scholarly journals Mesh Size Selectivity of Tie-Down Gillnets for the Blackfin Flounder (Glyptocephalus stelleri) in Korea

2021 ◽  
Vol 11 (21) ◽  
pp. 9810
Author(s):  
Pyungkwan Kim ◽  
Hyungseok Kim ◽  
Seonghun Kim
Keyword(s):  
Master Curve ◽  
Mesh Size ◽  
Catch Rate ◽  
Small Fish ◽  
Size Selectivity ◽  
Curve Estimation ◽  
Total Length

Although gillnet fisheries are increasingly common in Korea, few studies have conducted sea trials using tie-down gillnets. Here, we analyzed the mesh size selectivity using tie-down gillnets with four different mesh sizes (84, 90, 105, and 120 mm) to catch blackfin flounders. A total of 10 sea trials were conducted at depths of 100–140 m in the waters of Yangyang County, Gangwon Province, Korea, and the catching efficiency and mesh size selectivity were comparatively analyzed. The net with a mesh size of 84 mm showed the highest number of catches (373), followed by the 90-mm (363) and 105-mm (307) meshes. The results of the master curve estimation showed that the larger the mesh size, the higher the total length representing the same retention probability. Therefore, the catch rate of small fish decreased with the increasing mesh size. For the 84-mm net, the 50% selection length for small fish (total length ≤ 170 mm) was estimated at 186.9 mm, which was approximately 17 mm larger than the length limit. The results show that when using tie-down gillnets, the size of the fish caught changed according to the changes in the mesh size.

scholarly journals Catch and size selectivity of small-scale fishing gear for the smooth-hound shark Mustelus mustelus (Linnaeus, 1758) (Chondrichthyes: Triakidae) from the Aegean Turkish coast

2010 ◽  
Vol 11 (2) ◽  
pp. 213 ◽  
Author(s):  
T. CEYHAN ◽  
O. HEPKAFADAR ◽  
Z. TOSUNOGLU
Keyword(s):  
Mesh Size ◽  
Catch Rate ◽  
Small Scale ◽  
Fishing Gear ◽  
Size Selectivity ◽  
Small Scale Fisheries ◽  
By Catch ◽  
Catch Composition

Catch rate, CPUE, biomass ratios and size selectivity from traditional longline and trammel nets of Turkish coastal small-scale fisheries were investigated in order to describe the Smooth-hound shark (Mustelus mustelus) fishery. The SELECT method was used to estimate the selectivity parameters of a variety of models for the trammel nets inner panel of 150 and 170 mm mesh sizes. Catch composition and proportion of the species were significantly different in longline and trammel nets. While mean CPUE of longline was 119.2±14.3 kg/1000 hooks, these values for 150 and 170 mm trammel nets were 5.3±1.2 kg/1000 m of net and 12.7±3.9 kg/1000 m of net, respectively. Biomass ratios of the by catch to Smooth-hound catch were found to be 1:0.32 for 150 mm trammel net, 1:0.65 for longline and 1:0.73 for 170 mm trammel net. The estimated modal lengths and spreads were found to be 91.1 and 16.2 cm for 150 mm and 103.2 and 18.4 cm for 170 mm, respectively. The modal lengths of the species as well as the spread values increased with mesh size.

scholarly journals KERAGAAN TEKNIS JTEDs PADA ALAT TANGKAP ARAD DI PEKALONGAN

2017 ◽  
Vol 15 (2) ◽  
pp. 161
Author(s):  
Tri Wahyu Budiarti ◽  
Mahiswara Mahiswara
Keyword(s):  
East Coast ◽  
Small Fish ◽  
Total Catch ◽  
Size Selectivity ◽  
Fishing Vessel ◽  
Total Length ◽  
Trash Fish ◽  
The Future ◽  
By Catch

Peningkatan kebutuhan dasar hidup para nelayan di Pekalongan menyebabkan mereka mengembangkan alat tangkap serupa mini bottom seine (arad). Hal ini dapat mengganggu kelangsungan hidup sumber daya ikan di masa mendatang karena banyaknya hasil tangkapan sampingan ikan berukuran kecil yang belum layak tangkap. Menyikapi hal tersebut, telah dilakukan uji coba alat pereduksi ikan muda dan sampah dengan alat tangkap tangkap arad yang menggunakan perangkat JTEDs (Juvenile and Trash Excluder Devices) yang diopersikan dengan menggunakan kapal nelayan berdimensi 8,80 m panjang, 2,80 m lebar dan 1,10 m dalam di perairan utara Pekalongan pada akhir Juli 2006. Sebagai perlakuan digunakan JTEDs dengan lebar kisi-kisi 17,5 mm dengan bagian atasnya dibuat terbuka dan diberi cover net berbentuk kantong untuk menampung ikan yang lolos. Rata-rata hasil tangkapan ikan dalam condend adalah 5.774 kg dengan variasi total tangkapan per stasiun 2.630–10.250 kg. Rata-rata ikan yang masuk cover net adalah 10.241 kg dengan variasi total tangkapan per stasiun 5.640–14.340 kg. Hasil tangkapan dalam cover net menunjukkan bahwa ikan-ikan yang lolos tergolong ikan muda dan berukuran kecil. Selektivitas arad untuk ikan kuniran (Upenus sulphureus), petek (Leiognathus splenden dan L. decorus) masingmasing terjadi pada ukuran panjang 89,17 mm dan (67,43 dan 67,47 mm). The increase of basic live need of fishers in Pekalongan causes them to develop a gear like mini bottom seine (arad). This gear might disturb survival of fish resource in the future because of a large number of juvenile and trash fish caught. Therefore, the experiment on gear reducer for juvenile and by catch as well using JTEDs (Juvenile and Trash Excluder Devices) set in mini bottom seine operated by fisher’s fishing vessel with dimension size of 8.80 m in length, 2.80 m in body wide and 1.10 in depth, respectively was carried out on end of July 2006 in east coast water of Pekalongan. The treatment was JTEDs having 17.5 mm in grid equipped by cover net on the top side to hold small fish (juvenile) caught. The juvenile catch in the cod end averaged 5774 kg with variation from all stations of 5,640 – 14,340 kg. Total catch in cover net showed that un-seined fish was juvenile having small size. Selectivity of mini bottom seine (arad) for kuniran (Upenus sulphureus), petek (Leiognathus splenden and L. decorus) was observed for their total length of 89.17 mm, 67.43 and 67.47, respectively.

scholarly journals Mesh size selectivity of boat seine codend for anchovy larvae and juveniles

2006 ◽  
Vol 72 (3) ◽  
pp. 414-423 ◽  
Author(s):  
KOJI SAIURA ◽  
KEISUKE MORI ◽  
TADASHI TOKAI
Keyword(s):  
Mesh Size ◽  
Size Selectivity ◽  
Larvae And Juveniles

Size Selectivity of Diamond and Square Mesh Codends in Pelagic Herring Trawls: Only Small Herring Will Notice the Difference

1992 ◽  
Vol 49 (10) ◽  
pp. 2104-2117 ◽  
Author(s):  
Petri Suuronen ◽  
Russell B. Millar
Keyword(s):  
Relative Size ◽  
Mesh Size ◽  
The Other ◽  
Size Selectivity ◽  
The Difference ◽  
Catch Rates ◽  
Two Sides ◽  
High Catch

A twin codend trawl was fished in the northern Baltic to study the size selectivity of square mesh and diamond mesh codends of 36-mm nominal mesh size. For each codend, 15 hauls were completed with a small mesh (20 mm) codend deployed on the other side of the trawl. The relative size of the catches in the two sides of the trawl varied considerably from haul to haul (the separator section was not operating properly) and selection curves were estimated from each individual haul using a method that incorporated the differences in catching efficiency of the two sides. The length of 50% retention decreased with increased catch for both the diamond and square mesh codends, although in neither case was this relationship statistically significant. Selection curves fitted to the combined haul data were asymmetric. The square mesh codend retained significantly less small herring than the diamond mesh codend, and for larger herring the two codends had similar selectivity. In both codends, most escapes occurred at the front of the catch bulge, from the upper side of the codend. At high catch rates, mesh blockage was observed for several metres ahead of the catch bulge during the later part of the tow.

Size Changes, Mortality, and Equilibrium Yields in an Exploited Stock of American Plaice (Hippoglossoides platessoides)

1969 ◽  
Vol 26 (5) ◽  
pp. 1205-1235 ◽  
Author(s):  
P. M. Powles
Keyword(s):  
Mesh Size ◽  
Food Competition ◽  
Mortality Factor ◽  
Otter Trawl ◽  
Small Fish ◽  
Large Fish ◽  
Age Composition ◽  
Instantaneous Rate ◽  
Factors Affecting ◽  
Ecological Dominance

Records from research surveys and commercial landings for American plaice from the Magdalen Shallows, or the southwestern Gulf of St. Lawrence, showed decreases in percentage of old, large fish and in catch per unit of effort from 1955 to 1962. The changes in age composition were clearly relatable to the fishery, which was mainly by otter trawl. Ricker models indicated that wastage of deck-exposed subcommercial plaice is currently a greater mortality factor than predation by cod. Increased landings in particular years were associated with successful year-classes. Other factors affecting landings were annual differences in fleet dispersal, which were related to movements of cod, a cohabiting species. No clear decrease or increase in absolute recruitment of plaice was demonstratable because quantitative comparisons of research surveys by different vessels using different gears and with different skippers, would be misleading.Mortality estimates of adult plaice by three methods showed agreement, indicating that instantaneous rate of natural mortality was between 0.09 and 0.13. The instantaneous rate of fishing for 1957–62 was 0.46. Increasing mesh-size would reduce cod catches and have little effect in conserving plaice, but marketing small fish would increase plaice landings. Voluntary release of small plaice promptly on capture would help maintain the stock, as would reduction in numbers of large cod, the main predator of small plaice. Increased numbers of small cod since 1959, as reported by other workers, could result in greater food competition with small plaice, effectively reinforcing the ecological dominance of cod over plaice.

The size selectivity of whiting (Merlangius merlangus euxinus) caught by gillnet in the eastern Black Sea of Turkey

2014 ◽  
Vol 94 (7) ◽  
pp. 1539-1544
Author(s):  
Ferhat Kalaycı ◽  
Tuncay Yeşılçıçek
Keyword(s):  
Black Sea ◽  
Fish Species ◽  
Sexual Maturity ◽  
Mesh Size ◽  
Size Selectivity ◽  
Selectivity Curve ◽  
Merlangius Merlangus

The size selectivity of traditional gillnets for whiting, (Merlangius merlangus euxinus) was investigated in the eastern Black Sea between June 2010 and June 2011. Experimental fishing operations were carried out by using gillnets of 16, 17, 18, 20 and 22 mm mesh size. A total of 2038 specimens belonging to 16 different fish species were caught during the experiment. The Share Each Length's Catch Total method was used to fit gillnet selectivity curves. Gillnet selectivity was best described by a bi-modal selectivity curve. The modal catch sizes were estimated as 14.81, 15.74, 16.66, 18.51 and 20.37 cm for 16, 17, 18, 20 and 22 mm mesh sizes, respectively. Modal lengths and spread values increased with increasing mesh size. The majority of fish (71.8%) caught by 16 mm mesh size were less than the length at first sexual maturity.

scholarly journals Mesh size selectivity of the gillnet in East China Sea

2017 ◽  
Vol 77 ◽  
pp. 012013
Author(s):  
L Z Li ◽  
J H Tang ◽  
Y Xiong ◽  
H L Huang ◽  
L Wu ◽  
...  
Keyword(s):  
East China Sea ◽  
Mesh Size ◽  
East China ◽  
Size Selectivity ◽  
China Sea

Tailoring codend mesh size to improve the size selectivity of undifferentiated trawl species

2014 ◽  
Vol 21 (6) ◽  
pp. 503-508 ◽  
Author(s):  
D. E. Hunt ◽  
D. L. Maynard ◽  
T. F. Gaston
Keyword(s):  
Mesh Size ◽  
Size Selectivity

scholarly journals PERFORMANCE OF GILLNET-MESH SIZE SELECTIVITY FOR THREE FLYINGFISH SPECIES IN AMBON WATERS, MOLUCCAS PROVINCE

2010 ◽  
Vol 35 (2) ◽  
pp. 39-46 ◽  
Author(s):  
Barbara Grace Hutubessy ◽  
Augy Syahilatua
Keyword(s):  
Black Spot ◽  
Mesh Size ◽  
Maximum Size ◽  
Yellow Spot ◽  
Optimum Size ◽  
Size Selectivity ◽  
Flying Fish ◽  
Direct Applicability

The gillnets' performance for capturing flying fish was obtained from the selectivity parameters of each mesh size. Gillnet selectivity parameters for flying fish were estimated using multi-panel drift gillnets with four different mesh sizes in southern Ambon Island. The black-spot flying fish Cheilopogon suttoni reached peak selectivity at 20.34 cm for mesh size of 1.25", 24.37 cm (1.5") and 28.47 cm (1.75"). Peak selectivity occurred at 22.16 cm for the 1,25" mesh size in the yellow-spot flying fish Cheilopogon abei, with the maximum size selectivity at 31.61cm for the 1.75" mesh. The optimum size for the black-plain flying fish Hirundichthys oxycephalus was 18.67 cm for the 1.25" mesh size, and 22.37 cm for 1.50" mesh size. Selectivity was highest at 26.12 cm for the 1.75" mesh size. Gillnet used in this study was constructed specifically for targeting flying fish suggesting that information on mesh selectivity examined here should has direct applicability to local flying fish fishery.

scholarly journals Biological Aspects of Keperas Fish (Cyclocheilichthys apogon) in Batutegi reservoir, Tanggamus Regency, Lampung Province

2021 ◽  
Vol 1 (2) ◽  
pp. 72
Author(s):  
Marson Marson ◽  
Taufik Hidayah
Keyword(s):  
Experimental Method ◽  
Food Availability ◽  
Growth Pattern ◽  
Food Habits ◽  
Condition Factor ◽  
Eating Habits ◽  
Mesh Size ◽  
Total Length ◽  
Biological Aspects

The research aims to analyze several biological aspects of the squeezed fish in Batutegi Lampung Reservoir. The study used an experimental method of capture used net capture tool with mesh-size 1.5-2.5 inches. Sample fish measured their total length, weighed in weight, and examined their stomachs to determine what type of food they had. We researched in February, August, and November 2017. The example of keperas fish caught amounted to 415 individuals. Analysis of long-weight relationships showed that February and August were allometrically negative, while November allometric was positive. The condition factor is worth one at each station and month.  The eating habits of squeezed fish are plants 50%, fish 15%, insects 10%, worms 9%, phytoplankton 8%, and zooplankton 8%. The growth pattern of fish squeeze in November is isometric and allometric positive due to the development of gonads. The food habits of fish keperas are omnivorous, with the composition according to food availability in the environment. 

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