Size selectivity for four fish species of the deep groundfish assemblage off the Portuguese southwest coast: evidence of mesh size, mesh configuration and cod end catch effects

2003 ◽  
Vol 63 (2) ◽  
pp. 213-233 ◽  
Author(s):  
Aida Campos ◽  
Paulo Fonseca ◽  
Victor Henriques
2014 ◽  
Vol 94 (7) ◽  
pp. 1539-1544
Author(s):  
Ferhat Kalaycı ◽  
Tuncay Yeşılçıçek

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.


2019 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Olaniyi Alaba Olopade ◽  
Henry Eyina Dienye ◽  
Ogheneforon Oderhohwo

The purpose of this study was to investigate the species composition and size selectivity of gillnets commonly used by the artisanal fishers in the New Calabar River, Rivers State, Nigeria. The data was collected during February-July 2018 from 3 sampling stations: SI Choba, S2 Ogbogoro, and S3 Iwofe all along the stretch of the river. Twenty-eight fish species were found belonging to 15 families. The prevalent families were Cichlidae, Mugilidae and Clupeidae representing 32.22%, 30.36% and 10.23% of the total catch, respectively. The most dominant species in terms of number were Liza falcipinnis (12.58%) and Mugil cephalous (12.26%) while in terms of biomass, the most abundance species were Xenomystus nigri (24.12%) and Lutjanus agennes (12.50 %). The girth and total lengths of the fishes ranged from 5.20±0.20 to 21.00±0.00 cm and 8.85±0.15 to 28.19±1.13 cm respectively. The length at first capture (L50%) for the most abundant species (Liza falcipinnis) was calculated to be 14.13 cm while that of L25% and L75% were 12.70cm and 15.25cm respectively. It was concluded that the gill nets used in the New Calabar River exploit fish species of small sizes and few medium sized specimens relative to species potential maximum size. It is therefore recommended that for an improved and sustainable exploitation fish stock of the New Calabar River, the use of gillnets of less than 25 mm-mesh sizes and “other gears” should be prohibited.Keywords: gill nets; species composition; mesh size; selectivity; New Calabar River


2006 ◽  
Vol 72 (3) ◽  
pp. 414-423 ◽  
Author(s):  
KOJI SAIURA ◽  
KEISUKE MORI ◽  
TADASHI TOKAI

1992 ◽  
Vol 49 (10) ◽  
pp. 2104-2117 ◽  
Author(s):  
Petri Suuronen ◽  
Russell B. Millar

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.


2019 ◽  
Vol 66 (3) ◽  
Author(s):  
Angela Maria Jaramillo-Londono ◽  
Alejandra Vanina Volpedo ◽  
Jose Luis Diaz-Arevalo ◽  
Maria Eugenia Rodrigo-Santamalia ◽  
Vicent Bendito-Dura

This work provides data on the somatic growth and age of selected commercial fish species of the Cullera Coast, Spain. The biological information available that permits responsible fishing management of these species is relatively scarce. This study was conducted in the Bay of Cullera, Spain (39º 12’to 38º 59’N, and 0º 09’to 0º 15’W); and selected benthic fish species were analysed that are frequently fished by trammel nets (mesh size 28-76 mm) at a maximum depth of 30 m. Maturity , age and growth of 63 torpedoes, Torpedo torpedo (L., 1758), 115 red scorpionfish, Scorpaena scrofa Linnaeus, 1758, 280 red mullets, Mullus surmuletus Linnaeus, 1758, 139 stargazers, Uranoscopus scaber Linnaeus, 1758, and 476 Portuguese soles, Dagetichthys lusitanicus de Brito Capello, 1868 were analysed. The data obtained in this study revealed that 50% of individuals of all the species reached sexual maturity at a TL (total length) of 20.0-36.5 cm and at an age of 2-6 years. The von Bertalanffy growth equation derived were: TL=37.0 (1 - e(-0.2(t + 0.33))); TL =31.5(1 - e(-0.38(t + 0.54))); TL =35.5(1 - e(-0.2(t + 2.08))); and TL =34.3(1 - e(-0.14(t + 2.16))) for S. scrofa, M. surmuletus; U. scaber and D. lusitanicus respectively.


2020 ◽  
Vol 36 (6) ◽  
pp. 858-859
Author(s):  
Swathy Kottappilly Surendran ◽  
Raffi Sirajudeen Mohammed ◽  
Sreenath Mohanan Thittayil ◽  
Athul Subhash

Author(s):  
L Z Li ◽  
J H Tang ◽  
Y Xiong ◽  
H L Huang ◽  
L Wu ◽  
...  

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

2010 ◽  
Vol 35 (2) ◽  
pp. 39-46 ◽  
Author(s):  
Barbara Grace Hutubessy ◽  
Augy Syahilatua

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.


2021 ◽  
Vol 19 (3) ◽  
pp. 638-648
Author(s):  
Saptian Wisnu Sandra ◽  
Arlini Dyah Radityaningrum

Sampah plastik dapat terdegradasi menjadi mikroplastik (MP) dan nanoplastik (NP) melalui proses fisik, kimia, dan biologis. MP didefinisikan sebagai partikel plastik kecil berukuran < 5 mm. MP saat ini telah ditemukan di tubuh biota perairan, baik perairan permukaan maupun perairan laut. Tujuan penelitian ini adalah mengkaji MP pada biota perairan. Metode yang digunakan dalam penelitian ini adalah studi literatur terhadap artikel publikasi 10 tahun terakhir. Kajian dilakukan terhadap kelimpahan, ukuran, bentuk, warna, dan komposisi MP pada biota perairan permukaan dan laut. Review dilakukan terhadap penelitian di Indonesia dan berbagai wilayah di negara lain. Beberapa metode pengambilan sampel biota perairan yang digunakan dalam penelitian terdahulu yaitu menggunakan trawl atau pukat dasar (jaring polietilen), jaring pukat pantai (10 m x 1,5 m; ukuran mata jaring: 8 mm). Identifikasi MP pada saluran pencernakan biota ikan dilakukan menggunakan larutan KOH 10% selama 24 jam pada suhu 60°C, selanjutnya dilakukan penyaringan dengan kertas saring Whatman. Selanjutnya, proses identifikasi menggunakan mikroskop okuler dan FTIR untuk menentukan ukuran, bentuk, dan jenis polimer. Hasil kajian menunjukkan bahwa kelimpahan MP terbanyak pada biota perairan masing-masing yaitu 468 partikel MP/individu pada spesies Ikan Sapu-Sapu (Hypostomus plecostomus) di perairan sungai; 18 partikel MP/individu pada Ikan Nila Hitam (Oreochromis niloticus) di perairan payau; 1,4 – 7 partikel MP/individu pada spesies Tiram (Saccostrea cucullata) di perairan muara; 22,21 ± 1,7 partikel MP/individu pada spesies Ikan Thryssa kammalensis di perairan teluk; 2,7 ± 0,10 partikel MP/individu pada spesies Ikan Zeus faber di perairan selat; dan 22,3 partikel MP/individu pada Diadema sp. (Bulu babi) di perairan laut. MP yang dominan pada biota perairan adalah berukuran 20 μm – 50 μm, berbentuk fiber, dan berwarna hitam. Polyethylene (PE) ditemukan dominan pada biota perairan permukaan, serta polyprophylene (PP) dan polyethylene (PE) pada biota perairan laut.ABSTRACTPlastic wastes could be degraded into microplastic (MP) and nanoplastic (NP) through physical, chemical, and biological processes. MP was defined as the small particle of plastic with the size of < 5 mm. Currently, MP has been found in the body of aquatic biota both in the surface and sea water biota. This research aimed to investigate the microplastic content in aquatic biota. The study was conducted through literature review of the last 10 year published articles. The previous studies were reviewed in terms of abundance, size, shape, colour, and polymer type of MP in the aquatic biota in Indonesia and areas of other countries. Sampling of aquatic biota in the previous studies was conducted in several methods using trawling or bottom trawl (polyethylene net), beach trawl net (10 m x 1.5 m; mesh size: 8 mm). Identification of MP in the digestive tract of fish was conducted using 10% KOH solution for 24 hours at a temperature of 60°C, then was filtered using Whatman filter paper. Next, the identification process used an ocular microscope and FTIR to determine the polymer. The result demonstrated that the highest number of MP abundance was 468 MP particles/individual in the cattle fish (Hypostomus plecostomus) species in the river water; 18 MP particles/individual in the black nile fish (Oreochromis niloticus) species in the brackish water; 1.4 – 7 MP particles/individual in the oyster (Saccostrea cucullata) species in the estuary water; 22.21 ± 1.7 MP particles/individual in the Thryssa kammalensis fish species in the gulf water; 2.7 ± 0.10 MP particles/individual in the Zeus faber fish species in the strait water; and 22.3 MP particles/individual in the Diadema sp. (sea urchin) in the sea water. The most dominant MP size, shape, and colour in the aquatic biota was 20 μm – 50 μm, fiber, and black. Polyethylene (PE) was dominant in the surface water biota, whereas, polyprophylene (PP) and polyethylene (PE) in the sea water biota.


Sign in / Sign up

Export Citation Format

Share Document