Sustainable Fisheries Management Research Articles

Fish Biodiversity and Suggested Conservation Measures of Transboundary River Someshwari in Netrokona, Bangladesh

Considering the importance of fish biodiversity for sustainable management of river fisheries, this study aims to explore and evaluate the fish biodiversity of Someshwari River along with conservation measures from November 2020 to October 2021. Data collection was carried out in Jaria, Susang Durgapur, Shivganj Bazar and Bijoypur of Netrokona district. Questionnaire interview, Focus Group Discussion (FGD), Direct observations, Key Informant Interview (KII) was used to collect data. During the study period, 23 species under 12 families were determined. Among them 6 finfish species are endangered, 4 are critically endangered, 5 are vulnerable, 7 are data deficient, and 2 are not threatened, respectively which includes highest catch catfishes at about 26.62%. However, the lowest amount catch constituted the Miror carp of about 5.29%. After the catfish, the second highest catch was 15.9% of small prawn. Another dominant group major carps contained 11.26%, and barbs remained at 11% of the catch and the loaches constituted 1.3% of the total catch. In addition, other groups like Mola carplet 7%, gourami 2.20%, Spiny eels 9.86% etc. were found in the Someshwari river. There were about 81% fish for food and 17% ornamental fish. Fourteen distinct types of fishing equipment were used namely: nets, traps, hooks, and lines, and wounding equipment. Finally, indiscriminate use of harmful gear, extraction of sand and rock, inadequate supervision of Governments and Non Governemental orgazizations, pollution from the adjacent areas, high interest rate of bank loan were understood as common constraints in the study area. Therefore, recommendations were made to improve river fisheries management through habitat restoration, increasing public awareness, prohibition on exploiting brood fish and active participation for sustainable catch.

Puzzling parrotfishes: Radiocarbon age validation and updated longevity estimates for western Atlantic species in support of sustainable fisheries management

For management efforts to succeed in Caribbean fisheries, local fishers must support and be willing to comply with fishing regulations. This is more likely when fishers are included in a stock assessment process that utilizes robust scientific evidence, collected in collaboration with fishers, to evaluate the health of fish stocks. Caribbean parrotfishes are important contributors to coral reef ecosystem health while also contributing to local fisheries. Scientifically robust stock assessments require regional species-specific information on age-based key life history parameters, derived from fish age estimates. Evaluation of the accuracy of age estimation methods for fish species is a critical initial step in managing species for long-term sustainable harvest. The current study resulted from a collaborative research program between fish biologists and local fishers investigating age, growth, and reproductive biology of the seven parrotfish species landed in U.S. Caribbean fisheries; specifically, we validated age estimation for stoplight parrotfish Sparisoma viride and queen parrotfish Scarus vetula. This is the first study to directly validate age estimation for any parrotfish species through analysis of Δ14C from eye lens cores. Our age estimation validation results show that enumeration of opaque zones from thin sections of sagittal otoliths for a Sparisoma and a Scarus species provides accurate age estimates. The oldest stoplight parrotfish and queen parrotfish in the Δ14C age estimation validation series were 14 y and 16 y; while the oldest stoplight parrotfish and queen parrotfish we aged to-date using the Δ14C validated age estimation method were 20 y and 21 y, respectively. Fish longevity (maximum age attained/life span) is a key life history parameter used for estimation of natural mortality, survivorship, and lifetime reproductive output. Past reviews on parrotfishes from the Pacific and Atlantic concluded that most Caribbean/western Atlantic parrotfish species are relatively short-lived with estimated maximum ages ranging from 3–9 y. However, information from our collaborative research in the U.S. Caribbean combined with recently published age estimates for Brazilian parrotfish species indicate that many western Atlantic parrotfishes are relatively long-lived with several species attaining maximum ages in excess of 20 y.

Sustainable Fisheries Management of the Flying Fish (Decapterus spp.) with Rapfish Analysis in Pasongsongan Waters, East Java, Indonesia

Sustainable Fisheries Management of the Flying Fish (Decapterus spp.) with Rapfish Analysis in Pasongsongan Waters, East Java, Indonesia

Recruitment dynamics of juvenile salmonids: Comparisons among populations and with classic case studies.

Understanding recruitment, the process by which individuals are added to a population or to a fishery, is critical for understanding population dynamics and facilitating sustainable fisheries management. Important variation in recruitment dynamics is observed among populations, wherein some populations exhibit asymptotic productivity and others exhibit overcompensation (i.e., compensatory density-dependence in recruitment). Our ability to understand this interpopulation variability in recruitment patterns is limited by a poor understanding of the underlying mechanisms, such as the complex interactions between density dependence, recruitment, and environment. Furthermore, most studies on recruitment are conducted using an observational design with long time series that are seldom replicated across populations in an experimentally controlled fashion. Without proper replication, extrapolations between populations are tenuous, and the underlying environmental trends are challenging to quantify. To address these issues, we conducted a field experiment manipulating stocking densities of juvenile brook trout Salvelinus fontinalis in three wild populations to show that these neighboring populations-which exhibit divergent patterns of density dependence due to environmental conditions-also have important differences in recruitment dynamics. Testing against four stock-recruitment models (density independent, linear, Beverton-Holt, and Ricker), populations exhibited ~twofold variation in asymptotic productivity, with no overcompensation following a Beverton-Holt model. Although environmental variables (e.g., temperature, pH, depth, substrate) correlated with population differences in recruitment, they did not improve the predictive power in individual populations. Comparing our patterns of recruitment with classic salmonid case studies revealed that despite differences in the shape and parameters of the curves (i.e., Ricker vs. Beverton-Holt), a maximum stocking density of about five YOY fish/m2 emerged. Higher densities resulted in very marginal increases in recruitment (Beverton-Holt) or reduced recruitment due to overcompensation (Ricker).

Matching the elemental fingerprints of fish otoliths with water masses of the St. Lawrence River and its tributaries, Canada

The physicochemical heterogeneity of large river ecosystems generates a mosaic of habitats that support diverse fish communities. Understanding the connectivity between habitats and exploited fish populations is necessary for the sustainable management of fisheries. This study evaluates the spatial concordance between elemental fingerprints of fish otoliths and surface waters in the St. Lawrence River (Canada) and its tributaries. We sampled 16 tributaries and various freshwater habitats of the St. Lawrence River and collected 136 water samples and 930 fish, representing 21 species. We observed a high spatial variability of trace element composition in the water and fish otolith samples. Reclassification using Sr and Ba concentrations of the collected water and otoliths was sufficiently accurate to correctly assign most fish to their capture region. We also observed significant variation in the elemental deposition relationships for Sr and Ba among fish families. The development of this elemental fingerprint reference database is fundamental for understanding the structure of exploited fish populations, validating the connectivity among habitats, and reconstructing habitat use by invasive fish species.

Estimate of Growth Parameters of Penaeus kerathurus (Forskäl, 1775) (Crustacea, Penaeidae) in the Northern Adriatic Sea.

Crustacean fisheries are gaining prominence globally amid a decline in finfish stocks. Some decapod crustacean species have experienced increased landings in response to shifting market demands and environmental dynamics. Notably, the caramote prawn (Penaeus kerathurus-Forskål, 1775) in the northern Adriatic Sea, Geographical Sub Area (GSA) 17, has risen in both landings and economic importance in recent years. However, despite its significance, comprehensive information on fishery-dependent data, age, and growth in this region remains lacking. To address this gap, this study employs modal progression analysis and the ELEFAN approach, utilizing the "TropFishR" R package and newly developed functions, including bootstrapping procedures. These advancements aim to overcome issues identified in previous versions and enhance the accuracy and reliability of age and growth estimations. The study leverages one year of monthly length-frequency distributions (LFDs) collected from commercial bottom trawls in the northern Adriatic Sea. The results of the analysis confirm the presence of sexual dimorphism in the caramote prawn species, with females exhibiting faster growth rates compared to males. Additionally, the growth performance index supports this observation, further underscoring the importance of accounting for sexual dimorphism in growth modeling and fisheries management strategies. By contributing to a growing body of knowledge on the growth dynamics of the caramote prawn, this study provides valuable insights for sustainable fisheries management in the northern Adriatic Sea. Understanding the age and growth patterns of key crustacean species is essential for developing effective conservation measures and ensuring the long-term health and productivity of marine ecosystems. The findings of this study serve as a foundation for informed decision-making and proactive management practices aimed at preserving the ecological integrity and economic viability of crustacean fisheries in the region.

Age and Growth of Japanese Anchovy (Engraulis japonicus, Temminck & Schlegel, 1846) in Coastal Waters around Shandong Peninsula, China

Japanese anchovy (Engraulis japonicus) is a small pelagic fish with commercial and ecological importance. In spite of its importance, in recent years, specific research on anchovy in the Shandong Peninsula area has been relatively scarce and outdated. This study aims to estimate the age and growth characteristics of anchovy through year-round seasonal sampling from 2016 to 2017, utilizing length–frequency and otolith microstructure analysis. The higher coastal abundance and larger size observed in the spring and summer suggest a potential peak spawning period for anchovies dominated by larger-sized individuals. Based on otolith analysis, anchovies range in age from 0 to 4 years, with a limited presence at age 0 and dominance in the age-1 group. The length–weight relationship (LWR) equation shows hyper-allometric growth for each season, with a mean relative condition factor (Kn) of 1.025 ± 0.005, indicating good health. Additionally, the von Bertalanffy growth equation of can be expressed as Lt = 154.40 [1 − e−0.604 (t + 0.965)], suggesting a medium growth rate (K = 0.604). These findings contribute to the understanding of anchovy age and growth patterns, emphasizing the continuous need for research and monitoring to support rational and sustainable fisheries management and conservation efforts.

Diversity, challenges, and opportunities of Fishery Improvement Projects in the Latin America and the Caribbean region

Fishery Improvement Projects (FIPs) have become a popular tool to drive sustainable management among fisheries. FIPs, guided by a private sector-led governance structure motivated by market-driven incentives, aim to reduce environmental impacts in fisheries, using the Marine Stewardship Council (MSC) fishery standard as a guide. The Latin America and Caribbean (LAC) region is a FIPs global hotspot. This study provides a comprehensive analysis of FIPs in the LAC region and highlights their potential and limitations in driving fisheries toward sustainability. We used information from the FisheryProgress website to analyze the main characteristics, and challenges concerning the MSC fishery standard, as well as actions, and outputs taken by FIPs. FIPs in this region are diverse, and face similar challenges related to defining stock status, establishing harvest strategies and control rules, and implementing fishery-specific management given limited fisheries information. Data collection and engagement through meetings to modify fishing practices and policies were the most employed actions to address these challenges. Although many FIPs are ongoing, improvements are evident as FIPs advance to later stages. Overall, FIPs are seen as a multi-stakeholder tool that encourages fisheries to enhance their environmental performance in pursuit of sustainability. However, more time is required to ascertain the true extent of their impact. This research offers insights into the main challenges and strategies when implementing FIPs in LAC. Our results should, be valuable for stakeholders looking to support sustainable fisheries management through FIPs where fisheries conditions are similar.

Size Variation Survey of the Family of Cichlids in Lower River Benue

This study was designed to determine the size variations of the family of Cichlids in lower river Benue. The fish samples were collected bimonthly in batches for a period of three months (September- November, 2023). A total of 120 fishes comprising 60 each of Tilapia zilli and Oreochromis niloticus were sampled from fishermen at the Wadata landing site during this period. The fish sampled were transported in an ice-parked plastic container to the Fisheries laboratory in order to keep the integrity of the sample intact prior to analysis. The species were identified using taxonomic keys and morphometric parameters recorded. The results obtained shows the parameters of Oreochromis niloticus and Tilapia zilli as the cichlids species caught. The mean weight (53.70±3.13), mean length (14.09±0.28) and the mean standard length (11.13±0.24) of Tilapia Zilli was observed to be greater than the mean weight (43.01±2.17), mean length (12.83±2.0.21) and mean standard length (10.17±0.81) of Oreochromis niloticus. The results obtained reveals that the morphometry of Tillapia zilli is higher in their Morphometric measurements as compared to Oreochromis niloticus. This study therefore provides valuable information on the morphological characteristics in relation to the body weight of these two Cichlids for the sustainable management of fisheries in Lower River Benue, Makurdi and Nigeria at large.

Macroeconomic impact of an international fishery regulation on a small island country

This paper examines the macroeconomic impact of regulating tuna fishing on a small island economy that relies heavily on tourism and fishing for its foreign exchange earnings. While there is scientific consensus to limit the use of drifting fish aggregating devices (dFADs) worldwide, there is no agreement on their optimal number at sea. Resolution 23/02, adopted by the Indian Ocean Tuna Commission (IOTC) in February 2023, proposed a 72-day moratorium on dFADs, but this resolution has met with resistance from many contracting parties, including developing countries. To understand the reasons for this resistance, a recursive, multi-sectoral dynamic general equilibrium model is developed for the Republic of Seychelles, a small tuna-dependent country. The model assesses the short- and medium-term macroeconomic impacts of a seasonal dFAD closure for the Indian Ocean tuna fishery. The analysis suggests that a 12% decline in canned tuna exports would result in a −8.8% deviation from the real gross domestic product trend after seven years. Such an impact would have far-reaching effects on the domestic economy, affecting all components of aggregate demand. Consequently, the economy would become more dependent on tourism, which has shown its vulnerability during the recent pandemic crisis. The study highlights the importance of considering social and economic aspects in sustainable fisheries management and provides insights into the potential consequences of dFAD regulations for small island economies.

Energy efficiency and economics of small-scale fisheries (SSF) in India: A VIKOR based multicriteria decision-making model for sustainable fisheries management

The present study addresses the crucial sustainability concerns in small-scale fisheries (SSF) against the backdrop of escalating anthropogenic activities and climate change impacts on marine fishery and ecosystems. Our study focused on a traditional fishery exploitation area spanning 12,646.12 km2 along the Southwestern Coast of Kerala, India, and explored four widely used fishing gears. We established an integrated decision-making VIKOR framework, and preferential modelling by incorporating techno-economic and environmental aspects to draw the optimal solutions. Leveraging 10 sustainability indicators, the boat seine emerged as the most sustainable gear, showcasing significant profitability (US$ 16,126/year−1 net profit) and remarkable energy efficiency, surpassing gillnetters, longliners, and shore seiners by 8.4, 4.9, and 3.0 times, respectively. The Fuel Use Intensity (FUI) and CO2 emissions analysis (F value = 58.37, P < 0.0001) emphasizes the ecological implications. The developed VIKOR sustainability index, introduced in this study, effectively assesses gear efficiency and sustainability. Further, the study revealed that gear selectivity, technical specifications, and operational trajectories considerably influence the index dynamics. This research aligns with the global commitment to the Voluntary Guidelines for Securing Sustainable Small-Scale Fisheries (SSF Guidelines) and contributes scientifically to Sustainable Development Goals (SDGs). By bridging empirical rigor with international frameworks, the study could aid in sustainable fisheries management and environmental stewardship, deemed essential for the global pursuit of ecological, economic, and social sustainability in small-scale fisheries.

Learning, thinking, sharing, and working across boundaries in fisheries science

Abstract Fisheries science and practice are challenging and require learning, thinking, and sharing across boundaries. The idea of boundary crossing can be described as some form of multiple disciplinarity (e.g. interdisciplinarity, transdisciplinarity), yet that inherently implies that the boundaries crossed are purely disciplinary in nature. After working across various other boundaries (i.e. realms, regions, disciplines, sectors, domains, and knowledge systems) for most of our educational journeys and professional careers, we reflect on our lived experiences with a focus on identifying the benefits and challenges of engaging in different types of boundary crossing. We submit that our personal and professional lives have been enriched by stepping outside of our immediate comfort zones and expertise (i.e. fish ecology) and engaging in active listening and learning with colleagues in other disciplines (i.e. various social sciences) and with stakeholders and policymakers. We have learned much from working across boundaries and encourage others, especially early career professionals, to do the same. What may superficially appear to be a bridge too far may in fact provide novel ways of thinking about a given issue or topic that generates actionable science for sustainable fisheries management and conservation. Many of the projects that we consider to be our greatest successes represent ones that involved boundary crossing, examples of which we provide in this essay. There is a need to prepare the next generation of problem solvers for engaging in boundary crossing and celebrating examples of where such efforts have led to meaningful advances in fisheries science and practice. Ensuring that institutional and cultural barriers that may constrain boundary crossing are addressed while also supporting those doing such work will be key to address the many fisheries and aquatic science challenges of today and tomorrow in both marine and freshwater systems.

The fishing industry and the growing food insecurity in Africa: an empirical analysis with an instrumented quantile approach

ABSTRACT Sustainable fishing and inclusive aquatic food systems improve livelihoods sustainability of millions of individuals in developing countries, particularly in Africa. This paper presents a comprehensive assessment of the role of the African fishing industry in ensuring food security in 40 African countries between 2001 and 2018, using the smoothed instrumental-variables quantile regression strategy. The findings reveal a positive effect of the fishing industry on food security in Africa, consistent in both the landlocked and coastal, low and middle-income African countries, irrespective of whether they adopt the English common law, the Portuguese or the French civil law systems to govern their institutions. Similarly, the results reveal that fisheries production interacts with increased nitrate-oxide emission to produce positive synergy effects on prevalence of undernourishment. Addressing the concern of environmental degradation in the quest for ensuring food security, we established a net impact of fish production-environmental degradation nexus on the prevalence of undernourishment which still reveals a negative effect. Practical policy implications should be formulated with immediate action to ensure sustainable fisheries management in preserving aquatic organisms for sustainable food security.

Upper mesophotic reef fish assemblages at Bahía de Banderas, Mexico.

There is no information on the species associated with the mesophotic reefs of Banderas Bay, located in the central Mexican Pacific. This study analysed the reef fish assemblage from three depths (50, 60 and 70 m) in three sampling sites of the southern submarine canyon of the Bay: Los Arcos, Bajo de Emirio and Majahuitas. Several analyses were performed to test the hypothesis that there are important differences in fish abundance and species composition between sites and depths. Twenty-two species of bony fishes grouped in 14 families were recorded. PERMANOVA results showed that there were no significant differences in fish diversity parameters between sites, indicating a certain uniformity in their distribution. However, nine species were exclusive to one site and depth (five singleton species with only one individual recorded and four unique species recorded only once). On the other hand, there were significant differences between depths, mainly between 50 and 70 m. Diversity decreases with depth and species composition changes. SIMPER, Shade Plot and NMDS analysis show the most representative species at each depth, with at least half of the species (11) recorded only at 50 m and four species at the deeper levels (60 - 70 m). The observed assemblage includes several of the most caught species in the shallow water artisanal fishery, which is the most traditional and common type of fishery in the Bay. In addition, the Pomacanthuszonipectus (Cortés angelfish) is of particular interest, as it has a special protection status in the official Mexican standard (NOM-059-SEMARNAT, 2010) due to its use as an ornamental species in aquaria. We hypothesised that the mesophotic zone may serve as a refuge for these fishes, so we propose that the information obtained is an important basis for new research aimed at the sustainable management of fisheries in the area.

Strategies of Optimizing VMS to preventing IUU fishing by Indonesian fishermen in Papua New Guinea

Illegal, unreported, and unregulated (IUU) fishing presents a substantial obstacle to the effective administration of maritime affairs, specifically in areas such as Papua New Guinea, where Indonesian fishermen partake in unlawful operations within the Exclusive Economic Zone. The primary objective of this research endeavor is to assess the effectiveness of policy interventions that target IUU fishing by Indonesian seafarers in Papua New Guinea, with a specific emphasis on the deployment of vessel monitoring systems (VMS). This research identifies significant challenges and assesses alternative approaches for improving VMS policies by employing the Analytical Hierarchy Process (AHP). The findings underscore the significance of involving stakeholders, adhering to legal and regulatory requirements, and the consequences for maritime security. Identifying education and training as the most crucial options emphasizes the importance of equipping stakeholders with the essential knowledge and abilities to efficiently utilize VMS technology. The study also stresses how important it is for agencies to work together, for VMS coverage to grow, and for infrastructure to be improved in order to make policies more effective. The Indonesian Government can enhance its regulatory capabilities regarding illegal, unregulated, and unreported (IUU) fishing, thereby promoting maritime security and sustainable fisheries management in the region, by placing an equal emphasis on education and training in conjunction with these supplementary measures.

Length-Weight-Age Relationship of Schizothorax eurystomus Kessler, 1872 and Comparison to Other Snow Trout Species in Central Asia

This study presents a comprehensive analysis of the length-weight relationship, condition factors, and age of Schizothorax eurystomus in the Shakhimardan River basin in Central Asia, along with a comparative perspective to other Schizothorax species in the region. The study found that S. eurystomus exhibits positive allometric growth, which is consistent with similar patterns observed in this species from the Syr Darya River basin. The two analyzed condition factors showed mean values within the normal range, indicating good feeding and environmental conditions. However, significant disparities between minimum and maximum values of these factors indicated varied growth conditions which may be influenced by anthropogenic factors. Age estimation using opercular bones showed variations in the total length among fish of the same age, and a clear age distribution pattern across different sites. Younger fish predominantly inhabited the shallower, warmer, and lower sections of the river, which is impacted by agricultural water diversion, while older specimens were found in areas with higher discharge and deeper pools. Overall, this research provides valuable insights into the life history traits of S. eurystomus, underlining the need for sustainable fishery management and conservation strategies in the Shakhimardan River basin. The findings also emphasize the importance of considering habitat quality and anthropogenic pressures regarding understanding both fish population dynamics and growth patterns.

Reproductive features of data-deficient yellowfin snapper, Lutjanus xanthopinnis (Actinopterygii: Eupercaria: Lutjanidae), from east-coast of Peninsular Malaysia: Implications for sustainable fisheries management

Understanding the reproductive biology of fishes is crucial to making accurate and scientifically sound recommendations for fisheries management. The presently reported study is the first to report the reproductive characteristics of the data-deficient and recently described yellowfin snapper, Lutjanus xanthopinnis Iwatsuki, Tanaka et Allen, 2015, collected from the eastern South China Sea, Malaysia. A total of 572 fish specimens were sampled monthly from March 2022 to April 2023 using a gillnet and a trawl net. Subsequently, these specimens were measured and weighed. Their total length (TL) ranged from 15.3 to 26.8 cm (19.25 ± 2.04 cm; mean ± SD). Their body weight (WB) ranged from 53.5 g to 279.7 g (114.5 ± 40.3 g; mean ± SD). For the reproductive biology study, the following parameters were determined: the sex ratio, gonadosomatic index (GSI), hepatosomatic index (HSI), spawning period, fecundity, condition factor (K), length at maturity, and the gonadal maturity stages. In the sex ratio, males (M) were significantly dominant over females (F) (M:F = 1:0.75) (χ2 = 11.18). Consequently, the monthly mean GSI of pooled sex revealed a consistent trend from January to August, indicating spawning seasons with peak periods in March and April. The batch fecundity of 67 mature females (16.0–25.2 cm TL; 64.5– 279.3 g W), was determined to range from 16 405 to 94 357 oocytes. The fecundity increased with gonad weight in contrast to weight and length. The length at first maturity of females and males was 14.53 and 20.56 cm, respectively. Females matured earlier than males. Macroscopic and histological examination of gonads revealed monthly variation in the ratio of gonad stages for males and females. This study offers crucial data on the reproductive biology of L. xanthopinnis, which will help with sustainable fishery management in this area and can be used as a reference for the management of similar fish populations in other regions of the world.

Analysis of Climate Variable and Fisherman Perception on Climate Change Divers in Negombo Lagoon Area

&#x0D; &#x0D; &#x0D; Climate change has undoubtedly become one of the most contentious issues in the international environmental debates and has escalated the impacts on fishery industries and fishing communities globally. This study was conducted to quantify the variations in climate variables, and coastal vegetation that may affect the fisheries industry due to climate change over past three decades in the Negombo lagoon area. Further, the knowledge and awareness of fisheries and associated communities on climate change was investigate. To understand the dynamics of the precipitation and temperature, monthly data for 30 years (1989-2022) were collected from the Department of Meteorology and 19 Module Bio-climatic Variables (MBV) were calculated to determine the climatologycal variation. The change in the coastal vegetation was analyzed using the Landsat 8 satellite using ArcGIS 10.8. A questionnaire survey and a focus group discussion were carried out as assess the knowledge, awareness and impact of climate change in the fisheries community (n=80). The mean annual and minimum and maximum precipitation ranged from 118.6 mm-268.6 and 0.6 mm - 826.6 mm. The mean, maximum, and minimum temperatures varied from 28.8o C- 32.3o C, 33o C-34o C and 29o C-30o C. Out of 19 MBV variables, 9 variables had increasing trends while 3 variables had decreasing trend. The change percentage of coastal vegetation cover from 1992-2002, 2002-2012, 2012-2022 was observed as 35.71%, 4.99% and 6.13%. As per the peoples‘ knowledge of climate change, it was highlighted that around 50% of respondents does not have a proper idea on what is climate change (40% of respondents stated that the variation of precipitation and wind is the climate change drivers; Further, 40% of respondents attested that land use change with time has accelerated climate change while 30% of respondents mentioned that lack of coastal awareness and restoration programs is the second main reason for accelerated climate change that affect the fishery industry). The outcomes of the focus group discussion revealed that fishing activities are heavily affected by climate change drivers, and some engage in alternative jobs in extreme climatic conditions to feed their families. Finally, fishery communities highlighted the need for the government and other responsible authorities to take necessary actions to adapt and strengthen the resilience to climate change. This study corroborates the timely and topical obligation for sustainable fisheries management action planning for the Negombo area.&#x0D; Keywords: Climate change, Coastal mangrove vegetation-precipitation-temperature change, Fisheries communities, Knowledge, Awareness, Negombo&#x0D; &#x0D; &#x0D;

Predicting important fishing grounds for the small-scale fishery, based on Automatic Identification System records, catches, and environmental data

Abstract Effective and sustainable management of small-scale fisheries (SSF) is challenging. We describe a novel approach to identify important fishing grounds for SSF, by implementing a habitat modelling approach, using environmental predictors and Automatic Identification System (AIS)-B data coupled with logbook and First Sales Notes data, within the SE Bay of Biscay. Fishing activity patterns and catches of longliners and netters are used to determine the main environmental characteristics of the fishing grounds, and a habitat modelling approach is implemented to predict the zones that fulfil similar environmental characteristics across a larger geographical extent. Generalized additive mixed models (GAMMs) were built for 24 fish species, and to identify other zones that fulfil similar characteristics and, thus, could be considered relevant for the species targeted by each gear type. Most of the models showed a good prediction capacity. The models included between one and four predictor variables. ‘Depth of mixing layer’ and ‘benthic rocky habitat’ were the variables included more frequently for fish species captured by netter’s fleet. For longliners, the ‘seafloor slope’ and ‘benthic rocky habitat’ were the two most important variables. The predictive maps provide relevant information to assist in management and marine spatial planning.

Consumption of Post-Larval Swordfish (Xiphias gladius) by Dolphinfish (Coryphaena hippurus): New Ecological Insights into Both Species in the Tyrrhenian Sea

Knowledge of post-larval swordfish (Xiphias gladius) ecology in the world’s oceans is incomplete as they are rarely found in ichthyoplankton samplings or commercial catches and individuals are difficult to observe in the marine ecosystem. Analyses of stomach contents of apex predators can provide otherwise unobtainable ecological insights. Two well-preserved bills of post-larval swordfish were identified among the partially digested stomach contents of an adult male dolphinfish (Coryphaena hippurus) caught in the northern Tyrrhenian Sea. The lower jaw to fork lengths of the two predated swordfish were estimated at, respectively, 18 and 22 cm, corresponding to 81- and 99-day-old swordfish hatched in the 2022 spawning season. This analysis and recent information on the reproductive dynamics of swordfish in the same area reported in the literature shed light not only on the early stages of swordfish growth but also on dolphinfish ecology in the Tyrrhenian Sea. The two species share the same habitat and are both caught with commercial pelagic surface longlines. Environmental shifts associated with climate change could unpredictably modify the reproduction dynamics, growth, recruitment and distribution of both species. This knowledge is important for the sustainable management of regional fisheries.