Aquatic Resources Research Articles

Hazards Associated with Plastic Wastes in the Communities of Niger Delta, Nigeria

The goal of this study was to investigate into the negative impacts that the presence of plastic waste in the communities located in the Niger Delta may have on the environment and human health. The following physico-chemical properties of the water, fish, sediment, and human blood samples were measured and analyzed: pH, electrical conductivity, total dissolved solids, temperature, dissolved oxygen, nitrate, and phosphate. Furthermore, an assessment of polycyclic aromatic hydrocarbons (PAHs) was included of the inquiry. Gas chromatography mass spectrometry (GC-MS) was used to measure the concentrations of polycyclic aromatic hydrocarbons (PAHs). The data was analyzed using the Statistical Package for the Social Sciences, Version 25.0. Standard deviation, mean, and percentage were among the descriptive statistical metrics used. Furthermore, inferential statistical techniques like Turkey's Test and Analysis of Variance (ANOVA) were used to determine the presence of this correlation within a 0.05 confidence interval. The study's findings showed that polycyclic aromatic hydrocarbon (PAH) congeners came in 10, 9, and 11 distinct varieties in fish, water, and human blood, respectively. Therefore, it is essential to conduct routine monitoring to assess the effects that waste plastic is having on the aquatic resources and the local people in the Niger Delta. This will help evaluate how these environmental risks are now manifesting and how they affect public health.

Assessment of Fisheries Diversity in Mathabhanga River in the Southwestern Part of Bangladesh

Mathabhanga is an important and well-known river in the southwestern part of Bangladesh due to its role in fish production and as a vital income source for numerous fishermen. The study was carried out from August 2022 to July 2023 to reveal the existing aquatic resources and their composition, along with diversity, richness, and evenness indices. A comprehensive list of 57 distinct fish species has been documented, spanning across 8 orders, 22 families, and 42 genera. Within these, the Cypriniformes order exhibited the highest diversity in terms of both species count and observed individuals. Among the fish species inhabiting the Mathabhanga river, approximately 29.83% are considered threatened in Bangladesh, comprising 14.04% categorized as vulnerable (VU), 14.04% as endangered (EN), and 1.75% as critically endangered (CR). Overall values of the diversity index ranged from 2.45 to 3.15, richness was 3.81 to 6.17, and evenness index was 0.72 to 0.84. The investigation revealed that fish biodiversity in the Mathabhanga River has been steadily decreasing. This study suggested that fisheries should be managed through community-based fisheries management, establishing fish sanctuary, water pollution control, maintenance of fishing gear, and the implementation of the Fish Act for the sustainable management of fish biodiversity in the Mathabhanga River. Res. Agric. Livest. Fish. Vol. 11, No. 1, April 2024: 93-103

Sosialisasi dan Penanaman Mangrove Bersama Masyarakat Pesisir Desa Sungai Pasir, Kecamantan Lunci, Kabupaten Sukamara

One of the regions in Indonesia that has mangrove forests is Sukamara Regency, Central Kalimantan Province. With this location, this Community Service (PKM) will provide outreach regarding the understanding of the residents of Sungai Pasir Village about the Types, Characteristics and Habitat of Mangroves and 2) Planting Mangroves on the Coastal Coast of Sungai Pasir Village, Sukamara Regency. The method used is socialization in providing education to the community on the Coastal Coast of Sungai Pasir Village, Sukamara Regency. The PKM results show that there is cooperation between the community, the village government, representatives of the Watershed and Protected Forest Management Center (BPDASHL) and the Head of the Aquatic Resources Management Study Program, Faculty of Agriculture, Antakusuma University, Pangkalan Bun in preserving Mangroves.

A comparative survey between cascade correlation neural network (CCNN) and feedforward neural network (FFNN) machine learning models for forecasting suspended sediment concentration

Suspended sediment concentration prediction is critical for the design of reservoirs, dams, rivers ecosystems, various operations of aquatic resource structure, environmental safety, and water management. In this study, two different machine models, namely the cascade correlation neural network (CCNN) and feedforward neural network (FFNN) were applied to predict daily-suspended sediment concentration (SSC) at Simga and Jondhara stations in Sheonath basin, India. Daily-suspended sediment concentration and discharge data from 2010 to 2015 were collected and used to develop the model to predict suspended sediment concentration. The developed models were evaluated using statistical indices like Nash and Sutcliffe efficiency coefficient (NES), root mean square error (RMSE), Willmott’s index of agreement (WI), and Legates–McCabe’s index (LM), supplemented by a scatter plot, density plots, histograms and Taylor diagram for graphical representation. The developed model was evaluated and compared with CCNN and FFNN. Nine input combinations were explored using different lag-times for discharge (Qt-n) and suspended sediment concentration (St-n) as input variables, with the current suspended sediment concentration as the desired output, to develop CCNN and FFNN models. The CCNN4 model with 4 lagged inputs (St-1, St-2, St-3, St-4) outperformed the other developed models with the lowest RMSE = 95.02 mg/l and the highest NES = 0.0.662, WI = 0.890 and LM = 0.668 for the Jondhara Station while the same CCNN4 model secure as the best with the lowest RMSE = 53.71 mg/l and the highest NES = 0.785, WI = 0.936 and LM = 0.788 for the Simga Station. The result shows the CCNN model was better than the FFNN model for predicting daily-suspended sediment at both stations in the Sheonath basin, India. Overall, CCNN showed better forecasting potential for suspended sediment concentration compared to FFNN at both stations, demonstrating their applicability for hydrological forecasting with complex relationships.

Impact of Social Restrictions During COVID-19 on the Aquatic Levels of Antimicrobials and Other Drugs in Delhi.

The relative contribution of factors responsible for the environmental exposure of active pharmaceutical ingredients (APIs) is of interest for appropriate remedial measures. This study was carried out to evaluate the post-lockdown levels of APIs in water resources, in comparison to our previously published study from 2016. The environmental levels of 28 drugs from different classes were analyzed in surface water (Yamuna River), aquifers, and leachate samples collected from 26 locations in Delhi-NCR using the previously validated liquid chromatography-mass spectrometry (LC-MS/MS) methods. In addition, the prevalence of antimicrobial resistance in coliforms isolated from targeted surface water samples was also studied. This study revealed that more than 90% of APIs, including antibiotics, decreased drastically in both surface water and aquifers compared to our previous data. Selected samples subjected to antimicrobial resistance (AMR) analysis revealed the presence of cephalosporin-resistant coliform bacteria. Tracing cephalosporins in the surface and drain water samples revealed the presence of ceftriaxone in the drain and water samples from Yamuna River. Higher levels of ceftriaxone in landfill leachate were also found, which werefound to be associated with coliform resistanceand indicatethe un-segregated disposal of medical waste into landfills. Social restrictions enforced due to COVID-19 resulted in a drastic decrease in antimicrobials and other APIs in aquatic water resources. Increased ceftriaxone and cephalosporin resistance was seen in coliform from surface water and drain, indicating the possibility of hospital waste and treatment-related drugs entering Yamuna River. Enforcement of the regulations for the safe disposal of antibiotics at hospitals and preliminary disinfection of hospital sewage before its inflow into common drains might help minimize the spread of antibiotic resistance in the environment.

Sediment Toxicity Tests: A Critical Review of Their use in Environmental Regulations.

Sediments are an integral component of aquatic systems, linking multiple water uses, functions, and services. Contamination of sediments by chemicals is a worldwide problem, with many jurisdictions trying to prevent future pollution (prospective) and manage existing contamination (retrospective). The present review assesses the implementation of sediment toxicity testing in environmental regulations globally. Currently, the incorporation of sediment toxicity testing in regulations is most common in the European Union (EU), North America, and Australasian regions, with some expansion in Asia and non-EU Europe. Employing sediment toxicity testing in prospective assessments (i.e., before chemicals are allowed on the market) is most advanced and harmonized with pesticides. In the retrospective assessment of environmental risks (i.e., chemicals already contaminating sediments), regulatory sediment toxicity testing practices are applied inconsistently on the global scale. International harmonization of sediment toxicity tests is considered an asset and has been successful through the widespread adoption and deployment of Organisation for Economic Co-operation and Development guidelines. On the other hand, retrospective sediment assessments benefit from incorporating regional species and protocols. Currently used toxicity testing species are diverse, with temperate species being applied most often, whereas test protocols are insufficiently flexible to appropriately address the range of environmental contaminants, including nanomaterials, highly hydrophobic contaminants, and ionized chemicals. The ever-increasing and -changing pressures placed on aquatic resources are a challenge for protection and management efforts, calling for continuous sediment toxicity test method improvement to insure effective use in regulatory frameworks. Future developments should focus on including more subtle and specific toxicity endpoints (e.g., incorporating bioavailability-based in vitro tests) and genomic techniques, extending sediment toxicity testing from single to multispecies approaches, and providing a better link with ecological protection goals. Environ Toxicol Chem 2024;43:1697-1716. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Preface

The 2nd Aquatic Science International Conference 2023 Aquatic Science International Conference (ASIC) is an annual international conference organized by Faculty Fisheries and Marine Sciences, Brawijaya University. ASIC stands for International Conference on Sustainable Aquatic Resources. It provides a platform to exchange knowledge regarding development of aquatic sciences through sustainable Aquatic Resources. This year the main theme of the 2nd Aquatic Science International Conference (ASIC) 2023 is “Aquatic Science Roles in Supporting the Sustainable Aquatic Development” with a focus on aquatic sustainable resources. This conference topic is particularly important and necessary to support the sustainable aquatic resources sectors which play an integral role in the transformation of future development. The Aquatic Science is a recent field of study that encompasses economic activities that depend on aquatic sectors. The sub-theme of the 2nd ASIC 2023 consists of 1) Aquatic Biodiversity; 2) Aquatic Biotechnology; 3) Aquatic Ecotoxicology; 4) Aquatic Ecology/Limnology; 5) Aquatic Waste Management; and 7) Aquatic Conservation; 8) Aquatic Ecotourism.The aim of this conference is to present how science and new ideas can provide the best possible solutions to address challenges of aquatic science from sustainable aquatic resources, and evolving challenges which are evolving challenges which are essential for sustainable developmentThe technical program is varied with six (6) keynote speakers and two (2) invited speakers from various country such as Indonesia, Italia, India, Japan, and Malaysia. This program has not only been attended by local researchers and academicians, but also foreign researchers (Poland, Malaysia, Taiwan and Japan).Through the 2nd ASIC, all participants would find valuable findings, including the keynote speakers, invited speakers, and technical sessions in developing better world through the contribution of sustainable aquatic resources. Our thanks to go out to the International Scientific Committee of the 2nd ASIC, Keynote Speakers, Invited Speakers, Scientific Reviewers and Local Committee of the 2nd ASIC 2023 and all participants who have assisted to make this conference success. Abd. Aziz Amin, MSc Head Committee of the 2nd ASIC 2023List of Organizing Committee is available in the pdf

Promoting Water Sustainability through Degradation of 4-Nitrophenols by Spirodela polyrrhiza and Rhodococcus sp. Strain PKR-1 Association

The removal of chemicals from water sources that are harmful to humans and the environment can contribute to improving water quality. Biological treatment methods, such as bioaugmentation are an environmentally sustainable approach for pollutant removal. The 4-nitrophenol is the most hazardous nitrophenol chemical pollutant. In this study, a laboratory investigation was conducted on a flask scale to evaluate the rhizoaugmentation of 4-nitrophenol-polluted water. This was achieved by employing Rhodococcus sp. strain PKR-1, which was reintroduced into the roots of Spirodela polyrhiza. The selected strains were inoculated into the root at the rate of 104 to 106 colony-forming units (CFU) per plant. At high levels exhibited stability across five consecutive two-day degradation cycles, and full elimination of 4-nitrophenol was accomplished within these five repeated cycles. Therefore, the introduction of degraders into the root systems of aquatic plants has proven to be a successful method for treating effluents or aquatic resources contaminated with 4-nitrophenol.

Identification of key habitats and conservation threats of the Ganges River dolphin (Platanista gangetica) of Bangladesh

Ganges River Dolphins (Platanista gangetica) are known to inhabit all major river systems in Bangladesh. However, comprehensive spatial records for this globally endangered aquatic mammal are notably scarce nationwide. Furthermore, their habitats are increasingly threatened due to excessive utilization of aquatic resources and their habitats by the growing human population. To allocate limited resources in safeguarding high-priority dolphin habitats, we conducted field surveys and arranged stakeholder consultations to identify key dolphin habitats and the conservation threats they face across Bangladesh. Through this process, we have identified 14 river segments as high-priority winter habitats for Ganges River Dolphins. These dolphins encounter both direct and indirect threats within their habitats. Direct threats include entanglement and occasional intentional killing for traditional medicinal purposes and as fish attractants. Indirect threats leading to habitat degradation comprise the construction of dams and barrages for upstream water extraction, increasing industrial pollution in river waters, overfishing, and alterations to river morphology caused by siltation and sedimentation. The heavy reliance of local communities on dolphin habitats, coupled with a lack of widespread awareness and insufficient conservation efforts, pose significant challenges to the future survival of Ganges River Dolphins in Bangladesh. Bangladesh J. Zool. 51(3): 253-266, 2023

Biological indicators and commercial exploitation of main fish and river crayfish species of the Zaporizhzhia (Dnipro) reservoir

Aim: To analyze and summarize the biological indicators of the main industrial fish and river crayfish species in the Zaporizhzhia (Dnipro) reservoir under conditions of fishery exploitation. Methods: Biological analysis of fish was conducted according to classical methods in ichthyology, using the following parameters: standard and absolute body length, individual mass, gender, feeding coefficient. Crayfish, caught in fishing gear, underwent morphometric measurements to determine individual mass and gender. Biological sampling was carried out during the vegetation period of 2023 during both control and commercial fishing in the Zaporizhzhia (Dnipro) reservoir at three sites differing in hydrology and degree of anthropogenic impact. Research results: According to the data from the Department of the State Agency of Reclamation and Fisheries Management in Dnipropetrovsk Oblast, during 2023, 140,504 tons of fish were caught in the Zaporizhzhia (Dnipro) reservoir, nearly 8 times less than in 2021. In 2021, 1078.25 tons of aquatic resources were caught, which is 8 % less than in 2020. Silver carp was the dominant fish species in 2022, accounting for 80.5 % of the total catch in the reservoir. Herbivorous fish species accounted for 5.4 % of the catch, roach - 3.3 %, bream - 2.3 %, perch - 2.0 %. Based on the conducted research, recommendations have been provided regarding the establishment of forecasts and limits for the extraction of aquatic resources from the Zaporizhzhia (Dnipro) reservoir for the year 2024. Conclusions: The Zaporizhzhia (Dnipro) reservoir has potential for the development of fishing, fish farming, and aquaculture in the Prydniprovsky region. The research results suggest that limits can be set on the catch of certain fish species: bream- up to 210 tons, pike-perch - up to 42 tons, roach - up to 350 tons, and perch - up to 138 tons. However, the catch of silver carp, bleak, sprat, herbivorous fish, and sun-perch is recommended to be unrestricted. The forecasted catch of crayfish is within 1 ton. The catch of other aquatic resources should also be conducted within forecasted levels

Урожайність молоді риб прибережних ділянок р. Дністер у межах Івано-Франківської області

Purpose. Taking into account the unique ichthyological complex of the upper course of the Dniester River, the studies should be directed both at the structure of the ichthyofauna and at its quantitative parameters of the species structure, and fish with a special conservation status need special attention. Therefore, the purpose of our work was to determine the peculiarities of the current structural and functional organization of the ichthyocenosis of the Dniester River within the Ivano-Frankivsk region. Methodology. Quantitative assessment of fish juveniles was carried out using the area method. Fish juveniles were identified to the species level using A.F. Koblytska and Yu.V. Movchan identification keys. All fish, after some measurements, were released to the place where they were caught in an undamaged state and alive. After identification of fish species with a special conservation status, which were trapped into the fishing gear, they were immediately returned to their habitat without removing them from water. Findings. Fourteen fish species were observed in the community of fish juveniles on the nearshore areas of the Dniester River in the Ivano-Frankivsk region. According to the data of the analysis, following relative abundances of juvenile fish species were observed: vyrezub (40% of the total abundance), bleak (23% of the total abundance) and vimba (18% of the total abundance). The total relative abundance of fish juveniles with special conservation status in the total catch was 68%, which suggested the need to create additional zones in order to increase conservation measures. Given the high share of fish species with special conservation status, the assessment of species biodiversity in terms of biotope similarity is important. The area of Mariyampil village and floodplain coastal areas were characterized by the highest biodiversity in terms of species composition of ichthyofauna among the studied biotopes. The highest abundance of fish juveniles in absolute values was recorded in the mouth areas of the rivers, but its high values were achieved due to the juveniles of vyrezub. Also, this studied nearshore area was not characterized by a high biodiversity of ichthyofauna, which was confirmed by the Shannon-Weaver index at the level of 1.74. According to the results of our study, it can be stated that the nearshore areas of the mouth part of the rivers are important and unique for the formation of ichthyocenosis specifically for the vyrezub. Thus, it can be concluded that all analyzed stations were characterized by the presence of vyrezub, which allows classifying the studied area as important in terms of environmental protection. In view of the prevalence of juvenile vyrezub within the studied areas, protective measures are more important, which are aimed not only at ensuring control over the state of aquatic biological resources, but also at the organization of artificial replenishment of natural localities and the creation of new populations of this species with their purposeful acclimatization in specially selected ecological conditions of the water body. Originality. For the first time, the yield of fish juveniles in the nearshore areas of the Dniester River within the Ivano-Frankivsk Region was analyzed. The obtained data will be used to solve the problem of the preservation of species diversity and the abundance of fish species, which are valuable in terms of environmental protection. Practical value. As a result of the assessment of the current state of the ichthyofauna of the Dniester River within the limits of the Ivano-Frankivsk region, data were obtained regarding the natural localities of rare and endangered fish species in the specified area. Keywords: ichthyofauna, Dniester River, protected species, natural locality.

Попередня оцінка втрат для рибного господарства Харківської області внаслідок воєнних дій

Purpose. Based on the author’s materials, to carry out a preliminary assessment of ecological and economic losses caused to the fisheries complex of the Kharkiv region as a result of military actions. Methodology. Field studies on water bodies of the Kharkiv Region, which were affected by military actions, were conducted. Public data of the State Agency of Land Reclamation and Fisheries of Ukraine in the Kharkiv Region (2021–2023) were used. The following research methods were used during the assessment of the ecological consequences and economic losses caused to the aquatic biological resources of water bodies of the Kharkiv region: analytical – collection of information from official sources of enterprises and institutions carrying out economic activities, control and monitoring of water bodies; geoinformation – assessment of the actual hydrological regime of water bodies; identification of the spatial location, measurement of quantitative and qualitative characteristics of water areas formed after the reservoirs drying-up; hydrobiological – determination of fish species and other hydrobiont composition; statistical – for qualitative and quantitative assessment of commercial ichthyofauna and the economic damage inflicted to the fishery; forecast –assessment of the potential transformation of the species biodiversity of the ecosystem in time under different conditions of further development of the water sector of Ukraine. Findings. The impact of military actions on the conditions of existence of aquatic biological resources in the Oskil and Pechenegi reservoirs, on the functioning of special commercial fish farms, the production of aquaculture products, and the development of industrial and recreational fishing in the region has been preliminarily assessed. The calculation of economic losses for aquatic bioresources of water bodies of the Kharkiv region was carried out. Originality. For the first time, a preliminary assessment of losses for the fisheries industry (including commercial, recreational fishing, aquaculture) of the Kharkiv region due to military actions was carried out. Practical value. The obtained results have important and multifaceted practical value, in particular they can be used for: assessment of environmental damage caused to Ukraine as a result of military actions; rational management of water and fisheries management due to restoration of water ecosystems exposed to military impact; development of recommendations on restoration of ecosystem services; spread of social awareness about the post-war environmental challenges of the future; making decisions about investments in natural resources and the use of ecosystem services.

Enhanced dietary reconstruction of Korean prehistoric populations by combining δ13C and δ15N amino acids of bone collagen.

Compound specific stable isotope analysis of amino acids (CSIA-AA) is a powerful tool for determining dietary behaviors in complex environments and improving dietary reconstructions. Here, we conducted CSIA-AA on human (n = 32) and animal (n = 13) remains from two prehistoric archaeological sites (Mumun, Imdang) to assess in more detail the dietary sources consumed by prehistoric Korean populations. Results of estimated trophic position (TP) using Δ15NGlx-Phe show that the Imdang individuals consumed aquatic resources, as well as terrestrial resources. Principal component analysis (PCA) using δ13C and δ15N essential amino acid (EAA) values show that the Imdang humans closely cluster with game birds and terrestrial herbivores, whilst the Mumun humans closely cluster with C4 plants. Quantitative estimation by a Bayesian mixing model (MixSIAR) indicates that the Imdang humans derived a large proportion of their proteins from terrestrial animals and marine fish, whereas the main protein sources for the Mumun humans were C4 plants and terrestrial animals. Additionally, the comparison between the EAA and bulk isotope models shows that there is a tendency to overestimate the consumption of plant proteins when using bulk isotopic data. Our CSIA-AA approach reveals that in prehistoric Korea there were clear differences in human diets through time. This study adds to a growing body of literature that demonstrates the potential of CSIA-AA to provide more accurate estimations of protein consumption in mixed diets than previous bulk isotopic studies.

Ecological Insights, and Fin Fish Diversity in Carps Spawning Grounds: Case Studies from the Surma River and Tanguar Haor, Bangladesh.

This study aims to provide a thorough ecological understanding of fin fish diversity within carp spawning grounds in the Surma River and Tanguar haor. Over two spawning seasons, this research investigates ecological factors impacting fin fish diversity and abundance in carp spawning grounds of the Surma River and Tanguar haor, emphasizing water quality, habitat features, spawn availability, and environmental influences. Fish spawn samples were collected with eight "Savar nets" at chosen sites and reared in a fiberglass tank at the mini hatchery for species identification. The representative spawn samples were examined under a microscope for preliminary species identification before rearing. The study found that both the Surma River and Tanguar haor offer ideal conditions for carp spawning due to factors such as water quality, natural food availability, habitat suitability, and favorable climatic conditions. The study identified 39 fish species under the 10 fish groups from both locations, with a higher percentage of carp species (31.42%) in the Surma River in 2021 compared to 2022 (22.50%). In Tanguar haor, the percentage of carp species was 7.55% and 6.50% in 2021 and 2022, respectively. The Surma River's ecological indices (2021-2022) indicated decreased diversity, likely due to environmental degradation, while Tanguar haor showed lower diversity possibly attributable to multiple environmental stressors. The dominant carp species, Labeo calbasu, Labeo bata, and Labeo gonius, were identified in both the Surma River and Tanguar haor. The spawning distribution varied among different locations, with some sites showing a presence of carp species, such as Hajipur (T1) in the Surma River and Alam Duar (T2) in Tanguar haor. The findings highlight the importance of hydrological and environmental parameters in shaping carp spawning habitat distribution and abundance, contributing to aquatic biodiversity conservation and resource management.

Supplementation of Extender with Melatonin Improves the Motility, Mitochondrial Membrane Potential, and Fertilization Ability of Cryopreserved Brown-Marbled Grouper Sperm.

Sperm cryopreservation is a valuable tool for breeding, conservation, and genetic improvement in aquatic resources, while oxidative damage will cause a decline in sperm quality during this progress. Melatonin (MT), a natural antioxidant hormone, is used as an additive in sperm cryopreservation to reduce cellular damage from oxidative stress. Here, we aimed to investigate the effect of adding MT to the freezing medium in sperm cryopreservation of brown-marbled grouper (Epinephelus fuscoguttatus). Different concentrations of MT (0, 0.1, 0.25, and 0.5 mg/mL) were tested. We evaluated sperm motility, viability, apoptosis, mitochondrial membrane potential (MMP), and fertilization ability to assess the effects of MT supplementation. Our results demonstrated that the addition of MT to the extender improved the post-thaw motility, MMP, and fertilization ability of brown-marbled grouper sperm. The total motility, curvilinear velocity, straight linear velocity, and average path velocity in MT-treated groups (0.1 and 0.25 mg/mL) exhibited significantly higher values than that of the control group. A higher MMP (p < 0.05) was observed in the group treated with 0.25 mg/mL MT, suggesting that supplementation of MT in the extender might be able to protect mitochondrial membrane integrity effectively. Regarding fertilizing ability, 0.25 mg/mL MT yielded a significantly higher hatching rate than the control. An adverse effect was found with the concentration of MT up to 0.5 mg/mL, suggesting the possible toxicity of a high-dose addition. In this study, we optimized the sperm cryopreservation protocol of brown-marbled grouper, which might be valuable for sperm cryopreservation and sample commercialization of groupers and other fish.

Sustainable aquatic resource management and inland fisheries in tropical Asia: Interdisciplinary and transdisciplinary approaches

The intensive utilization of tropical inland water bodies for multiple and sometimes competing activities underlines the necessity for their integrated and holistic co-management. This paper presents our synthesis on lake and reservoir fisheries in South and Southeast Asia as social–ecological systems, based on a synopsis of our research findings from a previous EU-funded research programme in Sri Lanka, Thailand and the Philippines (FISHSTRAT project). The paper attempts to merge our results with recent developments in research, policy and practice. We explore the effects of the main external and internal control mechanisms of the trophic state and pinpoint to the high production potential of traditionally unexploited small indigenous fish species. The limitations of conventional centralized management systems highlight the importance of introducing transdisciplinary approaches which integrate limnology, fish ecology and fisheries with the interests of other resource using stakeholders and decision makers in order to develop locally appropriate co-management strategies for sustainable aquatic resource use.

Phytoplankton Composition in Waters Around Hot Water Waste of Steam Electricity Power Plant Nii Tanasa

Understanding the complex dynamics of aquatic ecosystems is very important for sustainable resource management in the field of aquatic resource management studies. This study aims to determine the distribution, abundance and diversity of phytoplankton and its correlation with water temperature around the PLTU Nii Tanasa area. The sampling method used is purposive sampling by taking water samples using a plankton net at predetermined stations. Data analysis of abundance, diversity, dominance, and correlation using Microsoft excel software. The number of samples found was 12 types of phytoplankton and came from several different classes. Abundance index (N) = low-moderate fertility (low enough), diversity index (H) = moderate category, dominance (C) = low, indicating stable community structure conditions. Water quality is classified as waters with moderate levels of pollution. Correlation of abundance, diversity and dominance of phytoplankton with water temperature has a positive and negative linear relationship.

Fostering Stewardship in Managing Fisheries and Aquatic Resources in the Lens of Green Criminology

Illegal fishing imperils Gulf ecosystems, prompting this qualitative study, rooted in green criminology and purposive sampling, to explore stewardship in fisheries and aquatic resource management. Police officers (Bantay Dagat), BFAR representatives, Barangay Officials, and Fisherfolks were interviewed. This study revolved around three main thrusts: (1) common law violations relative to the fishery and aquatic resources law violations; (2) the reasons/motivational factors of engaging in the fishery and aquatic resources law violations; and (3) measures on how the community can foster stewardship in managing fisheries and aquatic resources. The findings proved that the illegal fishing activities in municipal waters and marine protected areas were done for higher income and economic sustenance but posed various threats to the sustainability of aquatic and fishery resources and the environment in Leyte Gulf. The study also found that the community can foster stewardship through participatory enforcement of aquatic and fishery laws and programs and the provisions of equipment and resources needed for more effective patrol and surveillance of marine waters to prevent and combat illegal fishing. Keywords: Green Criminology, Illegal Fishing, Stewardship, Leyte Gulf

Effects of extreme rainfall events on phytoplankton community in a subtropical eutrophic lake: a mesocosm experiment

The impact of global climate change has led to an increase in extreme rainfall events, causing fluctuations in terrigenic inputs that significantly affect aquatic communities. Lake Changhu, the third-largest freshwater lake in Hubei Province, plays a crucial role as a reservoir of aquatic germplasm resources in the middle reaches of the Yangtze River. In recent years, the lake has experienced a series of extreme rainfall events. In response to recent extreme rainfall events, a 42-day mesocosm experiment was conducted to understand the effect of terrigenic inputs on various aspects of phytoplankton in Lake Changhu, such as species composition, abundance, biomass, diversity, community turnover rates, resource use efficiency, and stability. The experiment involved the application of different terrigenic treatments, including a control group (CK, using lake water), low terrigenic input (LT), medium terrigenic input (MT), and high terrigenic input (HT). The results showed a noticeable shift in phytoplankton composition from a co-dominated state of Chlorophyta and Cyanobacteria in the CK treatment to a Cyanobacteria-dominated state in the other terrigenic treatments. Furthermore, the terrigenic inputs increased phytoplankton abundance, community turnover rates, diversity, and resistance. Comparatively, the diversity index of phytoplankton increased by 82.61%, 73.83%, and 70.41% in the LT, MT, and HT treatments, respectively, in contrast to the CK treatment. However, phytoplankton abundance decreased by 6.99%, 15.55%, and 14.76% in the LT, MT, and HT treatments. Additionally, the resource use efficiency decreased by 1.94%, 5.16%, and 14.19% in the LT, MT, and HT treatments, respectively, compared to the CK treatment. These findings provide valuable insights into monitoring and managing the water ecology in Lake Changhu, offering a scientific basis for implementing effective management strategies.

Performance of fishery carbon sink of oyster aquaculture (mainly Crassostrea hongkongensis) in Guangxi, China: A long-term (2003–2022) analysis

Fishery carbon sink (FCS) is a concept of promoting the absorption of carbon dioxide (CO2) by ocean through enhancing the biological process in fishery resources, and then removing carbon from water body through harvesting aquatic fishery resources. Among marine organisms, bivalves are one of the seafood with high potential in developing FCS. Although the FCS of China bivalve aquaculture has been estimated, these studies were rough estimation without specified contribution of different bivalve species. In this context, based on 20 years data, this study was conducted to evaluate the FCS performance of oyster, especially Crassostrea hongkongensis (accounted for 30% of oyster production in China) farmed in Guangxi, China. The results of this study revealed that the oyster aquaculture plays an increasing role in FCS, especially in 2010 and onward. The oyster aquaculture industry in Guangxi removed about 0.05 million tons (average) of carbon from the sea every year through FCS, and is expected to remove more than 0.07 million tons of carbon from the sea in future. The results of this study not only can fill in the knowledge gap on the FCS of oyster aquaculture in Guangxi, China, but also can provide a guideline to study the FCS of other bivalve species in different regions.