Changes in the biological characteristics of walleye pollock related to demographic changes in the East Sea during the late 20th century

Title
Changes in the biological characteristics of walleye pollock related to demographic changes in the East Sea during the late 20th century
Author(s)
방민경; 장찬주; 강수경; 김수암
KIOST Author(s)
Bang, Minkyoung(방민경)Jang, Chan Joo(장찬주)
Publication Year
2017-11-04
Abstract
Walleye pollock was one of the most dominant fish species in Korean waters during the 1970s-1980s, but its catch rapidly decreased from the late 1980s and collapsed in the 2000s. The biological characteristics of fish species tend to depend on their biomass and the environmental conditions. To investigate the changes in the biological characteristics of pollock such as size frequency, condition factor, and maturation associated with biomass levels, as well as the possible causes of the stock collapse in terms of environmental change, we used data collected by the National Institute of Fisheries Science (NIFS) during high (1976-1985) and low (1991-2000) periods of pollock biomass. Density-dependent effects on the pollock population were evident in Korean waters: The pollock were becoming larger and heavier at length during the low biomass period. The gonado-somatic index (GSI) also indicated that the peak spawning season was broad (October to February) during the high biomass period and narrower (December to January) during the low biomass period. The population abundance and recruitment success of Korean pollock appear to have been affectedby the warming of theocean surface from the early 1990s. Thus, we suggest that the biomass fluctuations associated with environmental changes during their early life stages were thought to be responsible for the observed changes in the biological properties of pollock. on their biomass and the environmental conditions. To investigate the changes in the biological characteristics of pollock such as size frequency, condition factor, and maturation associated with biomass levels, as well as the possible causes of the stock collapse in terms of environmental change, we used data collected by the National Institute of Fisheries Science (NIFS) during high (1976-1985) and low (1991-2000) periods of pollock biomass. Density-dependent effects on the pollock population were evident in Korean waters: The pollock were becoming larger and heavier at length during the low biomass period. The gonado-somatic index (GSI) also indicated that the peak spawning season was broad (October to February) during the high biomass period and narrower (December to January) during the low biomass period. The population abundance and recruitment success of Korean pollock appear to have been affectedby the warming of theocean surface from the early 1990s. Thus, we suggest that the biomass fluctuations associated with environmental changes during their early life stages were thought to be responsible for the observed changes in the biological properties of pollock.
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/23612
Bibliographic Citation
제3차 한중 황해 해양포럼, pp.57, 2017
Publisher
해양수산부, 중국 국가해양국
Type
Conference
Language
English
Publisher
해양수산부, 중국 국가해양국
Related Researcher
Research Interests

upper ocean dynamics,regional climate modeling,ocean climate change,해양상층역학,지역기후모델링,해양기후변화

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