• 해양환경안전학회지
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• 제10권1호
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• pp.61-67
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• 2004

본 연구에서는 동해의 오징어 어획량이 급증한 최근 $1990{\sim}1999$년 기간에 주목하여 동해에서의 오징어 어황 변동과 해황과의 관계를 조사하였다. 동해에서 오징어 어획량의 경년변화 특징은 1970년대부터 1980년대 초반에 감소하고 1980년대 후반에 증가하였다. 이것은 기후변화에 따른 regime shifts의 변동과 관계하는 것으로 나타났다. 월평균 어획량은 9-12월까지 풍어기, 3-5월 사이가 흉어기를 보이고, 최대 어획량은 10월에, 최소어획량은 4월에 나타났다. 해구별 안정 어장의 지표로 제시한 변동계수 (coefficient of variation) 값이 1.0 이하로 매년 안정된 어장은 구릉포 연안역과 울릉도 주변해역에서 형성되었다. 또한, 오징어의 최대 어획적수온 $16^{\circ}C$를 기준으로 한 어획적수심은 해역이 북상함에 따라 얕아졌다. 이 결과로부터 해역에 따라 조업시의 어획적수심에 대한 차등성을 둘 필요가 있음이 시사되었다. 또한, 조업 어장과 수온의 관계는 흉어기인 4월에 $10{\sim}14^{\circ}C$이고, 풍어기인 10월에 $10{\sim}20^{\circ}C$의 범위로서 오징어 어장 형성은 계절에 따른 대마난류역의 확장과 밀접하게 관련된 것으로 생각된다.

• 한국수산과학회지
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• 제54권4호
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• pp.508-516
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• 2021

Although scientist have been reporting recently that changes in ocean environment influence the species composition, movements, and growth of fish in Korea waters. Previous studies on fish vulnerability owing to climate changes are insufficient to explain the effect of fluctuating ocean environments on fisheries ground. In this study, we suggested a method for the assessment of fisheries sensitivity to various factors in ocean environments in Korean waters. To evaluate the fisheries sensitivity, catch data (Chub mackerel, Hairtail, Common squid, small yellow croaker) from National federation of fisheries cooperatives in Korea (1991-2017) and oceanographic data from Korea Ocean Data Center (KODC; 1960-2017) were normalized using the z-score method. Thereafter, the fisheries sensitivity was calculated using the difference between the catch data and the oceanographic data. Finally, the fisheries sensitivity was evaluated based on evaluation grade ratings. Result revealed that in the south sea, variability in catch data was obviously higher than environmental fluctuation (evaluation grade 1), indicating that catch variability in response to environmental change is most sensitive in the south sea among Korean waters in 2017. These results would be helpful for fishery management and policy for sustainable yield in Korean waters.

• 수산해양기술연구
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• 제15권2호
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• pp.67-76
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• 1979

트로올선 No.85 Ptaro가 1975년 9월부터 1976년 8월까지 대서양 아프리카 연안 어장에서 조업한 어획상황을 분석한 결과 예망당 어획량의 일주기변동은 대략 다음과 같다. 1. 오징어는 일출후에 월등하게 많고 일몰후에 현저하게 적으며 주야간의 어획량비는 54:17로 획간에 많았다. 2. 갑오징어는 개체중량 300g이상의 대형어는 일출후에 다소 많고 일몰후에 적으며 주야간의 어획비는 45:28로서 획간에 많고, 개체중량 300g 미만의 소형어는 주야간의 어획량비가 40 : 32로서 큰 차이가 없다. 3. 문어는 개체중량 700g 이상의 대형어는 일출후에 적고 일몰후에 적으며, 오전보다 오후에 많은 경향이 있고, 주야간의 어획량비는 43 : 31로서 획간이 많으나, 개체중량 700g 미만의 소형어는 일출후에 적고 일몰후에 많은 경향이 있고, 주야간의 어획량비는 32 : 44로서 야간에 많았다. 4. 서대류는 일출후에 현저하게 적고 일몰후에 월등하게 많으며, 주야간의 어획량비는 16 : 41로서 획간에 많았다. 5. 돔류, 기타 A, B 잡어는 일출후에 월등하게 많고 일몰후에 현저하게 적으며, 주야간의 어획량비는 돔류 51 : 19, A 잡어류 50 : 19, B잡어류 42 : 25로서 획간에 많았다.

• 해양환경안전학회지
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• 제23권7호
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• pp.909-917
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• 2017

본 연구에서는 동해 연안의 경상북도(경북)와 강원도(강원)의 정치망어업에서 31년(1980~2010)간 5~11월에 어획된 방어 어획량과 연근해 수온과의 관계를 살펴보았다. 또한, NOAA 수온 영상을 이용하여 수온의 상승과 하강 시기에 외해수의 이안 및 접안으로 인한 방어의 북상시기(5~8월)와 남하시기(9~11월)의 어획량 변동을 분석하였다. 전체 방어 어획량의 변동은 연도별 차이는 있지만 방어의 북상 시기보다 남하시기에 높은 수온의 외해수가 연안에 접안할 때 어획량이 증가였다. 연안수온의 하강기는 북상 및 남하하는 모든 시기에 경북이 강원보다 방어 어획량이 많았다. 수온 상승기는 방어 어획량의 증감이 동시에 나타났고, 남하시기의 방어 어획량은 일반적인 현상과 달리 강원이 경북보다 어획량이 많았다. 이것은 하계의 $25^{\circ}C$ 이상의 수온이 강원도까지 분포하면서 추계까지 높은 수온($20^{\circ}C$)이 지속되어 방어의 체류시간이 길어졌기 때문이다.

• 수산해양기술연구
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• 제15권1호
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• pp.23-33
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• 1979

한국 연안에서는 연간 5~8만m/t정도의 멸치가 어획되고 있으나 주 어장은 경남 일원을 중심으로 남해안이다. 따라서 남해안의 어황변동을 예보할 수 있으면서 어업경영의 합리화에 크게 이바지 할 수 있을 것이고, 그에 따라 황멸치의 수급 계획 수립에도 크게 도움이 될 것이다. 여기서 먼저 1971~77년 7년간의 수온, 부유생물, 강수량과 열수지를 조사, 계산하고 그 해 봄철의 강수량을 조사하면 그 해의해황이 예측될 수 있고 그에 따라 멸치의 어황도 예보할 수 있을 것으로 기대된다

• 한국수산과학회지
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• 제48권4호
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• pp.489-497
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• 2015

To reveal the spatial and temporal variability in the distribution, growth, and maturation of skipjack tuna Katsuwonus pelamis in the western tropical Pacific, we compared two El $Ni{\tilde{n}}o$-Southern Oscillation (ENSO) signals and the sea surface temperature (SST) in the main fishing area with fishery and biological data. An index of skipjack tuna distribution was calculated using Korean purse seine fishery data from 1985 to 2003. Biological data for skipjack tuna were collected monthly from Korean catches during the 1994-2003 period. The catch was more closely related to the SST in the main fishing area than to the ENSO signals. However, cross-correlated function analysis showed delayed interactions between abiotic and biotic factors. The El $Ni{\tilde{n}}o$ events preceded the eastward movement of the fishing center by 2-3 months. El $Ni{\tilde{n}}o$ had a positive effect on the skipjack tuna catch, and the change in the Southern Oscillation Index (SOI) preceded the catch fluctuation by ca. 5-7 months. In addition, negative El $Ni{\tilde{n}}o$ effects on gonad maturation and the mean length of skipjack tuna were detected with time lags of 12 and 7 months, respectively. The length frequency indicated that the regime-specific growth pattern at each discrete period seemed to be related to the ENSO.

• 한국환경보건학회지
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• 제43권6호
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• pp.516-524
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• 2017

Objectives: The annual catch of the common squid Todarodes pacificus in Korean coastal waters has gradually increased since the late 1980s. We investigated the long-term effects of climate variability on the variation in catches of the squid in the offshore fisheries of Korea. Methods: Moving average method, correlation analysis, and regression analysis were used to determine the relationship between the environmental factors and fluctuation in the catch of the squid during the past 30 years (1981- 2010). A ten-year moving average was calculated and used for each variable. Results: Squid catches in Korean coastal waters increased over time, and there were significant variations within every ten years (p < 0.001). Air temperature, atmospheric pressure, and wind grade among the meteorological factors, alongside sea surface temperature (SST) and concentrations of phosphate phosphorous, and nitrite/nitrate nitrogen in the sea water increased and were positively related with the catch size of squid (p < 0.001). However, salinity decreased and was negatively related with the catch size (p < 0.001). The increase in air temperature and SST was almost parallel, although there was a time lag between the two factors. Conclusion: These results suggest that there is a causal association between climate change and squid populations. Climate change, especially ocean warming, appears to have been largely favorable for squid range expansion into Korean seas. Although the expansion may be helpful for the human food supply, the safety of the squid caught should be monitored since the concentrations of phosphorous and nitrogen in the sea water increased, which indicates that Korean seas have grown gradually more polluted.

• 한국수산과학회지
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• 제38권6호
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• pp.413-424
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• 2005

The study focused on the fluctuation of the fisheries conditions in fishing ground of yellow croaker, Pseudosciaena polyactis Bleeker. A long-term decreasing trend was observed in the accumulated catches of the species since 1926, with increasing-decreasing fluctuation repeating 6 times. Periodicity was observed in 10-year interval in good fishing years, but not in poor fishing years which had irregular fluctuations. From the geographical distribution of the past catch per unit effort, it was presumed that a group of the species seasonally migrated but most of the groups stayed throughout year in the western area off Cheju Island, which was different from the assumptions of the 1970's. The fishing grounds were distributed along the migration route differently by season, throughout the Yellow Sea and the East China Sea, but shifted gradually southward and narrowed down to the area of $32^{\circ}N-125^{\circ}E$ off Cheju Island, where the center of fishing grounds was given birth to throughout the year with a relatively high density from autumn to spring. It was noted that a negative correlation was shown between the area of fishing grounds and density distribution of catch.

• 한국어류학회지
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• 제23권3호
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• pp.206-216
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• 2011

To investigate seasonal and yearly variation of fishes composition in Yeoja Bay of Korea, fisheries survey were carried out using beam trawl from 2006 to 2009. A total of 44 fish species were collected. The major dominant species were Pennahia argentatus, Thryssa adelae, Thryssa kammalensis and Cynoglossus joyneri, which were occupied over 63% total individuals, and 50% of wet weight. The diversity index (H') was about 1.62 (1.46~1.77) by seasons, and seasons of similarity by fishes were divided into two groups, which were March with December and June with September. ANOVA test showed that there were not significant difference between individuals and catch weight (kg) per unit area (km$^2$) by year and season, except for catch weight per unit area by season.

• 수산해양교육연구
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• 제15권2호
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• pp.166-175
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• 2003

In order to offer fundamental data for the standard of comfilation of the budget on the compensation money for the reduction of fishing baot and index of investigation for computation on the average earnings of reduction of fishing boat, the fluctuation of actual outputs, expenses, earnings and the difference by type of coastal and off-shore fishery was investigated and analyzed. The results are as follows : 1. The average ouput money by large powered purse seine fishery was much with about 3,510 million won, but the average output money by off-shore gill nets fishery was little with about 8.4 million won. 2. The average catch by large powered purse seine fishery was many with about 296,000 M/T, but the average catch by eastern sea danish seine fishery was few with 4,600 M/T. 3. The average expense by large powered purse seine fishery was much with about 3,360 million won, but the average expense by diving fishery was little with 6.3 million won. 4. The average earning by large powered purse seine fishery was much with about 240million won, the average earning by offshore long line fishery was little with 18 million won. 5. The average earning rate by diving fishery was much with 31.62%, but the average earning rate by large powered purse seine fishery was little with 7.30%.