Modelling the contact probability and size-selectivity of toothed dredges

Mituhasi, Takahisa; Kitakado, Toshihide; Hu, Fuxiang; Tokai, Tadashi

doi:10.1111/j.1444-2906.2005.00996.x

Cited by 8 publications

(7 citation statements)

References 18 publications

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“…The parameters, α and β of the master curve for size selectivity of tooth spacing and contact probability δ i in the model of Mituhasi et al ., 12 were determined along with the split parameters p i in the SELECT analysis (Table 1). As shown by the likelihood ratio test, fits of the model of no size selectivity in tooth spacing and the equal split model were both very poor.…”

Section: Resultsmentioning

confidence: 99%

“…This study estimated the probability of a clam contacting the teeth of the dredge and the corresponding contact‐selection curve, by using the model proposed by Mituhasi et al 12 . This approach models simultaneously the teeth contact selection and the contact probability in an available‐selection curve of the dredge mouth.…”

Section: Discussionmentioning

confidence: 99%

“…They also proposed a contact‐probability model for analyzing the codend selectivity. Moreover, Mituhasi et al 12 . extended the cover‐escape model and the contact‐probability model 13,14 to express the available selectivity of toothed‐dredges during comparative fishing experiments.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, Mituhasi et al . 12 extended the cover-escape model and the contact-probability model 13,14 to express the available selectivity of toothed-dredges during comparative fishing experiments. The present study applies their model to the catches from paired-dredge tests carried out in Korea, 10 and evaluates the available selectivity of dredge netmouth by incorporating the probability of Venus clam contacting the teeth and contact selectivity of tooth spacing.…”

Section: Introductionmentioning

confidence: 99%

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Effect of tooth spacing on the contact selection and available selection of a dredge for the equilateral Venus clam Gomphina melanaegis

Kim

Mituhasi

et al. 2005

Fisheries Sci

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The effect of various tooth spacing on the contact selection and the net-mouth available selection of a dredge for the equilateral Venus clam Gomphina melanaegis is evaluated by applying a contact-probability model based on the SELECT method to the data of paired-gear tests with a control dredge of 12-mm tooth spacing and four test dredges of tooth spacing 16, 20, 24 and 35 mm. A master selection curve was estimated to be s ( R ) = exp( -11.23 R + 4.799)/(1 + exp[ -11.23 R + 4.799]) where, R is l / d , the ratio of the shell length, l , to the tooth spacing, d . The shell width of 50% retention was slightly smaller than the tooth spacing, which means that size selectivity of teeth was a type of contact selection which was dependent on the tooth spacing. Contact probability, d , of the clams coming into contact with the teeth were 0.625, 0.467, 0.563, 0.670 and 0.976 for tooth spacing 12, 16, 20, 24 and 35 mm, respectively. This indicates that some clams entered the dredge bagnet without contacting the teeth as the sand clogging the tooth spacing carried them into the bagnet. Available selection curve of the dredge net-mouth with teeth was obtained as d s ( R ) + 1 -d , and examined in terms of the legal landing size of the Venus clam.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of tooth spacing on the contact selection and available selection of a dredge for the equilateral Venus clam Gomphina melanaegis

Kim

Mituhasi

et al. 2005

Fisheries Sci

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“…The combination of contact selection and contact probability was termed the available selection model by Millar and Fryer [12]. This available selection model has been used to determine the separation of the grid separator [13,14], the square mesh bycatch reduction window [15,16], selectivity for the cod-end when the mesh of the cod-end is clogged by the catch [17], and the effect of the dredge tooth spacing on selectivity for bivalves [18,19].…”

Section: Introductionmentioning

confidence: 99%

Modeling of available size selectivity of the SURF-BRD for shrimp beam trawl

Kajikawa

Tokai

2013

Fish Sci

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The System of Unwants Ramp-way FilteredBycatch Reduction Device (SURF-BRD) was developed to reduce shrimp bycatch in a shrimp beam trawl. It consists of a pair of rectangular net panels, namely, the front panel (FP) and rear panel (RP), and two fish escape vents. In this study, numerical models for expressing available selection by the SURF-BRD were proposed and assessed in several fishing experiments conducted using two types of the BRD: a prototype and an improved type with the BRD attached at a higher point on the side-nets . Contact probability and selectivity parameters of the FP and the RP for four major species were estimated for each BRD type. The improved type with the higher BRD showed a larger contact probability for the FP. Size selectivity of the FP and RP for two species (cinnamon flounder and spotted swimming crab) was almost equivalent to the mesh selectivity of the net panel, but that for lizard fish seemed to depend not on mesh size of the FP but on the swimming behavior of the fish. These results suggest that the smaller mesh size of the RP would be helpful for releasing more fish of smaller size and to exclude more spotted swimming crab, which hinder ondeck sorting by fishermen.

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How well do we know the infaunal biomass of the continental shelf?

Powell

Mann

2016

Continental Shelf Research

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Highlights:1. A numerical model simulated survey gear types and sampling densities.2. Boxcore and grab samplers were simulated with the Atlantic surfclam as target.3. Typical survey sampling designs produced highly inaccurate clam densities. 4. Increased clam patchiness produced surveys with large density estimation errors. Biomass of large benthos may be routinely underestimated on the continental shelf. AbstractBenthic infauna comprise a wide range of taxa of varying abundances and sizes, but large infaunal taxa are infrequently recorded in community surveys of the shelf benthos. These larger, but numerically rare, species may contribute disproportionately to biomass, however. We examine the degree to which standard benthic sampling gear and survey design provide an adequate estimate of the biomass of large infauna using the Atlantic surfclam, Spisula solidissima, on the continental shelf off the northeastern coast of the United States as a test organism. We develop a numerical model that simulates standard survey designs, gear types, and sampling densities to evaluate the effectiveness of vertically-dropped sampling gear (e.g., boxcores, grabs) for estimating density of large species. Simulations of randomly distributed clams at a density of 0.5-1 m -2 within an 0.25-km 2 domain show that lower sampling densities

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Modelling the contact probability and size-selectivity of toothed dredges

Cited by 8 publications

References 18 publications

Effect of tooth spacing on the contact selection and available selection of a dredge for the equilateral Venus clam Gomphina melanaegis

Effect of tooth spacing on the contact selection and available selection of a dredge for the equilateral Venus clam Gomphina melanaegis

Modeling of available size selectivity of the SURF-BRD for shrimp beam trawl

How well do we know the infaunal biomass of the continental shelf?

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