scholarly journals Predicting the Size Selectivity Based on the Striped Red Mullet Morphology (Mullus surmuletus) in Bottom Trawl Fisheries

2018 ◽  
Vol 33 (3) ◽  
pp. 90-95 ◽  
Author(s):  
Enis Noyan Kostak ◽  
◽  
Adnan Tokac ◽  
Keyword(s):  
Bottom Trawl ◽  
Size Selectivity ◽  
Red Mullet ◽  
Mullus Surmuletus ◽  
Trawl Fisheries

scholarly journals Effect of a lateral square-mesh panel on the catch pattern and catch efficiency in a Mediterranean bottom trawl fishery

2020 ◽  
Vol 21 (1) ◽  
pp. 105
Author(s):  
SARA BONANOMI ◽  
JURE BRČIĆ ◽  
BENT HERRMANN ◽  
EMILIO NOTTI ◽  
ALESSANDRO COLOMBELLI ◽  
...  
Keyword(s):  
Mesh Size ◽  
Lateral Position ◽  
Bottom Trawl ◽  
Important Species ◽  
Commercial Fish ◽  
Trawl Fishery ◽  
Red Mullet ◽  
Commercially Important ◽  
The Mediterranean ◽  
Trawl Fisheries

The current legal codends used in Mediterranean bottom trawl fisheries are at high risk of retaining undersized individuals of several commercial fish species. This entails that codends alone are unable to provide the desired exploitation pattern. A simple technological measure that potentially can provide higher release efficiency of undersized fish are Square-Mesh Panels (SMPs). SMPs are often applied in the upper section of the trawl belly, just ahead the codend. However, recent studies in the Mediterranean have demonstrated that SMPs mounted in this position provided limited release efficiency, because very few fish came into contact with their meshes. In attempt to improve SMPs efficiency in the Mediterranean bottom trawl fisheries, we applied them on the lateral sides of the last tapered section of the trawl belly, just ahead of the codend, and fitted two guiding panels in the trawl belly to enhance fish-SMP contact. We compared the catch performance of a standard commercial trawl with a 52 mm diamond-mesh codend and of a similar trawl fitted with lateral SMPs (70 mm mesh size) in the belly using a twin trawl. The study focused on red mullet (Mullus barbatus), a commercially important species, but data for gurnard (Chelidonichthys lucerna and Chelidonichthys cuculus)  were also obtained and analysed. In contrast to previous research on SMPs mounted in the top panel of the trawl, in this study SMPs induced a significant effect on catch performance for red mullet, demonstrating that their lateral position involved greater fish-SMP contact. However, since the test trawl lost a significant amount of legal-sized red mullet compared with the standard trawl, the effect was not wholly positive, possibly due to an excessively large mesh size. Therefore, future studies should be encouraged to test lateral SMPs with smaller mesh sizes.

The importance of alien species to the food web and bottom trawl fisheries of the Northeastern Mediterranean, a modelling approach

2020 ◽  
Vol 202 ◽  
pp. 103253 ◽  
Author(s):  
İsmet Saygu ◽  
Johanna J. Heymans ◽  
Clive J. Fox ◽  
Hüseyin Özbilgin ◽  
Ahmet Raif Eryaşar ◽  
...  
Keyword(s):  
Food Web ◽  
Alien Species ◽  
Bottom Trawl ◽  
Trawl Fisheries ◽  
Modelling Approach

scholarly journals Feeding habits of the striped red mullet, Mullus surmuletus in the eastern Adriatic Sea

2018 ◽  
Vol 59 (1) ◽  
pp. 123-136
Author(s):  
Mišo Pavičić ◽  
Dajana Brajčić Jurica
Keyword(s):  
Adriatic Sea ◽  
Feeding Habits ◽  
Red Mullet ◽  
Mullus Surmuletus

Istraživana je ishrana trlje kamenjarke, Mullus surmuletus u istočnom dijelu Jadrankog mora. Analiziran je sadržaj želudca 203 jedinke (11.5 – 32.9 cm TL) prikupljenih pridnenom povlačnom mrežom koćom. Opće su prihvaćene metode i ključevi za determinaciju korišteni za određivanje sastava ishrane i determinaciju plijena. Istraživanjem je određeno 39 identificiranih vrsta plijena koji spadaju u 11 glavnih skupina: rakovi, puževi, školjkaši, ribe, žarnjaci, bodljikaši, mnogočetinaši, oblići, mahovnjaci, alge i krednjaci. Dominantna i poželjna kategorija plijena bili su dekapodni rakovi unutar svih veličinskih kategorija, dok je samo kod najvećih jedinki pronađena dominantnost školjkaša, a slijede ih mnogočetinaši i rakovi. Najveće jedinke također su pokazale veću raznolikost u konzumaciji različitih vrsta plijena i prosječno veći broj jedinki plijena u odnosu na manje ribe. Nije pronađena značajna razlika u ishrani između mužjaka i ženki \((p>0.05)\) i s obzirom na sezonu Istraživana je ishrana trlje kamenjarke, Mullus surmuletus u istočnom dijelu Jadranskog mora. Analiziran je sadržaj želudca 203 jedinke (11.5 – 32.9 cm TL) prikupljenih pridnenom povlačnom mrežom koćom. Opće su prihvaćene metode i ključevi za determinaciju korišteni za određivanje sastava ishrane i determinaciju plijena. Istraživanjem je određeno 39 identificiranih vrsta plijena koji spadaju u 11 glavnih skupina: rakovi, puževi, školjkaši, ribe, žarnjaci, bodljikaši, mnogočetinaši, oblići, mahovnjaci, alge i krednjaci. Dominantna i poželjna kategorija plijena bili su dekapodni rakovi unutar svih veličinskih kategorija, dok je samo kod najvećih jedinki pronađena dominantnost školjkaša, a slijede ih mnogočetinaši i rakovi. Najveće jedinke također su pokazale veću raznolikost u konzumaciji različitih vrsta plijena i prosječno veći broj jedinki plijena u odnosu na manje ribe. Nije pronađena značajna razlika u ishrani između mužjaka i ženki \((p>0.05)\) i s obzirom na sezonu \((p>0.05)\). Hranjenje širokim spektrom plijena bez značajnih varijacija u vezi sa spolom i sezonom sugerira da se trlja od kamena može prilagoditi pomacima u prostorno-vremenskim varijacijama obilja potencijalnog plijena. Prisutnost detritusa u probavnom traktu povezana je s načinom hranjenja istraživane vrste na muljevitim detritičnim dnima. Hranjenje širokim spektrom plijena bez značajnih varijacija u vezi sa spolom i sezonom sugerira da se trlja od kamena može prilagoditi pomacima u prostorno-vremenskim varijacijama obilja potencijalnog plijena. Prisutnost detritusa u probavnom traktu povezana je s načinom hranjenja istraživane vrste na muljevitim detritičnim dnima.

RFLP Analysis of Mitochondrial DNA to Evaluate Genetic Variation in Striped Red Mullet (Mullus surmuletus L.) and Red Mullet (Mullus barbatus L.) Populations

2001 ◽  
Vol 3 (3) ◽  
pp. 264-274 ◽  
Author(s):  
Zissis Mamuris ◽  
Costas Stamatis ◽  
Katerina A. Moutou ◽  
Apostolos P. Apostolidis ◽  
Costas Triantaphyllidis
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Variation ◽  
Rflp Analysis ◽  
Red Mullet ◽  
Mullus Barbatus ◽  
Mullus Surmuletus

scholarly journals Can a square-mesh panel inserted in front of the cod end improve size and species selectivity in Mediterranean trawl fisheries?

2018 ◽  
Vol 75 (5) ◽  
pp. 704-713 ◽  
Author(s):  
Jure Brčić ◽  
Bent Herrmann ◽  
Antonello Sala
Keyword(s):  
Deep Water ◽  
Bottom Trawl ◽  
Horse Mackerel ◽  
Trachurus Trachurus ◽  
Merluccius Merluccius ◽  
Low Probability ◽  
Low Efficiency ◽  
Trawl Fisheries ◽  
European Hake ◽  
Atlantic Horse Mackerel

An experiment was conducted to assess the selectivity in a typical Mediterranean bottom trawl, equipped with a square-mesh panel inserted in front of the cod end, for Atlantic horse mackerel (Trachurus trachurus), European hake (Merluccius merluccius), red mullet (Mullus barbatus), poor cod (Trisopterus minutus), broadtail shortfin squid (Illex coindetii), and deep-water rose shrimp (Parapaeneus longirostris). The release efficiency of undersized individuals through the panel was low. The differences in selectivity between the gear with and without the panel were very small. The low release efficiency of the square-mesh panel was caused by the lack of fish contact with the panel as they drifted towards the cod end, since the average contact probability was estimated not to exceed 9% for any of the species investigated. A low probability of contact with the selection device was thus found to be the reason for the low efficiency of the square-mesh panel.

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