Management Of Fishery Resources Research Articles

Calibration of commercial fisheries echo sounders using seabed backscatter for the estimation of fishery resources.

Acoustic methods are often used for fisheries resource surveys to investigate fish stocks in a wide area. Commercial fisheries echo sounders, which are installed on most small fishing vessels, are used to record a large amount of data during fishing trips. Therefore, it can be used to collect the basic information necessary for stock assessment for a wide area and frequently. To carry out the quantification for the fisheries echo sounder, we devised a simple method using the backscattering strength of the seabed to perform calibration periodically and easily. In this study, seabed secondary reflections were used instead of primary reflection because the fisheries echo sounders were not equipped with a time-varied gain (TVG) function, and the primary backscattering strength of the seabed was saturated. It was also necessary to use standard values of seabed backscattering strength averaged over a certain area for calibration to eliminate some of the effects of differences in seabed sediment and vessel motions. By using standard values of the seabed secondary reflections, the fisheries echo sounder was calibrated accurately. Our study can provide a reliable framework to calibrate commercial fisheries echo sounders, to improve the estimation and management of fishery resources.

Identification of Konosirus punctatus (Temminic and Schlegel, 1846) stocks in Korean waters via otolith shape analysis and comparison of growth parameters

Accurate identification of fish stocks is essential for the successful management of fishery resources. In this study, the populations of dotted gizzard shad, Konosirus punctatus, which is listed on the International Union for Conservation of Nature red list of the threatened species, were identified by combining two phenotypic methods: otolith shape analysis and comparison of growth parameters. Otolith shape analysis revealed two types of otoliths, pointing to the presence of two gizzard shad stocks in two areas along the Korean coast: the East Sea and the Yellow Sea + western Korean Strait. It is also supported by the result that the two stocks are significantly different in the shape indices (SI), and asymptotic fork length (FL∞). These results may be due to the influence of several environmental factors, such as temperature, salinity, and food availability. Overall, our findings suggest that there are two phenotypic stocks of K. punctatus in the Korean coastal waters and they should be managed differently.

Status of pink ear emperor (Lethrinus lentjan) fishery in the Sinjai and Bone waters, South Sulawesi, Indonesia

The pink ear emperor (Lethrinus lentjan) is a type of coral fish belonging to the Lethrinidae family, they usually eat mainly at night, namely benthic invertebrates or fish. L. lentcan included in the main family of food coral fish that live in coral reef ecosystems and in sandy bottom coastal waters. Good management of fisheries resources is by utilizing fish populations without having to deplete fishery resources. If fishing is carried out continuously without taking into account the ability to renew, over exploitation will occur. The research was conducted from March to May, 2023, in Sinjai and Bone waters, south sulawesi Indonesia which focused on fishing ports with L. lentjan landing potential. The highest class length was obtained in Sinjai Regency and in Bone regency which was negative allometric. Lc in Sinjai regency uses basic gillnet, and in Bone regency 21.9 uses basic longline. Gender comparison between L. lentjan males and females in Sinjai regency is 45% : 55%. Meanwhile for Bone regency it is 41% : 59%. L. lentjan males and females have a ratio of 1: 1.43 with the results of the chi square test tcount < ttable, this condition shows that H0 accepted, there is no real difference between the number of male and female biota. gonad maturity level L. lentjan in Sinjai regency it is 24 cm with a length range of 23 – 25 cm, and in Bone regency it is 24.6 cm with a length range of 24-25 cm.

Application of sea surface temperature remote sensing data in environmental assessment of fishing grounds

This article provides a comprehensive discussion of the application and importance of sea surface temperature (SST) remote sensing data in environmental assessment of fisheries. By analysing the collection, processing and practical application of SST data, the article demonstrates how this technology can help scientists and fisheries managers to better understand the impacts of ocean temperature changes on fisheries resources and its role in ensuring the sustainability of global fisheries. The article begins by describing the importance of the marine environment to fishery resources and explains the development of SST remote sensing technology and its application to fishery location and environmental monitoring. The article then discusses in detail the application of SST data in practical fisheries management, in particular how it can help predict fish migration, optimise fishing activities, and assess the impacts of climate change on marine ecosystems. In addition, the article explores the main challenges faced when applying SST data, such as technical limitations, complexity of data interpretation, and unequal access on a global scale. Overall, this article highlights the indispensable role of SST remote sensing data in modern fisheries management, while also pointing out the limitations of its application and future directions. With the continuous advancement of remote sensing technology and the ongoing impact of global climate change, SST data are expected to play an increasingly important role in future fisheries environmental assessment and resource management.

A water pollution haven hypothesis in a dynamic agglomeration model for fisheries resource management

A water pollution haven hypothesis in a dynamic agglomeration model for fisheries resource management

Analysis of Feeding Habits and Biological Aspect of Yellow Stripe Trevally (Selaroides leptolepis) Caught at the Lekok Coast, Pasuruan, East Java

The fish population in waters can decrease due to the uncontrolled utilization of fish resources. Food is one of the determining factors for the population and condition of fish in the waters. Considering the economic and ecological importance of the yellow trevally in food webs, this research was conducted to analyze the feeding habits and biological aspects of the yellow trevally in Pesisir Lekok. This study used a descriptive data analysis with complete randomized design. The research was conducted from May to July 2023 at Pesisir Lekok, Pasuruan, East Java. The results showed that the yellow trevally is carnivorous with the dominant food found being zooplankton from the genus Microcalanus sp. with a frequency of occurrence of 41%. The highest plankton composition found in the stomach of the yellow trevally was the phytoplankton of the Aulacoseira genus, which was 22.2%. Meanwhile, the foods most preferred by the yellow trevally are Rotifera and Charophyta with an index value of +1. The biological aspect of the yellow trevally seen from the length-weight relationship shows that the growth pattern of the yellow trevally is negative allometric with a b value of 2.651. While the condition factor range average values are 1.009 – 1.027. The results of this study are expected to be the basis for efforts to support the sustainable management of fisheries resources, especially the yellow trevally in the coastal waters of Lekok.

Can artificially induced habitat complexity alter macroinvertebrates diversity? A case study from a freshwater wetland ecosystem

Habitat complexity can enhance the resilience of wetlands against environmental stressors such as extreme weather events, pollution, and habitat loss. The introduction of artificial induced complexity (AIC) can play a significant role in reshaping the macroinvertebrate communities within wetland ecosystems by enhancing habitat quality in protected areas. Therefore, this study was designed to examine the variation of macroinvertebrates community structure in artificially induced complex sanctuary site (SS), partially protected (PP) and open sites (OS) from July 2019-April 2020. AIC in the sanctuary sites was established through the installation of cemented hexapods and ring pipes. Over the study period, a total of 665 macroinvertebrates were gathered, with 55.55% originating from SS, 31.14% from PP, and 18.21% from OS sites. The community consists mainly of Lymnaea acuminatatea and Tubifex tubifex, with the most abundant species being Limnodrillus hoffmeisteri and Branchiura sowerbyi. A notable positive impact of AIC was evident in the increased total abundance and diversity indices of macroinvertebrate communities. The Analysis of Similarity (ANOSIM) revealed significant distinctions in community structures among various intervention types, which was further corroborated by a non-metric multidimensional scaling (nMDS) plot. Similarity of Percentage Analysis (SIMPER) highlighted that Limnodrillus hoffmeisteri made the most significant contribution to the dissimilarity observed among the different intervention types. Canonical Correspondence Analysis (CCA) revealed a close association between the structure of the macroinvertebrate community and three key ecological factors: periphyton biomass, macrophyte cover, and sediment properties. These findings could offer a more effective approach for managers and policymakers engaged in the conservation of macroinvertebrates and the sustainable management of fisheries resources within wetland ecosystems.

Modelización bionómica de poblaciones de peces hiperestables. La pesquería de curvina golfina, Cynoscion othonopterus, como estudio de caso

Catch and fishing effort data are generally available, hence surplus production models are commonly used to conduct assessments. However, hyperstability resulting from spawning aggregations (SA) pose challenges to determine status and inform management of many fisheries resources. Using data from 1991 to 2019, we develop a method to study hyperstable fished stocks relaxing the assumption of constant catchability, hence direct dependence of catch-per-unit-effort and biomass. Information criterion was used to choose the best model including a Cobb-Douglas function for gulf corvina (Cynoscion othonopterus), a sciaenid fish endemic to the gulf of California managed through annual quotas. Bionomic stock-reduction models were fit using catch, effort, published natural mortality, virgin biomass, and economic structure. Models were solved using maximum likelihood and the best model chosen with Akaike information criterion. Current fishing effort is beyond bionomic optimum. This deserves a precautionary approach to protect this endemic species and sustain the fishery.

A comparative study of population management approaches in infectious disease control, population management of fisheries and wildlife, and integrated pest management in agriculture

AbstractThis paper provides a comprehensive study on the similarities and differences between infectious disease control in public health and various population management approaches, including fisheries resource management, wildlife management, and integrated pest management in agriculture. We aim to identify key strategies, and potential synergies that can contribute to the development of population management strategies within these domains. For example, scientists provide options but leave policy making itself to stakeholders, choose monitoring indicators with as little time lag or change thresholds between increasing and decreasing phases to account for time lag, consider economic feasibility, and clarify accountability, which are common to all fields. There are many elements to incorporate methods from other fields while making use of the accumulation gained in each field.

Analysis of Policy Strategy for Empowerment of Fisherman in Teluk Village, Labuan Sub-District, Pandeglang Regency

The community empowerment approach is sought to provide guidance for the sustainability of the livelihoods and lives of the fishing communities of Teluk Village, Labuan District, Pandeglang Regency, especially after being hit by the tsunami (22/12/2018) and the Covid-19 pandemic. Ecosystem preservation also requires commitment from stakeholders. The policy strategy is the government's task that needs to be analyzed, while the community has strong social capital, as a form of survival in facing opportunities, challenges and threats in the management of marine and fishery resources. This study aims to analyze the policy strategy for empowering fishermen in Teluk Village, Labuan District, Pandeglang Regency. The key theory used is the concept of strategy according to Hunger-Wheelen (2003: 9), through observing the external environment to describe opportunities and threats, then observing the internal environment of the organization to describe strengths and weaknesses known as Strengths, Weaknesses (weaknesses). Opportunities (opportunities), and Threats (threats). The approach used in this research is descriptive qualitative. Through this approach it is intended to be able to take a full picture of various phenomena that aim to describe, summarize various conditions, various situations or various social realities of empowering the fishing community in Teluk Village, Labuan District, Pandeglang Regency. The results of the study show that the policy strategy for empowering fishermen in Teluk Village refers to strengthening the internal and external sources of the Pandeglang Regency Maritime Service organization, including efforts in the field of empowering fishermen by carrying out various fisheries business development programs, carrying out fishermen technical guidance for business groups with fishermen. Furthermore, monitoring and evaluation, as well as carrying out reports. The suggestion that the researchers put forward is to increase various efforts to empower fishermen in the Bay Village by encouraging fishermen's involvement in accessing various institutional fishermen empowerment programs and revitalizing various facilities and infrastructure that require development and repair due to the tsunami disaster.

Spatial–temporal distribution characteristics of Harpadon nehereus in the Yangtze River Estuary and its relationship with environmental factors

To investigate the spatial–temporal distribution characteristics of Harpadon nehereus in the Yangtze River Estuary (YRE) and its relationship with environmental factors, this study used the data from resource and environmental surveys conducted in the YRE and adjacent waters during August (summer) and November (autumn), 2017–2022. Generalized additive models (GAM) were employed to analyze the relationships between the relative resources of H. nehereus and environmental factors and to predict the spatial–temporal distribution of H. nehereus resources in 2022. Our results revealed that the best model deviance explained in summer and autumn was 64.89% and 49.90%, with average effect sizes of 0.75 and 0.70, respectively, for cross-validated regression slopes. Water temperature and salinity were identified as the key environmental factors influencing the relative resources of H. nehereus in the YRE. Overall, there were notable seasonal differences in the relationship between the relative resources of H. nehereus and environmental factors. The relative resources of H. nehereus in the YRE were higher in the summer than in autumn. In summer, both water temperature and salinity exhibited multi-wave nonlinear relationships with the relative resources of H. nehereus, while in autumn, the relative resources of H. nehereus showed a positive linear relationship with water temperature and a non-linear relationship with salinity. Additionally, the predicted and observed values of the relative resources of H. nehereus in 2022 showed similar spatial distribution patterns. The relative resources of H. nehereus was higher in the northern branch than in the southern branch and the offshore regions compared to the near-estuary regions. Altogether, our study provides a scientific basis for conservation management and sustainable utilization of H. nehereus resources in the YRE, thereby contributing to the restoration and management of fishery resources in the region.

Assessment of Fish Species in Wanlv Lake, the Largest Drinking Water Source in South China, by Environmental DNA Metabarcoding Technology

As the largest lake in South China, Wanlv Lake is also an important drinking water source for Guangdong and Hong Kong and is responsible for water supplying of more than 40 million people in the Guangdong-Hong Kong-Macao Greater Bay Area. The study of fish diversity in Wanlv Lake can help us to effectively understand the changes and states of its aquatic ecosystem and provide scientific basis for natural ecological protection, biodiversity, sustainable use and scientific management of fishery resources. However, research on the lake’s fish is scarce. The high throughput environmental DNA metabarcoding technology (eDNA technology) of the mitochondrial 12S rRNA gene sequence was herein used to conduct a preliminary exploration of Wanlv Lake fish diversity. A total of 10 sampling sites were set up to monitor fish diversity and analyze the composition and richness of the species. The results revealed a total of 83 genera in 42 families and 17 orders of fish in the lake, with the highest proportion found in Cypriniformes (38 species), accounting for 45.24% of the total. Five alien species and eight rare and endangered species were also detected. The proportion of invasive species was 5.95%, and the combined proportion of rare and endangered species was 9.52%. The results indicated that Wanlv Lake serves as an important drinking water source, and overall, the condition of fish is satisfactory. However, proactive measures should be implemented to control the overpopulation of invasive species, as their unchecked proliferation may lead to a decline in species abundance, particularly among endangered species. This was the first overall assessment report on fish of the Wanlv Lake via 12S rRNA; the results herein lay a foundation for water quality assessment of Wanlv Lake as a drinking water source.

COI-high resolution melting analysis for discrimination of four fish species in the family Notopteridae in Thailand

Species identification is an essential and vital basis for biological research. Since several fish species have similar appearances and shapes at different developmental stages and researchers lack experience identifying these fish species, molecular techniques are needed. In Thailand, fish species of the family Notopteridae consist of two genera and four species, including Notopterus notopterus, Chitala ornata, Chitala blanci, and Chitala lopis. The combination of the cytochrome c oxidase I (COI) gene sequences with a nonsequencing approach, high-resolution melting (HRM), was developed to discriminate four target species in a rapid, reliable and cost-effective manner. One of three designed primer pair sets, Notop-HRMF1/Notop-HRMR1, was the most appropriate and provided four distinct melting curves. In addition, ten fish species of other families were used for the specificity test, and only the four target species of Notopteridae were specific for this primer pair set. The results of this study indicated that COI-HRM analysis is an efficient approach for identifying species of Notopteridae in Thailand. Applications of this technique may be used to investigate species of this family in processed fish products or larval fish species in several spawning grounds for sustainable fishery resource management.

Survivorship of discarded cuckoo ray in bottom trawl fisheries in the northern Bay of Biscay, Southern Celtic and Irish Seas

Estimating the survivorship of discarded fish is often crucial for stock assessment and resultant management of fisheries resources. In order to assess the survivorship of cuckoo ray (Leucoraja naevus) caught in commercial bottom trawl fisheries, experiments involving French and Irish fisheries were conducted. These experiments were particularly challenging considering the fisheries are offshore. Data from these experiments were analysed jointly in this study. Results from monitoring of individuals held in captivity in onshore facilities and observations of vitality status were combined to produce estimates of long-term survival rates across fishing trips in all four seasons. These rates varied greatly between fishing trips and ranged between 3.6% and 26%. Based on indications that the observed mortality may be at least partly attributable to the conditions of captivity, we propose an approach to reduce the underestimation bias when estimating discard survival. This approach produced higher bounds for the estimated discard survival rates. The estimated survival rates are lower than those of other skate species in the North-East Atlantic, suggesting the cuckoo ray is less resilient to trawl-and-release, although previous studies were conducted in shallower water and with shorter haul duration.

Status Identification in Support of Fishing Effort Estimation for Tuna Longliners in Waters near the Marshall Islands Based on AIS Data

Visualising the fishing behaviour of vessels and quantifying the spatial distribution of fishing effort is the scientific basis for assessing and managing fisheries resources. The information on the dynamics of fishing vessel voyages provided by the automatic identification system (AIS) of vessels serves as high-precision fishery data and provides a means of quantifying fishing effort with high spatial and temporal resolution in the tuna longline fishery. Based on the AIS data of five tuna longliners operating in the waters near the Marshall Islands from 2020 to 2021, this study used three methods, namely the threshold screening method, the construction of a BP neural network and the support vector machine (SVM) to identify the fishing and non-fishing status of the tuna longliners, respectively. This study investigates the status identification and fishing effort estimation of the tuna longliner (VESSEL A) in 2021 based on the constructed optimal model, and spatial correlation analyses are performed between the fishing effort estimated in hours based on AIS data and in hooks based on fishing logbook data, by month. The results showed (1) the recognition accuracy of the threshold screening method is 89.9%, the recognition accuracy of the BP neural network classification model is 95.11%, the kappa coefficient is 0.51, the recognition accuracy of the SVM classification model is 95.74% and the kappa coefficient is 0.52; (2) in comparison, the SVM classification model performs better than the other two status identification methods for tuna longliners; and (3) the correlation coefficients between the two types of effort of VESSEL A were greater than 0.79 on all fishing months, indicating that there was no significant difference in the spatial and temporal distribution between the two types of effort. This study suggests that the SVM model can be used to identify the status and estimate the fishing effort of longliners.

A short-term of starvation improved the antioxidant activity and quality of African catfish (Clarias gariepinus).

Clarias gariepinus is an important freshwater fish with high economic value and breeding potential in China. It is a fast-growing and adaptable catfish, but the main problems facing the current market are its low price and poor taste, although starvation is a good solution to these problems. In this study, the effects of starvation on the physiology, biochemistry, and muscle quality of C. gariepinus were investigated. The results showed that compared with the control group, the weight gain rate and specific growth rate of the starvation group were significantly different. Body weight, visceral weight, condition factor, viscerosomatic index, hepatosomatic index, and viscera fat index all decreased, while visceral weight and hepatosomatic index decreased significantly after starvation for 30days. The hardness and crude protein of muscle increased significantly and crude lipid decreased significantly. Taste-enhancing amino acids increased slightly, and fatty acids increased significantly. Compared with the control group, starvation led to changes in antioxidant defense parameters. The level of malondialdehyde (MDA) in liver increased significantly; the activities of superoxide dismutase (SOD) increased in serum after 30 days; the activities of glutathione peroxidase (GSH-Px) increased considerably in the serum and liver after 15 days; the activities of alanine aminotransferase (ALT) increased considerably in the serum and liver after 30 days. The in-depth study of changes in physiological, biochemical, and nutritional components of fish under starvation is helpful to understand the ecological strategy of fish to adapt to starvation and of great guiding significance for fishery resource management and aquaculture production.

Strengthening Blue Economy Policy to Achieve Sustainable Fisheries

Particularly in developing nations, the aquaculture and fisheries sector is vital to the nutrition and food security of the global population. Nevertheless, notwithstanding their substantial social and economic potential, fishery resources are susceptible to overexploitation and hurting the environment. This research assesses the significance of bolstering blue economy policies to enhance sustainable maritime policies. This study employs the methodology of normative legal research. The research findings, the deterioration of ecological equilibrium, as evidenced by the diminishing carrying capacity of the sea, can be attributed to conservation efforts that lack a stronger emphasis on sustainable management. Maintaining the fundamental tenets of equitable and sustainable fisheries management in nations endowed with oceans is paramount. State and government policies toward society and distributive equity are inextricably linked in managing fisheries resources; local governments may be entrusted with autonomous design and assistance responsibilities for these policies. As a result, a revised vision for constructing a sustainable, equitable, and ambitious blue economy is proposed. Promoting resource-based economic development in the marine and fisheries industrial sector while preserving coastal environments and marine resources through the blue economy concept is possible. This vision is founded upon the following five governance principles: inclusive and equitable processes, climate stability, sustainable consumption and production, circular processes, and the promotion of healthy ecosystems.

Evaluation of the Success of E-Log Book Implementation for Handline Fishing Gear at Bitung Fishing Port

Ensure optimal and sustainable management of fishery resources and the preservation of fishery resources, accurate fisheries data is essential. One way to achieve this, is by using fishing log books. Improvements have been made by developing an electronic-based fishing log book (e-log book) that is Android-based, paperless, and capable of offline mode. However, an evaluation of the use of e-log books in the perspective of captains (users), has not been conducted. This research aims at assessing user satisfaction propensity and evaluating the extent of the success of the implementation of the e-log book for handline fishing gear at Bitung Fishing Port (PPS) using the DeLone and McLean model. The sampling method employed is purposive sampling, with 115 respondents consisting of handline captains who use e-log books. The research was carried out for 3 (three) months in January – March 2023.The data analysis was conducted using propensity test and PLS-SEM. The propensity test results indicate that the implementation of e-log books at Bitung Fishing Port is in the high category at 77.39%. The PLS-SEM analysis results indicate that out of the four proposed hypotheses, not all were supported and accepted. The quality of the system and service influences user satisfaction, and user satisfaction also affects net benefits. However, the quality of information does not impact user satisfaction. The conclusion drawn from this study depicts that, the satisfaction of handline fishing gear captains regarding the implementation of e-log books at Bitung Fishing Port is at a "high" level. Meanwhile, the e-log book application implementation still faces some challenges or aspects that need improvement to achieve the expected level of success.

Otolith morphology and total length relationships in Schizothorax grahami

Otolith is important for studying fish populations and life histories. In this study, the dominant species of Schizothorax grahami in the source section of the Chishui River was taken to understand the relationships between otolith morphology and total length (TL). Results showed a large difference between the four TL groups (A/B/C/D), except group B is similar to group C. The combined discrimination success rate of linear discriminant analysis was 62.2%. Group A and D’s success rate is the highest, at around 75%. Meanwhile, the success rate for Group B and Group C is below 65%. The one-way ANOVA of the Shape Index and the Canonical analysis of Principal Coordinates with two coefficients (Fourier coefficients and Wavelet coefficients) showed that Group B is similar to Group C, with a large difference from the other two groups. When TL was greater than 100 mm (the pearl organs appearing), the otolith growth was lower changing. Otolith morphology still changes with growth after sexual maturity in fish, so the larger fish is more useful for conducting otolith morphology studies for accurate evaluation and management of local fishery resources.

Puerulus settlement forecasting in a harvest strategy evaluation of the rock lobster fishery in South Australia

AbstractHarvest strategies are utilised in the management of fishery resources globally. Critical to their success is harvest strategy evaluation, whereby future performance is assessed through projection modelling. Using the observed relationship between a puerulus settlement index and model‐estimated recruitment, we evaluated a southern rock lobster (Jasus edwardsii) harvest strategy in South Australia. Short‐to‐medium puerulus settlement recruitment forecasting was incorporated into future projections of catch, catch per unit effort, and percent unexploited egg production (%UEP) during 2019–2022. Observed values of indicators that closely aligned with projected outputs indicated that puerulus forecasting underpinned reliable evaluation of future fishery performance. A key objective of the harvest strategy was to increase egg production in the fishery, with a 20% unexploited egg production targeted by 2036. The target was reached under the proposed strategy, but was sensitive to recruitment, thereby highlighting the need to consider climate change impacts in forecasting scenarios.