Management Of Fishery Resources Research Articles

Status of fishery resource management through an ecosystem approach in the several fishery management models in the Kampar River, Riau Province, Indonesia

The Kampar River's high fish diversity dramatically benefits the local community. However, overfishing threatens the river's fishery resources. Urgent and concerted management efforts, including local wisdom implementation, are crucial to address this pressing issue. Law Number 45 of 2009 concerning Fisheries mandates sustainable fishery resource management, primarily through an ecosystem-based approach. From January to June 2024, researchers conducted a study in the Kampar River area to assess the status of ecosystem-based fishery resource management across several management models. The research combined qualitative and quantitative methods, using purposive sampling to select 5-10 participants from each village. Following guidelines from the Directorate of Fish Resources, the study developed indicators for each domain and converted them into composite indicators using the 'flag modeling' technique. Data analysis showed that the Lubuk Larangan management model achieved the highest ecosystem-based fishery resource status, scoring 13,374 points (green). The individual auction system, communal auction system, and government regulations scored 13,168, 13,120, and 10,899 points respectively (yellow). These results highlight the effectiveness of local wisdom-based approaches in sustainable fishery resource management for the Kampar River ecosystem.

A multimethod approach to assess marine recreational fishing activity in a Mediterranean area: A case study of the Balagne region (Corsica, France)

AbstractObjectiveRecreational fishing is a growing concern in the management of fishery resources given its economic impact, the number of people involved, and the magnitude of catches. Despite its significant impact on marine resources and ecosystems, recreational fishing has received less attention in research than commercial fishing.MethodsThis study focuses on marine recreational fishing in Balagne (Corsica, France, northwestern Mediterranean). It presents, for the first time in this region, valuable data on the population size of recreational fishers; their sociological profiles; fishing habits; and, specifically, catch data related to boat fishing.ResultThrough an extensive telephone survey involving 387 households, we estimated that recreational fishers constitutes 10.2% of the population, with the majority being men (84.84%). The average age varies significantly based on the type of fishing practiced: 38.4 years for spearfishing, 50.2 years for shore fishing, and 56.4 years for boat fishing. Additionally, the study found that shore fishers declare practicing no‐kill fishing more frequently than do boat fishers (90.00% and 56.67%, respectively). Photographic protocol, fishing logbooks, and boarding provided data on catch composition and fishing characteristics. In the case of boat fishers, catches per unit of effort, estimated from boarding data, were found to be 1.03 ± 1.51 individuals/h/fisher and 222.32 ± 318.94 g/h/fisher. Despite the great diversity among the species caught (49 species), Comber Serranus cabrilla, Blackspot Seabream Pagellus bogaraveo, Black Seabream Spondyliosoma cantharus, and Painted Comber Serranus scriba are overly represented in number among the species of marine fish caught by boat fishers and Common Dentex Dentex dentex, Greater Amberjack Seriola dumerili, Dolphinfish Coryphaena hippurus, and Bluefin Tuna Thunnus thynnus are overly represented in weight. Among all individuals caught and measured, about one out of two individuals (48.97% of catches) does not reach the legal size.ConclusionThis study reveals the need to establish monitoring, surveillance, and control programs to ensure the sustainability of fish stocks and fisheries, including recreational fisheries.

European anchovy's abundance, more affected by climatic conditions than fishing activities in the northwest African waters.

The marine waters off the coast of northwest Africa are known for being highly productive upwelling regions in the Eastern Atlantic Ocean. The present study evaluated the combined effects of climate change and sustainable fishing levels on the long-term sustainability of European anchovy (Engraulis encrasicolus), a target pelagic species found along the West African coastal waters. The present study used survey biomass time series from survey vessels and species catch time series from commercial fisheries operating in the region. Hence, we investigated the relationship between fishing dynamics and environmental factors. The status of anchovy stock was determined by analyzing changes in different initial depletion rates using a state-space Bayesian surplus production model. We used Principal component analysis to identify the essential environmental data set, while Generalized Additive Models (GAM) were employed to determine the influence of the environment on fisheries. The stock assessment model revealed that fishing intensity did not affect the abundance of anchovy in the region even when tested under different biomass depletion scenarios. However, by employing GAMs, the research assessed the impact of environmental variables on fish biomass, indicating that sea surface temperature (SST) significantly influences anchovy abundance in the region. The latitudinal gradient also had a significant influence on this species' abundance. These findings underscore the vulnerability of the small-scale fisheries sector in the tropical upwelling zone to climate change. The study concludes that even in the face of potential negative impacts from environmental factors, optimizing fishing methods can contribute to the preservation of pelagic resources in the region. It emphasizes the importance of managing fishery resources in a sustainable, economically viable, and socially acceptable way.

Training on Strengthening Fishery Business Groups in Development In Lambusa Village, Konda District, South Konawe Regency

The Training on Strengthening Fishery Business Groups in Lambusa Village, Konda District, South Konawe Regency, succeeded in improving the skills and knowledge of villagers in the cultivation, processing, and marketing of fishery products. Participatory training methods involving counseling and practice have proven to be effective in building internal group relationships as well as connectivity with governments, financial institutions, and market participants. The training includes fishery resource management, sustainable aquaculture techniques, marketing, and financial management, which supports increasing the productivity and income of fishery business groups. As a result, there has been an increase in solidarity and cooperation between members, as well as village social and economic welfare. The training also strengthens the concept of community empowerment through a participatory and sustainable approach, providing applicative skills to overcome concrete problems and achieve self-reliance. The evaluation showed the high enthusiasm of the participants and the significant application of knowledge, contributing to the sustainable development of the village and the capacity building of the fishery business group.

Spatial and Temporal Distribution of Habitat Pattern of Trichiurus japonicus in the Northern South China Sea Under Future Climate Scenarios

The impact of climate change on fish distribution has drawn increasing attention worldwide. Studying the distribution patterns and habitat evolution trends of largehead hairtail (Trichiurus japonicus), an important fishery resource in the northern South China Sea (NSCS), is of great significance for the management and sustainable utilization of fishery resources. This study uses an ensemble species distribution model to analyze the seasonal distribution patterns of T. japonicus in the NSCS and predict the changes in highly suitable habitats of T. japonicus under four future climate scenarios (IPCC Shared Socioeconomic Pathways SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5). The results show that the area of suitable habitats in the Beibu Gulf is expected to increase, while that in the offshore of Guangdong will significantly decrease. In different seasons, there are differences in environmental factors affecting the distribution of T. japonicus, among which sea bottom temperature (SBT) and bathymetry (BM) are key factors. Under the SSP1-2.6 scenario, the area of highly suitable habitats for T. japonicus is expected to decrease by 30.54% by the 2100s, while under the SSP5-8.5 scenario, it is expected to decrease by 53.67%. Our research results show that the active range of T. japonicus in the NSCS has different adaptive responses to different climate change scenarios, which has an important impact on the development and management of T. japonicus resources.

Blue Economy and the Impact of Industrialisation on Sustainable Livelihoods: A Case Study of Fisheries in the North Coastal Region of Java

This research explores the impacts of the blue economy and industrialisation on sustainable livelihoods in the coastal areas of the North Coast of Java, with a particular focus on the fisheries sector.The main objective of this research is to analyse how changes in blue economy practices, which include sustainable marine resource management approaches, interact with industrialisation processes and their impact on the survival of local fishing communities.The research method used was qualitative with a case study approach, where data was collected through in-depth interviews with fishermen, government officials, and relevant stakeholders, as well as direct observation in the field. Data analysis was conducted using thematic analysis techniques to identify patterns and significant relationships between the factors involved.The results of this study show that industrialisation in the coastal areas of Java's North Coast has vital and complex impacts on the sustainable livelihoods of local fishing communities. On the one hand, industrialisation provides new economic opportunities, such as jobs in the fishing and manufacturing sectors, which can increase community income. However, on the other hand, negative impacts on the aquatic environment due to industrial activities and overexploitation of natural resources threaten the sustainability of the marine ecosystem, which is the main source of livelihood for fishermen.The managerial implications of these findings emphasise the need to integrate blue economy policies with the maturity of sustainable industrial development planning. Policy development that accommodates the needs of local ecosystems and fishing communities, with a pattern of regulating marine protected zones and supporting the shift to environmentally friendly fisheries practices, is key to ensuring the sustainability of fishers' livelihoods and healthy coastal ecosystems. This research provides important insights for policy makers and practitioners involved in marine fisheries resource management and industry development in coastal areas.

Ecosystem Structure and Function in the Sea Area of Zhongjieshan Islands Based on Ecopath Model

Based on the field survey and reference data of the sea area of the Zhongjieshan Islands from 2021 to 2022, the Ecopath model was used to analyze the energy flow structure of the marine ecosystem of the sea area of the Zhongjieshan Islands; the energy structure of the marine ecosystem was divided into 21 functional groups, and its nutrient structure, energy flow, and total system characteristics were analyzed. The results show that the credibility of the model is 0.414, which is at a medium level. The trophic level of each functional group of the ecosystem in the sea area of Zhongjieshan Islands was 1–3.48, the energy flow structure of the system was mainly concentrated in the first five grades, and the trophic level was relatively simple, with the average energy transfer efficiency of the system being 8.11%, the energy flow range being 2.81–13.04%, the energy transfer efficiency of the primary producers of the system being 7.25%, and the energy conversion efficiency of the system debris being 9.12%. The total system throughput was 2125.96 t·km−2; The analysis of the overall characteristics of the ecosystem showed that the system connectance index and the system omnivory index were 0.45 and 0.24, respectively, while the Finn’s cycling index was 8.24, the Finn’s mean path length of the system was 2.72, and the total primary production/total respiration was 1.71. In this study, the marine ecosystem model of the sea area of the Zhongjieshan Islands was studied to understand the trophic structure and ecosystem status of the sea area, which is conducive to the sustainable utilization and scientific management of fishery resources in the sea area.

Strategic Development of Community Oral Traditions in the Management and Utilization of Fisheries Resources in the Maluku Islands

Strategic Development of Community Oral Traditions in the Management and Utilization of Fisheries Resources in the Maluku Islands

Metal accumulation in fish species of a vast hydrographic network in the Moyen-Ogooué and Haut-Ogooué Provinces of Gabon: Implications for human health

With an obsolete livestock sector, Gabon relies on its huge hydrographic network rich in fish to supply its populations with animal proteins. This study aimed to conduct metal analyses in four fish species (Oreochromis niloticus, Clarias gariepinus, Chrysichthys nigrodigitatus, Polydactylus quadrifilis) frequently consumed by human populations in the Moyen-Ogooué and Haut-Ogooué Provinces of Gabon and infer the potential human health risks for those populations who rely on these freshwater produces as a source of proteins. Fish were sampled from Ezanga, Oguemoué, Onangué, Nguenè (Moyen-Ogooué) and Grand Poubara (Haut-Ogooué) Lakes during the high flow period (HF) and low flow period (LF) from 2021 to 2022, and analysed for seven heavy metals (HMs) using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) techniques. Throughout the flow periods, and regardless of the lake and fish species, Fe was found to have the highest concentration, followed by Al > Mn > Hg > Pb> As> Cd. The relatively high concentration of Hg was recorded in the muscle tissues of C. gariepinus (6.65mg. kg−1) sampled during the LF period at Grand Poubara. The concentrations of Hg found in the muscle of all fish species also exceeded the maximum acceptable limits set by the American Environmental Protection Agency. The concentrations of Fe in C. gariepinus (Grand Poubara, LF) and O. niloticus (Onangué, LF), and those of Al in O. niloticus (Nguenè, HF), P. quadrifilis (Onangué, HF) and C. nigrodigitatus (Oguemoué, LF) were amongst the highest concentrations ever reported on the African continent. Health risk assessments indicated a heightened risk of cancer for local populations consuming the fish species from all the lakes investigated. There is a need to implement an increased surveillance programme at national level in order to raise awareness and improve the management of fishery resources while preserving the environment and the health of local populations that rely upon these resources for their subsistence.

Genome-Wide Genetic Diversity and Population Structure of Charybdis feriata (Crustacea, Decapoda, and Portunidae) Along the Southeast Coast of China Inferred from Genotyping-by-Sequencing (GBS) Approach.

The swimming crab Charybdis feriata is an important commercial fishery species and a major economic contributor to the southeast coastal fishing communities in China. Under the scenario of resource decline and shortage in the market over recent years, it has become more urgent and necessary to explore the fine-scale population genetic characteristics of C. feriata. In this study, the genotyping-by-sequencing (GBS) method was used to estimate the genome-wide genetic variation in and population differentiation pattern of C. feriata collected from four geographical locations (Zhoushan, Quanzhou, Yangjiang, and Qinzhou) along the southeast coast of China. A total of 18,815 high-quality single-nucleotide polymorphisms (SNPs) were identified and the results revealed the existence of high genetic diversity and low genetic divergence among the populations of C. feriata. Floating eggs and larvae transported by alongshore currents during the reproductive season might enhance the interpopulation genetic exchange. Principal component analysis (PCA) and a phylogenetic tree showed a high genetic connectivity of C. feriata across the southeast coast of China, but C. feriata distributed in the Zhoushan Archipelago might possess some genetic distinctiveness and diversification. The results supplemented basic genetic information of C. feriata at the genome level and also provided specific knowledge that could lead to the improved spatial management of fishery resources.

The Environmental Niche of the Light Purse Seine Fleet in the Northwest Pacific Ocean Based on Automatic Identification System Data

Ecosystem-based fisheries management requires high-precision fisheries information to provide relevant data for natural resource management, assessment, and marine spatial planning. This study utilizes Automatic Identification System (AIS) data from light purse seine vessels from the Chinese mainland that were collected from May to November between 2020 and 2022, along with the corresponding environmental data. By applying boosted regression trees (BRTs) and generalized additive models (GAMs), this study establishes nonlinear relationships between fishing intensity and predictor variables and explores the ecological and environmental drivers behind the spatial distribution of light purse seine vessels from the Chinese mainland in the Northwest Pacific. This research identifies the key influencing factors and reveals significant seasonal preferences for different marine environments in various months, with chlorophyll-a being the primary influencing factor. The predicted fishing effort closely resembles observed data, providing valuable information to support fisheries resource management and planning.

Sustainability of Small-Scale Capture Fisheries Based on Coastal Vulnerability in Pangpang Bay, Banyuwangi Regency, Indonesia

Graphical Abstract Highlight Research Climate change impacts on coastal vulnerability. Low coastal vulnerability in Pangpang Bay, Banyuwangi Regency. Sustainability of small-scale capture fisheries based on vulnerability. Sustainable small-scale fisheries management. Abstract Teluk Pangpang is one of the water areas that has considerable capture fisheries potential in Banyuwangi Regency, Indonesia. On the other hand, climate change impacts the vulnerability of coastal areas and coastal communities, especially small-scale fishers. This study aims to analyse the coastal vulnerability of Pangpang Bay and formulate a sustainable development of small-scale capture fisheries in Pangpang Bay. The research method used a descriptive method with a quantitative approach. Data collection techniques used geographic information systems and focus group discussions (FGDs). The data analysis used was Coastal Vulnerability Index (CVI) analysis with spatial approach and Participatory Prospective Analysis (PPA). From the CVI analysis, through the assessment of geomorphological parameters, erosion/accretion, coastal slope, distance of plants from the beach, wave height, and average tide range, the level of coastal vulnerability of Teluk Pangpang is included in the low category. Meanwhile, the PPA analysis resulted in seven variables that most influence the sustainability of small-scale capture fisheries, namely climate change, coastal vulnerability, coral reef area and density, number of small-scale fishers, catches, human resources of small-scale fishers, and management of small-scale fisheries resources. Furthermore, for the formulation of the sustainability scenario of small-scale capture fisheries in Pangpang Bay, is to minimise the impact of climate change and conduct disaster mitigation, improve the human resources of small-scale fishers, and equalise perceptions as outlined in the commitment between all interested parties and small-scale fishing communities.

Effects of Climate Change on the Distribution of Scomber japonicus and Konosirus punctatus in China’s Coastal and Adjacent Waters

Climate change has increasingly impacted the marine environment, with various marine environmental factors interacting to influence fish distribution. Assessing the impact of climate change on the future distribution of fish depends on understanding how biological responses interact with environmental conditions. Enhancing our understanding of the potential impacts of climate change is crucial for the sustainable development of marine fisheries. In this study, we analyzed the habitat suitability of Scomber japonicus and Konosirus punctatus in the coastal waters of China (17°–41° N, 107°–130° E) using marine environmental data, including, as follows: sea surface temperature (SST); sea surface salinity (SSS); pH; and biological occurrence data from 2000 to 2010. A maximum entropy (MaxEnt) model was employed to predict the future distribution of these two species based on the shared socioeconomic pathway (SSP) scenarios for 2040–2050 and 2090–2100. The results indicate that climate change will significantly affect the future habitat distribution of S. japonicus and K. punctatus, leading to a decrease in suitable habitat areas offshore China and a gradual shift northeastward in the center of these habitats. These findings are essential for understanding the impacts of climate change on the distribution of S. japonicus and K. punctatus, with significant implications for fisheries resource assessment and management.

Research Mapping of Fisheries Resource Management in Coastal Areas: A Bibliometric Analysis

This study conducts a comprehensive bibliometric analysis of the literature on government budget efficiency. This bibliometric analysis explores the evolution and integration of themes within fisheries management research from 1959 to 2024. Utilizing VOSviewer for keyword co-occurrence and network visualization, the study identifies dominant themes such as "fishery management system," "conservation," and "sustainability," along with their interconnections and shifts over time. The analysis highlights a multidisciplinary approach, integrating ecological, economic, and technological aspects to address the challenges of sustainable fisheries management. The prominence of terms related to management strategies and environmental conservation reflects a global commitment to sustainable practices. Collaborative patterns among leading researchers and the evolution of research themes underscore the dynamic nature of this field, emphasizing adaptive management strategies that are informed by both socio-economic and ecological dynamics. The findings suggest that the ongoing integration of advanced technologies and interdisciplinary approaches is crucial for developing effective fisheries management practices that can adapt to environmental uncertainties and ensure the sustainability of both marine resources and dependent communities.

Effects of Processing and Preservation Technologies on Keeping Quality of Labeo rohita: Attributes of Nutritional, Microbial and Sensory

Background: Fishes being major sources of protein are susceptible to post-harvest losses. Appropriate processing and preservation makes food healthier, safer, tastier, and more shelf-stable. Therefore, an attempt was made to evaluate the effectiveness of different processing and preservation technologies on keeping quality of Labeo rohita (rohu fish), a widely found ray-finned species in South Asia that is important for aquaculture. Methods: Raw fish fillets were subjected to different processing and preservation technologies including freezing, sun drying, mechanical drying, salting, microwave processing, and marinating to determine their effects on keeping quality. Consequently, sensorial attributes, proximate composition, mineral (calcium (Ca), iron (Fe), and zinc (Zn)) contents and microbiological analyses were carried out. Obtained data were analyzed statistically and compared using one-way analysis of variance (ANOVA) followed by Fisher’s LSD test at 5% level of significance. Results: The moisture, protein, fat, ash, and carbohydrate contents were 13.01-77.29, 8.62-52.57, 0.86-18.69, 1.34-12.72, and 1.13-27.22%, respectively in different processing and preservation technologies. Drying manifested to be the efficient method in terms of preserving proteins and fats while retention of sensory attributes was obtained in freezing. The contents of Ca, Fe, and Zn were 120.05-227.97, 0.54-1.14, and 0.72-2.04 mg/100 g, respectively. In addition, maximum retention of Zn, Fe, and Ca contents were observed in freezing, sun drying, and marinating, respectively. Furthermore, total bacterial count was in the range of 0-2.6×104 Colony Forming Unit (CFU)/g and no coliforms were detected in any of the raw and processed fish fillets. Results of microbiological study revealed that microwave processing is highly efficient to reduce microbial loads in processed fish. Conclusion: Combination of different processing and preservation technologies might be useful to the efficient management of fishery resources. Therefore, further research into these combinations is essential to ensure that the nutritional value of fish is preserved.

Contribution of legal architecture toward strengthening co-management platforms in small-scale fisheries in Sri Lanka

The importance of a robust and supportive legal framework to encourage community involvement in resource management is undeniable. The legal landscape of Sri Lanka's fisheries sector is examined in this paper, with a specific focus on co-management - a collaborative approach involving fishers, government agencies, and other stakeholders for sustainable fisheries management. A systematic review of relevant Acts, Regulations, and other related literature explores how the existing legal framework enables the establishment and function of co-management platforms. The appropriateness and sufficiency of current legal provisions towards implementing "co-management good practices" outlined in the FAO's Assessment Sheet for co-management design and performance and the practical application of legal provisions aimed at promoting co-management are also examined. The Fisheries and Aquatic Resources Act No. 35 of 2013 emerges as the cornerstone legislation supporting co-management. Particularly significant is the provision for establishing Fisheries Management Coordinating Committees within designated Fisheries Management Areas. These Fisheries Coordinating Committees include representatives from village-level Fisheries Management Committees, government bodies, and key stakeholders appointed by the Director General of the Department of Fisheries and Aquatic Resources. This represents a crucial step towards collaborative management of fisheries resources. The analysis reveals satisfactory compliance of existing legal provisions with the FAO's "co-management good practices". However, some deficiencies and practical limitations have been identified. For instance, there is no legal mandate to make Fisheries Management Committees or Fisheries Coordinating Committees compulsory within designated Fisheries Management Areas, nor is there a requirement for regular meetings. While the legal framework generally supports co-management, there is substantial room for improvement. The paper recommends that the government should address legal and administrative challenges that hinder the effective implementation of co-management initiatives.

Sustainable Development Strategy Based on Value-Addedin the Fisheries Sector: Study on the Kangean Islands, Sumenep Regency, Indonesia

Objective: Kangean Islands is a group of small islands in Sumenep Regency, East Java Province, Indonesia, which is administratively divided into three sub-districts, namely Arjasa District, Kangayan District, and Sapeken District. This archipelago has very large fisheries potential as seen from its contribution to the Gross Regional Domestic Product (GRDP) of Sumenep Regency, but the utilization of the fisheries sector in this archipelago is still carried out traditionally and tends to be exploitative. This study aims to see the level of sustainability of fisheries sector management and recommend fisheries resource management strategies, in order to increase the economic added value of the fisheries sector and maintain the sustainability of fish resources and the environment in the archipelago. Method: The analytical method used to analyze the degree of sustainability in fisheries resource management in the Kangean Islands is Rapid Appraissal for Fisheries (RAPFISH) with the Multi-Dimensional Scaling (MDS) ordination technique. While the analytical tool used to compile a hierarchy of fisheries sector development strategies to increase economic added value is the Analytical Hierarchy Process (AHP). Results and Discussion: The results of the sustainability analysis in the management of the fisheries sector found that, of the five aspects identified, the results showed that the financial aspect and infrastructure aspect had the category of "Sustainable Sustainability", with values of each aspect of 63.113 and 53.885. While the other three aspects, namely: Human Resources (HR) Aspect, Natural Resources Aspect, and Social Aspect are included in the category of "Less Sustainable". Meanwhile, based on the results of the analysis of the hierarchy of fisheries sector development policies, it shows that the most priority policy to be carried out in the development of a sustainable fisheries sector is the "identification of investment potential and opportunities" program with a priority value of 46%. Furthermore, the strategy that must be chosen is to map the potential of the fisheries sector with a limiting value of 21%. With a Rater Agreement value strength of 0.472727 or 47%, it means that the informants agree in providing an assessment on the paired comparison questionnaire, in determining problems and strategies in the development of the fisheries sector in the archipelago.

Analysis of fishing intensity in the South China Sea based on automatic identification system data: A comparison between China and Vietnam

AbstractObjectiveRecently, the South China Sea has been facing a crisis of depleted fishery resources, primarily due to the impacts of illegal, unreported, and unregulated fishing activities, as well as overfishing. Accurately understanding the fishing activity intensity in the South China Sea holds significant implications for the sustainable management of fisheries resources.MethodsLeveraging the automatic identification system trajectory data from 2018, this paper employs spatial statistical methods and fishing effort indicators to comparatively analyze the spatial variations in fishing intensity between Chinese and Vietnamese fishing vessels.ResultThe results of this study show that (1) in 2018, the total fishing effort of Chinese fishing vessels in the South China Sea was 7.65 times that of Vietnamese vessels, but during China's South China Sea fishing moratorium, the fishing effort exerted by Vietnamese vessels surpassed that of China and (2) the top 10 ports in China and Vietnam support approximately 30% and 55.13% of their respective fishing intensities in the South China Sea.ConclusionThe study highlights significant variations in fishing intensity between Chinese and Vietnamese vessels and the substantial support provided by major ports. These findings offer valuable insights for fisheries resource monitoring and maritime spatial planning, contributing to the sustainable management of the South China Sea's fisheries resources.

Non-lethal biomarkers as promising tools for fish health assessment: In situ exposure to bifenthrin as a case study

Non-lethal biomonitoring should provide an innovative approach to establish bioethical protocols for the management of both aquaculture and wild fisheries resources. We aimed to assess non-lethal biomarkers in Piaractus mesopotamicus caged in a rice field during a bifenthrin (BF) application. We analyzed parameters related to the immune system, energy metabolism and oxidative stress in fish skin mucus and blood plasma. Fish exposed to BF showed a significant increase in skin mucus glucose levels and the enzymatic activities of protease, alkaline phosphatase and superoxide dismutase. Regarding plasmatic parameters, BF increased the levels of glucose, total protein and albumin, but decreased triglycerides. In addition, increased activities of lysozyme and alkaline phosphatase were found in the blood plasma of exposed fish. Our results indicated an increased energy demand, altered immune function and a mild oxidative stress response in fish exposed in situ to BF. We have shown that skin mucus and blood plasma are very promising matrices for the development of non-lethal biomarkers to assess fish health in a stressed environment.

A Study on the Automation of Fish Species Recognition and Body Length Measurement System

The rapid depletion of fishery resources has led to the global implementation of Total Allowable Catch (TAC) systems. However, the current manual survey methods employed by land-based inspectors show limitations in accuracy and efficiency. This study proposes an automated system for fish species recognition and body length measurement, utilizing the RT-DETR (Real-Time Detection Transformer) model and ARCore technology to address these issues. The proposed system employs smartphone Time of Flight (ToF) functionality to measure object distance and automatically calculates the weight of 11 TAC-managed fish species by measuring their body length and height. Experimental results reveal that the RT-DETR-x model outperformed the YOLOv8x model by achieving an average mAP50 value 2.3% higher, with a mean recognition accuracy of 96.5% across the 11 species. Furthermore, the ARCore-based length measurement technique exhibited over 95% accuracy for all species. This system is expected to minimize data omissions and streamline labor-intensive processes, thereby contributing to the efficient operation of the TAC system and sustainable management of fishery resources. The study presents an innovative approach that significantly enhances the accuracy and efficiency of fishery resource management, providing a crucial technological foundation for the advancement of future fisheries management policies.