Sorting Grid Research Articles

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.

Improving the size selectivity of crayfish fyke-net codend, applying the hexagonal mesh and sorting grid

Context Owing to the use of fyke-nets with poor size selectivity in crayfish fishery, 40.7% of the landed undersized catch is discarded as bycatch. Aims This study investigated the effects of using hexagonal mesh (Hex34) instead of diamond nets (Com34) in the traditional crayfish fyke-net and the application of a sorting-grid (SG20, SG25, SG30) and stiff-rigged net (SRN34, SRN42, SRN50) on size selectivity. Methods A covered codend technique was used for determining the size selectivity of codends. Key results The average length at 50% retention probability (L50, in total length) for the trial groups of Com34, Hex34, SG20, SG25, SG30, SRN34, SRN42 and SRN50 was estimated as 9.1, 9.5, 10.1, 11.0, 12.3, 10.0, 10.3 and 11.1 cm respectively. Additionally, the discard rates were computed in the same order as 37.0, 27.3, 14.9, 5.8, 1.9, 19.1, 9.4 and 7.7%. Conclusions In conclusion, commercial crayfish (Com34) fyke-nets have a significantly high discard rate. In the modifications tested, the discard rate has been reduced to as low as 1.9%. When taking into account both L50 and fishing efficiency indicators, SRN42 was determined as the most successful trial group. Implications The application of the study results will make a significant contribution to the sustainability of natural crayfish stocks of Türkiye.

Understanding size selectivity of trawls using structural models: Methodology and a case study on fish sorting grids

Fish behaviour affects the performance of selection devices in fishing gears. Traditionally, fish behaviour in relation to selection devices is assessed by direct observation. However, this approach has limitations, and the observations are not explicitly incorporated in the selectivity models. Further, underwater observations and quantification of fish behaviour can be challenging. In this study we outline and use an indirect method to explicitly incorporate and quantify fish behaviour in trawl selectivity analysis. We use a set of structural models, which are based on modelling the actual processes believed to determine the size selection of the device, to discern which behaviours are most likely to explain the selectivity process. By bootstrapping we assess how confident we can be in the choice of a specific structural model and on discerning the associated behavioural aspects. We collected size selectivity data in the Barents Sea demersal trawl fishery targeting gadoids, where the use of a sorting grid is compulsory. Using our modelling approach, we obtained deeper understanding of which behavioural processes most likely affect size selectivity in the sorting grids tested. Our approach can be applied to other fishing gears to understand and quantify fish behaviour in relation to size selectivity.

Identifying priorities for Australian disability research using Q methodology

BackgroundGlobally, there are over an estimated one billion people with disability. Research priorities with a focus on diagnosis and treatment of conditions or policy and service initiatives, traditionally decided by researchers, may not align with priorities of those with lived experience of disability. ObjectiveTo explore and inform disability research for Australia, including perspectives of people with disability. MethodsAs part of a research program, we used Q methodology to explore “what should guide the Australian research agenda?” People with disability, their families, community organizations and researchers were purposively recruited and sorted 25 statements, developed iteratively using data collated from systematic research mapping and a prior consultation process. The sorting grid ranged from −4 to +4, according to “Which topics should guide disability research the least to the most?” Factor analysis revealed four distinct but interrelated participant viewpoints. Results52 participants (65 % female, aged 18–65+ years, 37 % people living with disability), sorted the statements. Viewpoint 1 – design and delivery of services across the lifespan. Viewpoint 2 – understanding the diverse experience of those with disability. Viewpoint 3 – designing systems to address impacts of disability for the individual, their families and society. Viewpoint 4 – addressing mental health for those with disability no matter where they live. ConclusionThese viewpoints focused on design and delivery of services to address the impacts of disabling environments and attitudes on individuals living with impairments, their families and society. The four viewpoints provide a framework for future disability research in consultation with those with lived experience.

Are rigid sorting devices necessary to control size selectivity in demersal trawl fisheries?

Diamond mesh codends are the most common size selectivity devices in trawls for releasing bycatch and undersized individuals. However, codend selectivity can vary due to the flexibility of the netting meshes, making discrimination by size between retained and released fish difficult to control. In some trawl fisheries, rigid sorting devices have been introduced to make size selection more controlled with sharper discrimination by size. However, the resulting size selectivity often does not show a sharp size selection. In the present study, we tested and compared the size selectivity performance of two “diamond-mesh codend designs” in the Barents Sea gadoid-trawl fishery: a four-panel codend, which was more rigid than a traditional two-panel codend design due to the additional selvedges, and a fully rigid codend design, that included a metal frame. The aim was to investigate the effect of added codend rigidness on the size selectivity of cod (Gadus morhua), haddock (Melanogrammus aeglefinus) and redfish (Sebastes spp.). In addition, the obtained results were compared to earlier research on size selectivity in this fishery including codends with different levels of rigidness and sorting grids. The results demonstrated that using a fully rigid codend did not result in a sharper size selectivity compared to a four-panel codend. Further, there was no indication that a rigid sorting grid makes size selectivity sharper than what can be obtained with a four-panel diamond mesh codend alone. There was also no proof that other codend stabilizing mechanisms such as shortened lastridge ropes could make the size selection sharper compared to the four-panel codend.

Pregnant women's informational needs prior to decisions about prenatal diagnosis for chromosomal anomalies-A Qmethodological study.

To study pregnant women's subjective viewpoints on what is important when receiving information prior to decision-making regarding prenatal testing for chromosomal anomalies. Data were collected using Q methodology. During January 2020-October 2021, 45 pregnant women in Sweden completed a 50-item Q sort. Statements regarding what is important when receiving information about prenatal screening and diagnosis were prioritized through ranking in a fixed sorting grid on an 11-point scale, from "most important" to "least important." Socio-demographics and coping styles were surveyed through questionnaires. Three groups represented different viewpoints on what pregnant women consider important when receiving information about prenatal screening and diagnosis. Factor 1: Stepwise information and decision-making: viewing information and decision-making as a step-by-step process. Factor 2: Decision-making as a continuous process based on couple autonomy: Striving for an informed decision as a couple about tests, test results and conditions screened. Factor 3: As much information as early as possible-the importance of personal autonomy in decision-making: Prioritizing autonomous decision-making based on non-directive information early in the pregnancy. This study highlights the complexities involved when providing information. As shown by the differing viewpoints in this study, pregnant women's informational needs differ, making individual and personalized information preferable.

Effect of grid section design on trawl size selectivity

Sorting grids are introduced in trawl fisheries to improve size selectivity and reduce the variability of results obtained with sorting devices constructed of netting e.g., codends. Grids are rigid or semi-rigid structures where the bar spacing defines the sizes of fish that can pass through. However, for size selection to occur, fish need to be oriented towards the grid in specific ways, which may depend on the netting construction where the grid is installed. In the Barents Sea gadoid trawl fishery, fishermen are allowed to use different netting configurations within the same type of grid, but it is unclear to which degree the performance of sorting grids depends on the construction characteristics of the netting section where they are installed. This study compares the size selective properties of a steel grid mounted in three different netting section configurations: 2-panel section, 4-panel section, and 4-panel section with a modified lifting panel. Overall, the results of the study demonstrate that the 2-panel configuration performs better than the two 4-panel configurations tested. The differences were smaller when the 2-panel and the 4-panel section with a modified lifting panel were compared. Specifically, the grid contact probability for haddock with the 2-panel configuration was 0.92 (0.90 – 0.95) and significantly higher than for the 4-panel configuration, which was estimated to be 0.82 (0.77 – 0.89). For cod, the grid contact probability between the different configurations did not vary more than 6% and the differences were not significant. The 4-panel configuration led to significantly higher retention of cod between 40 to 60 cm and haddock between 20 and 54 cm than the 2-panel configuration. The results also show that despite having been assumed to provide constant size selectivity, the performance of sorting grids is sensitive to relatively small design changes in the section where they are mounted.

Used vs. new: Does it have consequences for the performance of fishing gear?

Sea trials to test size selectivity equipment in trawls are often limited in time because they are costly, and the results can be influenced by multiple factors that are often overlooked. In the Barents Sea gadoid trawl fishery, the use of a size sorting grid in front of the codend is compulsory. The flexigrid, a netting section containing two flexible grids, is the most widely used grid section in this fishery. However, earlier selectivity studies with this device have shown inconclusive results. It has been speculated that the differences observed resulted from the difference in age and usage of the grid sections in the studies compared. To reveal whether potential changes in the device construction over time can lead to differences in size selection properties, we performed comparative fishing trials where we compared a brand new flexigrid section and a well-used flexigrid section used continuously by a commercial trawler for approximately four years. The results showed that the new flexigrid released significantly more cod below ∼60 cm than the used flexigrid. However, when the grids were fished with a subsequent diamond mesh codend, there was no difference in the overall selectivity of the two gears, meaning that the size selectivity in the codend compensates for the potential reduction in selectivity performance of the grids. This study shows the importance of considering the age and earlier use of size selection devices like sorting grids before they are compared with other devices, as their size selection properties can change significantly over time and with use.

Exploring the feasibility of technological transfers of two by-catch reduction devices in the crustacean bottom trawling of the central Mediterranean

IntroductionMost Mediterranean fish stocks are overexploited owing to high fishing efforts and poor exploitation patterns. Demersal trawl fisheries are considered the most impactful fishery type because of the high quantities of unwanted catch that is then routinely discarded at sea.MethodsIn the present study, two types of by-catch reduction devices (BRDs), that is a sorting grid (Grid-T45 40 mm) and a T90 50 mm codend, were compared to a typical commercial bottom trawl net (control) in terms of size structures and catch per unit effort to assess the effect of gear modification on the selectivity of crustacean fisheries in the central Mediterranean Sea. In particular, three randomly selected trawlers were involved in a paired hauls experiment fishing at the same time in the same fishing ground. Each trawler carried out four hauls per day during a 3-day campaign for a total of 36 hauls. The target species of the fishery is Parapenaeus longirostris (herein DPS), and the main commercial by-catch is Merluccius merluccius (herein HKE).ResultsThe results showed that the landing per unit effort (LPUE) of DPS was higher for Grid-T45 40 mm net, although it did not differ significantly from that of the control net. Conversely, the discard per unit effort (DPUE) of the control net was significantly higher than of both BRD configurations. For HKE, a slightly higher LPUE was recorded using the T90 50 mm codend compared to that of the control, but this result was not statistically significant. The lowest DPUE was found for the T90 50 mm codend, with significant differences compared to that of the control and Grid-T45 40 mm net. The catch comparison of the size structures analysed through generalised linear mixed models highlighted that the Grid-T45 40 mm net was more effective in catching adult DPS, whereas the T90 50 mm codend was more selective for adult HKE.DiscussionIn conclusion, although further studies should be carried out in future to test the performance of the BRDs in different areas and seasons, the investigated gear seems to be promising for reducing the catch of undersized individuals and contributing to mitigating the current overfishing of DPS and HKE.

Using Q Methodology to Understand Faculty Development Needs to Prepare for Next Generation NCLEX.

Using Q Methodology to Understand Faculty Development Needs to Prepare for Next Generation NCLEX.

A new concept for bycatch reduction in small-scale accordion-shaped trap fisheries of the Yellow Sea, China

The bycatch issue is a major concern in small-scale accordion-shaped trap fisheries in the Yellow Sea of China because of the poor species and size selectivity of fishing gear and the co-occurrence of multispecies. Two threatened flatfish species assessed by the IUCN, marbled flounder (Pseudopleuronectes yokohamae) and stone flounder (Platichthys bicoloratus), are the two main bycatches in accordion-shaped trap fisheries. This fishery also captures a large proportion of juvenile target species, resulting in both recruitment and growth overfishing of these species. In this study, we introduced a new concept of a combined sorting grid and escape vent (CSEV), a selection device aimed at reducing the bycatch of flatfish and undersized target species in mixed-species trap fisheries. We used a catch comparison method to assess the performance of the CSEV in field experiments, with conventional traps as the baseline. Our results demonstrated that the CSEV significantly improved the species and size selectivity of the traps. Test traps mounted with the CSEV significantly reduced the catch rates of marbled flounder and stone flounder by 70% and 74% throughout the length class, respectively, compared with conventional traps. The catch of undersized target species, namely, fat greenling (Hexagrammos otakii), black rockfish (Sebastes schlegelii), and Asian paddle crab (Charybdis japonica), was reduced by 79%, 75%, and 80%, respectively, while the catch rates of target-sized individuals were maintained or even improved. Given these promising results, the CSEV may have great potential for application in accordion-shaped trap fisheries and similar fisheries.

Improved bycatch reduction in the mixed demersal trawl fishery for Norway pout (Trisopterus esmarkii)

In this study, we compared the bycatch reduction capacity of a trawl fitted with a standard rigid sorting grid with that of a trawl fitted with a newly developed, flexible system called the Excluder. We conducted the fishing trials in the Norway pout (Trisopterus esmarkii) small-meshed trawl fishery in the North Sea. Catch data were analysed by species and length using the catch comparison and catch ratio method. The Excluder significantly reduced the bycatch (in weight) relative to the standard grid for blue whiting (Micromesistius poutassou) (−35.6%), mackerel (Scomber scombrus) (−93.3%), horse mackerel (Trachurus trachurus) (−99.3%), herring (Clupea harengus) (−89.9%), haddock (Melanogrammus aeglefinus), (−98.6%), whiting (Merlangius merlangus) (−99.3%), cod (Gadus morhua) (−97.1%), European hake (Merluccius merluccius) (−98.0%), and greater argentine (Argentina sphyraena) (−24.5%). For Norway pout there was a marginal decrease in the overall catch efficiency of −1.4%. The observed bycatch reduction efficiency is explained by the larger sorting area of the Excluder relative to the grid's area and by the differences in behaviour between Norway pout and the bycatch species. While it contributes to reduce bycatch of quota regulated species, the Excluder also can potentially affect the profitability of the fishery.

Selectivity Characteristics of the Sorting Grid in Shrimp Beam Trawls used to Reduce Bycatch in the Sea of Marmara

Considerable by-catch problems have occurred in the commercial beam trawl fishery targeted at deep water pink shrimp in the Sea of Marmara. In this study, the grid systems were used to reduce the untargeted catch and improve the species' selectivity. By-catch reduction ratios of the beam trawls deployed with and without the grid were compared by the parallel hauling method. Selectivity values of 20 mm bar spacing grid and 24 mm mesh size cod-end were also analyzed by SELNET program. In general, by-catch reduction ratios of the grid beam trawl were determined as 50.6% and 56.9% in terms of number and weight, respectively. The reduction of target catch (Parapenaus longirostris) in the same gear was found to 23.1% in terms of number and 23.2% in terms of weight. In the model for rose shrimp, obtained according to the lowest AIC value, the selectivity parameters of the grid for L50 were 13.51 cm and for SR 4.76 cm. Selectivity parameters of the same species for 24 mm mesh size cod-end were; L50 = 8.99 cm and SR = 5.56 cm. These results indicated that grid usage benefits and contribute to sustainable fishery in the target catch-oriented fishing applications.

Managing size selectivity: the relevance of compulsory and alternative selection devices in the Northeast Atlantic bottom trawl fishery

AbstractTwo decades of use of the compulsory selectivity gear configuration in the Northeast Atlantic bottom trawl fishery, which consists of a rigid sorting grid followed by a diamond mesh codend, have revealed problems with performance and efficiency. Size selectivity gear alternatives to this configuration are being pursued, and recent studies of codends with shortened lastridges have reported promising results. In this study, we compared the size selectivity and catch efficiency for cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) caught using a sorting grid with 55 mm bar spacing followed by a 130 mm knotted diamond mesh codend (i.e. the compulsory gear) that same configuration but considering only the catch in the 130 mm diamond mesh codend (regular codend), and an alternative knotless codend with shortened lastridge ropes and a thinner twine. We also addressed the question of whether size-selective gear is even needed to avoid exceeding the bycatch limits of the fishery. Our results demonstrated that the alternative codend improved size selectivity by reducing the loss of fish above minimum legal size (MLS), with a minor increase in the retention of fish below MLS, compared to the compulsory combined grid and codend configuration. The regular codend also reduced the loss of fish above MLS, but the retention of haddock below MLS approached the legal limit of 15% by number. Our results also showed that the abundance of cod below MLS in the fishing area during the trials was low. They also suggested that spatial and seasonal closures in combination with a flexible choice of selection device and modern monitoring tools could be an alternative to rigid enforcement of the use of selective fishing gear.

The effect of grid size on catch efficiency and by-catch in the demersal trawl fishery for Norway pout (Trisopterus esmarkii)

Norway pout (Trisopterus esmarkii) is caught with large trawls with small meshed codends, inevitably causing the fishery to have large by-catch issues. To reduce the amount of by-catch, a rigid sorting grid was made compulsory in 2010. However, there is still a severe by-catch issue, as well as the loss of target species because of the grid. A possible cause might be clogging of the grid, which could be solved by increasing the grid area. Therefore, this study compared the size selectivity of by-catch species and target species in a double-trawl configuration in which one trawl was equipped with a standard grid (6.30 m2), and the other trawl was equipped with a grid that had a 50% larger surface area (9.45 m2). The results demonstrated that the size selectivity and catch efficiency of the target species were unaffected; neither was there any significant difference between the two grids in terms of wanted by-catch species [blue whiting (Micromesistius poutassou), horse mackerel (Trachurus trachurus), and greater argentine (Argentina silus)]. However, the larger grid caught significantly more unwanted by-catch species [haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), and hake (Merluccius merluccius)]. Approximately one-third of the accumulated catches comprised the target species, one-third of wanted by-catch species, and one-third of unwanted by-catch species, demonstrating the by-catch challenges in this fishery. Simultaneously, none of the by-catch limits were exceeded.

A Novel Architecture of Asynchronous Sorting Engine Module for ASIC Design

A novel sorting engine called Sorting Grid (SG) is presented in this paper. SG is intended to be used as a hardware module for ASIC design which can be employed for any ASIC chip requiring fast sorting operation. The SG is implemented by simple modular architecture so that it is easily synthesized with conventional ASIC tools. SG allows inputs with the same key and provides stable sorting for those inputs. SG sorts m-bit N binary inputs in (m+1) cycles with variable cycle time. SG employs a self-timed asynchronous clock of which the period changes according to the operation time of each cycle. The clock period greatly decreases along the cycle. With this clock and a multi-level bypassing scheme, SG has O(N+m) time-complexity for pseudo-random binary inputs. By the simulations with 1.2V-0.13 μm process technology, the sorting rate of the SG is about 1 ns per input for 16-bit inputs.

Increasing catch efficiency for Nephrops in deep-water shrimp (Pandalus borealis) trawl fisheries

In Skagerrak and the North Sea, coastal vessels harvest deep-water shrimp (Pandalus borealis) in a mixed fishery, in which catches of Nephrops (Nephrops norvegicus) are of economic importance for the fleet. Fishermen targeting shrimp in this area must use a sorting grid with a maximum bar spacing of 19 mm, which means that only the smallest Nephrops can pass through the grid to be retained in the main codend. Although fish collection bags may be mounted to the grid’s fish outlet, most Nephrops escape through the large meshes in these bags. Using data from 70 hauls collected during three different commercial cruises, we investigated whether inserting a 15 cm gap in the lower part of the compulsory sorting grid could help retain a higher fraction of the commercial sizes of Nephrops. We also evaluated whether this lower gap in the grid would change the catch pattern for the most relevant fish bycatch species in the fishery. The results showed that the gap in the grid significantly increased the catches of Nephrops above the minimum legal size and increased the catches of commercial-size shrimp. However, absolute catch rates of Nephrops were still low and, from a management point of view, the modest catch increase does not justify the significant increase in the catch of juveniles of a range of fish species as well as undersized Nephrops.

Effect of the T90-codend on the catch quality of cod (Gadus morhua) compared to the conventional codend configuration in the Barents Sea bottom trawl fishery

The aim of this study was to compare the catch quality of Northeast Atlantic cod (Gadus morhua) in the Barents Sea bottom trawl fishery caught using the conventional configuration (a sorting grid followed by a diamond mesh (T0) codend) and a T90° turned mesh codend (T90) without a grid. Twenty hauls were conducted, consisting of 10 hauls with the conventional configuration and 10 hauls with the T90-codend. The catch quality was assessed using the catch-damages-index (CDI) and a newly developed method using VIS/NIR hyperspectral imaging to estimate the residual blood abundances in the fish muscle. The probability of obtaining fish with no damage was 23.4% (CI: 16.3–31.1%) for cod captured by the conventional configuration, and 21.2% (CI: 15.4–27.2%) for cod captured by the T90-codend. The average blood abundance (in arbitrary unit) was 0.86 (CI: 0.85–0.87) for cod captured by the conventional configuration and 0.88 (CI: 0.87–0.88) for cod captured by the T90-codend. Catch quality of the hauls obtained using the two gears did not differ significantly in terms of catch damage or residual blood levels in the cod. Hence, this study demonstrated that T90-codends do not compromise catch quality compared to regular diamond meshed codends.

New codend designs to improve the size selectivity of fyke net for narrow-clawed crayfish (Pontastacus leptodactylus)

The narrow-clawed crayfish (Pontastacus leptodactylus) is one of the most ecologically and economically important freshwater species in Turkey. However, the harvest of this species has declined from 7937 t in 1984 to 696 t in 2019. One of primary reasons for this decrease in stock is the use of fishing gears with poor size selectivity. In this study, new codend designs were investigated to improve the size selectivity of fyke nets forP. leptodactylus. Seven codends of three different designs were tested: (1) a commercially used standard codend with 34 mm mesh size (Com34); (2) sorting grids with 20 (SG20), 25 (SG25) and 30 mm (SG30) bar spacing attached to the last circle of the net; and (3) a stiff rigged net, the last part of the fyke nets (codend) with 34 (SRN34), 42 (SRN42) and 50 mm (SRN50) mesh size. The average length at 50% retention probability (L50) and selection range (SR) (L75–L25) values ofCom34were 9.4 cm and 3.1 cm, respectively. For theSG20,SG25andSG30grids, theL50values were 11.3 cm, 11.6 cm and 12.0 cm, while theSRvalues were 1.4 cm, 1.3 cm and 0.6 cm, respectively. For theSRN34,SRN42andSRN50codends, theL50values were 10.9 cm, 11.6 cm and 11.6 cm, while theSRvalues were 2.1 cm, 2.1cm and 1.1 cm, respectively. Overall, the commercial codend resulted in lowerL50values when the minimum conservation reference length of 10 cm was considered. However, all tested new codend designs showed improved selectivity compared with the standard, with optimum results obtained withSG20.SG20grid decreased discarding by 15.7% compared to the classic commercial fyke net; thus, this is a very important result for the sustainability of naturalP. leptodactylusstocks.

Potential for codends with shortened lastridge ropes to replace mandated selection devices in demersal trawl fisheries

In many trawl fisheries, codend size selectivity is supplemented by adding selection devices to the gear. In the Barents Sea gadoid fishery, combining diamond mesh codends with sorting grids is compulsory. However, the use of grids increases the costs and complexity of the gear, causing discontent among fishermen and prompting researchers to seek alternative solutions. Lastridge ropes are ropes attached to the selvedges of the codend. In this study, we tested the effect of shortening the lastridge ropes of two diamond mesh codends with different mesh sizes on the size selectivity of cod (Gadus morhua), haddock (Melanogramus aeglefinnus), and redfish (Sebastes spp.). Shortening the lastridge ropes by 15% increased the mesh opening during the fishing process, which significantly improved the size-selective properties of the codends. Further, the L50 values were always higher for the codends in the short lastridge configuration. Therefore, codends with shortened lastridge ropes may be a simpler alternative to sorting grids in this fishery, and they may be applicable to many other fisheries in which additional selection devices are used.