scholarly journals THE CATCH COMPOSITION OF BOTTOM TRAWL FISHING IN THE WESTERN BLACK SEA (ŞİLE-İĞNEADA)

Author(s):  
Taner Yıldız ◽  
F. Saadet Karakulak
2018 ◽  
Vol 23 (2) ◽  
pp. 79
Author(s):  
Asep Priatna ◽  
Suprapto Suprapto

Any fish on swept area of bottom trawl could not be caught due to some technical factors during towing. However, it could be estimated by integrated of bottom trawl and acoustic survey. This paper describes the determination of some factors that affect the performance of trawl net during the bottom trawl survey in the waters of Tarakan. Surveys were carried out in May, August, and November 2012. A total of 57 stations of simultaneously acoustic-trawl were completed. Data collected from each station include catch composition, and variables of trawling operation (i.e. bottom depth, warp length, trawl door opening, towing speed, towing duration, and acoustic fish density). Principal component analysis was applied to identify variables might impact of trawling performance (i.e. fish density at the waters area, towing speed, towing duration, warp length, horizontal opening of trawl door, density of non-demersal at cod end, and bottom depth). Both towing speed and towing duration were not major component for trawl operation. According to test of significance for four variables (i.e. bottom depth, warp length, horizontal opening, biota non-demersal at cod end) which affected to fish density at waters area, that both of variable (i.e. warp length and bottom depth) were significant as the principal components for the performance of bottom trawl. 


2021 ◽  
Vol 322 ◽  
pp. 03006
Author(s):  
Naliyana Fitriya ◽  
Nahlah Alfiatuunisa ◽  
Suwarman Partsuwiryo ◽  
Eko Setyobudi

Demak is a coastal area on the North Coast of Java with a large enough potential for demersal fish resources. This research aimed to determine the composition, the length and weight distribution, and catch per unit effort (CPUE) of demersal fish caught using mini bottom trawl at the north coast of Demak Regency. The research was carried out in October-December 2020 by observation of ten trips of mini bottom trawl fishing. Each fish captured was then grouped by type, identified, and measured its length and weight. The result showed that 38 species consist of 31 fishes, four mollusks, and three crustaceans. The fish captured dominated by pony fish (Leiognathus equulus) as much as 31.23% and largehead hairtail (Trichiurus lepturus) of 23.52%. The catch per unit effort (CPUE) average of mini bottom trawl was 44.77 kg/trip. Mainly fish (more than 95%) caught in small size compared it’s the maximum attainable length (L-max), with all the weight ranges from 0.3 to 520 g and more than 98% sized 0.3-80 g. Mini bottom trawl catches many types of fish and small size; therefore, mini bottom trawl is classified as a type of fishing gear with a very low selectivity level.


2020 ◽  
Vol 155 ◽  
pp. 104875 ◽  
Author(s):  
Fabio Crocetta ◽  
Emilio Riginella ◽  
Marco Lezzi ◽  
Valentina Tanduo ◽  
Liliana Balestrieri ◽  
...  

2018 ◽  
Vol 35 (2) ◽  
pp. 189-193
Author(s):  
Naciye Erdoğan Sağlam ◽  
Serap Samsun
Keyword(s):  

2019 ◽  
Vol 89 (11) ◽  
pp. 1105-1119
Author(s):  
Dmitry Ya. Fashchuk

In this paper, the history of the formation, dynamics of structure, and species composition of the main objects of the national fishery in the Black Sea from the moment of the fall of the Crimean Khanate in 1783 up to today are analyzed, as well as the structure of commercial biological resources of the sea formed throughout the geological history of development of the Ponto-Caspian Basin (more than 30 million years). The geography and catch composition, scales, and methods of fish harvesting in the twentieth and twenty-first centuries are examined. The stages of intensification and reduction of fish harvesting success and the causes of these fluctuations (natural dynamics of population abundance, press of predatory species, hydrotechnical construction, marine pollution, overfishing, poaching) are identified. The author shows that at the end of the twentieth century, the Russian fishing industry entered a depressed state, while the other Black Sea countries increased their average annual total catch. At the same time, starting at the beginning of the twenty-first century, due to the lessening of press of warty comb jelly (Mnemiopsis leidyi), a decrease in the level of oil and chemical pollution of coastal and shelf waters in the northern Black Sea, and a reduction in industrial production on the seacoast and watershed territories, the ecological situation in the Russian territorial waters improved significantly and many formerly commercial fish populations started to recover.


2014 ◽  
Vol 15 (3) ◽  
pp. 613 ◽  
Author(s):  
F. ORDINES ◽  
M.T. FARRIOLS ◽  
J. LLEONART ◽  
B. GUIJARRO ◽  
A. QUETGLAS ◽  
...  

The teleosts Chelidonichthys cuculus, Trigloporus lastoviza, Serranus cabrilla and Trachinus draco, are important by-catch species, in terms of landed biomass and commercial value, from the continental shelf bottom trawl fishery off the Balearic Islands (western Mediterranean). The main biological parameters of these species were calculated from monthly biological samplings, and were used along with three years pseudo-cohorts (2008-2010) obtained from monitoring on-board of the bottom trawl fleet, to assess their exploitation level through Virtual Population Analysis (VPA) and Yield per Recruit (Y/R) analysis. Time series of fishery independent indicators based on MEDITS surveys data such as the evolution of the abundance and biomass, the distribution range, and the Conservation Status of Fish b (CSFb), were also analyzed. All four species analyzed showed growth overfishing. The reductions of the fishing effort required to reach the Y/RF0,1 reference point were lower, 66-73% depending on the species, to those reported for the target species M. merluccius (87%), but higher than that reported for M. surmuletus (53%), in the study area in the period 2000-2010. The abundance and biomass, and the distribution range did not show any trend for the period 2001-2011, whereas the CSFb showed signs of recovery that may be due to the displacement of the trawl fishing effort from the shelf to the slope during the last decade. Our results underline the necessary incorporation of monitoring and assessment of by-catch species to the management of fisheries as their populations can show a more pronounced overexploitation than target ones.


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