Fish Caught Research Articles

Making the Invisible Visible: The Effects of Gas Flaring on Artisanal Fisheries in the Down-Stream Area of Taylor Creek, Bayelsa State, Nigeria

RATIONALE: Gas flaring is a significant environmental concern in many regions, including the downstream area of Taylor Creek, Bayelsa State, Nigeria. Its impact on artisanal fisheries, a vital economic activity in the area, warrants investigation to understand the extent of its effects. OBJECTIVES: This study aimed to assess the effects of gas flaring on artisanal fisheries in the downstream area of Taylor Creek, Bayelsa State, Nigeria, from August 2023 to January 2024. METHODS: Structured questionnaires were utilized in a descriptive survey research design to collect data during the specified period. RESULTS: The study found that gas flaring profoundly affects artisanal fisheries activities in the area. These effects include a drastic reduction in fish catch, extinction of certain fish species, increased fish prices, indiscriminate fish mortality, disrupted fishing schedules, altered water body dynamics, impaired spawning activities, fish migration, and economic hardships for fishers. Additionally, gas flaring contributes to fish size reduction, abandonment of the fishing sector by artisanal fishers, increased time spent on fishing, and accelerated degradation of fishing implements. CONCLUSION: Gas flaring negatively impacts artisanal fisheries in the downstream area of Taylor Creek, Bayelsa State, Nigeria. Urgent measures are necessary to mitigate these effects and preserve the local ecosystem. RECOMMENDATION: To address these issues, it is recommended that gas flaring be utilized for beneficial purposes such as gas injection or electricity generation. Government intervention is needed to restore extraction areas, and companies must adopt safe and environmentally friendly operations to prevent further environmental degradation. Additionally, new legislation should be enacted to protect the environment and control pollution caused by gas flaring in the study area. These measures are essential for safeguarding the environment and sustaining artisanal fisheries in the region.

INFORMATION SEEKING BEHAVIOR OF COASTAL SOCIETY IN SOUTHEAST SULAWESI

The goal of this study was to discover the information-seeking behaviour of coastal communities in Southeast Sulawesi, which has the second highest marine catch (fish) income in Indonesia, despite the fact that the majority of its territory is made up of oceans, but the people's income is still low and less prosperous, as evidenced by the export value of marine catches still falling under East Java, Jakarta, and South Sulawesi. The data for this study were collected from 105 respondents who used a quantitative technique to fill out a list of information seeking behaviour, while 10 respondents used a qualitative approach, namely in-depth interviews about the hurdles experienced when seeking information. According to the findings of this study, the information seeking behaviour of coastal populations in Southeast Sulawesi is still manual, that is, they still use experiences and feelings by 45.8% of the time, and the barriers they confront in obtaining information are related to technology by 29.1% of the time. The outcomes of the study are directly related to the income obtained by the coastal villages of Southeast Sulawesi, which is still poor and less prosperous

Israeli Intelligence Was Caught Off Guard: The Hamas Attack on 7 October 2023—A Preliminary Analysis

On the morning of 7 October 2023, at 6:29 AM, Israel was surprised when forces of the Hamas organization attacked Israel from the Gaza Strip, along the border between Gaza and Israel, and caused enormous damage to human life and property. On that day, about 1,300 Israelis were killed, most of them civilians and the rest soldiers. About 240 Israelis were kidnapped and taken into Gaza as hostages. Israel had no concrete warning of the coming attack. It was a complete surprise to the Intelligence Community (IC) and security system. Following this attack, Israel went to war against Hamas, in Gaza, calling it the Iron Swords War, with the intent of collapsing its military power and governing rule. The lack of intelligence warning raises many questions about the capability of the Israeli IC, especially the Israel Military Intelligence Directorate (IMI) and the Israel Security Agency (ISA). Israel’s intelligence had known of the strengthening of Hamas, but there was an assumption that Hamas had changed its objectives and aimed to establish its rule and statehood in Gaza. As a result, it was assumed that Hamas would refrain from offensive action that would, in turn, provoke counterattacks by Israel, which would not serve its interests. The Israeli IC assumed that if Hamas decided to attack, the ISA and the IMI would provide early warning. Only on 7 October did Israel learn that Hamas was secretly intensifying its efforts to prepare an attack on Israel.

Classification of set-net fish catch volumes in Iwate Prefecture, Japan using machine learning with water temperature and current distribution images at migration depth

Efficient management of set-net fisheries can be achieved by predicting fish catches in advance. We aimed to estimate fish catch volumes using machine learning based on the data obtained from past set-net fisheries. We also suggested that the estimation can be conducted without the installation of special sensors, such as fish finders, sonars, and cameras, in the set nets. Therefore, a special feature of this study is the construction of a machine learning model using marine environmental images around the set net. In particular, the distribution images of water temperature and current at a certain water depth were applied to the model. In set-nets where migratory fish are caught, ocean data related to migration routes can be useful for estimation. The images used in this study included the water temperature at a depth of 100 m, absolute velocity at a depth of 50 m, and sea surface temperature for comparison. We then classified the fish catch into three classes as follows: chum salmon, yellowtail, and Japanese common squid in Iwate Prefecture, Japan. Consequently, our results achieved an accuracy of approximately 70–80% compared with the validation and test dataset with the water temperature at depths of 100 m. They showed higher accuracy than the sea surface temperature and absolute velocity at a depth of 50 m. This study indicates the usefulness of image-based classification for predicting the volumes of fish caught by set nets.

The illegal exploitation of threatened manta and devil rays in the Chagos Archipelago, one of the world’s largest no-take MPAs

Illegal fishing is a concern within marine protected areas (MPA) worldwide, particularly for threatened species such as manta and devil rays (mobulids). However, due to the lack of taxonomic knowledge of enforcement personnel, illegal fishing catch records relating to mobulids can be limited. Here, an examination of illegal catch photographs from local enforcement authorities of the Chagos Archipelago’s vast no-take MPA revealed approximately 79 individual mobulids from just seven vessels, equating to an estimated 20 tonnes. This is likely a vast underestimation due to the limited detection of illegal fishing activity and species-specific reporting. If catches of this magnitude are commonplace within the MPA, they are likely having a detrimental effect on local mobulid populations. Accurate and consistent catch data recording and reporting are crucial to fulfil mobulid conservation responsibilities, as is comprehensive research on the movement ecology and habitat use dynamics of all mobulid species in the region.

A recreation demand model for warmwater fishing in Delaware with welfare effects for improvements in catch rates, species diversity, and water clarity

Abstract We estimate a recreation demand model for warmwater fishing in Delaware and then use it to measure welfare gains associated with improved fishing quality as measured by catch rate of fish, diversity of species, and clarity of water. We use a “linked” site choice – trip frequency model with data gathered by the Delaware Division of Fish and Wildlife. Our site choice model includes 118 rivers and lakes in the state with detailed characteristics of each. We develop hypothetical scenarios of fishing quality improvement involving combinations of fish catch, fish diversity, and water clarity and apply it to individual water bodies, water basins, selected water body groupings, and statewide. Values are reported in seasonal per angler and aggregate terms.

Obtaining accurate population estimates with reduced workload and lower fish mortality in multi-mesh gillnet sampling of a large pre-alpine lake.

The EU Water Framework Directive requires monitoring of the ecological status of lakes, with fish as a relevant class of biotic quality indicator, but monitoring fish populations in large lakes is demanding. This study evaluated use in Lake Constance of a novel multi-mesh gillnet modified to reduce catch numbers. In direct comparison with conventional European Committee for Standardization (CEN) nets we achieved 48% reduction in fish mortality with 38% less labour for tasks directly influenced by fish catch numbers, while maintaining comparable species composition and catch per unit effort. Comparison of mesh sizes indicated no significant reduction in species detection in area-reduced panels of the small mesh sizes, while total observed species richness was greater when using the modified nets. Differences in benthic species communities among depth strata were common, while those of pelagic zones were more homogeneous and did not differ significantly with depth. Catches of different net types from the same depth stratum did not exhibit significant differences. The dominance structure of the most common species, relevant to lake assessment, was similar in catches of both net types, suggesting overall superiority of the modified nets in Lake Constance. Sampling conducted according to standard European CEN protocol, while deploying 60% fewer nets, yielded sufficiently precise abundance estimates for monitoring shallow areas of the benthic zone. A 50% difference in the abundance of dominant species was detected among sampling events with a certainty of 95%. The sample did not provide comparable accuracy in deep benthic strata or the pelagic zone, but was adequate to record complete inventories of species present. Based on this trial data, a new stratified sampling design is proposed for monitoring large lake fish communities for ecological assessment. Depth-dependent fish communities were used to calculate the required number of nets, which resulted in a 69% reduction for the entire lake compared to the CEN calculation method. Using the modified nets increases the feasibility of performing WFD surveys, by reducing effort and cost, while the simultaneous halving of fish mortality minimises the negative impact of fish surveys.

Socio-economic baseline for oil-impacted communities in Ogoniland: towards a restoration framework in Niger Delta, Nigeria

This study documents the socio-economic baselines in selected oil-impacted communities prior to the commencement of the Ogoni clean-up and restoration project. Adopting mixed approach consisting of semi-structured interviews, focus group discussions (FGDs), key informant interviews (KIIs), and household surveys, we surveyed the pre-remediation socio-economic conditions in the Ogoniland communities between July 2018 and March 2019. Results indicated that almost all respondents (99.6%) agreed that the smell of petroleum products or crude oil was evident in the air they breathed even as there were visible black particles (soot) in the respondents’ nostrils, on their clothes, and in water. The respondents described the ambient air as smoky and choked with an offensive smell. The household waters were smelly, brownish, or oily, and most respondents (76%) cannot afford to treat their water. Forty-two percent of the respondents who relied on fishing and farming for a living sought for alternative means of subsistence and acknowledged that oil pollution caused stunted growth and low crop yield. The majority of respondents (91%) reported falling fish catches, while the fish caught smell and taste of oil, lowering their market value and posing a potential health risk to consumers. It is evident that oil pollution has impacted the socio-ecological values and sustainable livelihood in Ogoniland. This study provides baseline data for monitoring post-remediation socio-economic improvements in Ogoniland. It also highlights areas of urgent intervention to improve livelihood, and access to basic amenities (e.g., potable drinking water), waste management infrastructure, and statutory policy changes for sustainable development in Ogoniland.

Biodiversity in Swamp Ecosystem in Sukamaju Village, Malind District, Merauke Regency, South Papua Province, Indonesia

Background: The level of diversity has a crucial role in the stability of the ecosystem. The higher the variety, the more stable an ecosystem, including agricultural land cultivated by farmers. Increasing of population affected the higher demanding of community towards their consumption activities. Especially, the natural resources that comes from local area such as Sukamaju District. Biodiversity of resources urgently needed to preserve the ecosystems meanwhile being the potential source to fulfilled nourishment of the people. This study aims to determine the diversity of peatland ecosystems by using a purposive sampling method in every selection of subject groups based on the characteristics or characteristics of a specific population. Methods: Field and Laboratory activities are needed in this research. Sample collection using several methods according to the targeted sample. Most of the sample using purposive sampling but also line intercept transect method. Fish sampling used a fishing gear called a gill net with a mesh size of 2-7 inches. The fish caught is placed in a labeled coolbox. Insect collection was running in the morning at 07.00-11.00 and in the afternoon at 3-5 pm (UTC+09:00). Sampling is held once a month for three months at predetermined coordinate points. Diversity was analyzed using Shannon-Wienner diversity, evenness index, dominance index and intensity on peatlands. Result: The results found seven orders and 30 families, with a total population of 1,231 individuals. The most dominant types of insects are the orders Coleoptera, Hemiptera and Lepidoptera. High diversity index (H'=3.021), high evenness index (E= 0.86243) and low dominance index (D=0.3101). Fish community structure obtained diversity index (H¢) included in the medium category, for uniformity values in the high class and dominance index values in the low sort. The dominant fish species found were Channa striata, Anabas testudineus, Lates calcalifer, Mugil cephalus, Plotosus papuensis and Toxotes chataerus, while Oreochromis niloticus, Oreochromis mossambicus, Hexanematichthys sagor and Megalops cyprinoides. While the types of molluscs found to have the highest abundance were Pila ampullacea, Pomacea canaliculata and Pilsbryoconcha exilis.

“I am a Fisher”: Identity and livelihood diversification in Lake Tanganyika Fisheries, Tanzania

Human-environmental interaction is central to natural resources management. This interaction determines how the resource is utilized in a given cultural context. In Lake Tanganyika, evidence indicates a decline in fish catches. Despite this decline, fishers have demonstrated little motivation to leave fishing or diversify. A qualitative study was conducted to explore how identity influenced the phenomenon. Interviews, focus group discussions, and observation were employed to generate data. The findings of this study indicated that interactions between the fishing communities and the Lake generated identity, in which fishers came to identify themselves with the Lake. This identity shaped the fishing practices and influenced the motivation to not leave fishing or diversify. Strong attachment to the Lake and fishing activities contributed to little motivation to leave fishing or engage in other sources of livelihood, especially for old fishers. This was also the case for some young fishers in rural areas of the studied communities. This study concludes that considering how fishers identify with the resource is vital for developing future strategies to improve fisheries management. This may include options to expand. Highlights Identity shapes and influences fishing practices How fishers identify themselves with fisheries resources influences their likelihood to diversify or leave fishing activity It is necessary to consider the role of identity in designing future fisheries management strategies

Challenges in collecting age composition data from commercial catches of the Barents sea bottom fishes

The paper presents the rationale for collecting information on the structure of catches and the distribution of bottom fish species (and in particular North-East Arctic cod) on fishing vessels in the Barents Sea and adjacent waters by observers of the Polar Branch of FSBSI «VNIRO» («PINRO» named after N.M. Knipovich). The problems that arise during the work of a scientific observer are described. Possible solutions to solve the problems of collecting materials on commercial catches are proposed. Increase of the scientific observers number on bottom fish fisheries and elevation of their legal status is recommended. A fundamentally new scheme for collecting information on the size distribution of fish in commercial catches by the crews of fishing vessels has been proposed.

Analysis of Socio-Economic Activities of Coastal Communities Case Study of Fishermen in Padelegan Village

This research uses a qualitative approach with a descriptive type. Sources of data obtained through interviews, observation and documentation. The type of interview used was semi-structured, while the type of observation used was non-participant observation. The informants are fishermen, fish traders, fish managers and fishermen groups in Padelegan village. The results of this study indicate that first the socio-economic activities of coastal fishermen in Padelegan village, Pademawu sub-district, Pamekasan district, there are three socio-economic activities, namely buying and selling fish, boat rental services, fish management and fishermen groups. The two supporting factors in the socio-economic activities of coastal fishermen in Padelegan village, Pademawu sub-district, Pamekasan district from buying and selling fish, namely (1) good and complete facilities, (2) orderly and safe administrative activities, and (3) affordable purchase prices. The inhibiting factors for buying and selling fish are (1) decreased fish catches, (2) buyer dissatisfaction, and (3) unemployed fish customers.

Spatial distribution and movement of Atlantic tarpon (Megalops atlanticus) in the northern Gulf of Mexico.

Atlantic tarpon (Megalops atlanticus) are capable of long-distance migrations (hundreds of kilometers) but also exhibit resident behaviors in estuarine and coastal habitats. The aim of this study was to characterize the spatial distribution of juvenile tarpon and identify migration pathways of adult tarpon in the northern Gulf of Mexico. Spatial distribution of juvenile tarpon was investigated using gillnet data collected by Texas Parks and Wildlife Department (TPWD) over the past four decades. Generalized additive models (GAMs) indicated that salinity and water temperature played a significant role in tarpon presence, with tarpon occurrences peaking in the fall and increasing over the past four decades in this region. Adult tarpon caught off Texas (n = 40) and Louisiana (n = 4) were tagged with acoustic transmitters to characterize spatial and temporal trends in their movements and migrations. Of the 44 acoustic transmitters deployed, 18 of the individuals were detected (n = 16 west of the Mississippi River Delta and n = 2 east of the Mississippi River Delta). Tarpon tagged west of the Mississippi River Delta off Texas migrated south in the fall and winter into areas of south Texas and potentially into Mexico, while individuals tagged east of the delta migrated into Florida during the same time period, suggesting the presence of two unique migratory contingents or subpopulations in this region. An improved understanding of the habitat requirements and migratory patterns of tarpon inhabiting the Gulf of Mexico is critically needed by resource managers to assess the vulnerability of each contingent to fishing pressure, and this information will guide multi-state and multi-national conservation efforts to rebuild and sustain tarpon populations.

Counteracting effects of “hook avoidance” and “hook habituation” on angler catch rates in a catch‐and‐release fishery

AbstractCatch‐and‐release (C&R) angling is often used to maintain high catch rates but fish vulnerability to capture may decrease following hooking, thereby decreasing angler catch per unit effort (CPUE) (hyperdepletion). To determine if fish post‐capture response affected recapture probability and population‐level CPUE, individual capture histories of Largemouth Bass in two lakes were compared before and after doubling angling effort in a Before‐After Control‐Impact (BACI) analysis. Previous capture and day‐of‐season both affected recapture probability. Counteracting effects of previous capture and reduced late‐season catch rates caused no hyperdepletion of angler CPUE. Our results highlight the complexity of fish behavioral responses to angling and suggest that hyperdepletion of angling catch rates may not be an issue in C&R fisheries.

Tropical fishery nutrient production depends on biomass-based management

The need to enhance nutrient production from tropical ecosystems to feed the poor could potentially create a new framework for fisheries science and management. Early recommendations have included targeting small fishes and increasing the species richness of fish catches, which could represent a departure from more traditional approaches such as biomass-based management. To test these recommendations, we compared the outcomes of biomass-based management with hypothesized factors influencing nutrient density in nearshore artisanal fish catches in the Western Indian Ocean. We found that enhancing nutrient production depends primarily on achieving biomass-based targets. Catches dominated by low- and mid-trophic level species with smaller body sizes and faster turnover were associated with modest increases in nutrient densities, but the variability in nutrient density was small relative to human nutritional requirements. Therefore, tropical fishery management should focus on restoring biomass to achieve maximum yields and sustainability, particularly for herbivorous fishes.

PEMANFAATAN IKAN MANYUNG (Arius thalassiunus) SEBAGAI PUPUK BOKASHI UNTUK MEDIA TANAM BIBIT TREMBESI (Samanea saman)

Kusan Hilir Sub-district is one of the coastal sub-districts in Tanah Bumbu Regency where most of the people work as fishermen. Fish caught by fishermen that do not have high selling value such as otek fish or manyung fish, and tembang fish or sardinella fish are often thrown into the sea so that they can pollute marine waters. The remaining fish or fish that are wasted have organic value, both organic-N, organic-P, and organic-K. The purpose of this study was to analyze the effect of using otek fish bokashi, firewood husks, and subsoil soil on the growing power of trambesi plants and determine the best composition of fish bokashi produced based on biomass in plants. The research was carried out using the Completely Randomized Design (CRD) method with 6 treatments and 5 replications with 3 plants and placed randomly by doing random numbers in the excel application with the treatment code P0 100% subsoil soil, 0% fish bokashi, 0% burnt husk, P1 subsoil 90%, fish bokashi 5%, burnt husk 5%, P2 subsoil 80%, fish bokashi 10%, burnt husk 10%, P3 subsoil 70%, fish bokashi 15%, burnt husk 15%, P4 subsoil 60%, fish bokashi 20%, burnt husk 20%, and P5 soil 50%, fish bokashi 25%, burnt husk 25%. Data analysis used in this study used the Anova test followed by the DMRT (Duncan Multiple Range Test) test. The results of observations or weighing on the wet weight and dry weight of plant biomass show that the treatment with the composition of 50% soil planting media, 25% fish bokashi, 25% burnt husk with an average wet weight of 174.44g and a dry weight of 88.64g has a very significant effect on 90 day trambesi seedlings, although the treatment with the composition of 90% subsoil soil planting media, 5% fish bokashi, 5% burnt husk, and the composition of 80% subsoil soil planting media, 10% fish bokashi, 10% burnt husk is not significantly different.

Temperature‐Dependence Assumptions Drive Projected Responses of Diverse Size‐Based Food Webs to Warming

AbstractFood web projections are critical for evaluating potential risks to ecosystems and fisheries under global warming. The temperature dependence of biological processes and regional differences in food web structure are two important sources of uncertainty and variation in climate forced projections of fish communities, but we do not know their magnitude or relative contribution. Here we systematically evaluated a range of different assumptions about temperature‐dependence on rates, including size‐dependent effects, controlling food intake, metabolism, and non‐predation mortality in fishes using species‐resolved size spectrum food web models that link individual‐level physiological processes to population and community dynamics. We simulated the physiological effect of warming in a range of size‐structured food web models calibrated to different marine ecosystems and in simplified trait‐based models. Higher food intake in warmed conditions increased total fish biomass, catches, and mean body weight, but these effects were offset by the negative effects of warming on metabolism and mortality, which combined resulted in lower total biomasses and catches for most food webs. These effects were enhanced when warming increased metabolic rates more than food intake, and the outcomes were also sensitive to size dependency of temperature responses. Importantly, these general patterns were not uniform across all food webs—individual functional groups and fish species within food webs responded to warming in different ways depending on their position in the food web and its structure. Hence, caution is warranted when generalizing food web or species outcomes to warming because they are mediated by community interactions. Uncertainty related to temperature dependence and ecological interactions will impact food web projections and should be represented in climate change projections.

ECONOMIC IMPLICATIONS OF DECLINING FISHERIES IN PAKISTAN

The entry of fishing vessels to the coastal waters of Pakistan stands out extra vividly in relation to the ascending number of declining catches of fish in the country. Unlike other reports, which depend only on media, this study which is qualitative employs local stakeholder insights to bring up this issue in its full context in the Pakistani coastal artisanal fisheries sector. Developing it further brings out the complexity of the study and deconstructs the simplistic narratives, showing the multifaceted difficulties the area is going through. The analysis finds that the interaction of poverty and the degradation of resources is complex in its complexity and dynamic nature of the poverty–credit market relationship. This issue could not only resolve the existing inefficiencies in credit and product markets but also pave the way for more effective interactions between the banks and the public. Besides, fishery degradation is not only a single factor of poverty that necessitates comprehensive actions to improve the overall capability of the communities and to treat the root causes.

Decline of Artisanal Fish Catch by Species in the Croatian Section of the Sava River

Abstract The aim of this study is to analyse the development of artisanal fish catch by species in the Croatian section of the Sava River. For Abramis brama and Silurus glanis, a significant decline in catches (in kg) was observed throughout the study period (2004-2021). Since 2013, this has also been the case for Cyprinus carpio, Esox lucius, Sander lucioperca, other autochthonous species and alochthonous species, while catches of Leuciscus idus have declined significantly since 2014. The catches of three species (Acipenser ruthenus, Leuciscus aspius and Tinca tinca) fluctuated without a trend, which can be attributed to the low quantities. This decline in catches of the most sought-after species in the Sava was greater than that of the other less sought-after autochthonous species (mainly other cyprinids), whose share of the total catch increased significantly.

An assessment of demersal fisheries by trawling in less than 50 m of water off Egypt’s Mediterranean coast

Trawl fishing is identified as one of the most significant factors that could affect the diversity of demersal fish groups but not for all depth strata. Since the increased exploitation of Non-Indigenous Species (NIS) has caused the trawl fishing grounds to shift towards shallower seas where their biomass density is maximum, this study aimed to assess demersal fisheries by bottom trawls in the Mediterranean water off Egypt at depths less than 50 m. In this study, data from eight bottom-trawl hauls were used to describe the diversity of the demersal fish catch. The hauls varied in their species composition and both in the number and the weight of individuals. The length frequency distribution of the most occurred species was studied. A total of 87 species were identified in the catch, out of which 32 were recognized as NIS. The percentages of most of the NIS decreased from the east to the west of the surveyed area. There are always changes in fish diversity because of increasing fishing efforts on demersal fish communities, but not for all depth strata, therefore, a monitoring program has to be designed for better assessment of fisheries resources in the Mediterranean water off Egypt.