal production. As a keystone species, S. bentincki is highly sensitive to environmental variability during early development, which can reduce recruitment and threaten long-term population sustainability. This interdisciplinary approach integrates ecological and biotechnological perspectives to assess the feasibility of controlled juvenile sardine production in land-based Ecological Aquaculture (EA) systems, including Recirculating Aquaculture Systems (RAS) and Integrated Multi-Trophic Aquaculture (IMTA), which are designed to reduce environmental impacts. These systems enable precise control of temperature, feeding regimes, and water quality, facilitating investigations into larval and juvenile survival, growth performance, and physiological responses under variable thermal and nutritional conditions. Emphasis is placed on fatty acid metabolism during ontogeny, particularly docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), which are essential for somatic growth, reproductive development, and thermal tolerance. Developing standardized protocols for juvenile S. bentincki culture addresses key gaps in husbandry and physiology (temperature threshold, nutrient density, larval growth rate, etc.) while introducing a novel ecological–aquaculture integration framework. This approach links early-life ecology with applied rearing techniques to support stock enhancement, strengthen artisanal fisheries, and promote sustainable aquaculture diversification under increasing environmental variability. Full article

Mangrove ecosystems underpin coastal livelihoods and biodiversity in Mozambique, yet gendered patterns of resource use and their implications for management remain underexplored. This study explores how artisanal fishing and shellfish collection differ between men and women on Inhaca Island (Maputo Bay), focusing on how these gender-specific practices shape livelihood outcomes, spatial use of mangroves, and perceptions of ecological change. To address this question, we combined structured interviews (n = 35; 51.4% men, 48.6% women) and camera-trap monitoring in two mangrove areas during September 2024 to document fishing practices, catch characteristics, spatial patterns, and ecological perceptions. We found pronounced gendered divisions of labor and space use: men, using boats and nets, harvested a median of 15 kg of fish per day for commercial sale, generating cash income, whereas women collected a median of 3 kg of shellfish by hand, primarily for household consumption. Camera traps confirmed pronounced spatial segregation in mangrove use: women foraged in targeted areas, and men traversed broader zones, both synchronizing their activities with tidal and daylight cycles. By integrating social and ecological data, the study revealed nuanced gender roles and resource pressures, with 82.9% of participants reporting declines in fish and shellfish stocks, emphasizing mangroves’ critical role in livelihoods, biodiversity, and climate resilience. Our findings highlight the value of mixed-method approaches for understanding socio-ecological dynamics and advocate for gender-sensitive conservation policies, strengthened Community Fisheries Councils, and infrastructure investments to regulate resource use, enhance mangrove management, and promote equitable livelihoods in Mozambique’s coastal communities. Full article

The speckled smooth-hound Mustelus mento is an endemic coastal shark from the southeastern Pacific, currently listed as “Critically Endangered” due to intense fishing pressure and the absence of species-specific management across its distribution range. Between November 2021 and October 2023, 925 individuals were examined from artisanal landings in northern Chile to describe their reproductive biology and embryonic development characteristics. The total length ranged from 27.6–159.3 cm in females and 14.2–165.0 cm in males, with a sex ratio of 1:1.2, which was slightly biased towards females. The estimated size at 50% maturity was 53.6 cm for females and 48.7 cm for males, with 70.6% of females and 66.0% of males caught below these thresholds, indicating a predominance of immature individuals in landings. Nine gravid females (106–139 cm) contained 71 embryos, which were classified into five developmental stages (encapsulated ovum, early organogenesis, fin differentiation, pigmentation and growth, and pre-partum) based on their external morphology and yolk sac reduction. The litter size ranged from 4 to 12 embryos, and the estimated size at birth was 13–14 cm in length. Embryos were recorded only during the summer months, suggesting a seasonal reproductive cycle with parturition in the early autumn. The persistent yolk sac connection throughout development and the absence of placental structures confirm that M. mento exhibits aplacental viviparity. These results document the first population-level description of the reproductive biology of M. mento, redefine its reproductive mode, and provide baseline information essential for implementing species-specific management and conservation measures in Chilean waters. Full article

Issues related to malnutrition are addressed primarily through the consumption of fish meat, as it is both affordable and accessible to economically weaker sections of the population. Therefore, challenges observed in the aquaculture and fishery sectors, such as the detection of environmental changes, disease outbreaks, hindered growth, and poor fish health management, need to be addressed to increase production. The employment of modern technologies, such as (bio)sensors, helps to enhance production in artisanal and large aquaculture systems, because these can timely detect challenges, including climate change factors, sea-level-rise-induced salinity load, changes in inland temperatures, ocean acidification, changes in precipitation patterns, ammonia toxicity, infectious diseases, and stress factors in aquatic systems. As a result, appropriate and timely measures can be taken at various stages of fish culture to address common problems. Using major scientific electronic databases, we comprehensively reviewed the topic of emerging needs, expanding applications, and recent technological advances in biosensors, with a particular focus on pisciculture. We highlight the biosensor technology used in the fisheries industry, which represents a pivotal step towards addressing its various aspects. Full article

Toxic Shock Syndrome Toxin-1 (TSST-1) is produced by Staphylococcus aureus strains encoded by the tst gene. Toxic shock syndrome (TSS) is a severe disease caused by TSST-1 toxin and associated with staphylococcal food poisoning (SFP). The aim of the present review was to present data on the occurrence of S. aureus TSST-1 in foods published in various countries. PCR-based assays are most frequently used for the detection of S. aureus TSST-1 in foods. S. aureus TSST-1 is predominantly detected in foods of animal origin. The highest occurrence has been observed in mastitic ruminants’ milk, indicating that mastitis is a risk of milk contamination with the pathogen. High occurrence rates of S. aureus TSST-1 have also been identified in raw milk and artisanal cheeses. Various occurrence levels have also been reported in beef, pork, lamb, and chicken meat. Low occurrence levels have also been reported for fish or other seafood products. The tst gene was also found in combination with other toxigenic genes in S. aureus TSST-1 isolates (e.g., MRSA or Panton-Valentine Leukocidin, PVL). Monitoring S. aureus TSST-1 in food is important for public health because food can be a vehicle for transmitting the antibiotic-resistant pathogen to humans. Full article

Punta Carola beach, located on San Cristóbal Island in the Galápagos Archipelago, exemplifies how island environments of recent human settlement can rapidly acquire cultural significance. Drawing on a survey of 201 residents, this study examines perceptions of the ecosystem services provided by Punta Carola, their relationship to subjective wellbeing, and attitudes toward alternative tourism and governance strategies. The findings reveal that the inhabitants of San Cristóbal recognize a wide range of tangible and intangible benefits that the natural environment of Punta Carola contributes to their quality of life, sense of belonging, and cultural identity, as well as recreational and aesthetic values. Life satisfaction was positively associated with perceptions of nature’s contribution, the maintenance of local ecological knowledge, and household income, while formal education correlated negatively. Residents identified freshwater and artisanal fishing as the most critical ecosystem services, reflecting their centrality to local livelihoods and wellbeing. The results also underscore widespread criticism of large-scale tourism projects perceived as exclusionary or unsustainable and highlight the importance of participatory governance schemes that legitimize local values. Punta Carola thus emerges as a “cultural landscape of resistance”, where external pressures catalyze identity construction and territorial rootedness. This case contributes to academic debates on socio-ecological resilience in fragile island contexts and offers actionable insights for inclusive planning in the Galápagos. Full article

In southern Chile, harmful algal blooms (HABs) pose a threat to public health, artisanal fisheries, and the aquaculture industry (mussels and salmon). However, little is known about the environmental factors contributing to outbreaks of HABs in fjord systems. In summer 2017, an oceanographic cruise was carried out to study the physical processes associated with a bloom of the dinoflagellate Karenia spp. in the Gulf of Penas and Taitao Peninsula, Chilean Patagonia, causing a massive mortality of salmon (approximately 170,000 fish, worth USD 390,000). Satellite images from Sentinel-3 were utilized to distinguish between areas with high and low densities of Karenia cells. Cell densities were highest in the waters of the northern Taitao Peninsula (70 × 10³ cells L⁻¹), and lowest at the Gulf of Penas. Support vector classification (SVC) based on bands 1 (400 nm), 2 (412.5 nm), and 6 (560 nm) from the Sentinel-3 images and the normalized fluorescence line height (FLH) classified bloom presence/absence with an 83% coincidence rate. The SVC model correctly identified non-bloom areas, with limited false positives, and successfully captured bloom zones where Karenia densities were highest. These results demonstrate the importance of incorporating satellite tools in the design and implementation of monitoring programs for the early detection of HABs, particularly in remote, difficult-to-access areas. Full article

Catsharks are benthic elasmobranchs that share spatial niches with littoral and demersal bony fishes. The genus Schroederichthys includes five species, two of which, S. chilensis and S. bivius, occur in the waters of Chile. These species are morphologically similar and are often misidentified because of their overlapping external features and color patterns. To improve species discrimination, we analyzed the egg case morphology of both species based on 36 egg cases (12 S. chilensis, 24 S. bivius) collected from gravid females captured as bycatch in artisanal fisheries between Iquique and Puerto Montt (July–December 2021). Nine morphometric variables were measured and standardized using the total egg case length. Although the egg cases were similar in general appearance, multivariate analyses revealed significant interspecific differences, with egg case height and anterior border width emerging as the most diagnostic variables. Linear discriminant analysis achieved a 100% classification accuracy within this dataset. To confirm species identity, 24 tissue samples (12 per species) were sequenced for the mitochondrial cytochrome c oxidase subunit I (COI) gene. The haplotypes corresponded to previously published sequences from Chile (S. chilensis) and Argentina (S. bivius), with reciprocal monophyly and 100% bootstrap support. While COI barcoding provided robust confirmation, the core contribution of this study lies in the identification of species-specific egg case morphometrics. Together, these findings establish a dual-track toolkit, egg case morphology for primary discrimination and COI barcodes for confirmatory validation, that can be incorporated into bycatch monitoring and biodiversity assessments, supporting the conservation of poorly known catsharks in the Southeast Pacific. Full article

Mercury (Hg) pollution from artisanal and small-scale gold mining (ASGM) is a global environmental and public health concern. In Indonesia, ASGM remains widespread, yet assessments of multimedia contamination and health risks are limited. This study quantified Hg concentration in water, sediment, soil, fish, and cassava to evaluate environmental pollution and potential health risks in Waluran, Sukabumi, Indonesia. Mercury concentration in ASGM was higher than in the reference area, especially in fish (median: 4.76 mg/kg dw), cassava leaves (median: 15.7 mg/kg dw), and tailing sediments (median: 171 mg/kg dw). A remarkably high Hg concentration (9760 mg/kg dw) was detected in soil from amalgam-burning spots. An elevated Hg concentration was observed in the reference area, suggesting widespread contamination and potential for long-range dispersion. Over 85% of ASGM samples were categorized as heavily to extremely contaminated by the geo-accumulation index (I_geo). Bioaccumulation assessment indicated a high bioconcentration factor (BCF) in fish and moderate bioaccumulation factor (BAF) in cassava roots. Hazard Quotients (HQ) were greater than 1 for most exposure pathways in both adults and children, with the greatest risk deriving from cassava leaf consumption. These findings indicate severe Hg contamination within ASGM-affected communities and underscore the urgent need for public health interventions, environmental monitoring, and strengthened regulations to reduce Hg exposure in Indonesia. Full article

Artisanal fishing is a central pillar of the Angolan economy, particularly in the southern province of Namibe, where it serves as the primary economic activity for numerous coastal communities. However, these communities face significant challenges, including competition from expanding industrial fisheries and inadequate infrastructure at fishing centers, which hampers the storage, preservation, and transportation of catches. These limitations contribute to post-harvest losses and the reduced market value of products, despite the region’s rich diversity of pelagic and demersal resources. This study evaluated the economic viability of artisanal fishing in Namibe under three production scenarios, varying in catch levels and the inclusion of fish processing activities such as dried fish and fishmeal production. Scenario A (pessimistic) assumed a 10% reduction in production compared to the best estimates; Scenario B (intermediate) was based on average reported catches; and Scenario C (optimistic) considered a 10% increase in catches, accounting for seasonal and environmental variability. Results indicated that artisanal fishing was economically viable under all scenarios, with the Internal Rate of Return (IRR) consistently exceeding the Minimum Attractive Rate of Return (MARR) of 7.5%. IRR values ranged from 34.30% (Scenario A, without by-product commercialization) to 106.28% (Scenario C, with dried fish and fishmeal production and sales), representing a more than threefold increase in profitability. This substantial gain underscores the transformative potential of processing by-products into higher-value commodities, enabling integration into larger-scale and more liquid markets. Such value addition supports the concept of a proximity economy by promoting short production cycles, reducing intermediaries, and strengthening local value chains. Beyond financial returns, the findings suggest broader socioeconomic benefits, including local economic growth, job creation, and the preservation of traditional production knowledge. The payback period was less than four years in all cases, decreasing to 1.94 years in the most favorable scenario. By-products such as dried fish and fishmeal exhibit commodity-like characteristics due to their higher commercial value, increasing demand, and potential integration into regional and animal feed markets. In conclusion, diversifying marketing strategies and maximizing the use of fish resources can significantly enhance the economic sustainability of artisanal fishing, foster socioeconomic inclusion, and support the development of artisanal fishing communities in Namibe. Full article

Bigeye grunt (Brachydeuterus auritus) is a dominant fish species and mostly a major target species in both artisanal and industrial fisheries in the coastal waters of Sierra Leone. It was listed as near threatened in 2015 by the International Union for Conservation of Nature (IUCN) Red List. Although this species has been repeatedly assessed as overexploited by the Fishery Committee for the Eastern Central Atlantic (CECAF) in the majority of its range in the Eastern Central Atlantic, there have never been studies of stock assessment in the coastal waters of Sierra Leone. We conducted a study on the population dynamics of bigeye grunt in the coastal waters of Sierra Leone, which is crucial for completing the resource status of this species in the Eastern Central Atlantic. The results showed that the bigeye grunt had a wide distribution in the coastal waters of Sierra Leone, with significant spatiotemporal variation characteristics in biomass and abundance. The growth parameters of bigeye grunt varied across different months, but all E values were below 0.5, indicating that no overfishing occurred. These findings were further corroborated by the results of the Length-Based Bayesian Biomass Estimation method (LBB). The results of the Generalized Additive Model (GAM) show that there is a certain nonlinear relationship between the resource abundance of the bigeye grunt and both environmental factors and geographical locations, among which the influence of latitude is the greatest. This study posits that the bigeye grunt in Sierra Leone’s coastal waters exhibits moderate exploitation potential. The findings are anticipated to provide a scientific framework for informing evidence-based management strategies for this fishery resource. Full article

Elasmobranch species are considered a global conservation priority due to their susceptibility to fishing pressure. In the Madeira Archipelago, Northeastern Atlantic, most elasmobranch species are caught as bycatch in artisanal drifting longline fishery targeting scabbardfishes. All commercial elasmobranch landings carried out in this archipelago over three decades (1990–2020) were analysed, aiming to provide a reliable overview of Madeira’s elasmobranch fisheries and their evolution. A total of 2316 tonnes of elasmobranchs were landed during the study period, corresponding to approximately EUR 2.1 million in first-sale value. The most representative period occurred from 2003 to 2013, corresponding to 75.21% of the total elasmobranch landings. A general pattern of supply and demand was evident, with mean price values typically showing an inverse trend to landed tonnage. At the species level, Centrophorus squamosus appears as the dominant species, representing about 89% of the total elasmobranch species landed, followed by Prionace glauca, with approximately 3%. The high dominance of C. squamosus in the scabbardfish fishery raises significant ecological and management concerns, as this deep-water shark species is known for its vulnerability to overexploitation. Management measures currently in place need to be updated and ought to be based on studies on the type and size of hooks for each fishery, to ultimately infer about species-specific survival rates, as well as the fishing gears’ soak time. Moreover, studies on the enhancement of food supply through fisheries discards are still missing, even though it is highly likely that this input may alter the dynamics of marine food webs. Full article

Addressing environmental challenges requires the inclusion of local communities with relevant knowledge of the social–ecological system in which they are embedded, in addition to using transdisciplinary approaches that are critical to the co-production of successful and sustainable environmental solutions. A qualitative methodology was used to examine stakeholders’ views of decadal changes in Ria de Aveiro, a coastal lagoon on Portugal’s Atlantic coast. Seven focus groups were conducted, which included 42 stakeholders from coastal parishes, in order to obtain identical geographical representation with a study conducted a decade ago. Participants represented a diverse sample of groups interested in or affected by management options and activities in the lagoon system and were asked to reflect on the main changes that occurred over the last decade. Positive changes reflected an increase in the levels of environmental awareness, a positive trajectory of the environmental status of Ria de Aveiro, and a decrease in illegal fishing activities. Persisting concerns referred to the lack of an efficient management body for Ria de Aveiro, pressures related to changes in the hydrodynamic regime of the lagoon, the disappearance of native species and increase in invasive alien species, the abandonment of traditional activities (e.g., harvesting of seagrass and seaweed, salt production, agriculture in lagoon margins, and artisanal fishing), and the degradation and lack of maintenance of salt pans. Our findings highlight the importance of longer-term transdisciplinary and social–ecological research and illustrate how stakeholder views regarding the shortfalls of the movement towards the integrated management of ecosystems remain. Full article

Artisanal small-scale gold mining (ASGM) is the largest source of global mercury (Hg) emissions. This study investigated Hg contamination in water, soil, sediment, fish, and cassava plants around ASGM sites in Gunung Pongkor, West Java, Indonesia. Hg concentration ranged from 0.06 to 4.49 µg/L in water; 0.420 to 144 mg/kg dw in soil; 0.920 to 150 mg/kg dw in sediment; 0.259 to 1.23 mg/kg dw in fish; 0.097 to 5.09 mg/kg dw in cassava root; and 0.350 to 8.84 mg/kg dw in cassava leaf. Geo-accumulation index (Igeo) analysis revealed moderate to heavy soil contamination upstream, likely due to direct ASGM input. In contrast, sediment Igeo values indicated heavy contamination downstream, suggesting Hg transport and sedimentation. Bioconcentration factors (BCFs) in fish were predominantly high in downstream and midstream areas, indicating enhanced Hg bioavailability. Bioaccumulation factors (BAFs) in cassava were higher in upstream areas. Health risk assessment, based on the Hazard Quotient (HQ) and Hazard Index (HI), identified ingestion as the primary exposure route, with children exhibiting significantly higher risks than adults. These findings highlight the significant Hg contamination associated with ASGM in Gunung Pongkor and emphasize the need for targeted mitigation strategies to protect human and environmental health. Full article

Small pelagic fishes such as Sardinella aurita (Valenciennes, 1847) and Sardinella maderensis (R. T. Lowe, 1838) are key intermediate-level components of the marine food web of the southwestern African coast. Their biomass off Angola has shown significant interannual variability, and information about their reproduction is insufficient in the region for adequate stock management. Thus, we aimed to unveil the reproduction period and reproductive traits of these two Sardinella species and establish a link with the prevailing ocean temperature conditions. Adult fish samples were obtained monthly from artisanal and semi-industrial fleets, and the ichthyoplankton samples were collected with a Hydro-Bios Multinet off southwest Angola by Instituto Nacional de Investigação Pesqueira (Angola). The macroscopic inspection of gonads showed that females of both species were more abundant than males. The gonadosomatic index and maturity stages indicate that S. aurita spawns during the Austral summer (December through March), while S. maderensis has a longer spawning period, from October to April. The spawning peak occurs in February for S. aurita and S. maderensis. The mean monthly condition factor of both species was high before and after spawning seasons. The females of S. aurita reach sexual maturity at a smaller size than males, and 50% of the population reaches sexual maturity at a total length of 31.3 cm. The males of S. maderensis reach sexual maturity at a smaller size than females, and 50% of the population reaches sexual maturity at a total length of 28.4 cm. We also found that both species use the southern coast of Angola as a spawning area during the Austral summer and avoid the area during periods of intense upwelling. Currently, these species are managed as a single unit, and the minimum capture size is set at 22 cm, well below the size at sexual maturity registered in the study area. Therefore, we strongly recommend increasing the minimum capture size to guarantee long-term stock viability. Full article