• Title/Summary/Keyword: Warmer regime

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Long Term Changes Pattern in Marine Ecosystem of Korean Waters (우리나라 주변 해양생태계의 장기 변동)

  • Rahman, S.M.M.;Lee, Chung-Il
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.18 no.3
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    • pp.193-198
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    • 2012
  • Long term changes in winter time(JFM) sea surface temperature(SST) and marine ecosystem of different Korean waters during last five to six decades were illustrated. Fishing intensity with climate-ocean variability(e.g. SST) have been increasing since 1970s in all of the Korean marine waters. Winter SST around Korean waters went to colder regime in early 1980s and after the late 1980s increased gradually. After 1988/89 CRS all of the waterbody started warmer regime and well coincided with the CRS phenomena. Large predatory, small pelagic and crustacean and mollusks abundance were well coincided by the warmer SST regime after 1988/89 CRS and changed the fishery from demersal fishery to pelagic fishery. Ecosystem parameter of Mean Trophic Level(MTL) showed continuous decreasing trend since mid of 1970s which was mostly affected by the increasing of lower trophic level species. Fishing in balance(FIB) index showed increasing pattern since early 1970s to the late of 1970s and from early 1980s it was almost stable until now. Finally wasp-waist population of anchovy and Japanese sardine have a greater impact to the whole MTL since early 1970s.

Long-term variation in catch of Spanish mackerel (Scomberomorus niphonius) related to environmental change in Korean waters (환경변화에 따른 한국 연근해 삼치 (Scomberomorus niphonius) 어획량의 장기변동)

  • Lee, Seung-Jong;Kim, Byung-Yeob;Chang, Dae-Soo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.2
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    • pp.99-107
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    • 2011
  • The relationships among long-term variation in catches of Spanish mackerel (Scomberomorus niphonius) and main food organism such as common mackerel (Scomber japonicus), anchovy (Engraulis japonicus), and oceanic condition in Korean waters were analyzed using 40 years of time-series data from 1971-2010. In the 1990s, oceanic conditions around the Korean peninsula shifted to a warmer regime with higher SST (sea surface temperature). The total catch of Spanish mackerel in Korean waters increased dramatically since the early 2000s, and main fishing ground form into South Sea in winter season from December to January. From the results of correlation analysis, we found a significant relationship between the Spanish mackerel catch and environmental factor such as SST, common mackerel and anchovy catch in Korean waters.

Long-term Variation in the Catch of Major Small Pelagic Fishes Related to Winter Warming in the South Sea, Korea

  • Lee, Seung-Jong;Go, You-Bong
    • Fisheries and Aquatic Sciences
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    • v.10 no.1
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    • pp.43-52
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    • 2007
  • The relationships among long-term climatic change in the southern part of the Korean peninsula, oceanic conditions of the South Sea, Korea, and winter catches of major small pelagic fishes were analyzed using 33 years of time-series data from 1971-2003. In the early 1990s, winter climatic conditions in the southern part of the Korean peninsula shifted to a warmer regime with higher air temperature, weaker wind speed, and lower relative humidity. Also, winter sea surface temperature (SST) became consistently higher in the South Sea. The annual catch of major small pelagic fishes in the South Sea increased dramatically in the mid 1990s, whereas the catch of total fishes decreased in the late 1980s. In particular, the winter catch started to increase markedly in the late 1980s, and has remained over 120,000 M/T since the late 1990s. Correlation analysis of the winter catch of major small pelagic fishes and environmental factors showed that catch was correlated with air temperature (r=0.468, P< 0.01), wind speed (r=-0.732, P< 0.01), relative humidity (r=-0.73l, P< 0.01), and SST (r=0.672, P< 0.01). Multiple regression analysis between the winter catch of major small pelagic fishes (Y) and environmental factors (X) resulted in the equation: $Y=-0.017-0.217\;X_3-0.486\;X_4+0.325\;X_5(R^2=0.754,\;P<0.000)$.

Fishing Characteristics of Pacific Herring Clupea pallasii and Relationship between Its Catch and Sea Temperature during the Past 50 Years in Korean Waters (50년간 우리나라 청어(Clupea pallasii)의 어획 특성 및 어획량과 수온과의 관계)

  • Yoo, Joon-Taek;Kim, Jung Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.2
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    • pp.208-217
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    • 2021
  • This study described the fishing characteristics of Pacific herring Clupea pallasii and examined the relationship between its catch and sea temperature in Korean waters from 1970 to 2019. Although the herring catch in Korean waters stayed below 1,000 tons per year from the mid-1970s to mid-1980s, the catch in the winters in the East Sea of Korea started to increase markedly after 1987-1988, when the sea surface temperature (SST) seemed to shift to a warmer regime. Since the mid-2000s, overall, herring was caught throughout the year in the East Sea and eastern South Sea of Korea, and its catch significantly increased by around 30,000 tons per year. The main fishing grounds of herring in the poor fishing years until the mid-1980s were possibly formed in the western offshore of Korea, and subsequently the fishing grounds were distributed in the eastern coast of Korea. While the standardized catch per unit effort (CPUE) for two main fisheries of herring catch was significantly correlated with the herring catch since the 2000s, there was a gradual decline since the 2010s. The herring catch in the East Sea had significant positive correlations with SSTs, but that in the West Sea had a significant negative correlation.