1970-1990년대 동해에서 어획된 명태(Theragra chalcogramma)의 체장에 따른 체급별 어획 마릿수 추정
Size-class Estimation of the Number of Walleye Pollock Theragra chalcogramma Caught in the Southwestern East Sea during the 1970s-1990s
0
조회
0
다운로드
16
인용
0
참고문헌
키워드
초록
Walleye pollock Theragra chalcogramma fisheries in Korean waters have changed dramatically during the last three decades: the highest catches occurred in 1981, followed by continuous decreases through the 1990s, ending with a complete collapse of the population in the 2000s. The major spawning ground of walleye pollock is located in North Korean waters, and some juveniles (called nogari in Korean, <300 mm) migrate to the south for feeding and growth. Since the 1960s, Korean fishermen have often caught juveniles, and the weight (metric tons) of juvenile catch was recorded from 1975–1997. However, because the walleye pollock were not aged, the population age structure was not delineated. We developed a model to estimate the number of walleye pollock of each size class based on catch statistics of adults and juveniles, the catch proportion of each size class, and length and weight information on specimens collected by Danish-seine and drift-gill-net fisheries. The model results demonstrated that the recruitment size of walleye pollock was consistently within the 200-250mm size class, and the highest number of this size class occurred in 1981, although values greatly fluctuated interannually. The number of juvenile pollock was 10.4 times higher than that of adult pollock during 1975-1997. The total yield of juvenile pollock was 0.95 million tons, which was equivalent to about 68.2% of total pollock production. The number of juvenile pollock caught during the same period, however, was 16 billion, comprising about 91.2% of the total number caught. Such high fishing pressure on juvenile pollock is considered one of the main factors causing the collapse of the pollock population.
Abstract
Walleye pollock Theragra chalcogramma fisheries in Korean waters have changed dramatically during the last three decades: the highest catches occurred in 1981, followed by continuous decreases through the 1990s, ending with a complete collapse of the population in the 2000s. The major spawning ground of walleye pollock is located in North Korean waters, and some juveniles (called nogari in Korean, <300 mm) migrate to the south for feeding and growth. Since the 1960s, Korean fishermen have often caught juveniles, and the weight (metric tons) of juvenile catch was recorded from 1975–1997. However, because the walleye pollock were not aged, the population age structure was not delineated. We developed a model to estimate the number of walleye pollock of each size class based on catch statistics of adults and juveniles, the catch proportion of each size class, and length and weight information on specimens collected by Danish-seine and drift-gill-net fisheries. The model results demonstrated that the recruitment size of walleye pollock was consistently within the 200-250mm size class, and the highest number of this size class occurred in 1981, although values greatly fluctuated interannually. The number of juvenile pollock was 10.4 times higher than that of adult pollock during 1975-1997. The total yield of juvenile pollock was 0.95 million tons, which was equivalent to about 68.2% of total pollock production. The number of juvenile pollock caught during the same period, however, was 16 billion, comprising about 91.2% of the total number caught. Such high fishing pressure on juvenile pollock is considered one of the main factors causing the collapse of the pollock population.
참고문헌 (27)
- Bailey KM, "Shifting control of recruitment of walleye pollock Theragra chalcogramma after a major climatic and ecosystem change", Mar Ecol Prog Ser, 198, pp.215~224 (2000)
- FAO, "FAO yearbook, Fishery statistics: Capture production, 2005", pp.539~ (2005), Food and Agriculture Organization of the United Nations
- "Theragra chalcogramma (Pallas, 1814) Alaska pollock" (2013)[URL]
- Gong Y, "walleye Pollock (Theragra chalcogramma) stock in Korean waters", INPFC Ground Fish Symposium, (P-2), pp.27~ (1983)
- Hollowed AB, "Pacific basin climate variability and patterns of Northeast Pacific marine fish production", Prog Oceanogr, 49, pp.257~282 (2001)
- Huh SH, "Morphological comparison between adults and juveniles of Alaska Pollack, Theragra chalcogramma (Pallas) (Gadidae: Teleostomi), collected in Korean waters", 석사, pp.1978
- Hunt GL, "Climate change and control of the southeastern Bering Sea pelagic ecosystem", Deep Sea Res II, 49, pp.5821~5853 (2002)
- Aleutian Islands regions. section 1, "Assessment of the walleye pollock stock in the Eastern Bering Sea, In Stock assessment and fishery evaluation report for the groundfish resources of the Bering Sea", pp.2012, Ianelli JN
- Iwata M, "Population identification of walleye Pollock, Theragra chalcogramma, PALLAS), in the vicinity of Japan", Memoirs of the Faculty of Fisheries, Hokkaido University, 22, pp.193~258 (1975)
- Kendall AW Jr, "Buoyancy of walleye pollock (Theragra chalcogramma) eggs in relation to water properties and movement in Shelikof Strait, Gulf of Alaska", Can J Fish Aquat Sci Spec Pub, 108, pp.169~180 (1989)
- Kim S, "Spawning behavior and the early life history of walleye Pollock, Theragra chalcogramma, in Shelikof Strait, Gulf of Alaska, in relation to oceanographic factors", 박사, pp.1987
- Kim S, "Status of fishery and science of Bering Sea walleye Pollock: (I) History and importance of fisheries", Ocean Res, 12, pp.117~128 (1990)
- Kim S, "Status of fishery and science of Bering Sea walleye Pollock: (II) Biological characteristics (Early life history)", Ocean Res, 14, pp.149~170 (1992)
- Kim S, "Status of fishery and science of Bering Sea walleye Pollock: (III) Biological characteristics (Adult)", Ocean Res, 14, pp.171~189 (1992)
- Kim YM, "Stock assessment of small size fishes of Alasca pollack, Theragra chalcogramma (PALLAS), in the Eastern Sea of Korea", Bull Fish Res Dev Agency, 19, pp.53~61 (1978)
- Kim S, "The status and research direction for fishery resources in the East Sea", Sea of Japan, 1998, pp.1, 44~58
- Suam Kim, "Climate Variability and Its Effects on Major Fisheries in Korea", Ocean Science Journal, 42(3), pp.179~192 (2007), 한국해양과학기술원
- Lee JU, "Estimation on optimum fishing effort of walleye pollock fishery in the east coast of Korea: Based on the economic analysis between Danish seine fishery and trawl fishery for walleye pollock", Susan-gyungyoung-nongib, 22, pp.75~99 (1991)
- 이윤, "Measuring Surface Water Temperature Effects on the Walleye Pollock Fishery Production using a Translog Cost Function Approach", 자원환경경제연구, 19(4), pp.897~914 (2010), 한국환경경제학회
- Muigwa NM, "Vertical distribution pattern of prespawning and spawning pollock (Theragra chalcogramma) in Shelikof Strait", Proceedings of the International Symposium on the biology and management of walleye pollock, pp.403~431 (1988)
- Ecology and fishing ground of fisheries resources in Korean waters, "NFRDI", National Fisheries Research and Development Institute, 405~ (2010)
- Oh TG, "The Relationship between spawning area water temperature and catch fluctuation of walleye pollock in the East Sea", Sea of Japan, 2004, pp.6, 1~13
- Park BH, "Age and growth of Alaska pollack, Theragra Chalcogramma, in the Eastern Sea of Korea", Bull Fish Res Dev Agency, 20, pp.33~42 (1978)
- Park BH, "Spawning and maturity of Alaska pollack, Theragra Chalcogramma (PALLAS), in the Eastern Sea of Korea", Bull Fish Res Dev Agency, 22, pp.33~38 (1979)
- Park SK, "Bio-economic research in fishery resource management: walleye Pollock", Nongchon-gyungje, 9, pp.59~68 (1986)
- Park HH, "Prediction of walleye pollock, Theragra chalcogramma, landings in Korea by time series analysis : AIC", Bull Korean Soc Fish Tech, 32, pp.235~240 (1996)
- Seo H, "Variability in scale growth rates of chum salmon (Oncorhynchus keta) in relation to climate changes in the late 1980s", Prog in Oceanogr, 68, pp.205~216 (2006)