• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.633-641
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• 2009

Maturity and spawning of the atka mackerel, Pleurogrammus azonus, was investigated based on the samples collected by gill net and set net in the East Sea from January 2006 to March 2009. Gonadosomatic index (GSI) began to increase in October, and reached a maximum between November and December. After spawning GSI began to decrease from January. The spawning period was from October to January, and main spawning period was from November to December. Annual reproductive cycles of this species could be divided into five successive stages in females; early growing stage (June), late growing stage (July to August), mature stage (September to October), ripe and spent stage (November to January), and recovery and resting stage (January to May). Males showed four successive stages: growing stage (June to August), mature stage (September to October), ripe and spent stage (October to December), and recovery and resting stage (January to May). P. azonus could be one of polycyclic species spawning two times or more during one spawning season. Number of total and mature eggs in the fecundity were proportional to fork length. The fork length at 50% group maturity was estimated to be 26.9 cm.

• Journal of Nutrition and Health
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• v.26 no.3
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• pp.254-267
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• 1993

Fatty acid contents of 59 food items which are major fat sources in Korean diet were analyzed. The contents of EPA and DHA in fish were 0.02-2.66g and 0.02-3.01g per 100g edible portion, respectively. Items with high amount of EPA and DHA were canned Sardine, Mackerel, Mackrel pike, Atka-fish, Hair tail, Conger eel and Herring. But white fish such as Croaker, Gindaro, Flounder and frozen Alaskan pollack contained less than 0.1g of EPA and DHA per 100g edible portion. Other sources of n-3 fatty acid were perilla oil, rapeseed oil, soybean oil and walnuts all of which contained relatively high amounts of linolenic acid.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.567-575
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• 2015

Species composition in the coastal waters off Ulleungdo of Korea were examined based on catches bimonthly collected by trammel net in 2013. A total of 711 individuals and 181.9 Kg were caught and catches were composed of 4 classes 15 orders 27 families 52 species including 44 Pisces, 4 Gastropoda, 3 Cephalopoda, and 1 Echinodermata. The dominant species in biomass were File fish (Thamnaconus modestus), Atka mackerel (Pleurogrammus azonus), and Greenling (Hexagrammos otakii). Data were summarized using hierarchical cluster analysis (HCA) and detrended correspondence analysis (DCA) to examine similarity in species composition for each month, and community structure in Ulleungdo was divided into two groups. Community structures in February, April and December with low temperature and well-mixed surface water were distinguished from those in June, August and October with high temperature and strong stratification, which could be attributed to temporal changes in dominant species. Atka mackerel and Spear squid mainly caught in February and April, disappearing in June, August and October, and File fish outburst was shown in October. Because the water off Ulleungdo has been under low human pressure, it could be a good case study to elucidate effects of climate change on community structure and ecosystem in the East sea. Continuous surveys and further studies are required to demonstrate migration route and distribution of dominant species and long-term changes in community structure in the water of Ulleungdo.

• Korean Journal of Ichthyology
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• v.12 no.4
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• pp.250-253
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• 2000

Pleurogrammus monopterygius was first collected from Daejin-ri, Goseong-gun, Gangwon-do, Korea on April 1999. This species is distinguished from its related species by having four to five broad blackish bands on the side of its body and different patterns of lateral lines. We gave P. monopterygius the new Korean name, "Dan-Gi-Im-Yon-Soo-Eo" and described the species in detail based on the study of specimens.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.1
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• pp.54-64
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• 2018

The age and growth of Pleurogrammus azonus in the coastal of Gangwon-do, East Sea were determined, from monthly samples of commercial catches, caught by the gill net and set net fishery from January to December in 2008. Gonadosomatic index (GSI) began to increase in September, and reached the maximum between November and December. After spawning GSI began to decrease from January. The annuli of P. azonus are formed once a year, with the boundary between opaque and translucent zones forming from December to January. The relationships between fork length (FL) and body weight (BW) were $BW=0.005FL^{3.240}$($R^2=0.963$) for females and $BW=0.006FL^{3.238}$($R^2=0.946$) for males. The FLs at annuli formation in otoliths were back-calculated from the otolith-length relationship and were adjusted to von Bertalanffy growth curves to $FL_t=70.54(1-{\exp}^{(-0.099(t+1.188))})$ for females and $FL_t=51.87(1-{\exp}^{(-0.135(t+1.697))})$ for males. Until the age of 3 years, males grew faster than females; however, from the age of 4 years, females grew faster than males. In the future, we want to study the relationship between early growth and water temperature changes in the East Sea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.3
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• pp.348-354
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• 2015

Experiments for catch and cluster analysis on the catch by gillnet for the Pacific herring were conducted using traditional nylon net (PA) and developing biodegradable net (PBS) with different monofilaments of #2 (=0.23 mm) and #3 (=0.28 mm) in diameter between 2011 and 2012, and of #2, #2.5 and #3 in 2013 in the eastern coastal waters of Samcheok, Korea. The total catch during the experiments was 3,337kg in weight and 16,757 individuals in number. Though the catch ratio of the Pacific herring in 2011 and 2012 was 97.4% and 98.7%, respectively, that of the Pacific herring in 2013 was 73.6% as the biggest and followed by goldeye rockfish (8.6%), black edged sculpin (8.4%), atka mackerel (7.2%) and Alaska cod (1.0%). The ANOVA analysis on the total catch in relation to net material showed that there was not statistically significant difference at the 5% level between nylon net (PA) and biodegradable net (PBS) (p=0.91). With the cluster analysis on the catch in relation to net material (PA, PBS) and twine thick (#2, #3), it showed the influence of net material on the catch was greater than that of twine diameter in this experiment. From the test of homogeneity on the catch by the gillnet with PA and PBS in which several species were caught in 2013, there was not statistically significant homogeneity in relation to net material (p<0.005). That meant the traditional gillnet of nylon (PA) was more efficient than the biodegradable (PBS) gillnet to catch several kinds of fish, however the PBS gillnet was better than the PA gillnet to catch the target Pacific herring.