Catch composition and codend selectivity of inshore trawl fishery with the legal minimum mesh size

Abstract Suuronen, P., Tschernij, V., Jounela, P., Valentinsson, D., and Larsson, P-O. 2007. Factors affecting rule compiance with mesh size regulations in the Baltic cod trawl fishery. – ICES Journal of Marine Science, 64: 1603–1606. In this study, we evaluate the efficiency and applicability of a series of gear-based management measures, enforced since 1990, whose purpose was to improve size selectivity in the trawl fishery for Baltic cod (Gadus morhua). In general, our study revealed that these measures had no marked effect on the capture and discard of young cod. Legal and illegal manipulation of selective codends was widespread. The adoption of a codend design that offered a modest increase in selectivity, but had a good match with the legislated minimum landing size (MLS), led to greater compliance, demonstrating that a mismatch between MLS and selectivity should be avoided. It was also obvious that, generally, the fishing industry did not tolerate large short-term losses. Our evaluation is that overly ambitious rules will be circumvented, and frequent and incoherent changes in the regulations represent bad management practice. A gradual introduction of restrictions and participation by fishers in the decision-making process will increase compliance.

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Bycatch composition of cutlassfish trawlers during fishing season in Bushehr and Hormozgan, Persian Gulf, Iran

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d190635 ◽

2018 ◽

Vol 19 (6) ◽

pp. 2275-2282

Author(s):

AHMAD FOULADI SABET ◽

SEYED YOUSEF PAIGHAMBARI ◽

MOJTABA POULADI ◽

HADI RAEISI ◽

REZA ABBASPOUR NADERI

Keyword(s):

Data Collection ◽

Persian Gulf ◽

Mesh Size ◽

Similarity Analysis ◽

Fishing Season ◽

Trichiurus Lepturus ◽

Significant Difference ◽

Catch Composition

Fouladi Sabet A, Paighambari SY, Pouladi M, Raeisi H, Abbaspour Naderi R. 2018. Bycatch composition of cutlassfish trawlers during fishing season in Bushehr and Hormozgan, Persian Gulf, Iran. Biodiversitas 19: 2275-2282. This investigation was conducted to determine the bycatch composition of cutlassfish (Trichiurus lepturus) trawlers in Bushehr and Hormozgan waters during fishing season 2013. Data collection was carried out in the summer for Bushehr and in the autumn for Hormozgan province for one month. All trawler vessels were equipped with a 36 m head rope and 75 mm stretched mesh size in the codend and 90 to 200 mm stretched mesh size in the panel. 47 species included 35 species of teleosts, 9 species of elasmobranches and 3 species of invertebrates were identified in Bushehr. Also, 48 species included 38 species of teleosts, 7 species of elasmobranches and 3 species of invertebrates were identified in Hormozgan. The weight and numerical averages of bycatch species were 25.41 (kg h-1) and 205.9 (n h-1) in Bushehr, and 92.58 (kg h-1) and 440.4 (n h-1) in Hormozagan. I. megaloptera, S. tumbil, N. japonicus, D. acuta, C. sexfasciatus, L. equulus in Bushehr and P. sextarius, I. megalopteran, M. cinereus, P. macrophthalmus, N. japonicus and S. tumbil in Hormozgan had highest catch weight. Based on the weight and number, PCA and nMDS methods were indicative of two different assemblages in hunting places. Furthermore, ANOSIM similarity analysis confirmed the results of PCA and nMDS and showed a significant difference in the catch composition of two fishing zones.

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Prediction of delayed mortality using vitality scores and reflexes, as well as catch, processing, and post-release conditions: evidence from discarded flatfish in the Western Baltic trawl fishery

ICES Journal of Marine Science ◽

10.1093/icesjms/fsy129 ◽

2018 ◽

Vol 76 (1) ◽

pp. 330-341 ◽

Cited By ~ 2

Author(s):

S B M Kraak ◽

A Velasco ◽

U Fröse ◽

U Krumme

Keyword(s):

Scientific Evidence ◽

Handling Time ◽

Fishing Ground ◽

High Survival ◽

Trawl Fishery ◽

Fishing Vessels ◽

Reflex Action ◽

Delayed Mortality ◽

Catch Composition ◽

The Eu

Abstract The EU discard ban and its high-survival exemption exposed our lack of scientific evidence on discard survival in the fisheries. Discard survival is known to be highly variable and influenced by numerous factors, including conditions during the catch, on-board the fishing vessels, and post-discard. Therefore, obtaining unambiguous results in discard survival experiments is challenging. We conducted the first systematic year-round discard survival study of flatfish in the Western Baltic Sea on-board a commercial stern trawler under realistic fishing conditions (13 monthly hauls from May 2015 to May 2016) to test whether delayed mortality can be predicted by vitality scores and reflex action mortality predictor (RAMP) scores in combination with variable conditions during catch, processing, and post-release. The factors vessel type, gear, haul duration, fishing ground, depth, handling time, and processing procedures were kept constant as much as possible. On-board, live individual flatfish were tested for vitality and the presence of reflexes for RAMP, then “discarded” and kept in cages on the bottom of the seafloor for about a week after which the delayed mortality was determined. The proportions of “discarded” plaice, flounder, and dab that were dead after being kept in the cages ranged from 5% to 100%, 0% to 96%, and 33% to 100%, respectively. Higher mortalities occurred in summer-autumn when air and water temperatures were higher, catches smaller, and catches contained smaller proportions of roundfish. Relationships between RAMP scores and mortality probabilities varied substantially across the monthly trials. Indeed, in addition to RAMP or vitality scores and individual reflexes, the factors air and water temperature and catch weight and catch composition were significant in logistic GLMs explaining delayed mortality. Cross-validations indicated that delayed mortality could be predicted by these models with a reasonable accuracy. Nevertheless, the presence of possible confounding effects calls for caution in inferring causality and extrapolating the conclusions on predictability.

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Understanding the release efficiency of Atlantic cod (Gadus morhua) from trawls with a square mesh panel: effects of panel area, panel position, and stimulation of escape response

ICES Journal of Marine Science ◽

10.1093/icesjms/fsu124 ◽

2014 ◽

Vol 72 (2) ◽

pp. 686-696 ◽

Cited By ~ 33

Author(s):

Bent Herrmann ◽

Harald Wienbeck ◽

Junita Diana Karlsen ◽

Daniel Stepputtis ◽

Erdmann Dahm ◽

...

Keyword(s):

Escape Response ◽

Gadus Morhua ◽

Atlantic Cod ◽

Mesh Size ◽

Accumulation Zone ◽

Trawl Fishery ◽

Trawl Fishing ◽

Panel Effects ◽

The Baltic ◽

Stimulation Of

Abstract Based on size selectivity data for more than 25 000 cod (Gadus morhua) collected during experimental trawl fishing with six different codends, all of which included a square mesh panel, we investigated the effect on cod-release efficiency based on the size of the square mesh panel area, position of the square mesh panel, and stimulation of the escape response. Based on the results, we were able to explain why the BACOMA codend, applied in the Baltic Sea cod directed trawl fishery, releases juvenile cod efficiently, whereas other designs, including a square mesh panel with similar mesh size, are less efficient. Our main findings reveal that the release efficiency of the square mesh panel in the BACOMA codend depends largely on the overlap of the square mesh panel and the catch-accumulation zone in the codend, where cod do not have the option of just drifting further back in the trawl when proximate to the panel. On the contrary, the reduction in panel size by 50% did not significantly affect the release efficiency when the panel overlapped with the catch-accumulation zone. It was possible to stimulate an escape response for cod to achieve a release through a square mesh panel positioned away from the catch-accumulation zone. Our findings demonstrated that this release was as efficient as for a panel mounted in the catch-accumulation zone of the codend. Devices that stimulate behaviour may improve the release efficiency of cod through square mesh panels in other fisheries where this is a problem.

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Diamondvs.square mesh codend in a multi-species trawl fishery of the western Mediterranean: effects on catch composition, yield, size selectivity and discards

Aquatic Living Resources ◽

10.1051/alr:2007003 ◽

2006 ◽

Vol 19 (4) ◽

pp. 329-338 ◽

Cited By ~ 51

Author(s):

Francesc Ordines ◽

Enric Massutí ◽

Beatriz Guijarro ◽

Ramon Mas

Keyword(s):

Western Mediterranean ◽

Size Selectivity ◽

Trawl Fishery ◽

Catch Composition

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CATCH RATE AND CATCH COMPOSITION OF FISH TRAWL BASED IN SIBOLGA, NORTH SUMATERA

Indonesian Fisheries Research Journal ◽

10.15578/ifrj.17.2.2011.63-73 ◽

2017 ◽

Vol 17 (2) ◽

pp. 63

Author(s):

Agustinus Anung Widodo ◽

Mahiswara Mahiswara

Keyword(s):

Indian Ocean ◽

Fishing Ground ◽

Fuel Price ◽

Fishing Trip ◽

Trawl Fishery ◽

The Indian Ocean ◽

Catch Composition ◽

Operation Results ◽

Engine Power ◽

Design And Construction

To obtain data and information of fish trawl fishery performance operated in the Indian Ocean, a research was carried out through observation on board by observers as well as port sampling inSibolga Fishing Port by enumerators in September 2007, with the aimed to study the performance fish trawl fishery. These include fleet structure, trawl net design and construction, catch, fishing trip, fishing ground, and fishing operation. Results of research showed that there were 71 registered fish trawlers in Sibolga Fishing Port and only 25 boats active due to increasing of fuel price. The fleet structure of fish trawler consist of boat with size 31-114 GT which can be classified into 3 categories i.e. small(<60 GT), medium (60-150 GT), and large fish trawler (>150 GT). Design and construction of fish trawl net indicated that fish trawl net operates in the Indian Ocean was high opening trawl with head and ground rope of 27.8-41.5 m and 29,7-45.8 m, respectively. Fishing trip generally 10-12 days with effective days 7-9 days per trip and the number of net setting was 5-6 times each day. The fishing grounds of fish trawl based in Sibolga were the coastal waters area with maximum depth of 91 m. At least 40 species of fishes and shrimps identified during research and dominant fish species was ponyfish (Leiognathus spp.) threadfin bream (Nemipterus spp.), tall fin goatfish (Upeneus spp.), seacatfish (Arius sp.) as well as yellow striped goatfish (Upeneus vitattus). The average of catch of fish trawler fleet in the year of 2007 was 249.3 kg/haul and that number seems smaller than average of catch/haul previous years. This situation indicates that decreasing of catch per haul of fish trawlers based in Sibolga continues occurring and in other hand price of fuel raises significantly so that big fish trawlers size 150 GT with engine power more than 600 HP are not able to continue their fishing operation.

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