Fishing Activities Research Articles

IMPACT OF SEA ROBBERY ON ARTISANAL FISH PRODUCTION IN AKWA IBOM STATE, NIGERIA

The study assessed the Impact of Sea Robbery on Artisanal Fish Production in Akwa Ibom State, Nigeria. Specifically, this study compared the income of the fisher-folks affected by sea robbery and those not affected; estimated and compared costs and returns in artisanal fish production by both groups of fisherfolks; determine and compare the effect of socio-economic characteristics on the level of fish output of fisher folks affected by sea robbery and those not affected. Multi-stage random sampling technique was used among others to select the sample size of 202 respondents (fisher-folks) for the study area. Data were collected using a structured questionnaire and interpersonal interviews. The data collected were analyzed using descriptive statistics and multiple regressions, were employed to test the hypotheses also budgetary technique was used to estimate the costs and returns in artisanal fish production. Distribution of respondents by income showed the mean income of ₦351,990.10 for fisher-folks affected by sea robbers, while fisher-folks not affected by sea robbers had the mean income of ₦764,534.65. Costs and returns analysis revealed returns on investment (ROI) of ₦0.55 for fisher folks attacked by sea robbers, while returns on investment (ROI) revealed ₦0.79 for fisher folks not attacked by sea robbers. The multiple regression results for both fisher folks attacked and those not attacked by the sea robbers on the output (k.g) and socio-economic characteristics showed a positive relationship for both groups. The study recommended increase surveillance and patrol along waterways in the study area especially rural fishing settlements. This will assist to abate the surge of sea robbery which has high level of negative interference with fishing activities in the study area.

Improving impact assessments to reduce impacts of deep-sea fisheries on vulnerable marine ecosystems

Robust impact assessments (IAs) for deep-sea fisheries are essential for safeguarding deep-sea ecosystems against the impacts of bottom fishing. In the high seas, United Nations Resolution commitments require States (independently or through Regional Fisheries Management Organisations (RFMOs)) to conduct IAs to evaluate if fishing is putting vulnerable marine ecosystems (VMEs) at risk. To enhance the efficacy of future IAs, this study evaluated nine IAs against the criteria in the FAO International Guidelines for the Management of Deep-Sea Fisheries in the High Seas. We find that in all IAs, the information required by the FAO Guidelines is either completely lacking or only partially addressed. The main shortcoming of the IAs was inadequate description of the ecosystems potentially affected by fishing. Additional shortcomings include incomplete description of the proposed fishing activities, lack of baseline data and risk assessments, and limited consideration of the indirect impacts of fishing. This study identifies several ways to strengthen the IA process; i) making IAs publicly available; ii) improved collection of baseline data and VME identification; iii) assessment of impacts on broader range of species associated with VMEs or potentially impacted by deep-sea fishing; iv) enhanced cooperation between RFMOs and more streamlined IA processes; v) comprehensive assessment of different types of impacts from fishing and climate change, and vii) improved consideration of uncertainty. Fully compliant IAs are a minimum requirement for the effective function of RFMOs, since they are the primary tool for preventing significant adverse impacts upon vulnerable marine ecosystems and the wider deep-sea environment.

Study of the relationship between uniaxial compressive strength vs non-destructive testing and specific weight in bank rocks from the Seybaplaya Campeche Mexico

This research study focuses on analyzing the uniaxial compressive strength of rocks and its correlation with non-destructive testing (Schmidt hammer) and specific gravity. It is important to note that Seybaplaya, located in Campeche, Mexico, is known for its fishing, industrial, and commercial activities. Samples from one of the main active quarries in the state of Campeche were used for the investigation. As a result, equations were developed to predict the simple uniaxial compressive strength based on values obtained from the Schmidt hammer and specific gravity. It is relevant to highlight that these relationships are only valid for rocks with lithological characteristics similar to those used in this study. The results of the analysis and the conclusions demonstrate the non-linearity of the relationships between simple uniaxial compressive strength, non-destructive testing, and specific gravity.

Biodiversity and Vulnerability of Fisheries Resources in Berau Bay, West Papua Province

Berau Bay, located in West Papua Province, is one of Indonesia's marine areas rich in biodiversity. This aquatic ecosystem is a crucial habitat for various fish species, which hold ecological and economic value for the local communities reliant on fisheries. However, increased human activities, including intensive fishing, pollution, and climate change, pose severe threats to the sustainability of fish resources in this region. This research aims to assess the biodiversity and vulnerability levels of fish resources in the waters of Berau Bay. The methods used include field surveys, fish sampling, species identification analysis, and calculating the diversity index. The vulnerability levels of fish resources are determined by categorizing their conservation status according to the IUCN Red List. The study results indicate that Berau Bay has a relatively high level of biodiversity with low dominance. The highest biodiversity index value in Berau Bay waters is 3.35, dominated by the families Carangidae and Scombridae. The vulnerability analysis results show that 85.71% have a low vulnerability level. However, several species exhibit high vulnerability due to excessive fishing activities, pollution, and climate change. These findings emphasize the importance of implementing effective conservation measures to ensure the sustainability of fish resources in this area. Efforts to protect habitats, manage sustainable fishing practices, and educate the local community are expected to reduce vulnerability and enhance the sustainability of the Berau Bay aquatic ecosystem.

Assessment of the Impact of Anthropogenic Activities on Physicochemical Parameters and Phytoplankton Compositions of Kalgo River, Kebbi State

Study’s Novelty/Excerpt This study comprehensively assesses the impact of washing, fishing, and agricultural activities on the physicochemical parameters and phytoplankton composition in the Kalgo River, revealing critical insights into anthropogenic effects on aquatic ecosystems. The research identified 341 phytoplankton species across seven classes, with chlorophyceae being the dominant class, and documented significant seasonal variations in water quality parameters such as pH, EC, and nutrient concentrations. The findings underscore the need for further investigation into the specific impacts of these activities on individual phytoplankton species and their health, contributing valuable knowledge to the field of aquatic ecology and environmental management. Full Abstract Anthropogenic activities can have significant and often detrimental effects on aquatic ecosystems, including water quality, biodiversity, and the overall ecosystem. This study aimed to assess the impact of washing, fishing, and agricultural activities on physiochemical parameters and phytoplankton composition in the Kalgo River. Water samples were collected from stations A (farming and irrigation), B (fishing activities), and C (washing site) using plankton nets and one-liter plastic bottles following standard methods. Phytoplankton species were identified through comparative morphological examination using a binocular light microscope (Olympus BH2) at a magnification of 100x after centrifuging the water samples. In August, higher values of pH (7.90±0.23), EC (793.91±3.56 µs/cm), P (0.31±0.05 mg/l), NH4 (0.63±0.23 mg/l), and TDS (529.27±0.13) were recorded. The highest temperature (29.66±1.50°C) and maximum concentrations of DO (7.52±0.25 mg/l), BOD (22.4±10.29 mg/l), Ca2+ (164.0±13.21 mg/l), and Cl- (15.40±0.59 mg/l) were found in June. A total of 341 phytoplankton species distributed across 37 genera and belonging to seven classes were identified. The dominant class was chlorophyceae (31.43%), followed by Bacillariophyceae (25.72%) and Cyanophyceae (20.00%), with Rhodophyceae recording the lowest percentage (2.86%). Station B exhibited the highest species composition (41.35%), while station C had the lowest (26.96%). No significant difference (P>0.05) was observed in phytoplankton composition variations between the stations. Crucigenia sp. had the highest occurrence (8.50%), followed by Navicula digitoradiata (7.33%), Volvox sp. (6.16%), and Craticula sp. (5.28%). Asterionella sp., Vaucheria sp., and Melosira variants each accounted for 0.88% of the composition. Despite the diverse phytoplankton assemblage in the Kalgo River, further studies are necessary to evaluate the specific impacts of anthropogenic activities on different phytoplankton species and their overall health in the river.

Impact of Anthropogenic Activities on Vandiyur Lake: An Ecological and Chemical Analysis

This study investigates the environmental and ecological health of Vandiyur Lake in Madurai City, Tamil Nadu, India. GIS mapping reveals the lake’s proximity to residential and commercial areas, contributing to pollution from various sources, including domestic, hospital, and industrial sewage. Chemical analysis shows alterations in the lake’s pH, dissolved oxygen, CO2, and phosphate levels. The lake also suffers from the overgrowth of the invasive species Eichhornia crassipes. Despite these challenges, the lake serves as a crucial source of groundwater and supports local fishing activities. The study underscores the urgent need for sustainable management practices to preserve this vital ecosystem.This study investigates the environmental and ecological health of Vandiyur Lake in Madurai City, Tamil Nadu, India. GIS mapping reveals the lake’s proximity to residential and commercial areas, contributing to pollution from various sources, including domestic, hospital, and industrial sewage. Chemical analysis shows alterations in the lake’s pH, dissolved oxygen, CO2, and phosphate levels. The lake also suffers from the overgrowth of the invasive species Eichhornia crassipes. Despite these challenges, the lake serves as a crucial source of groundwater and supports local fishing activities. The study underscores the urgent need for sustainable management practices to preserve this vital ecosystem.

Quantitative determination of flow rate variations in reservoir Eco-scheduling: A case study of Yangqu dam in the upper yellow river

Accurate quantification of flow dynamics during reservoir ecological scheduling hinders the maintenance of normal reproductive activities in downstream riverine fish. This study proposed a quantitative method for determining the flow rate changes in reservoir ecological scheduling. The approach utilized the daily flow rate and daily flow-rate increment to characterize the flow process. Adopting the perspective of shifting spawning grounds of adhesive egg-laying fish species in response to flow rate variations, we introduced the Spawning Ground Overlap Rate as an indicator and utilized it to determine flow rate changes. Focusing on the downstream area of the Yangqu Hydropower Station in the upper reaches of the Yellow River, we calculated the distribution of spawning grounds and the Spawning Ground Overlap Rate in the region. We set a threshold for the Spawning Ground Overlap Rate to restrict the flow rate changes. The results indicated that during the fish spawning period, the ecological flow range in the downstream area of the Yangqu Dam was 480–1200 m3/s. It was required to maintain a daily flow rate change of less than 49.45 m3/(s·d) and a maximum seven-day flow difference of less than 227.76 m3/s to maintain the optimal level of spawning ground overlap rate. Additionally, it was necessary to keep the daily flow rate change below 123.83 m3/(s·d) and the maximum seven-day flow difference below 368.84 m3/s to maintain the minimum spawning ground overlap rate. The findings provide foundational data for determining flow dynamics during the ecological scheduling of the spawning period for viscous-spawning fish.

Analisis Strategi Adaptasi Dalam Pemenuhan Kebutuhan Rumah Tangga

This study explores adaptation strategies in fulfilling the household needs of fishing families on Bajo Medang Island, Sumbawa. Bajo Medang Island is mostly inhabited by the Bajo tribe who depend on fishing for their livelihood. Fishermen on Bajo Medang Island depend on natural conditions, namely the fishing season and the lean season. This season affects the catch obtained. In the fishing season the fishermen are busy at sea, on the other hand, in the lean season fishing activities are reduced so that many fishermen are forced to be unemployed. The measurement variables include; household income, allocation of household needs and adaptation strategies carried out by household members. The purpose of the study was to find out (1) How much household income, and use it for what needs. (2) How is the community's adaptation strategy in fulfilling household needs? The research used a descriptive-exploratory quantitative method, determining the sample; the community was determined by quota sampling (rationed), namely 50 households, (10.14%) of the total population of 493 RT. While the sample was selected by stratified proportional random sampling; semi-modern (40%) and traditional (60%) fishermen. The data collection was conducted with structured interviews using questionnaires, observation and documentation. The results showed that most (73.67%) of the fishermen's household income was allocated for basic needs, while the allocation for secondary needs was 18.85% and the allocation for tertiary needs was 7.48%. The community's adaptation strategy in meeting household needs is borrowing from family and or neighbors (52%). This is done because it is easier to meet and has a close emotional relationship. While those who increase the time allocation for the main job are only 48%. This is because the timing of fishing activities depends on natural/climatic conditions.

Nilai-Nilai Luhur bagi Orang Bajo di Desa Tapi-Tapi Kecamatan Marobo Kabupaten Muna

This study aims to determine and describe the Bajo people's views on noble values, and how the implementation of noble values for Bajo people in Tapi-Tapi Village, Marobo District, Muna Regency. The method used in the research is ethnographic method, researchers try to describe, describe and explain how the Bajo people view noble values-using in-depth observation and interview techniques. The data collected was then analyzed using Koentjaraningrat's theory of cultural values (1984). The Bajo people who live in Tapi-Tapi Village, Marobo District, Muna Regency are a fishing community that upholds noble values that have been passed down from generation to generation in the value of responsibility, namely: (a) Sipakkulong (supporting each other), (b) Mapulus jamaah itu dolo modi bunang (completing the work given), in the value of social care, namely: (a) Nggai kole sikalasa kadadarua (there should be no misunderstanding of others), (b) Sitabangang (helping each other in work), (c) Nggai kole mangasora'dialo (should not damage the sea), in the value of honesty, namely: (a) Nggai kole malaponggang aha sadiri (do not like to lie), in the value of independence, namely: (a) Ngajama diriang (work independently). The implementation of noble values for Bajo people is realized in several values, namely: (a) Si tuluh (helping), (b) Dianggo (mutual respect), (c) Sitabangang (cooperation) d Bapongka (group fishing activities).

Developing U.S. West Coast recreational fishing community measures: Applying an index approach in the context of COVID-19 and social vulnerability

Despite the socio-economic importance of recreational fishing across many coastal communities, a well-defined conceptualization for place-based recreational fishing communities has remained noticeably absent across the U.S. West Coast. Following the framework of natural-resource dependence, this study constructs and evaluates recreational fishing indices, which serve as tools for assessing the involvement and impact of recreational fishing within different communities at the scale of the Census Designated Place. Components of the indices are selected to construct an engagement index of the overall economic activity related to recreational fishing, while a reliance index considers engagement per capita. The indices were then conceptually validated through correlation analyses with proxies for participation and interest. Temporal variations in both indices were evaluated in the context of the COVID-19 pandemic through a series of mixed-linear models, providing the first detailed assessment of the pandemic's impact on recreational fishing activity across the region. Despite shifts in individual angler participation and interest, the indices remained stable, with engagement declining following the pandemic. Additionally, the communities are evaluated with regard to their social vulnerability, finding communities with higher engagement as less vulnerable than those with higher reliance. Overall, this work provides valuable insights for identifying and assessing recreational fishing communities, potentially informing more sustainable and socially equitable management approaches.

Phenytoin causes behavioral abnormalities and suppresses kisspeptin expression, reducing reproductive performance in Japanese medaka

Phenytoin, an antiepileptic drug, induces neurotoxicity and abnormal embryonic development and reduces spontaneous locomotor activity in fish. However, its effects on other endpoints remain unclear. Therefore, we investigated the effects of phenytoin on the swimming behavior and reproductive ability of Japanese medaka. Abnormalities in swimming behavior, such as imbalance, rotation, rollover, and vertical swimming, were observed. However, when phenytoin exposure was discontinued, the behavioral abnormality rates decreased. Phenytoin exposure also significantly reduced reproductive ability. By investigating reproduction-related gene expression of gnrh1, gnrh2, fshb, and lhb remained unchanged in males and females. In contrast, kiss1 expression was significantly suppressed due to phenytoin exposure in males and females. kiss2 expression was also significantly suppressed in females but not in males. We filmed videos to examine phenytoin exposure effects on sexual behavior. Females showed no interest in the male's courtship. As the kisspeptin 1 system controls sexual behavior in Japanese medaka, phenytoin exposure may have decreased kiss1 expression, which decreased female reproductive motivation; hence, they did not spawn eggs. This is the first study to show that phenytoin exposure induces behavioral abnormalities, and suppresses kiss1 expression and reproductive performance in Japanese medaka.

Estimating fisheries catch from space: Comparing catch estimates derived from AIS fishing effort with reported catches for Indian Ocean industrial fisheries

Indian Ocean Rim countries (IOR) rely on fisheries for socio-economic well-being and food security. Monitoring fisheries equipped with Automatic Identification Systems (AIS) enables the evaluation of fishing activities. However, only small fractions of large vessels use AIS, and increasingly vessels are avoiding or circumventing AIS use. We used Global Fishing Watch AIS fishing effort data for 2018–2020, combined with independently derived gear- and country-specific catch rates to estimate catch volumes by AIS equipped industrial vessels in the Indian Ocean. We compared these estimates to the catches reported by countries to the Food and Agriculture Organization (FAO), which represent global accountability. Results suggest that AIS-equipped industrial vessels caught an average of 400,000 t∙year−1, of which 57% was by Distant-Water Fishing (DWF) vessels from countries outside the region. Spain, France and South Korea had AIS derived catch estimates substantially lower than catches officially reported by these countries, suggesting these vessels may turn off AIS transponders to potentially elude detection either by authorities or for other operational reasons. In contrast, Taiwan and China had 6 and 4 times more AIS estimated catches than they reported to the FAO. This suggests that these countries may not meet their international reporting obligations. Underreporting fisheries catches undermines management efforts and contributes to the unsustainable use of marine resources. Our study revealed an important role AIS technology can play in estimating fishing activities in the Indian Ocean, despite its currently limited adoption and the increasing evasion tactics by some fleets. Discrepancies between AIS-derived catch estimates and officially reported data underline the challenges in fisheries monitoring and enforcement, and highlight the lack of compliance enforcement by many flag countries.

Building collaborative monitoring programs to manage for ecological sustainability in multi-use marine protected areas: Parks Canada’s national marine conservation areas

Parks Canada collaborates with partners to manage a growing system of national marine conservation areas (NMCAs) and national marine conservation area reserves (NMCARs). These ecologically and culturally varied marine protected areas are established to represent the rich diversity of Canada’s oceans and Great Lakes. They support a broad range of uses within specific zones, including recreation, tourism, fishing, shipping, and Indigenous rights-based activities. Long-term monitoring is a critical tool for tracking changes in marine ecosystems, developing strategies to protect and conserve ecological and cultural values, responding to environmental threats, and ensuring ecologically sustainable use of marine resources that provide long-term societal benefits. Monitoring involves working closely with Indigenous partners, federal departments, provincial/territorial governments, coastal communities, and others (e.g., fishing and tourism sectors, non-governmental organizations, academia). As part of larger seascapes, NMCAs are managed using an ecosystem approach, which requires information on the state of marine biodiversity, threats, and pressures on marine ecosystems, including levels or impacts of marine uses. Each NMCA monitors a site-specific suite of indicators covering these key characteristics that are then integrated to inform decision-making. The monitoring framework is intended to enable a comprehensive, nationally consistent approach to monitoring and reporting while adapting to local needs and governance. Successes, challenges, and lessons learned through the implementation of the framework are highlighted through place-based examples.

The education of fishing workers about accidents caused by marine animals: a study in the Região dos Lagos of Rio de Janeiro

Fishing exposes workers to various occupational risks, including accidents caused by poisonous, venomous and traumatizing marine animals. With this in mind, the aim of this study is to present educational activities for people working in the fishing activities in the Região dos Lagos (Lakes Region) of Rio de Janeiro, southeastern Brazil, with a focus on accidents caused by marine animals (ACMA). The protocol was approved by the Human Research Ethics Committee of the Universidade Federal de Viçosa (CAAE: 53959421.8.0000.5153). The activities were carried out in the municipalities of Armação dos Búzios, Arraial do Cabo and Cabo Frio and included a workshop on the subject, lasting an average of four hours, preceded (pre-test) and followed (post-test) by an assessment consisting of objective questions on the ACMA. A total of 47 workers (with an average working time of 15.2±12.8 years) took part in the activity. Each professional suffered an average of three ACMA. A comparison of the pre-test and post-test results showed a higher percentage of correct answers to almost all the questions. Further studies are needed to estimate the risks of ACMA among fishing workers and to improve educational actions to minimize the impact of these injuries on this population.

Management of Swanggi Fish (Priacanthus Macracanthus) in the Waters of the Port of Nusantara Fishery Port Ratu

Indonesia has two-thirds of its territory covered by sea, making it rich in marine resources, especially fish. According to the Census of Marine Life, there are around 950 thousand species that inhabit the world's oceans, but only about one percent have been exploited. In Indonesia itself, FishBase records around 4743 types of fish, making it the country with the largest Marine Mega-Biodiversity in the world (Jabbar, 2018). There are two main problems in the fisheries sector in Indonesia: economics and biology. Biological problems include threats to the sustainability of fish stocks, while economic problems are related to the lack of profits obtained by fishermen from catches and sustainable use of fish resources (Akoit and Nalle, 2018). The Archipelago Fisheries Port (PPN) plays an important role in supporting fishing activities in the Indian Ocean, including in Palabuhanratu, West Java. Palabuhanratu is an important location for landing various types of fish, especially large pelagic fish such as tuna and skipjack, as well as swanggi fish (Priacanthusmacracanthus), which experienced a significant increase in production from 573 tonnes in 2013 to 18,730 tonnes in 2015 (Sadewi et al., 2018). Swanggi fish is a demersal fish with high economic value that is in demand by the public and is an export commodity to Korea, Japan and China. However, high demand results in overfishing and a decline in adult fish stocks (Jabbar et al., 2017). This research is descriptive quantitative research which aims to measure the level of variables through samples. The analytical methods used include analysis of biological aspects of swanggifish, catch analysis methods, and sustainability analysis methods using Rapid Appraisal for Fisheries (RAPFISH). It is hoped that the results of this research can provide a sustainable shrimp resource management strategy based on the data obtained.

Dietary inclusion of insect oil: Impact on growth, nutrient utilisation, lipid metabolism, antioxidant and immune-related responses in European catfish (Silurus glanis L)

In this study, we investigated the black soldier fly (Hermetia illucens) larvae oil (IO) as replacement of fish oil and vegetable oil in the diets of European catfish. The formulated diets included a control diet (CTR) containing fish oil (FO) and rapeseed oil (RO), and two experimental diets replacing FO and RO, with 50% and 100% IO, respectively. The nutritional trial comprising 630 European catfish juveniles (average initial body weight: 28.1 ± 0.17 g) randomly distributed into triplicated dietary groups (CTR, IO50, and IO100) was conducted for 8 weeks in a recirculation aquaculture system. The study was focused to evaluate the impact of IO on fish growth and nutrient utilisation, lipid metabolism, antioxidant, and immune-related responses in juvenile fish. Results obtained indicated that all the diets promoted adequate fish growth and feed utilisation, with no significant differences in these parameters between the dietary fish groups. It appears that the diets did not impact the activity of digestive enzymes, but a decrease in the apparent digestibility coefficients was observed. Significant differences were observed in tissue fatty acid (FA) composition. The significantly higher levels of whole-body total saturated fatty acids and arachidonic acid in fish fed IO-based diets relative to those fed CTR diet were accompanied by significantly lower levels of whole-body monounsaturated fatty acids and n-3 polyunsaturated fatty acids (n-3 PUFA). However, some deviations in this trend were observed in the liver highlighting the sparing effect for long chain polyunsaturated fatty acids (LC-PUFAs). Gene expression analysis showed a significant upregulation of genes encoding lipoprotein lipase (lpl), carnitine palmitoyl transferase (cpt1a), and hepatocyte nuclear factor 4 alpha (hnf4α) in the livers of fish fed the IO100 diet. Among the five immune-related genes examined in the spleen, only interferon regulatory factor 1 was significantly upregulated in fish fed IO50 relative to the CTR. These results indicated upregulated metabolic activities in fish fed the IO100 diet probably due to a higher level of dietary medium chain saturated fatty acids (MCSFA) and a lower level of LC-PUFA, creating the need for fish to oxidise more MCSFA and to deposit more LC-PUFA in the tissues in order to maintain fatty acid balance.

Thyroid and neurobehavioral effects of DiNP on GH3 cells and larval zebrafish (Danio rerio)

Diisononyl phthalate (DiNP) has been used to replace bis(2-ethylhexyl) phthalate (DEHP) and is frequently found in the environment and humans. DiNP is reported for its anti-androgenic activity; however, little is known about its effects on thyroid function and neurodevelopment. In the present study, the thyroid disruption and neurobehavioral alteration potential of DiNP and its major metabolites were assessed in a rat pituitary carcinoma cell line (GH3) and embryo-larval zebrafish (Danio rerio). In GH3 cells, exposure to DiNP and its metabolites not only increased proliferation but also induced transcriptional changes in several target genes, which were different from those observed with DEHP exposure. In larval fish, a 5-day exposure to DiNP caused significant increases in thyroid hormone levels, following a similar pattern to that reported for DEHP exposure. Following exposure to DiNP, the activity of the larval fish decreased, and neurodevelopment-related genes, such as c-fos, elavl3, and mbp, were down-regulated. These changes are generally similar to those observed for DEHP. Up-regulation of gap43 and down-regulation of elavl3 gene, which are important for both thyroid hormone production and neurodevelopment, respectively, support the potential for both thyroid and behavioral disruption of DiNP. Overall, these results emphasize the need to consider the adverse thyroid and neurodevelopmental effects in developing regulations for DEHP-replacing phthalates.

Use of electroencephalogram (EEG) to optimize stunning efficiency and animal welfare in commercial catfish production

The welfare of farmed fish has gained increasing attention during recent decades, and as technological advances have facilitated measurements of brain activity in fish, the slaughter process has been highlighted as an area for assessment and potential improvement. Here, we used electroencephalograms (EEG) to assess brain activity in channel catfish (Ictalurus punctatus), and used commercial slaughter practices to guide optimization of stunning conditions in a laboratory setting. Following in-air electro-stunning at processing plants, individual fish responses to the shock varied based on EEG and corresponding ventilation measurements prior to physical euthanasia. Results from laboratory experiments showed stunning efficacy is dependent on shock duration and the location where electrodes contact fish. Electrodes contacting the head for 1 s using 50 Hz 132 AC VRMS, with a current >380 mARMS, caused immediate loss of consciousness lasting 10–40 s. When the exposure period was prolonged to 6 s, recovery time was significantly longer, ranging from 45 to 240 s (mean 125 s). If the electrodes contacted the body instead of the head, shock delivered for 6 s resulted in a shorter recovery time of 0–100 s (mean 48 s). These findings highlight that shock duration and electrode position are important when stunning channel catfish and presumably other fishes, and indicate the time from stunning to killing should be kept as short as possible.

Spatio-temporal variation in water quality due to the anthropogenic impact in Rudrasagar Lake, a Ramsar site in India.

Rudrasagar Lake, a vital habitat for diverse flora and fauna, supports over 2000 households to sustain their daily livelihoods. The current study attempts to examine the impact of human activities on spatio-temporal variation in the water quality of the study area. The study integrates extensive field surveys, sample processing, and statistical analysis to assess the recent status of wetland health. Latin Square Matrix (LSM) was employed to select the sampling sites while the Inverse Distance Weighting (IDW) interpolation technique was used for spatial variation mapping. Modified Weighted Arithmetic Water Quality Index (MWAWQI) and Comprehensive Pollution Index (CPI) were utilized for assessing seasonal variation water quality and pollution loads, respectively. The results showed that dissolved oxygen (DO) was strongly influenced by the tributaries, and recreational activities have substantially influenced the highest concentrations of biochemical oxygen demand (BOD), and total suspended solids (TSS). The central portion of the lake is particularly susceptible to pollution from extensive fishing and recreational activities while peripheral sites are strongly influenced by agricultural run-offs, seepages from brick industries, and municipal wastes characterized by high concentrations of pH, total hardness (TH), oxidation-reduction potential (ORP). The findings reveal remarkable spatio-temporal fluctuations and highlight the areas within the lake susceptible to anthropogenic activities. The study proposed a sustainable management model to ameliorate anthropogenic threats. Moreover, the study contributes to the scientific understanding of the challenges and ensures the long-term viability of wetland health as a vital ecological and socio-economic resource.

Emergent geopolitical risks from fishing activities and past conflicts in the Pacific Ocean

Pacific Ocean longline fisheries support numerous international fleets targeting various species. However, global fishing activities has increased the density of vessels flagged to different countries fishing near each other. Such spatial competition increases the risk of fisheries conflicts by potentially introducing resource sharing, gear interactions, or territorial disputes. As international fisheries conflicts increase and fishing patterns evolve, it is important to know who is fishing nearby whom, and where. Enduring rivalries, or countries with historical disputes, can also contribute to a cycle of future conflicts. Here, we use network and geospatial analyses to examine which countries, country pairs, and regions in the Pacific Ocean may be at an elevated risk of fisheries conflict from spatial competition and enduring rivalries. Certain countries dominate fishing activities: Taiwan and Chinese-flagged vessels fish the largest area at 64 million km2 each (33 % greater than the next ranked country), with 7.9 and 7.2 million fishing hours respectively (nearly 2 times greater than the next ranked country). These countries and others (Japan, United States, South Korea) rank among the highest in conflict risk because of large overlapping fishing areas with enduring rivals. International diversity is most widespread in the tropical Pacific, though highest in the south Pacific, reflecting international participation in tropical bigeye and yellowfin fisheries and south albacore fisheries. High-risk regions primarily occur in the tropical Pacific across jurisdictions and similarly appear influenced by regional fisheries management. Overall, our research takes an international-level approach to study how spatial and temporal interconnectedness may influence conflict risk.