This study aimed to identify the selectivity of catches according to mesh size of gillnets, and to collect basic data for fisheries resource management plans for gillnets. The mesh selectivity test was conducted with five different mesh sizes (60, 66, 69, 75, and 96 mm) gillnet in coastal sea of Mukho port and the selectivity was analyzed using the Kitahara method. In results of the selectivity test, a total of 143 (36,249 g) of atka mackerel were caught and the 60 mm gillnet was the highest at 83 (18,596 g), which is about 58.0% of the total catch. The relative growth equation between body length and weight showed that weight tends to increase proportional to body length. The maximum length/mesh size value was showed 0.490 by the master curve of selectivity, and the 50% selection range was showed 0.138. Therefore, it was found that the size of the caught fish increased proportional to the mesh size. The results of this study were intended to be used as data for establishing a plan for efficient management of atka mackerel resources.

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 = 0.005 FL3.240(R2 = 0.963) for females and BW = 0.006 FL3.238(R2 = 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 FLt = 70.54 (1–exp(-0.099(t+1.188))) for females and FLt = 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