• 한국수산과학회지
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• 제36권6호
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• pp.735-742
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• 2003

In order to develop a logical method for using selective fishing gear, the behaviour and habits of the aquatic animals must be investigated. However, until now, little national research has been carried out to investigate the behaviour and habits of the common octopus (Octopus minor). The purpose of this study henceforth, is to compile necessary behavioral data to develop fishing gear to catch the common octopus. Behaviour and habits of the common octopus were observed while breeding in a water tank from February to May, 2003. The feeding habits of common octopus are more vigorous at night than in the daytime. The common octopus feeds on 1-4 bait crabs per day and consume each crab in 40-50 min. The sensory organs of the common octopus are more influenced by the sense of touch and smell, than by vision. Using live bait is more effective and advantageous than using dead bait, as the common octopus responded more to live bait. The hiding habits of the common octopus were very intensive, as they hid around all the shelters that were provided in this study. They demonstrated territorial behavior and struggled to maintain their sphere of influence. In addition, out of the various colors for shelters and bait supplied, the common octopus preferred light colors.

• 수산해양기술연구
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• 제59권3호
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• pp.221-230
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• 2023

Although the abundance of Metapenaeus joyneri resources with high commercial value was recently confirmed in the outer waters of Gomso Bay, located between Buan-gun and Gochang-gun, Jeollabuk-do, Metapenaeus joyneri resources have not been efficiently utilized due to the absence of fishing gears and methods for a selective Metapenaeus joyneri capture. Therefore, in this study, we adopted shrimp dredge as a trial fishing gear for the Metapenaeus joyneri capture, and analyzed the species composition and cluster community structure of aquatic organisms caught by the shrimp dredge, from May to September 2021 at the coastal waters of Gochang-gun, Jeollabuk-do. During the experimental period, 28 types of marine species of 29,190 individuals and 250,136 g of total biomass were caught. Among them, the population of Metapenaeus joyneri, the target species, dominated by 80.7%, followed by Thrysa chefuensis with 7.1%, and Leiognathus nuchalis with 6.0%, confirming that the fishing ratio of Metapenaeus joyneri was the highest among all species.

• 수산해양기술연구
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• 제45권1호
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• pp.1-13
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• 2009

Experimental fishing operation by the shrimp beam trawl was carried out to investigate the bycatch in order to develop the selective fishing gear of the shrimp beam trawl fishery. The experimental trawling was performed by the prototype fishing gear in coast sea of Boryeong, Buan, Kangjin, Tongyeong and Geoje from 30 April to 13 November 2005. Bycatches of the experimental trawling were analyzed species composition, total length composition. The results obtained can be summarized as follows; Target fishes caught by the shrimp beam trawl were Palaemon gravieri, Crangon Hakodatei, Trachysalambria curvirostris, Parapenaeopsis tenellus, Rhynchocinetes uritai and Matapenaeus joyneri. And their fishing rate and total length range were 50.0%, 46.0%, 2.6%, 0.4%, 0.3%, 0.3% and 40-80mm, 40-80mm, 120-150mm, 60-80mm, 60-80mm, 60-120mm respectively. Bycatches caught by the shrimp beam trawl consisted of fishes of 30 kinds, 6 kinds of mollusk, 5 kinds of shellfishes and 3 kinds of crabs. The main fish was Engraulis japonicus, Platycephalus indicus, Paralichthys olivaceus, Leiognathus nuchalis and Conger myriaster, their occupied rate were 47.0%, 16.6%, 13.6%, 5.5%, 2.7% respectively, and their total length range were 60-150mm, 80-410mm, 80-600mm, 30-80mm and 150-460mm respectively. A number bycatch rates of shrimp beam trawl fishery were 99.7% in Buan, 60.0% in Kangjin, 14.6% in Boryeong, 10.6% in Tongyeong and 2.7% in Geoje, The weight bycatch rate were 99.9% in Buan, 75.1% in Kangjin, 57.1% in Tongyeong, 47.4% in Boryeong and 15.4% in Geoje.

• 수산해양기술연구
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• 제50권3호
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• pp.351-360
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• 2014

The experiments were carried out to decide the selective fishing gear of the shrimp beam trawl fishery. The model nets were made of General type, Double-level type and Grid type. The model experiments were carried out to test opening efficiency and towing tension. The experimental tanks were the flume tank [$8.0L{\times}2.8W{\times}1.4H(m)$] and the towing tank [$85L{\times}10W{\times}3.5H(m)$] in National Fisheries Research and Development Institute. The full scale experiments were carried out to compare the selectivity of General type net, Double-level type net and Grid type net in the southern sea of korea. The vertical opening (net height) of the model nets can be expressed as a function of the towing velocity as the straight line. The towing tension of the model nets can be expressed as a function of the towing velocity as the parabola. The shrimp catching rates of upper cod end in Boryeong and tongyeong were 78%, 9% respectively, but the rates of lower cod end were 23%, 91% respectively. The number bycatch rates of General type and Grid type were 23%, 11% respectively, and the weight bycatch rates were 34%, 31% respectively. A selective shrimp beam trawl net is Grid type in korea coastal sea.