Net Selection Research Articles

Hyperglycemia, Ischemic Lesions, and Functional Outcomes After Intracerebral Hemorrhage.

Background Ischemic lesions observed on diffusion-weighted imaging (DWI) magnetic resonance imaging are associated with poor outcomes after intracerebral hemorrhage (ICH). We evaluated the association between hyperglycemia, ischemic lesions, and functional outcomes after ICH. Methods and Results This was a retrospective observational analysis of 1167 patients who received magnetic resonance imaging in the ERICH (Ethnic and Racial Variations in Intracerebral Hemorrhage) study. A machine learning strategy using the elastic net regularization and selection procedure was used to perform automated variable selection to identify final multivariable logistic regression models. Sensitivity analyses with alternative model development strategies were performed, and predictive performance was compared. After covariate adjustment, white matter hyperintensity score, leukocyte count on admission, and non-Hispanic Black race (compared with non-Hispanic White race) were associated with the presence of DWI lesions. History of ICH and ischemic stroke, presence of DWI lesions, deep ICH location (versus lobar), ICH volume, age, lower Glasgow Coma Score on admission, and medical history of diabetes were associated with poor 6-month modified Rankin Scale outcome (4-6) after covariate adjustment. Inclusion of interactions between race and ethnicity and variables included in the final multivariable model for functional outcome improved model performance; a significant interaction between race and ethnicity and medical history of diabetes and serum blood glucose on admission was observed. Conclusions No measure of hyperglycemia or diabetes was associated with presence of DWI lesions. However, both medical history of diabetes and presence of DWI lesions were independently associated with poor functional outcomes after ICH.

Analyzing the Ability of Investment Managers in Equity Mutual Funds during the Covid-19 Pandemic in Indonesia

Mutual fund is one of the investment instruments widely used as an investment option. There are two essential things to be considered by the Investment Manager as a mutual fund manager: the stock selection and the market timing ability. The Covid-19 pandemic has caused many investors to experience potential investment losses. Understanding stock selection and market timing will be needed for determining which Investment Managers perform well in managing equity mutual fund, especially while dealing with the Covid-19 pandemic. The objective of this study is to analyze the ability of Investment Managers to perform stock selection and market timing, the performance of equity mutual fund, and the effect of stock selection and market timing ability on the performance of equity mutual fund in Indonesia. This study applies the Fama net selectivity methods to assess stock selection ability and Treynor-Mazuy and Henriksson-Merton models to analyze market timing ability. Sharpe, Treynor, and Jensen's alpha methods are also used for measuring mutual fund performance. The data is processed per mutual fund to recognize each mutual fund's stock selection and market timing ability. Furthermore, the research spans two time periods: before and following the Covid-19 pandemic. A dataset of 104 equity mutual funds from 2016-2021 has been analyzed. The findings show that only 9 and 12 Investment Managers have stock selection ability prior to and following the Covid-19 pandemic, respectively. According to Treynor Mazuy model, there are only two Investment Managers with market timing ability prior to the Covid-19 pandemic, and only twelve Investment Managers have market timing ability during the Covid-19 pandemic, according to the Henriksson-Merton model. Every mutual fund with stock selection ability outperformed the benchmark. However, not all equity mutual fund with market timing ability outperformed the benchmark.

A model of size-spectrum dynamics to estimate the effects of improving fisheries selectivity and reducing discards in Mediterranean mixed demersal fisheries

Size-spectrum models are good candidates to examine the effects of fishery management because predation and fishing are largely body-size dependent. We examine the effects of increasing trawl fisheries’ selectivity through the application of a size-spectrum model to a “continental shelf system” in the NW Mediterranean. This system is sustained by detritus, as background resource, and by benthic invertebrates that channel the energy to the fish community. The “continental shelf system” in our model consists of three components: 1) demersal and benthic fish and invertebrate species modelled by size spectrum dynamics, 2) carrion and 3) detritus. The model was able to exemplify the effects of changes in fishing patterns on the different biological components of the shelf system. According to the model outputs, in the short term the main target species, hake and red mullet, would be the main beneficiaries of the increased net selectivity and reduction of fishing effort. Discards reduction would have negligible effects. Despite the positive outcomes, this exercise was not exempt of challenges, mainly due to the data-demanding nature of the approach applied to a system with high diversity of life-histories and feeding strategies of invertebrate and fish species. And yet, our work is a first and crucial step to understand the size-spectrum dynamics of a continental shelf ecosystem subjected to fishery activities.

Estimation of selectivity parameters for target and bycatch fishes of the trammel net fisheries in the northern Aegean Sea (eastern Mediterranean Sea)

The size selectivity of trammel nets was investigated in the northern Aegean Sea using 10 different inner-panel mesh sizes ranging from 16 to 70 mm nominal mesh size (bar length). Selectivity estimates were made for the eight most abundant target and bycatch fish species, namely black scorpionfish, Scorpaena porcus Linnaeus, 1758; annular seabream, Diplodus annularis (Linnaeus, 1758); red mullet, Mullus barbatus Linnaeus, 1758; surmullet, Mullus surmuletus Linnaeus, 1758; round sardinella, Sardinella aurita Valenciennes, 1847; European hake, Merluccius merluccius (Linnaeus, 1758); greater weever, Trachinus draco Linnaeus, 1758; and blotched picarel, Spicara flexuosum Rafinesque, 1810, which accounted for 51.5% by number and 42.7% by weight of the fish caught with trammel nets in the sea trials. The SELECT method was used to estimate the selectivity parameters. Five different selectivity functions (i.e., normal scale, normal location, gamma, log-normal, and bi-normal) were applied with the bi-normal function providing the best fit as it had the lowest deviance value for all species and the lowest values for the dispersion parameter ( D /df). The mesh size of 16 mm in most of the cases retained specimens below the size at first maturity ( L m ). The mesh size of 19 mm seems more appropriate for red mullet, surmullet, and blotched picarel, the mesh size of 22 mm for annular seabream and round sardinella, while for European hake and black scorpionfish, the mesh size larger than 26 mm would be more appropriate.

Temperature modeling of wave rotor refrigeration process based on elastic net variable selection and deep belief network

Optimal operation modeling plays an important role in wave rotor refrigeration process; however, considering covariance among multiple variables and high nonlinearity in wave rotor refrigeration process, it becomes more and more difficult to establish an accurate operation modeling using first-principles methods. This study proposed a novel modeling algorithm for the temperature parameter of the wave rotor refrigeration process based on elastic net and dingo optimization deep belief network (Enet-DOA-DBN). Firstly, to determine the correlation between the input variables and reduce the dimension of the input variables, the elastic net (Enet) algorithm is used to select the input variables that are irrelevant to the temperature parameter of the wave rotor refrigeration process. In this way, the covariance between multiple variables is eliminated and the model structure is simplified. Secondly, in order to improve the generalization of the temperature parameter model, a deep belief network (DBN) deep learning is proposed for modeling the temperature parameter of the wave rotor refrigeration process. Considering that the numerous hyperparameters of DBN algorithm have a great impact on the training and prediction results, the hyperparameters are optimized by the dingo optimization algorithm (DOA). The proposed Enet-DOA-DBN algorithm is validated by simulation using the benchmark data sets and the wave rotor refrigeration industrial process data sets. The simulation results show that the proposed Enet-DOA-DBN algorithm has good generalization ability, meanwhile it can effectively implement variable selection and simplify the model structure.

Performance Evaluation and Comparison of Heart Disease Prediction Using Machine Learning Methods with Elastic Net Feature Selection

Performance Evaluation and Comparison of Heart Disease Prediction Using Machine Learning Methods with Elastic Net Feature Selection

Peripheral lymphocytes and lactate dehydrogenase correlate with response and survival in head and neck cancers treated with immune checkpoint inhibitors.

Little is known regarding associations between peripheral blood biomarkers (PBBMs) and survival, response, and toxicity in recurrent/metastatic head and neck squamous cell carcinomas (R/M HNSCC) treated with immune checkpoint inhibitors (ICIs). In this single-institution retrospective cohort study, a dataset of patients with R/M HNSCC treated with ICIs between 08/2012-03/2021 was established, including demographic and clinicopathologic characteristics. Pretreatment PBBMs were collected and evaluated for associations with grade ≥3 adverse events (G ≥ 3AE) by CTCAEv5, objective response (ORR) by RECIST 1.1, overall survival (OS), and progression-free survival (PFS). Multivariable models for each outcome were created using elastic net variable selection. Our study included 186 patients, with 51 (27%) demonstrating complete or partial response to immunotherapy. Multivariable models adjusted for ECOG performance status (PS), p16, and smoking demonstrated that pretreatment higher LDH and absolute neutrophils, as well as lower percent lymphocytes correlated with worse OS and PFS. Higher LDH and lower % lymphocytes also correlated with worse ORR. In the largest study to date examining PBBMs in ICI-treated R/M HNSCCs, our variable selection method revealed PBBMs prognostic for survival and response to immunotherapy. These biomarkers warrant further investigation in a prospective study along with validation with CPS biomarker.

Determination of fishing efficiency and selectivity of multifilament trammel nets in pearl mullet, Alburnus tarichi (Güldenstädt, 1814), fishing in Lake Van, Turkey

This study aimed to determine the selectivity of multifilament trammel nets in pearl mullet, Alburnus tarichi (Güldenstädt, 1814), and fishing in Lake Van (east of Turkey). In line with this objective, the multifilament trammel nets with 20, 22 and 24 mm mesh sizes were tested in trials. The current study was conducted between September 2019 and April 2020. Thirty-four fishing operations were conducted in the 40–60 m depth range. The “SELECT” method was applied to determine the selectivity parameters. According to the results, the lengths of the optimum catching using nets with 20, 22 and 24 mm mesh sizes were calculated as 20.76 cm, 22.07 cm and 24.11 cm, respectively. The highest average CPUE in weight was 24 mm (6.007 kg/ 100 m / day). Considering the data obtained in the present study, the best optimum catch length and CPUE values for pearl mullet fishing were determined in multifilament trammel nets with a 24 mm mesh size. In conclusion, this study suggests that using a 24 mm mesh size in a lake for pearl mullet fishing will benefit fish stocks and local fishermen.

Testing experimental devices in the extension piece to increase the selectivity of bottom trawl in the Nw Mediterranean

In the Mediterranean, experiments and technical measures aimed at improving the selectivity of bottom trawl nets mostly concern modifications to the codend. Grids have been tested in various areas, but have not been adopted for management purposes so far. The present study aims to evaluate whether the adoption of diamond meshes turned by 90° (T90 configuration) and a selection grid with 2 cm bar spacing, both placed in the extension piece of a commercial bottom trawl net, can contribute in reducing the capture of specimens under the Minimum Conservation Reference Size (MCRS) for the main commercial species. The results indicated that the T90 configuration has no effect compared to the commercial net commonly used by fishers. The grid showed a reduction of the catches of European hake individuals between 11 and 19 cm Total Length (TL). However, the use of this device reduced the catch of many species, such as red mullet, deep-water rose shrimp and broad tail short fin squid. This reduction was observed also for specimens above MCRS. In conclusion, the T90 applied to the extension piece does not provide any improvement in selectivity, contrary to what has been observed when the T90 is placed at the codend. In contrast, the grid could be a possible way to increase selectivity. However, the use of grid should be further investigated to identify settings that can avoid the loss of a substantial fraction of commercial catch.

Insect netting: effect of mesh size and shape on exclusion of some fruit pests and natural enemies under laboratory and orchard conditions

To improve exclusion systems for fruit trees, insect nets of various types were evaluated for their permeability to different beneficial and pest species, under laboratory and field conditions. Pests studied were the apple maggot, Rhagoletis pomonella (Diptera: Tephritidae) and the spotted wing drosophila, Drosophila suzukii (Diptera: Drosophilidae). Beneficials were Aphidoletes aphidimyza (Diptera: Cecidomyiidae), Aphidius matricariae (Hymenoptera: Braconidae) and Aphelinus abdominalis (Hymenoptera: Aphelinidae). Mesh nets with five different apertures (square, rectangle, triangle, rhombus and hexagon) and six different sizes (from 0.4 to 2.8 mm) were 3D-printed from strands of polylactic acid and tested in the laboratory along with two commercially available nets made of polyethylene. The physical and behavioral characteristics of the six studied species affected their ability to cross the nets. For an equal size (open area), the intrusion rate was generally greater through the square- and/or hexagonal-shaped meshes. Rectangular-shaped apertures totally excluded the apple maggot in both laboratory and field trials, provided their shortest side did not exceed 1.9 mm. For the spotted wing drosophila, a maximum of 1.0 mm was similarly required for exclusion in the laboratory. The shape factor (length/width ratio) of the apertures appeared to affect net selectivity. Field trials confirmed that more aphid predators and leafroller parasitoids colonized trees covered with larger mesh nets (2.3 × 3.4 mm), while still excluding the apple maggot. Thus, for a similar aperture size (area), an elongated rectangular-shaped mesh appears to facilitate access for beneficials, while continuing to provide effective protection against apple pests.

Bycatch estimation of narrow‐clawed crayfish (Pontastacus leptodactylus) in Turkish fyke net fisheries

AbstractWe quantified bycatch rates and determined selection criteria of landed narrow‐clawed crayfish (Pontastacus leptodactylus) in Turkey's most crucial crayfish production centres in 2020 and 2021. Subsamples (6078 individuals) of catches from 225 commercial fishermen were compared to 4836 crayfish landed without selection criteria during research fishing. Selection criteria used by traders for crayfish in commercial fishing purchasing centres included: (i) undersized; (ii) dead; (iii) soft shells; (iv) missing extremities; (v) lesions; and (vi) covered with moss. Based on the selection criteria, 77.2% ± 4.1 (95% confidence interval: 68.4–86.0) of the commercial catch were removed from the production chain as landed bycatch. The bycatch rate was higher than the global marine bycatch rate (40.4%). New studies are needed to improve fyke net selectivity, reduce the bycatch rate (40.7%) of undersized individuals, and determine the fate of bycatch.

Size selectivity of trammel nets applied in small-scale fisheries of Lake Nasser, Egypt

In spite of the significance of trammel nets for small-scale fisheries (SSFs) in Egypt in what concerns landings, economic value, vessels and fishermen numbers, few studies on their size selectivity have been conducted. This study investigates the trammel nets’ size selectivity as a key métier of SSFs in three areas of Lake Nasser. A full survey of the commercially used trammel nets and experimental fishing trials using different models of trammel nets were carried out. The results of the survey indicated that the catch had a limited species variation, which included mango tilapia (Sarotherodon galilaeus), Nile tilapia (Oreochromis niloticus), and redbelly tilapia (Coptodon zillii). Regarding experimental fishing, four different mesh sizes (83, 95,108, and 120 mm) were applied and the nets selectivity curves indicated that the size-frequency distributions of all species showed shifting of the mean length to the right with increased mesh size in all nets. The best model was determined from the outcomes of model comparisons and it was the log-normal model for O. niloticus and bimodal for both S. galilaeus and C. zillii. This information can be useful in applying the technical measures for fisheries that depend on the trammel nets.

Machine learning approach in diagnosing Takotsubo cardiomyopathy: The role of the combined evaluation of atrial and ventricular strain, and parametric mapping

BackgroundCardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) is a key diagnostic tool in the differential diagnosis between non-ischemic cause of cardiac chest pain. Some patients are not eligible for a gadolinium contrast-enhanced CMR; in this scenario, the diagnosis remains challenging without invasive examination. Our purpose was to derive a machine learning model integrating some non-contrast CMR parameters and demographic factors to identify Takotsubo cardiomyopathy (TTC) in subjects with cardiac chest pain. Material and methodsThree groups of patients were retrospectively studied: TTC, acute myocarditis, and healthy controls. Global and regional left ventricular longitudinal, circumferential, and radial strain (RS) analysis included were assessed. Reservoir, conduit, and booster bi-atrial functions were evaluated by tissue-tracking. Parametric mapping values were also assessed in all the patients. Five different tree-based ensemble learning algorithms were tested concerning their ability in recognizing TTC in a fully cross-validated framework. ResultsThe CMR-based machine learning (ML) ensemble model, by using the Extremely Randomized Trees algorithm with Elastic Net feature selection, showed a sensitivity of 92% (95% CI 78–100), specificity of 86% (95% CI 80–92) and area under the ROC of 0.94 (95% CI 0.90–0.99) in diagnosing TTC. Among non-contrast CMR parameters, the Shapley additive explanations analysis revealed that left atrial (LA) strain and strain rate were the top imaging markers in identifying TTC patients. ConclusionsOur study demonstrated that using a tree-based ensemble learning algorithm on non-contrast CMR parameters and demographic factors enables the identification of subjects with TTC with good diagnostic accuracy. Translational outlookOur results suggest that non-contrast CMR features can be implemented in a ML model to accurately identify TTC subjects. This model could be a valuable tool for aiding in the diagnosis of subjects with a contraindication to the contrast media. Furthermore, the left atrial conduit strain and strain rate were imaging markers that had a strong impact on TTC identification. Further prospective and longitudinal studies are needed to validate these findings and assess predictive performance in different cohorts, such as those with different ethnicities, and social backgrounds and undergoing different treatments.

Influences of Divalent Ions in Natural Seawater/River Water on Nanofluidic Osmotic Energy Generation.

Besides the dominant NaCl, natural seawater/river water contains trace multivalent ions, which can provide effective screening of surface charges. Here, in both negatively and positively charged nanopores, influences from divalent ions as counterions and co-ions have been investigated with respect to the performance of osmotic energy conversion (OEC) under natural salt gradients. As counterions, trace Ca2+ ions can suppress the electric power and conversion efficiency significantly. The reduced OEC performance is due to the bivalence and low diffusion coefficient of Ca2+ ions instead of the uphill transport of divalent ions discovered in the previous work. Effectively screened charged surfaces by Ca2+ ions induce an enhanced diffusion of Cl- ions which simultaneously decreases the net ion penetration and ionic selectivity of the nanopore. As co-ions, Ca2+ ions have weak effects on the OEC performance. The promotion from charged exterior surfaces in OEC processes for ultrashort nanopores is also studied, with an effective region of ∼200 nm in width beyond pore boundaries independent of the presence of Ca2+ ions. Our results shed light on the physical details of the nanofluidic OEC process under natural seawater/river water conditions, which can provide a useful guide for high-performance osmotic energy harvesting.

Population Characteristics of Brook Trout in Idaho Streams and Alpine Lakes

In western North America, nonnative brook trout (Salvelinus fontinalis) frequently threaten native salmonids via competition and hybridization, so fisheries managers often implement eradication programs for conservation purposes. In conjunction with such programs, managers often construct population models to evaluate the effects of different management strategies designed to control the undesirable population, but such models require demographic data (e.g., age, growth, sex ratios, and survival), which are lacking for western brook trout populations. Brook trout were sampled from 12 alpine lakes and two streams in Idaho, with total length varying from 80 to 380 mm and age varying from 1 to 11 yrs. Across all waters, the von Bertalanffy growth parameters L∞ varied from 231 to 490 mm (mean = 345 mm) and K varied from 0.15 to 0.76 (mean = 0.37). Survival estimates, constructed from age-length keys, were corrected for streams with mark-recapture data; for alpine lakes, corrections were made via gill net selectivity data. Survival varied from 0.30 to 0.56 (mean = 0.45), and except for one waterbody, estimates were minimally affected by correcting for capture efficiency. The proportion of the population that was male varied from 0.34 to 0.75 (mean = 0.53). Our results indicate that brook trout population vital rates in Idaho were similar to those observed in their native range, and were surprisingly similar between alpine lake and stream environments.

Prediction of potential net panel selectivity in mesopelagic trawls

The growing interest in harvesting mesopelagic fish species has increased the need for knowledge about how trawls should be designed for optimizing the catch efficiency of these resources. Since the net herding efficiency for small mesopelagic fish species is unknown, trawls targeting these species need to consider the potential net panel selectivity along the entire trawl body. Therefore, trawl engineers and net makers who design trawls for harvesting mesopelagic species need to know which design parameters, such as mesh size, mesh opening angles, and trawl tapering angles, can be used along the trawl body to avoid potential net panel selectivity, thus maximizing catch efficiency. This study addresses these knowledge gaps using an approach based on laboratory experiments with mesopelagic fish and a simulation model that can help in predicting the potential net panel selectivity. Three trawl designs that have been used in experimental fisheries in the Northeast Atlantic are investigated in this study. Two of them (trawl 1 and trawl 2) had small-mesh liners in the belly and extension piece while the third trawl didn't. The simulation model shows that trawls with small-mesh liners in the belly and extension piece reduces panel selectivity and can increase catch efficiency.

Gill Net Selectivity for Fifteen Fish Species of the Upper San Francisco Estuary

Gill-net size selectivity for fifteen fish species occurring in the upper San Francisco Estuary was estimated from a data set compiled from multiple studies which together contained 7,096 individual fish observations from 882 gill net sets. The gill nets considered in this study closely resembled the American Fisheries Society’s recommended standardized experimental gill nets for sampling inland waters. Relationships between gill-net mesh sizes and the sizes for each fish species retained in them were estimated indirectly using generalized linear modeling and maximum likelihood. Selectivity curves are provided for each species to inform researchers about population characteristics of fishes sampled with similar gill nets.

Dolphin depredation and damage accumulation on different set nets in the northeastern Mediterranean Sea

Small-scale fisheries represent an economically marginalized sector, that struggles to balance operational costs and profit from catches. Economic revenues from catches have declined due to overfishing, and additional costs may jeopardise the sustainability of the sector. In Greece, reported net damage from interaction with marine megafauna, especially the bottlenose dolphin (Tursiops truncatus) is a common occurrence for many coastal areas, where small-scale fisheries operate. A seasonal experimental trial took place during 2016–2017 in the northern Aegean Sea, in an area where large actively swimming marine organisms other than dolphins were lacking. Three gangs of different panels of net (mixed gill nets and trammel nets) were deployed in three different depth zones. For each gang, we recorded the number, size, and position of holes on each net, and assessed overall damage. Multifactor analysis was used to identify possible links between fishing practices and damage intensity. Results showed a correlation between reduced net damage by dolphins with larger mesh sizes and increasing depth. In the case of small mesh sizes, one should seek a combination of solutions, as changes in deployment depths alone, do not seem to be adequate for the depth ranges studied. The adoption of larger than 22 mm mesh size is proposed for all set nets, to increase net selectivity and decrease accumulated damage. Fishers should focus on adjusting, substituting or even ceasing specific fishing tactics to have the lowest possible economic loss, whereas fisheries scientists, managers and policy makers must monitor and offer guidance for this transition.

Selected by the tide: Studying the specificities of a traditional fishing method in mangroves

For centuries, intertidal fishing in mangroves using block nets has been of socio-economic and cultural importance to many tropical fishing communities. However, data characterising these fisheries are scarce, and no study on their selectivity has been conducted. Additionally, assessing the impact of block net fisheries is complex because they target migrant fish species with different life cycles and morphologies in highly dynamic environments. Here, we investigated the catch composition and selectivity of intertidal fishing in northeastern Brazil to discuss how this should be considered for management purposes. We described the spatiotemporal variability of catch composition in four estuaries with distinct physicochemical parameters. We used three model species (Eucinostomus argenteus, Mugil curema, and Centropomus undecimalis) to understand how block net selectivity varied according to fish morphology (body height (BH)) and life cycle (size at first maturity and ontogenetic stages). We found an important spatiotemporal variability in catches that are likely linked to local (geomorphology, precipitation) and seasonal factors (species reproduction). Immature individuals dominated the catch of the three species of interest, confirming that mangroves are a nursery for many migratory species. Moreover, for the first time, we described the S-shaped curve selectivity pattern of block nets, which is unusual for passive nets and prevents the escape of larger individuals, making this gear very efficient to capture a wide range of sizes. We found that comparing length at first catch (Lc) and size at first maturity constituted a simple way to consider fisheries’ interference with the species life cycle. In addition, the body height at Lc was similar between species, making the ratio BH/TL a possible proxy of Lc in a data-poor context. The main concern about block net fisheries is the growth overfishing of long-lived species targeted at the coast. Since mangrove and coastal fisheries explore the same species at different ontogenetic stages, an ecosystem approach to fisheries should be applied to the entire coastal continuum. This approach should involve effort regulation to control the overall fishing pressure, but not mesh size limits that would considerably be detrimental to block net fisheries yield.

Trammel net size selectivity and determination of a minimum legal size (MLS) for the haffara seabream, Rhabdosargus haffara in the Gulf of Suez

The size selectivity of trammel nets used in the Suez Bay in small-scale fishing operations was calculated for the haffara seabream Rhabdosargus haffara using length-frequency distributions of the catch from three different mesh sizes (34, 37 and 40 mm) of the inner layer of the trammel net. Three experimental fishing trials were conducted in the Suez Bay during October 2018, andJanuary and September 2019. The SELECT method has been used to estimate selectivity parameters using five major models (log-normal model, normal location model, normal scale model, gamma model, and bi-normal model). The bi-normal was assessed as the most appropriate model for the haffara seabream. Modal sizes were estimated as 11.8, 12.1, 16.1 cm for 34, 37 and 40 mm mesh sizes, respectively. The calculated lengths at first maturity (Lm) were 13.67 cm for males and 14.15 cm for females. Our findings revealed that the fish lengths caught by the inner layer 34 and 37 mm mesh sizes were less than the length at first maturity, while, those caught with 40 mm were more than the length at first maturity. The minimum legal size (MLS) for R. haffara was fixed at 14.15 cm. Finally, the results revealed that increasing the mesh size of the trammel nets, especially the inner layer mesh, can lead to significant improvements in size selectivity and allow the protection of this valuable fish resource.