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 Comparison of selectivity of the trawl codends for whiting (Merlangius merlangus euxinus) in the Black Sea

2019 ◽  
Vol 36 (3) ◽  
pp. 301-311 ◽  
Author(s):  
Mustafa Zengin ◽  
İlkay Özcan Akpınar ◽  
Muharrem Hakan Kaykaç ◽  
Zafer Tosunoğlu
Keyword(s):  
Black Sea ◽  
Mesh Size ◽  
Bottom Trawl ◽  
The Black Sea ◽  
Size Selectivity ◽  
Minimum Landing Size ◽  
Merlangius Merlangus ◽  
First Maturity

A large part of the total whiting (Merlangius merlangus euxinus) fishing in the Black Sea is carried out with the traditional bottom trawl nets along the coast of Turkey. Diamond mesh shape with 40 mm mesh size (40D) has been used in the codends of these trawls. In this study, the traditional trawl codend (40D) and square-mesh codend with different size (36S and 40S) were compared for whiting size selectivity in August 2014. Selectivity data were collected by using a covered codend method and analysed taking between haul variations in to account. The selectivity parameters were estimated by using CC2000 software. Results showed that commercially used 40D trawl codend is not selective enough to release immature of whiting. However, the net change in square mesh (36S and 40S) instead of a diamond-shaped (40D) mesh significantly improved the mesh selectivity for whiting. The 40S trawl codend is even higher than the first maturity size (LM50) with a length at fifty percent retention (L50) of 15.74 cm. In conclusion all square mesh codends with different mesh size tested here supplied appropriate selection considering minimum landing size (MLS) of whiting.

scholarly journals Plastic Occurrence in Commercial Fish Species of the Black Sea

2021 ◽  
Vol 22 (Special Issue) ◽  
Author(s):  
Ulgen Aytan ◽  
Fatma Basak Esensoy ◽  
Yasemen Senturk ◽  
Esra Arifoglu ◽  
Kaan Karaoglu ◽  
...  
Keyword(s):  
Black Sea ◽  
Fish Species ◽  
The Black Sea ◽  
Plastic Pollution ◽  
Commercial Fish ◽  
Vital Functions ◽  
The Status ◽  
The Mean ◽  
Merlangius Merlangus ◽  
Sarda Sarda

The occurrence of micro- (<5 mm), meso- (5–25 mm) and macroplastics (>25mm) was investigated in seven commercial fish species of the Black Sea. Plastics were found in gastrointestinal track of all species analysed: Engraulis encrasicolus, Trachurus mediterraneus, Sarda sarda, Belone belone, Pomatus saltatrix, Merlangius merlangus and Mullus barbatus. A total of 352 plastic particles were removed from 190 individuals (29% of all individuals examined). The mean number of plastic particles per fish was 0.81±1.42 par.ind-1 (considering all fish analysed, n=650) and 2.06±1.09 par.ind-1 (considering only the fish that ingested plastic, n=190). The most common types of plastics were fibres (68.5%), followed by films (19%), fragments (11.9%), foams (0.3 %) and microbeads (0.3%). The most common plastic colour was black (39.3%) followed by blue (19.5%) and transparent (18.1%). The length of plastics ranged from 0.05 to 26.5 mm with an average of 1.84±2.80 mm. 93.2% of plastics were microplastics, 6.5 % as mesoplastics and 0.3% macroplastics. Plastic occurrence was higher in S. sarda (plastic in 70% of the analysed individuals) and lower in M. merlangus (plastic in 9% of the analysed individuals). The main synthetic polymers identified by Fourier-transform infrared (FTIR) spectroscopy were polypropylene (29.8%), polyester (17.5%), acrylic (15.8%), polyethylene (14%) and polystyrene (1.8%) and 21.1% of polymers were cellulosic. Results show that commercial fish of the Black Sea is contaminated by plastics. This might affect vital functions of fish and pose a risk to ecosystem and human health. The study contributes to a better understanding of the status of plastic pollution in the fish from different habitats of the Black Sea and provides baseline data to implement the Marine Strategy Framework Directive in the basin.

scholarly journals Effects of depth and season on catch volume of bottom gillnets employed along the Fatsa coasts of the South-eastern Black Sea

2020 ◽  
Vol 37 (2) ◽  
pp. 187-194 ◽  
Author(s):  
İsmet BALIK
Keyword(s):  
Black Sea ◽  
Fish Species ◽  
Water Depth ◽  
Horse Mackerel ◽  
Shallow Waters ◽  
The South ◽  
Summer Period ◽  
South Eastern ◽  
Water Layers ◽  
Merlangius Merlangus

The study was conducted along the Fatsa coasts of the South-eastern Black Sea, to investigate the effects of depth and season on catch volume of the bottom gillnet fishery. During the study, fishing was carried out using multifilament gillnets with mesh sizes of 32, 34, 36 and 38 mm in each of the four different depth strata (0-14 m, 15-29 m, 30-49 m and ≥50 m) three times per month between March 2013 and February 2014 (except for July and August), with a total of 30 gillnet hauls performed. The results of the study revealed that in all seasons whiting (Merlangius merlangus) was caught most in the 30 m and deeper water layers. However, whiting catch increased with increasing water depth. Most red mullets (Mullus barbatus) were caught in the 0-14 m depth waters during spring, winter and autumn periods, while its catch was the greatest in the 15-29 m during the summer period. Catch of this species decreased gradually with increasing water depth. Another fish species was pontic shad (Alosa immaculata) which was caught least in the shallow waters. However, during all seasons its catch increased gradually with increasing water depth up to the 30-49 m depth strata. Nevertheless, it was determined that catch volume for this species decreased in the ≥50 m level again. On the other hand, Mediterranean horse mackerel (Trachurus mediterraneus) was mostly caught in the shallow waters (0-14 m and 15-29 m) during all seasons. Especially in the ≥50 m waters, no Mediterranean horse mackerel was sampled during the study. This study presents that amounts of catch for the fish species sampled were affected especially by water depth and seasons.

scholarly journals Fish species composition and size structure exploited by gill net fishery in The New Calabar River, Nigeria

2019 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Olaniyi Alaba Olopade ◽  
Henry Eyina Dienye ◽  
Ogheneforon Oderhohwo
Keyword(s):  
Species Composition ◽  
Fish Species ◽  
Size Structure ◽  
Mesh Size ◽  
Maximum Size ◽  
Abundant Species ◽  
Fish Stock ◽  
Size Selectivity ◽  
Gill Nets ◽  
Gill Net

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

Body shape and trawl cod end selectivity for nine commercial fish species

2003 ◽  
Vol 83 (6) ◽  
pp. 1309-1313 ◽  
Author(s):  
Zafer Tosunoğlu ◽  
Yeliz Doğanyilmaz Özbilgin ◽  
Hüseyin Özbilgin
Keyword(s):  
Fish Species ◽  
Body Shape ◽  
Morphological Characteristics ◽  
Mesh Size ◽  
Sea Bream ◽  
Merluccius Merluccius ◽  
Commercial Fish ◽  
Red Mullet ◽  
Common Pandora ◽  
Merlangius Merlangus

This study investigates the catch components of a commercially used demersal trawl cod end in Izmir Bay, and reveals some of the morphological characteristics of nine commercial fish species; red mullet (Mullus barbatus), hake (Merluccius merluccius), whiting (Merlangius merlangus euxinus), poor cod (Trisopterus minutus capelanus), tub gurnard (Trigla lucerna), common pandora (Pagellus erythrinus), axillary sea bream (Pagellus acarne), picarel (Spicara smaris) and annular sea bream (Diplodus annularis) in relation to mesh size and shapes. Furthermore selectivity of 40-mm polyethylene netting cod end for red mullet, hake, common pandora, axillary sea bream, picarel and annular sea bream is presented. The results are discussed in a way to understand the probable effects of fish body shape on mesh selectivity.

HEAVY METALS IN WATER, SEDIMENTS AND MARINE FISHES FROM BULGARIAN BLACK SEA

2017 ◽  
Author(s):  
Katya Peycheva ◽  
Katya Peycheva ◽  
Mona Stancheva ◽  
Mona Stancheva ◽  
Stanislava Georgieva ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Black Sea ◽  
Fish Species ◽  
Distribution Patterns ◽  
Marine Fishes ◽  
Marine Water ◽  
Mean Values ◽  
Sprattus Sprattus ◽  
Cu And Zn

In this study, the ecosystem marine water-sediment-biota was investigated and the pollution was assessed. The concentrations of eight elements were determined in marine water, sediments and four fish species collected from Black Sea (Varna), Bulgaria during 2013. Marine water recorded the highest concentrations of Zn (15-22 μg/L), As (1.1–1.2 μg/L) and Pb (0.7-0.8 μg/L) while Zn (31-52 μg/g), Pb (21-29 μg/g) and Cu (20-34 μg/g) and show the highest concentrations in sediments. Water and sediments showed similar spatial distribution patterns for the highest mean values of the different metals. In the analysed fish species, the highest concentration of the metals Cu and Zn were found in Trachurus Mediterrneus (0.42 mg/kg w.w) and in Sprattus Sprattus (12.7 mg/kg w.w), respectively while the heavy metals As and Hg were found with maximum values in Pseta Maxima (3.99 mg/kg w.w and 0.08 mg/kg w.w respectively). The results from this study were compared with our data for a previous period (2004-2006) and they show decrease in the levels of heavy metal.

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.

Sign in / Sign up

Export Citation Format

Share Document