Fish diversity and functional diversity of the catches from gillnet fisheries of the Chao Phraya River (CPR) and the Bang Pakong River (BPR) in the central of Thailand were analyzed, using the monitoring data from 2010 to 2023 and 2007 to 2023, respectively. The study focuses on the inter-annual assessment of fish community dynamics at the whole-river scale, which aims to provide essential insights for the sustainable management of both rivers. Long- and short-term variations as well as the stress of fish assemblages were also assessed. A total of 93,998 individual fish were recorded from 121 species in the CPR, and 108 species in the BPR, in which the species from family Cyprinidae were most diverse in both rivers. Both rivers exhibited substantial species diversity and functional trait diversity, with the CPR generally supporting higher abundance and diversity indices than the BPR. The long-term variation indicated that most species were stable in the catches. Meanwhile short-term variations were influent by fishing pressure year by year. Abundance-biomass comparisons revealed that the fish assemblages in both rivers were minimal disturbance, except for occasional specific years, suggesting localized or temporal stress events. Overall, results indicate that fish assemblages in both the CPR and BPR remain largely intact, with functional diversity contributing to ecosystem resilience despite high fishing pressure and other ongoing anthropogenic influences.

The Chilean jack mackerel (Trachurus murphyi) is an economically important pelagic fish widely distributed across the South Pacific Ocean. Due to intense fishing pressure and the lack of high-quality genomic resources, the development of sustainable fisheries management strategies has been hindered. Here, we present a highly contiguous chromosome-level genome assembly of T. murphyi using PacBio and Hi-C sequencing data. The assembled genome spans 818.31 Mb, with a contig N50 length of 24.89 Mb and a scaffold N50 length of 34.34 Mb. The assembly is anchored on 24 pseudo-chromosomes, covering 95.80% of the genome. BUSCO analysis indicates a high level of completeness at 99.0%. Telomeric repeat motifs were detected at 12 single chromosome ends, whereas putative centromeric regions were identified on 12 chromosomes. Repetitive sequences account for 23.86% of the total genome, and 47,734 protein-coding genes were annotated, 90.98% of them with assigned function. This high-quality genome assembly serves as a valuable resource for studying the genetic diversity and population structure of the Chilean jack mackerel and provides a solid foundation for future management and conservation efforts.

Into new depths: climate-driven habitat expansion of the endangered skate Dipturus chilensis (Chondrichthyes, Rajiformes).

ABSTRACTBycatch is the accidental capture of non‐target animals in fishing gear, and is a critical threat to many wildlife populations, impeding recovery and conservation efforts. Northwest Africa hosts a significant population of loggerhead turtles (Caretta caretta), particularly around Cabo Verde, which is among the world's top three largest loggerhead turtle nesting colonies. However, high‐risk areas for turtle bycatch have not yet been comprehensively investigated. This study addressed this by analysing biologging data from loggerhead turtles (n = 26), quantifying their spatial and vertical overlap with fishing in the Northeast Atlantic. Results revealed extensive overlap of loggerhead turtles with fishing across seven countries, with particularly intense overlap in Cabo Verde, Senegal and Mauritania. Turtles also generally occupied the same depths as fishing gear, intensifying bycatch risk. Among fishing methods, trawling showed the greatest overlap with loggerhead turtles, and current protections appear to align poorly with our predictions of bycatch risk. Coupled with increasing fishing pressure, these findings highlight the need for strengthened conservation measures. These include gear modifications such as turtle excluder devices, as well as time and space‐based fisheries management strategies. Going forward, improved bycatch reporting and monitoring across all fisheries sectors will be essential to expand upon these findings.

Abalone is a highly valued marine gastropod with a declining wild population due to increased fishing pressure. To meet market demand, there is growing interest in the cage culture of abalone juveniles. However, the most commonly used substrate in cage culture, polyvinyl chloride (PVC), has been linked to environmental and health risks. This study examined the efficacy of bamboo as an alternative substrate for the bottom and suspended cage culture of tropical abalone Haliotis asinina Linnaeus, 1758. Two culture experiments were conducted using (1) sea bottom cages and (2) suspended sea cages in Binduyan, Puerto Princesa City, and Pamantolon, Taytay, Palawan, respectively. Abalone juveniles grown with bamboo substrate (BS) had significantly higher weight gain, specific growth rate, and shell length growth rate compared to those reared with PVC substrate (PS) (P < 0.05). In addition, after 90 days and 150 days of culture, abalone juveniles on BS exhibited positive allometric growth compared to those on PS, which showed isometric growth. Moreover, the survival rates of abalone juveniles with BS were not significantly different from those with PS at P < 0.05. These findings suggest that BS is a viable alternative to PS for abalone juvenile culture, as it is indigenous, inexpensive, and environmentally friendly. The study's results can promote sustainable aquaculture practices for abalone while raising awareness of the potential environmental and health risks associated with PVC for cultured abalone and humans consuming cultured abalone.

Defined as the controlled breeding and rearing of aquatic organisms, conservation aquaculture has emerged as a strategy to support the management and conservation of natural resources. This study provides a comprehensive review of the literature on the subject, covering articles published between 1990 and 2025. Conservation aquaculture can be classified into three categories. The first, enhance , involves the restocking of populations at risk of extinction and encompasses strategies such as restocking, stock enhancement, and sea ranching. The second, restore , focuses on the recovery of native habitats through the use of cultivated species with key roles in environmental stability. Finally, replace refers to supplementing market demand with cultured organisms, thereby compensating for the removal from wild stocks, reducing fishing pressure, and contributing to the long-term sustainability of natural populations. The findings suggest that conservation aquaculture cannot be regarded as a universal solution to population declines and should be applied cautiously, preferably as a last resort, due to its considerable economic demands and potential ecological risks. Among the strategies evaluated, replace emerges as the most promising approach for mitigating the impacts of extractive fisheries. The development of standardized metrics and operational guidelines is strongly recommended to guide future interventions and improve the effectiveness of aquatic biodiversity conservation. • Conservation outcomes of fish restocking programs are examined • Ecological roles of released species in enhancement initiatives are discussed • Case studies from marine and freshwater systems are reviewed • Ecological risks associated with species releases are highlighted • Monitoring and governance challenges in restocking programs are analyzed

Intense fishing pressure can drive rapid evolution in wild populations, yet the underlying genomic mechanisms often remain elusive. Here, we investigate the genomic consequences of five decades of intense harvesting on the cichlid fish Copadichromis mloto in Lake Malombe, Malawi. By comparing whole-genome data from almost 200 individuals from the heavily fished Lake Malombe with less-fished populations in Lake Malawi, we identified a widespread signal of recent, population-specific positive selection. This genomic footprint, spanning hundreds of loci, is consistent with a rapid, polygenic adaptive response. The candidate genes under selection were significantly enriched for high-level developmental processes, including neurogenesis and the formation of the heart and muscle, providing a plausible mechanistic link to the dramatic reduction in size and age at maturity observed in this population. Furthermore, our strongest candidate loci include genes with known roles in controlling somatic growth (zdhhc13, myh7, csrp3, gnb1l) and reproductive timing (mpped2a, kitlga, kat6a, stra6). We also found that candidate genes were nearly five-fold more likely to be differentially expressed in male gonad tissue, providing a strong link between selection and regulatory changes in a key reproductive organ. Our findings point towards a polygenic basis for fisheries-induced evolution in this tropical system and highlight how intense harvesting can rapidly reshape the genetic architecture of complex life-history traits, with important implications for the long-term resilience of exploited fish stocks.

Ecological function of the Ariake Bay as a scalloped hammerhead shark (Sphyrna lewini) nursery in the northwestern Pacific

Larimichthys polyactis is a transboundary migratory fish species targeted intensively by fisheries in China, Japan and South Korea, and it is currently subjected to substantial fishing pressure. Clarifying population delineation is critical for the sustainable management of overexploited fish stocks such as this species. For skeletal phenotypic analysis, we collected 30 adult specimens from each of six sampling stations in the Southern Yellow Sea and East China Sea during 2017-2018. Discriminant analysis cross-validation yielded an average classification success rate of 74%. Canonical variate and cluster analyses further divided the populations into four distinct units: Group I (West Coast of Korea Group), an independent cluster from the Yellow Sea offshore station; Group II (Northern Yellow-Bohai Group: Haizhou Bay); Group III (Southern Yellow Sea: Yancheng and Lusi); and Group IV (East China Sea: Zhoushan and Xiangshan). Thin-plate spline analysis revealed that L. polyactis from the Southern Yellow Sea exhibited a lower head height and shorter spine length. In contrast, the East China Sea population displayed a higher head height and longer spine length, exhibiting the streamlined morphological characteristics of a "smaller head, slender body". This study provides evidence for the reliability of skeletal morphology in delineating the population structure of L. polyactis. Knowledge of this population structure contributes to resource assessment and effective fishery management.

The Goldblotch Grouper (Epinephelus costae) is listed as “Data Deficient” by the IUCN, yet it faces intense fishing pressure across the Eastern Mediterranean. In Syria, more than a decade of conflict has dismantled fisheries monitoring infrastructure, leaving managers without essential biological parameters for evidence-based conservation. Traditional methods for age and maturity assessment are destructive, require specialized laboratories, and are infeasible in post-conflict settings. To address this gap, this study presents the first non-destructive artificial neural network (ANN) model to simultaneously estimate age and maturity status using total length as the sole input. The model was trained exclusively on 150 specimens collected from six Syrian coastal sites, Ras al-Bassit to Tartous, during a 12-month period from March 2024 to March 2025. Age was determined by scale reading, and maturity status was assessed by macroscopic examination of gonads after dissection, revealing a contemporary length-at-first-maturity (Lm = 30 cm) in Syrian waters. The feedforward multilayer perceptron (MLP) architecture (1–10–2) achieved high predictive accuracy, with a Pearson’s correlation coefficient of R = 0.9995 for age estimation (MSE = 0.0091 on the test set), and 100% maturity classification accuracy on the current independent test subset. However, real-world performance may vary in other populations. Our dataset includes individuals up to 74.3 cm and 12 years old, which are substantially larger and older than those reported in recent studies from neighboring regions. This underscores the value of targeted sampling methods, such as speargun, in accessing cryptic, large-bodied spawners. This ANN-based tool provides the first rapid, non-destructive, and field-applicable method for estimating population structure of E. costae under data-poor, conflict-affected conditions. By requiring only a length measurement, it offers a potential pathway for real-time decision support in data-poor contexts, supporting science-informed management where traditional monitoring systems have collapsed.

The Eastern Tropical Pacific (ETP) Spotted Eagle Ray, Aetobatus laticeps Gill, 1865, is an understudied species with limited information on its ecology and conservation status. Only in the last 10 years has this lineage been re-described as a distinct species from the formerly widespread Aetobatus narinari species complex (Euphrasen, 1790) (ANSC). The sampling in the studies that divided the ANSC was not geographically balanced, with most individuals (50) collected from the Atlantic and only (5) from the ETP. Given the vast extent and environmental heterogeneity of this region, it is possible that a significant portion of the genus’s genetic variation, and possibly even the presence of undescribed species, is being overlooked. Because eagle rays have relatively low fecundity and are subject to targeted and incidental fisheries, they are highly susceptible to population declines. Consequently, elucidating the genetic diversity, distribution range, genetic variability and interconnectivity of this species is crucial to assess its conservation status correctly. Through a mixed genetic marker approach, we assessed ETP eagle rays’ phylogeny, genetic diversity and phylogeography. First, we confirmed that eagle rays in this region correspond to A. laticeps. Second, we found low levels of genetic variability across all markers, coupled with a high degree of geographic-genetic structure. Finally, our data suggested three potential mechanisms that could explain the population structure we encountered: a) Isolation by distance b) Isolation by philopatry, and c) Isolation by depth. To date, this is the first comprehensive study of the genetic diversity of eagle rays in the Eastern Tropical Pacific, shedding light on a species that has long been overlooked. Our findings suggest that this species is more susceptible to direct and bycatch fishing pressures, as well as other indirect human impacts. Therefore, we recommend a re-evaluation of the conservation status of this species.

Abstract Reef fisheries underpin the economy, culture, and food security of Indo-Pacific island nations, yet many target species are depleted due to inadequate management. Despite its reputation as a regional leader in fisheries management, Palau has experienced declines among key reef fish species, necessitating a comprehensive stock status assessment amid ongoing discussions to lift the national export ban. Conventional stock assessments are not feasible for most species due to limited data. To address this, we compiled life history information and applied data-limited, length-based stock assessment methods across 32 parameter scenarios. Analyses were based on a decade of fishery-dependent landing data (2014–2024) for 45 key species, with comparisons to historical landings (1976–1991) to evaluate changes in catch composition. Using Length-Based Spawning Potential Ratio as the primary assessment method, we found most species are in poor condition: 24.4% classified as “Depleted”, 51.1% “Vulnerable”, and 17.8% “Depleting”. Only 6.7% met criteria for “Sustainable” status (spawning potential ratio > 40% of unfished levels and a fishing mortality below natural mortality). Landings data indicate a clear shift from historically dominant large-bodied species to smaller taxa, reflecting target species depletions and regulatory changes. Despite life history parameters uncertainty, results were robust across alternative length-based approaches and consistently indicated widespread stock depletion. These findings highlight an urgent need for stronger management, including effective size limits, the protection of spawning aggregations, and retention of the export ban. Lifting the ban would likely increase fishing pressure and further accelerate declines of Palau’s already depleted reef fish populations.

The critically endangered fan mussel Pinna nobilis is under strict protection in the Mediterranean waters and exhibited a documented fishing history in Greece dating back to 19th and early of 20th centuries. The present study examined historical documentary evidence from Greek archives, technical reports, and oral testimonies to reconstruct traditional fishing methods and their ecological implications. Historical records revealed the widespread use of specialized fishing tools called “pinologos”, a Y-shaped iron attached to a wooden poles, deployed primarily in shallow waters (2–7 m depth) across various Greek coastal regions in the Ionian and Aegean Seas. Two types of fishing gear existed, a simple Y-shaped tong and a scissor-type gear, both designed to encircle and extract individual fan mussels, through quarter-turn rotation. Fishers selectively targeted only large, established individuals of fan mussel, as small specimens with thin shells were unsuitable for this method. Historical fishing pressure on the species was spatially and size-limited, unlike current basin-wide mortality events. These findings demonstrate that structured populations persisted even under traditional exploitation, suggesting potential for recovery if contemporary threats are mitigated. Management strategies should reference historical population structures as restoration targets.

Knowledge of the distribution and reproductive habitats of the Lusitanian cownose ray (Rhinoptera marginata) in the northeastern Mediterranean remains limited, and potential nursery areas for the species have not yet been clearly identified. This study reports new records of pregnant females and newborn individuals and reviews available occurrence data to evaluate whether İskenderun and Mersin Bays may function as potential nursery habitats. Opportunistic records obtained from fisheries and observational sources were compiled together with newly documented captures from the northeastern Mediterranean coast of Türkiye, and spatial and seasonal patterns were examined. The combined dataset provides additional insight into the seasonal occurrence of pregnant females and near-term embryos in the region. Recurrent records from İskenderun and Mersin Bays suggest that these coastal areas may represent a potential nursery habitat. Environmental conditions, including muddy shelf sediments enriched by riverine inputs, may provide suitable feeding grounds for both adults and juveniles. However, demersal fishing grounds overlap with these areas, potentially exposing vulnerable life stages to fishing pressure. Although the available data are largely opportunistic, the findings highlight the ecological importance of the region and the need to conserve breeding populations in the northeastern Mediterranean.

Spatial distribution and environmental drivers of Northern anchovy (Engraulis mordax) from acoustic-trawl surveys along Mexico’s northwestern coast (2019–2022)

Abstract This study analyzes the community structure and biodiversity of demersal biota caught using trammel nets in the coastal waters of Alue Naga Village, Banda Aceh City. The research, conducted from January to February 2025 through 30 fishing trips, aims to provide baseline data to support sustainable fisheries management. A total of 41 species were identified, consisting of 3 target species and 38 bycatch species, dominated by Fenneropenaeus merguiensis , Portunus sanguinolentus , and Stolephorus commersonii . The Shannon-Wiener index (2.85), Simpson’s index (0.91), and Evenness (0.74) indicate a stable community structure and high biodiversity. However, most individuals were below the biological size limit as regulated by the Ministry of Marine Affairs and Fisheries (MMAF) Regulation No. 17/2021, indicating potential fishing pressure on juvenile stocks. This study provides the first quantitative assessment of demersal biodiversity in Alue Naga using trammel nets and serves as a scientific reference for future monitoring and management of coastal fisheries resources. The findings highlight the need to regulate mesh sizes, strengthen fisher education, and establish conservation zones to maintain ecosystem balance. Moreover, the study contributes to the implementation of Sustainable Development Goal (SDG) 14 on the conservation and sustainable use of marine resources.

The blue crab, Callinectes sapidus, supports one of the most significant fisheries in Lake Maracaibo and western Venezuela, although several previous studies suggest signs of overexploitation. This study analyzed the population dynamics of the species as a basis for resource management, based on 46 monthly samples of landings at the main ports of Lake Maracaibo from 2010 to 2014. Monthly length-frequency data were analyzed using the FiSAT II software to estimate growth parameters (ELEFAN I), mortality (length-converted catch curve) and recruitment (cohort analysis). Natural mortality was estimated using several methods due to its complexity. The estimated growth parameters were L_∞ =14.67 cm, and K = 0.87 yr-1, with higher growth rates in males. Recruitment was continuous, with peaks during the rainy season. Total mortality was estimated at 7.74 yr-1, natural mortality ranged from 0.87 and 2.05 yr-1, and fishing mortality from 5.79 and 6.87 yr-1, showing strong fishing pressure, mainly on females. It was determined that C. sapidus has a short life cycle, with first entry into the fishery at 7-8 months of age and 7.0 cm, remaining until 24 months of age and 12 cm. The catch curve suggests full recruitment between 12 and 13 months of age and 8.7 cm. It is concluded that the high fishing intensity has altered the population structure and limits the adequate renewal of the stock, highlighting the need to strengthen management measures.

China's rapid economic development has triggered an unparalleled freshwater biodiversity crisis since the 1950s. To restore fisheries resources, the Yangtze River Fishing Ban was implemented in 2021 to cease all basin-wide commercial fishing. We evaluate the effectiveness of this large-scale conservation action by assessing fish communities across mainstem habitats before and after the ban (2018 to 2023). The seven-decadal biodiversity loss was halted with improvements in fish biomass, body condition, species diversity, and initial recovery of threatened species. Eliminating fishing pressure was likely key to this recovery, in addition to actions targeting water quality improvement, hydrological and riparian habitat restoration, and vessel traffic reduction. Ambitious conservation actions can halt biodiversity loss in the Yangtze River, bringing hope for biodiversity recovery in other large rivers.

Ethiopia hosts a rich aquatic biodiversity, with over 200 freshwater fish species belonging to 75 genera, 31 families and 12 orders. The objectives of the current study were to identify potential lakes and fish species, assess their production trends, identify challenges in the fish production value chain, and indicate possible intervention mechanisms. Data were collected using tools including key informant interviews, focus group discussions, field observations, in-situ measurements, and lab analysis of water samples. Physicochemical and nutrient analyses were conducted for Lakes Beseka, Dembel, Langano, Abijata, and Hara Habas, as well as for the Koka and Gidabo reservoirs. Fish post-harvest loss assessment was carried out by adopting the Informal Fish Loss Assessment Method (IFLAM) to quickly generate fish post-harvest losses. A total of nine fish species from the eight water bodies were identified as commercially important. During the study time, the actual fish production in tons was 720, 363.8, 214.3, 88.2, 41.06, and 9.54, respectively, from Abijata, Dembel, Koka, Langano, Hawassa, and Beseka. Nile tilapia fish in lakes Dambal, Habas, Langano and Koka are highly decreasing in catch and size in the surveyed lakes during the last two decades due to high fishing pressure and use of non-standard fishing gears. The production of Nile tilapia has been exceptionally increasing in Lake Abijata since 2020, when it reappeared in the lake after two decades, because of the increase in lake volume and relative dilution of the concentration of carbonate salt in the lake. The major challenges in the fishery are the lack of fisheries management practices, the involvement of non-registered fishermen and fish traders in the fishing activity, and the use of illegal and non-standard fishing gear. Concentrations of nitrate and soluble reactive phosphorus in the Koka reservoir, particularly at the Awash River inlet, are due to surface runoff and intensive anthropogenic activities, such as the application of fertilizers, sewage, and industrial effluents from highly populated towns with poor wastewater treatment and drainage systems. DO, pH, temperature, depth, and redox potential of these water bodies were stable. The genetic loss of Nile tilapia in the major Rift Valley Lakes, such as Hara Dambal, Langano, and Hara Habas, can be restored by stocking improved strains; mass multiplication of these improved strains is needed.

Abstract The Rowley Shoals, off northwestern Australia, are renowned as a biodiversity hotspot. This remote system comprises three atolls, Clerke, Imperieuse and Mermaid, which in recent years have been increasingly targeted by illegal fishing, a pressure rising across the Indo‐Pacific. The objective of this study was to quantify recent changes in sea cucumber assemblages across the Rowley Shoals. We surveyed nine sea cucumber species at monitoring sites in 2018 and 2023 to assess changes in their abundance. Total assemblage densities declined significantly across all atolls and habitats. Documented seizures of illegally harvested holothurians by the Australian Fisheries Management Authority over this period suggest that illegal fishing pressure likely contributed to the observed declines. Notably, IUCN‐listed species Holothuria whitmaei and Actinopyga miliaris declined severely, raising concerns about their recovery potential. These findings provide the first quantitative evidence of widespread declines within this protected reef system and bring renewed attention to its conservation.