• 수산해양기술연구
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• 제27권4호
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• pp.247-254
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• 1991

1982~88년 사이 한국건착망 어업의 망선 48척의 어황일보에 의한 조업해구, 어종별 어획량의 자료를 이용하여 5개 해역별로 어획량의 특성을 분석하였다. 이들 해역중 제주도 연안해역(CC)은 양망회수와 어획량은 많으나 양망당어획량이 타해역보다 적으므로, 조업중 어구의 형상에 대해 계측한 자료를 이용하여 저층류에 의한 망형변화에 대해 분석한 결과를 요약하면 다음과 같다. 1. 건착망의 평균 CPUE는 31.6톤인데 음 10~4월은 평균보다 높고, 음 5~9월은 낮았다. 2. 건착망 어장 5개 해역중 CC해역은 양망회수비 42.4%로서 가장 높고 CPUE는 25.7톤으로 낮았으며, 각 해역별 CPUE는 1%의 유의수준에서 차가 인정되었다. 3. 고등어 CPUE의 계절변동지수는 음 11~1월에 평균 136.3%였고, 음 5~10월에 평균 63.7%였다. 4. 저층류에 의한 역조시 선망권의 직경은 가장 짧았고, 이때 납줄에 의한 포위면적은 더욱 좁아지며 어군의 포위효율은 낮아졌다. 5. 저층류에 의한 납줄의 형상은, 순조의 경우 유향으로 장원형이 되었고, 역조의 경우 유향과 직교되는 방향으로 장원형이 되면서 포위면적이 급히 축소되었으며, 망의 변형은 역조의 경우 가장 심하였다.

• 해양환경안전학회지
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• 제19권5호
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• pp.459-466
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• 2013

본 연구에서는 충남 연안에서 연안조망의 어획 특성을 파악하기 위하여, 2008년 3월부터 2009년 2월까지 매월 2~4회 연안조망을 사용하여 어획조사를 실시하였다. 조사 해역은 동경 125도 50분~126도 05분, 북위 36도 15분~36도 25분의 해역이었고, 총 19목 63과 96종이 채집되었다. 그 중 어류가 54종, 갑각류가 27종, 복족류 및 이매패류가 9종, 그리고 두족류가 6종이었다. 생체량은 어류가 51.4 %로 가장 많았으며, 갑각류는 34.2 %를 차지하였다. 꽃새우는 7월~11월에 출현량이 많았고, 12월부터 5월까지는 적은 양이 출현하였다. 연안조망의 목표종인 꽃새우는 전체 어획물의 2.1 %로 낮은 채집 비율로 출현하였으며, 꽃새우 이외 어종의 부수적 어획물의 양적 비율이 높아, 꽃새우 어획이 부수어획으로 어획되는 종들의 수산자원에 미치는 영향이 클 것으로 판단된다.

• 수산해양기술연구
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• 제49권4호
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• pp.368-376
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• 2013

Fishing experiments were carried out in the adjacent sea of Yeongil Bay, the eastern cost of Korea from 2003 to 2004 using the dome-shaped pots with different five mesh sizes (17.1, 24.8, 35.3, 39.8, and 48.3mm) in order to determine the size selectivity of pots for the whelk, Buccinum opisthoplectum. The catch species were composed of Buccinum opisthoplectum (45.4%), Buccinum striatissimum (30.1%), Pandalopsis japonica (9.3%), Chionoecetes opilio (8.9%), and so on. The shell height (l) of Buccinum opisthoplectum caught in the experimental fishing pots was measured. The SELECT (Share Each Length's Catch Total) analysis method was applied with fishing data to obtain master selection curve. The model with the estimated split parameter was found to fit the catch data best. The master selection curve was estimated to be s (R)〓exp (7.833R-10.871)/[1 + exp (7.833R-10.871], where R is the ratio of shell height to mesh size. The relative shell length for 50% retention was 1.388, and the selection range was 0.281. It means that the pots of larger mesh size allow more whelks of small size to escape.

• 수산해양기술연구
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• 제54권4호
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• pp.315-323
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• 2018

Fossil fuel combustion during fishing activities is a major contributor to climate changes in the fishing industry. The Tier1 methodology calculation and on-site continuous measurements of the greenhouse gas were carried out through the use of fuel by the coastal and offshore gillnet (blue crabs and yellow croaker) and trap (small octopus and red snow crab) fishing boats in Korea. The emission comparison results showed that the field measurements are similar to or slightly higher than the Tier1 estimates for coastal gillnet and trap. In offshore gillnet and trap fisheries, Tier1 estimate of greenhouse gases was about $1,644-13,875kg\;CO_2/L$, which was more than the field measurement value. The $CO_2$ emissions factor based on the fuel usage was $2.49-3.2kg\;CO_2/L$ for coastal fisheries and $1.46-2.24kg\;CO_2/L$ for offshore fisheries. Furthermore, GHG emissions per unit catch and the ratio of field measurement and Tier1 emission estimate were investigated. Since the total catch of coastal fish was relatively small, the emission per unit catch in coastal fisheries was four to eight times larger. The results of this study could be used to determine the baseline data for responding to changes in fisheries environment and reducing greenhouse gas emission.

• 한국수산과학회지
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• 제44권4호
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• pp.390-396
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• 2011

Southern rough shrimp Trachysalambria curvirostris is exploited mainly by small shrimp beam trawl in coastal regions of Korea. To determine the size selectivity of a shrimp beam trawl for this species, a series of comparative fishing experiments was conducted in the sea adjacent to Geoje Island off the southern cost of Korea in June and November, 2010, using codends with four different mesh sizes(14.2, 17.8, 25.5, and 35.3 mm). The extended Share Each Length's Catch Total(SELECT) analysis method, based on a multinomial distribution, was applied to the fishing data to obtain a master selection curve. The model with the estimated split parameters fit the catch data best. The master selection curve was estimated to be: s(R)=exp(15.183R-7.872)/[1+exp(15.183R-7.872)], where the relative carapace length, R, is the ratio of carapace length to mesh size. The relative carapace length for 50% retention was 0.518, and the selection range was 0.145. The results suggest that codends with a larger mesh size allow more small-sized shrimps to escape.

• 수산해양기술연구
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• 제51권3호
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• pp.396-404
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• 2015

Morotoge shrimp Pandalopsis japonica is caught by pot and others in the eastern coastal waters of Korea. Comparative fishing experiments were carried out in the eastern coast of Korea, using the dome-shaped pots with different five mesh sizes (17.1, 24.8, 35.3, 39.8, and 48.3 mm) in order to estimate the mesh selectivity of the pot for the morotoge shrimp, Pandalopsis japonica. The SELECT (Share Each Length's Catch Total) analysis method was applied to the catch data. The master selection curve of the pot for the shrimp was estimated to be s(R) = exp(15.770R-10.573)/[1+exp(15.770R-10.753)], where R is the ratio of carapace length to mesh size. From the selection curves, the carapace lengths of 50% retention were 11.6, 17.0, 23.9, and 34.1 mm for 17, 25, 35, and 50 mm mesh-size pot, respectively. It means that the pots of larger mesh size allow more shrimp of small size to escape.

• 수산해양기술연구
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• 제53권4호
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• pp.317-326
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• 2017

Comparative fishing experiments were conducted in the eastern coastal waters near Uljin, Korea from 2002 to 2004, using the experimental trammel nets to estimate the selectivity for spinyhead sculpin Dasycottus setiger. The inner panels of the nets were made of nylon monofilament with four mesh sizes (82.2, 89.4, 104.8, and 120.2 mm) while its two outer panels were made of twisted nylon multifilament with a mesh size of 510 mm. The SELECT (Share Each Length's Catch Total) procedure with maximum likelihood method was applied to obtain a master selection curve. The different functional models (normal, lognormal, bi-normal, and logistic model) were fitted to the catch data. The lognormal model with the fixed relative fishing intensity was chosen as the best-fitted selection curve through comparison of model deviance and AIC (Akaike's Information Criterion). The optimum relative length (the ratio of fish total length to mesh size) with the maximum relative efficiency was obtained as 2.492.

• 수산경영론집
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• 제36권1호
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• pp.121-138
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• 2005

This study was conducted to investigate the economic effect of the release of seed flounder to the central area of the West Sea, which was analyzed into both direct and indirect effects. The results showed that based on the data collected from partial area, the economic effect of flounder seed release reached 6.97 times, average catch proportion was 32.27$\%$, and recapture rate was 11.26$\%$, suggesting that economic effect was very high. In addition, it was observed that the recapture rate was greatly higher than 2.05$\%$, that of Break-Even-Point. It was noted that the increased catch by the release of seed flounder resulted in the increase in commission of sales and the increase in sports fishing. Another economic effect observed were diverse including the increase in income of fishing village, elevated spirit to proper management of fisheries resources, maintaining of willingness to live in fishing village through activation of local fishing village, prevention of illegal fishing including capture of juvenile fish, and the increase in the supply of sea food of high quality. It is emphasized that although the investigation was conducted in the same area, the results will vary by size at release, time at release and other factors. Finally, there is a need to expand species and area of study for more active economic analysis incorporating natural sciences.

• 수산해양기술연구
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• 제50권3호
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• pp.284-291
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• 2014

Finely-striate buccinum Buccinum striatissimum, a species of whelks, is caught mainly by pot in the eastern coastal waters of Korea. In order to determine the size selectivity of pot for the species, comparative fishing experiments were conducted near Yeongil Bay from June to September in 2003 using the dome-shaped pots with different five mesh sizes (17.1, 24.8, 35.3, 39.8, and 48.3 mm). The parameters of logistic equation were estimated by the SELECT (Share Each Length's Catch Total) method based on a multinomial distribution. The model with the estimated split parameter was found to fit the catch data best. The master selection curve was estimated to be s (R)=exp (13.044R-16.438)/[1 + exp (13.044R-16.438)], where R is the ratio of shell height to mesh size. The relative shell height of 50% retention was 1.260, and the selection range was 0.168. Enlargement in mesh size of the pot allows more small-sized whelks to escape.

• 수산해양기술연구
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• 제43권4호
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• pp.329-338
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• 2007

Data collected by on-board observers and from experimental surveys during 2004-2006 were analyzed to figure out the status of shark bycatch in Korean tuna longline fishery. Results obtained from 10 surveys indicated that 14, 13 and 1 species of shark were incidentally caught in Korean tuna longline fishery operated in the Pacific, Indian and Atlantic (Mediterranean) Ocean, respectively, and that shark bycatch accounted for about 29-31% of the total catch. Sharks brought aboard were processed in 3 ways; out of 1,127 sharks observed, 575 sharks (51.0%) were discarded after finning, 299 sharks (26.5%) were stored frozen after finning for future use and 253 sharks (22.4%) were released into the sea immediately after caught. The fin to body weight ratio of sharks was estimated to be about 4.7% which is similar to the guideline of 5% established by the international fisheries organizations. The underestimate of shark bycatch in Korean tuna longline fishery was significant because it was general practice that fishermen on-board did not count the discarded shark as a catch.