Fishing Gear Research Articles

Profile of Traditional Fishermen on the Barito River

Fishermen are residents who do the work of looking for fish to meet their living needs. The fishing gear used is a simple fishing tool that is still traditional, these fishermen are trying to meet their living needs, in an era that is increasingly advanced. These traditional fishermen look for fish in the Barito River. With traditional fishing gear, these river fishermen are trying to find luck in catching fish. These traditional fishermen gain knowledge in going to sea from the teachings of their previous parents. The purpose of this study is to describe the profile of traditional fishermen and their fish catches in the Barito River. Qualitative methods and descriptive approaches used by researchers. This research is located in Anjir Village, Serapat Muara. The instrument for writing this study is the researcher himself and the data collected by the data collection techniques used are observation, interviews and documentation. The subject of this study is fishermen in Anjir Serapat Muara Village. The results of the research are that fishermen in Anjir Serapat Muara village are traditional fishermen both in terms of tools, materials and transportation used. They go to sea because it is done from generation to generation. The catch of this traditional fisherman is still small. Because by using simple fishing gear, the catch of fish is still minimal. The conclusion of this study is that in Anjir Serapat Muara Village, there are people who work as river fishermen who use fishing gear and simple transportation to sea. Fishermen have the knowledge to go to sea to find fish obtained by fishermen from their parents who have been taught since childhood and have been passed on until now to meet their needs.

The hovering pontoon trap: The tougher, younger sibling in the pontoon trap family

Trap nets are a large, stationary, and fixed type of passive fishing gear that has traditionally been used for catching fish in shallow coastal environments. Despite their large size, catches are often retrieved using small boats, making them less energy demanding compared to active gear types. This, along with the stationary nature of the trap, allows for fishing with relatively low environmental impact due to minimal disturbance of the benthic community. The combination of minimal benthic impact, live catch, low fuel, and selectivity offers great potential for the development of sustainable coastal fisheries.Here, we describe the development of the hovering pontoon trap, a fishing gear with a robust design to resist strong waves and currents, and usable in both shallow and deep waters to catch both pelagic and benthic species. We present results from early case studies targeting benthic Baltic Sea species, including perch (Percha fluventaliis), Atlantic cod (Gadus morhua) and vendace (Coregonus albula), showing similar or improved catches in relation to earlier studies. Further, we show that the hovering pontoon trap was able to withstand harsher conditions than previous bottom-set models, making it a possible solution for the targeting of benthic fish communities in coastal environments.

Development of Low-Resistance Coastal Stow Net Using Numerical Analysis and Model Experiments

In coastal stow net fishing, the heavy weight of a typical anchor (750–1000 kg) can increase the risk of capsizing the boat and crew member injury during hoisting operations. Thus, to prevent these accidents, a reduction in the anchor weight is required. One strategy to achieve this is to reduce the resistance force of the fishing gear used, which would allow lighter anchors to be employed. This requires the accurate estimation of the resistance force for various gear designs. Therefore, the resistance force and shape during the operation of two representative types of coastal stow nets currently employed in the Korean coastal stow net fishing industry were investigated using simulations and modeling experiments. The modeled fishing gear was divided into four sections according to the mesh size. Based on the results, the twine thickness was reduced in order to target areas of the gear where the greatest resistance was observed, while the front part of the gear was redesigned to prevent the front of the net from being pushed back into a suboptimal shape. The proposed low-resistance fishing gear has the potential to improve occupational safety in the coastal stow net fishing industry.

A Study on the Catch Losses and Mesh Selectivity Related to the Attachment of Marine Mammal Bycatch Reduction Devices on Midwater Trawl Gear

The National Institute of Fisheries Science in Korea is developing marine mammal bycatch reduction devices (BRDs) for high-risk fishing gear, such as trawls. We experimented with two BRD types (guiding nets) attached in front of codend at 30° and 45° angles, and catch losses and mesh size selectivity were investigated. Experimental fishing operations were conducted along the East Coast of South Korea where whales and dolphins are commonly sighted. The catch was classified according to fishing location, BRD type, codend, and covernet, with measurements recorded for body length, maximum girth, and weight. The average selectivity for each haul was analyzed using the ‘selfisher’ package. The catch loss rates with the BRD attached at tilt angles of 30° and 45° were 11% and 29% for common flying squid, 6% and 28% for sailfin sandfish, and 5% and 8% for pearlside. While the mesh selectivity rates for common flying squid and pearlside remained at 0.2–0.5 across all lengths and tilt angles, the mesh selectivity curve for sailfin sandfish was estimated. There were significant differences in catch loss between 30° and 45° angles, with the 30° angle being more effective in catch loss. We observed a masking effect in the codend.

Detailed Insight into Gillnet Catches: Fish Directivity and Micro Distribution

Gillnets are widely used in research and commercial fishery activities. As passive gear, gillnets can be selective and dependent on the diel migration of fish. In areas with limited littoral extent, inshore–offshore migration may cause bias in the gillnet catch. Our hypothesis was that some factors, such as gillnet saturation, fish depletion, or chemical cues, could be the cause of the bias. We used a total of 66 CEN gillnets deployed at Římov Reservoir parallel to the shore at different positions of littoral-pelagic gradient. Individual fish direction was recorded from inshore, offshore, or unknown direction (i.e., entangled fish). A total of 5791 fishes from nine different species were caught. For most fish, it was possible to determine their directivity, and most fish were captured in littoral or first pelagic gillnets. Shallower and deeper benthic gillnets differed in their bleak (Alburnus alburnus) catch. No significant differences were found between fish directions. At the species level, only asp (Leuciscus aspius) and ruffe (Gymnocephalus cernua) showed differences between the captured directions in one case. The results support the assumption that gillnet capture is a random process that to a great extent is connected to random local movements. This is good news for fish monitoring projects. Sampling catch is likely to reflect true changes in the fish community, and not the effects of the deployment of the sampling gear. The experiment also showed that fish directivity statistics can be used for investigation of fish behavior and gear performance.

Is my fishing gear impacting the habitat? An impact assessment in four fisheries in the Northwest Mexican Pacific

The impacts of fishing activities on habitats for commercially important species may, directly and indirectly, influence species and associated communities. These effects include those on target species, bycatch species, habitats, etc. In this study, the impact of small-scale fisheries on habitats was evaluated in four fishing communities from the Northwest Mexican Pacific. The species and size selectivity of several fishing gear were evaluated, and the spatial distribution of catches was studied to assess the impacts of fishing gear using a Consequence Spatial Analysis (CSA). Our results showed that in finfish fisheries from Guaymas and Isla Natividad, the catch of the target species represents more than 75% of the total catch and in El Rosario, the catch represents less than 50%. We assessed 42 habitat types in four communities, which were qualified with low-risk scores. The fishing gears used to target commercial species are selective to optimal sizes above their maturity size. The results contribute to improving management in data-poor fisheries by evaluating the impacts of fishing on habitats and discussing their relevance for implementation.

Pengaruh Penggunaan Waktu Operasi Penangkapan yang Berdeda pada Alat Tangkap Bagan Tancap terhadap Hasil Tangkapan Ikan Teri (Stolephorus Sp) di Perairan Karangantu Serang Banten

Bagan stepper is a productive fishing tool for catching pelagic fish, especially anchovies. Utilization of existing resource potential can be improved by knowing the best transportation time, so it is necessary to analyze the level of effectiveness of the step-by-step fishing gear. The aim of this research is to determine the best transportation time for catches obtained using step-on fishing gear in order to improve the welfare of Karangantu fishermen. The method used in this research is the experimental fishing method by observing each treatment then calculating the weight (kg) of the catch using a step chart with 2 treatments (transport time 20.00 WIB and transport time 22.00 WIB) and 16 repetitions (trips). From the analysis results obtained, the calculated F value = 1.32, and the F table value = 1.15, so the data is not homogeneous. For the calculated t value = 0.10, and for the t table value = 3 then Ho is not rejected. So it can be concluded that there is a real difference between the anchovy catches using transportation times of 20.00 WIB and 22.00 WIB. Transport time 20.00 WIB provides the most fish catches

VARIAÇÃO BIOMÉTRICA E REPRODUÇÃO DO BIVALVE Anomalocardia flexuosa (BIVALVIA; VENERIDAE) EM DIFERENTES ÁREAS DE PESCA

The bivalve Anomalocardia flexuosa is one of the main fishing resources utilized in artisanal fishing in northeastern Brazil. The objective of the study was to identify the reproductive and biometric variations in the A. flexuosa shell across different fishing areas in the estuary of the Goiana and Megaó rivers in Northeast Brazil, generating information to support strategies for its conservation. Three bimonthly sampling points were used, with P1 being characterized by manual fishing; P2 by more intensive fishing than P1, with the use of less potent fishing gear; and P3 by high-intensity fishing with tools that enhance the collection capacity, such as long-handled nets. For each specimen collected, shell length, shell height, shell width, total weight wet weight, and meat yield were measured to assess size patterns of the organisms and meat yield. Histological analyses were also conducted to identify the reproductive stages. From the analysis of 5,188 captured specimens, it was observed that with P3 presented the lowest body sizes, possibly reflecting overfishing at the site. Growth models were isometric for shell measurements and negative allometric for the length-weight relationship in P1 and P2, and positive allometric in P3. Photomicrographs were taken of 32 specimens for P1, withe 45% males, 48% females and 7% unidentified; and 25 specimens in P3, 12% males, 52% females and 36% unidentified. Regarding reproductive stages, the most representative were the “maturation” and “mature” stages. Due to the evidence of overfishing in P3 and high potential yield in other points, we highlight the need for efficient management actions that mitigate the impacts of overfishing, such as rotation of fishing areas.

Observing fish behavior in towed fishing gear—is there an influence of artificial light?

Fish behavior is important to consider when developing selective fishing gear. In studies designed to investigate the size selective properties of towed fishing gears such as trawls, fish behavior is mainly documented by underwater video recordings. Because fishing gear can be operated at great depths or in other low light environments, artificial light is often required for underwater recordings. However, artificial light can influence fish behavior, which casts doubt on the validity of behavioral observations obtained in the presence of artificial light. However, removing artificial light disables video recordings and the possibility to study fish behavior in relation to selectivity devices towed fishing gears in low light environments. To date, little is known about the extent to which artificial light used for video observations affects fish behavior with respect to fishing gear. Therefore, we conducted fishing trials in the Barents Sea demersal trawl fishery to assess the effect of light sources on fish behavior by using size selectivity results in towed fishing gears. We found that the behavior of cod (Gadus morhua) was unaffected by the light sources, whereas the behavior of haddock (Melanogrammus aeglefinus), saithe (Pollachius virens) and redfish (Sebastes spp.) significantly changed when red light and white light were employed. Our results also demonstrated significant differences in fish behavior between white and red light.

Variation in the Health Status of the Mediterranean Gorgonian Forests: The Synergistic Effect of Marine Heat Waves and Fishing Activity.

Over the past thirty years, the red gorgonian Paramuricea clavata in the Mediterranean Sea has faced increasing threats, including heat waves and human activities such as artisanal and recreational fishing. Epibiosis on damaged gorgonian colonies is generally used as an indirect indication of stressed conditions. The density and height of P. clavata and the percentage of colonies affected by epibiosis and entangled in lost fishing gear were monitored to investigate the phenomenon and its trend over time in the Ligurian Sea. Analyses were based on transects collected during ROV campaigns between 2015 and 2022 at depths of 33-90 m. A strong correlation was observed between fishing efforts in the study area and the level of epibiosis. Maximal percentages of colonies affected by epibiosis and entanglement were recorded at depths of 50-70 m. Temporally, marine heat waves before 2019 were identified as the primary cause of damage to P. clavata. The decrease in epibiosis percentages after 2019, despite the 2022 heat wave, may be due to a quick recovery ability of the populations and a reduction in fishing activities during the COVID-19 lockdown in 2020. Long-term monitoring programmes are essential to understand the changes in marine benthic communities exposed to different stressors.

The gendered dimensions of small-scale fishing activities: A case study from coastal Kenya

Although women contribute substantially to the small-scale fisheries sector globally, in many countries there is a severe lack of gender-disaggregated data on fishing activities. This gender data gap hampers a comprehensive understanding of small-scale fisheries dynamics with implications for fisheries management and food security. In this study, we investigate women's and men's engagement in small-scale fishing through a case study in coastal Kenya, a region characterized by a high dependence on fisheries for local livelihoods and nutritional needs. We applied a mixed method approach, combining participant observation, photography, semi-structured interviews on gender identities (n = 11) and gendered fishing practices (n = 28), an individual survey (n = 141), and pebble games (n = 35). Our results reveal a marked gendered division of labor across the seascape, with women mostly fishing in intertidal areas and men beyond the reef. Further, we find that women's fishing practices are characterized by less fishing gear, less catch, a lower functional diversity of catches, less fishing effort, and less income than those of men. However, women's catches contribute significantly to local diets, accounting for up to 50% of the fish and seafood consumed in fisherwomen-headed households. Despite women's fishing activities appearing less productive and profitable that those of men, they are important for achieving food security in Kenyan coastal communities. Results from this study contribute to broadening our understanding of the gendered dimensions of small-scale fishing and highlight relevant information for developing gender-inclusive management strategies. We conclude by providing key recommendations for fisheries research, management, and governance.

Demersal fishery Impacts on Sedimentary Organic Matter (DISOM): a global harmonized database of studies assessing the impacts of demersal fisheries on sediment biogeochemistry

Abstract. Marine sediments are among the largest carbon reservoirs on the planet and play a key role in the global cycling of organic matter. Bottom fisheries are the most widespread anthropogenic physical disturbance to seabed habitats, prompting NGOs and governments to act on regulating mobile bottom-contacting fishing gear. However, the scientific evidence of the effects of bottom trawling on sediment biogeochemistry is highly diverse and presents contrasting results. Here we present a global harmonized dataset of 71 independent studies that assess the effects of demersal fisheries on sedimentological (i.e. grain size, porosity) and biogeochemical (i.e. organic carbon, phytopigments, nutrient fluxes) properties: the Demersal fishery Impacts on Sedimentary Organic Matter (DISOM) database (Paradis, 2023; https://doi.org/10.3929/ethz-b-000634336). We identify considerable gaps, namely in the geographical extension of the data; coverage of environmental predictors (i.e. seasons); fishing descriptors such as the availability of true controls, quantification of fishing effort, and distribution of fishing gear types; and biogeochemical variables that study the remineralization of organic matter. Future studies should address these data gaps to enhance the comprehensiveness of the dataset. With this harmonized database, we aim to allow researchers to explore the effects of demersal fisheries in variable environmental settings to disentangle the effects of this disturbance and provide efficient management strategies.

Sorting grid usage to reduce the catch of undersized narrow‐clawed crayfish (Pontastacus leptodactylus Eschscholtz, 1823) in fyke net fisheries

AbstractSustainability of natural stocks of crayfish is critical because of their economic and ecological importance. Crayfish (Pontastacus leptodactylus), one of the most important species in Turkish inland fisheries, has been facing serious threats recently. One threat the species faces is high landed bycatch of undersized crayfish because of selective fishing gear, such as fyke nets. We estimated size‐selectivity of sorting grids with various bar spacings for crayfish to reduce bycatch. Six bar spacings (15.0, 17.5, 20.0, 22.5, 25.0, and 30.0 mm) were tested alongside commercial crayfish fyke nets. Mean selectivity (L50) (±95% CI) was 6.90 (6.63–6.99) cm for 15.0 mm bar spacing, 7.52 (7.16–8.02) cm for 17.5 mm, 8.52 (8.32–8.71) cm for 20.0 mm, 9.70 (9.28–9.90) cm for 22.5, 10.75 (10.34–11.17) cm for 25.0 mm, 11.80 (11.31–12.24) cm for 30.0 mm, and 8.79 (8.05–9.29) cm for commercial fyke nets. The proportion of undersized specimens caught be reduced from 32.27% for commercial fyke nets to as low as 2.46% by using sorting grids. The codend of 22.5 mm bar spacing was more selective, with significantly lower discard rates, and more effective for individuals above the minimum conservation reference size than commercial fyke nets.

Disentangling marine plastic impacts in Life Cycle Assessment: Spatially explicit Characterization Factors for ecosystem quality

Inputs of persistent plastic items to marine environments continue to pose a serious and long-term threat to marine fauna and ecosystem health, justifying further interventions on local and global scales. While Life Cycle Assessment (LCA) is frequently used for sustainability evaluations by industries and policymakers, plastic leakage to the environment and its subsequent impacts remains absent from the framework. Incorporating plastic pollution in the assessments requires development of both inventories and impact assessment methods. Here, we propose spatially explicit Characterization Factors (CF) for quantifying the impacts of plastic entanglement on marine megafauna (mammals, birds and reptiles) on a global scale. We utilize Lagrangian particle tracking and a Species Sensitivity Distribution (SSD) model along with species susceptibility records to estimate potential entanglement impacts stemming from lost plastic-based fishing gear. By simulating plastic losses from fishing hotspots within all Exclusive Economic Zones (EEZs) we provide country-specific impact estimates for use in LCA. The impacts were found to be similar across regions, although the median CF associated with Oceania was higher compared to Europe, Africa and Asia. Our findings underscore the presence of susceptible species across the world and the transboundary issue of plastic pollution. We discuss the application of the factors and identify areas of further refinement that can contribute towards a comprehensive assessment of macroplastic pollution in sustainability assessments. Degradation and beaching rates for different types of fishing gear remain a research gap, along with population-level effects on marine taxa beyond surface breathing megafauna. Increasing the coverage of impacts specific to the marine realm in LCA alongside other stressors can facilitate informed decision-making towards more sustainable marine resource management.

Fishing Eco-Efficiency of Ports in Northwest Spain

Fishing is an essential economic activity and source of livelihood for millions of people worldwide. However, overfishing and unsustainable practices have led to a decline in fish populations and the degradation of marine ecosystems. Moreover, fishing activities can contribute to climate change through the emission of greenhouse gases (e.g., carbon dioxide and methane) from fishing vessels and seafood transportation. To mitigate the environmental impacts of fishing activities, sustainable fishing practices must be implemented to minimize the negative impacts of fishing on the environment while maintaining the productivity and diversity of fish populations and ecosystems. These practices include using selective fishing gear, avoiding fishing in vulnerable habitats, implementing fishery management plans, and reducing the carbon footprint of the fishing industry. To this end, and as a first step in defining efficient and effective measures towards the sustainability of capture fishing activity, an analysis of the environmental sustainability of the Galician fishing sector, one of the main European regions in this field, is presented in this work. An ecosystem-based indicator (ecological footprint, calculated by adding the so-called fishing ground footprint and the carbon footprint) was employed to quantify the main impacts of capture fishing during extractive activity. The catch composition and fuel consumption of the fleet based on the vessels’ power, and economic benefits, were the parameters used in this analysis. The results showed that ports with larger vessels and fleets seem to be more eco-efficient than those concentrating smaller vessels in targeting lower trophic level species.

Blue nests: The use of plastics in the nests of the crested oropendola (Psarocolius decumanus) on the Brazilian Amazon coast

Birds have been impacted by plastic pollution via entanglement, accidental ingestion, and exposure to chemical contaminants. However, plastics were also observed as a nesting material for several species. For the first time, we describe the occurrence and composition of plastics in 36 nests of the crested oropendola (Psarocolius decumanus) in three different sites on the Amazon coast. Plastics were present in 67 % of abandoned, fallen nests. At the mangrove site, all nests contained plastics, while at the grassy clearing and the fishermen's village, plastics were present at 35.3 and 90 % of the nests, respectively. Blue fibers and ropes were the main plastics observed, probably derived from discarded fishing gear. Of 79 analyzed fibers, 97.5 % were composed of Polyethylene, and 83.5 % contained Cobalt Phthalocyanine as an additive. Our results showed a widespread use of plastics by P. decumanus, which may increase the exposure of both juveniles and adults to potential contaminants.

Influence of knot strength on the mechanical performance of a biodegradable gillnet

Ghost fishing is a global issue that can be addressed using fishing gear materials that do not persist in the marine environment. However, for these alternatives to be widely adopted, they must meet the same mechanical specifications as current commercial materials while degrading without any negative impact. The objective of this study was to compare a conventional gillnet made of polyamide 6 (PA6) with an alternative made of poly(butylene succinate-co-adipate-co-terephthalate) (PBSAT) at three different scales: monofilament, knot, and net. While the PBSAT monofilament’s strength was half that of the conventional PA6 net, knot and net losses were even more significant. This indicates a greater sensitivity of the material to the knot. Since the results between the knot and net scales were coherent, testing whole net panels is not necessary. Studying the curvature and the behaviour of the knot revealed its complex geometry and mechanical behaviour. Testing the weaver’s knot is a good indicator for studying the relevance of an alternative to conventional fishing gear materials. This should be considered when developing biodegradable nets in order to reduce ghost fishing at sea.

Review and Analysis of Electronic Monitoring (EM) Minimum Standards for Pelagic Main Fishing Gear

Review and Analysis of Electronic Monitoring (EM) Minimum Standards for Pelagic Main Fishing Gear

Methodological Aspects of using the frequency of occurrence Indicator for an analysis of Ichthyocenoses, the Ichthyofauna of the Baltic Sea Coastal zone Taken as an Example

The specificity of utilizing the frequency of occurrence indicator in relation to the study of the species structure of a fish community is considered. The coastal ichthyocenosis of the Baltic Sea within the Kaliningrad Region was used as a study object. Fishing was carried out at up to 20 m depths using a set of collection of gillnets with a mesh size of 12 to 80 mm in the period 2006–2022. In total, data on 894 catches were summarized, in which 11.8 thousand fish were caught. It is shown that the frequency of occurrence of a species can be presented in several ways: (1) as the average for the catches of the entire set of mesh, (2) as the maximum for the mesh size optimal for a given species, (3) as a structural characteristic that determines the nature of an ichthyocenosis’ species organization. In general, in the catches of a collection of gill nets the coastal ichthyocenosis was found to be represented by 29 species of fish, among which the river flounder, Baltic herring, round goby and smelt dominate in terms of occurrence. In the interannual aspect, the occurrence rate is demonstrated to show certain stability and is characterized by a confidence interval ranging within ±10–20%. Taking into account that the indicator of occurrence is quite simply determined just through the capture record of a species, it is recommended to use it in addition to the traditional indicators of the relative abundance and biomass of the species. Using multi-cell fishing gear for the assessment of the structure of a fish community is prerequisite.

Catch Composition of Portunus pelagicus from Different Fishing Gear Used along Palk Bay Water of Ramanathapuram Coast of Tamil Nadu, India

Catch Composition of Portunus pelagicus from Different Fishing Gear Used along Palk Bay Water of Ramanathapuram Coast of Tamil Nadu, India