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

The sea between the Korean Peninsula and the Japanese Archipelago is mainly called “Sea of Japan” in the international society. Concerning this, two Koreas have raised complaint under the rationale of the historical background and the international norms. The complaint of the Korean people concerning the naming issue most deeply lies in the fact that the name “Sea of Japan” which is “favorable” to Japan has been used as the (sole) official international name, whereas the name “East Sea” which is “favorable” to Korea has not been adopted even as the second official international name, regardless of its exact historical background. In the naming dispute like this, the best solution is to create a neutral single name through negotiations by the countries concerned. In case the countries concerned fail to create a neutral single name, the second-best solution is to use multiple names. From this kind of viewpoint, concerning the naming dispute, this article requests three countries, Japan, South Korea and North Korea, to negotiate to create a neutral single name.

매오징어 Watasenia scintillans 유생분포양상을 알아보기 위해 2015년 8, 9, 11월 R/V 탐구 21호로 동해 남서부연안 28개 정점 에 대해 CTD관측 및 IKMT(망목: 500 μm)를 사용하여 저층(최대 수심 100 m)에서 표층까지 경사채집을 실시한 결과, 채집된 매오징어 유생의 개체수는 총 238개체로 외투장(ML) 범위는 0.6 ~ 18.5 였다. 조사기간 중 8월이 9월과 11월보다 유생의 출현정점 수, 출현개체 수, 유생분포밀도에서 현저히 높았다. 특히 8월에 냉수괴가 분포하는 포항 ~평해까지의 동해연안에서 가장 높은 밀도를 보였다. 유생이 채집된 정점의 연직수온분포에서 매오징어의 부화수온(6 ~ 16 )은 주로 40 ~ 180 m의 수심에 위치하였다.

This study is aimed to analyze the change of chinese fishing vessels’entry into the East Sea off North Korea and suggest directions for countermeasures. Based on the real landing data in China, Chinese fishing vessels’squid catch volume and value in the East Sea off North Korea are estimated. Results show that at least 205 thousand tons of squid was caught by Chinese fishing vessels in 2014. If the catch amount is calculated by the unit price per kilogram at the same year in Korea, it would be 556.3 billion KRW. As the UN sanctions become stricter with the recent resolution 2371 passed, Chinese fishing vessels’entry may increase in the future to compensate decreased seafood supply from North Korea. Even though there are not many options left for Korea to decrease the impact of Chinese depletive fishing, the study suggests countermeasures such as strengthening cooperative crack down on the Chinese illegal fishing vessels in Korean waters; increasing cooperation with UN member countries to incorporate banning the trade of fishing rights in the next UN sanctions; establishing regional fisheries management organization and managing migratory species with China and Japan cooperatively in the long term.

This study was conducted to understand the relationships between fish and zooplankton of distribution in the coastal waters of the East Sea from May to August 2016 using hydroacoustic. To distinguish between fish and zooplankton, we used the time varied threshold (TVT) method at the frequency of 120 kHz. As a result, the mean nautical area scattering coefficient (NASC) of fish was highest at 913 m2/n.mile2 in June and lowest at 315 m2/n.mile2 in July. The mean NASC of zooplankton was highest at 247 m2/n.mile2 in May and lowest at 70 m2/n.mile2 in July. The mean NASC of fish and zooplankton showed a significant difference (P < 0.05) with high correlation (R2 = 0.84). In addition, there was no significant difference in the mean NASC of fishes and zooplankton by depth (t-test, person correction = -0.17, p > 0.05).

The age and growth of pointhead flounder, Hippoglossoides pinetorum caught by gill nets was analyzed in this study from March 2015 to July 2017. New annuli were formed in H. pinetorum otoliths annually, and the boundary was set between the opaque and translucent zones from March and April. The relationships between total length (TL) and body weight (BW) were BW = 0.0025 TL3.409 (r2 = 0.9551) for females and BW = 0.0057 TL3.138 (r2 = 0.9163) for males. In this study, the ring of pointhead flounder, H. pinetorum was formed between 3 and 8 for females and between 3 and 6 for males. Total length (TL) and otolith radius (OR) were measured as follows: TL = 7.142 OR + 0.769 (r2 = 0.793) for females and TL = 6.498 OR + 1.706 (r2 = 0.652) for males. The mean distances of first ring (r1) were 0.92 mm and 0.91 mm for females and males respectively. The TLs at the time of annulus formation, back-calculated from the otolith-length relationship by reference to the von Bertalanffy growth curves, were Lt = 43.59 (1-e-0.15(t+0.007)) for females and Lt = 28.13 (1-e-0.26(t+0.006)) for males while the growth between female and male was different.

본 연구에서는 연안용승이 발생하는 한국 동해연안을 대상으로 용승류 발생분포와 용승유량을 파악하고자 수치실험을 실시 하였다. 여기서 연안용승이 발생한 2013년 하계의 CTD 관측자료 및 정선자료(NIFS) 에서 수온 염분 값을 모델에 적용하였다. 또한, Case 별 실험은 하계에 가장 높은 빈도를 보이는 남풍과 남서풍에 풍속의 변화(3, 6 m/s 그리고 9 m/s)를 주었다. 풍속이 강한 조건일수록 상 승류의 강도와 분포범위가 넓게 나타났다. 그리고 남서풍은 남풍에 의한 용승역의 분포와 상승유속의 강도에 비해 강하고 넓었다. 동해 안의 5개 연안에서 용승유량을 산정한 결과 포항, 영덕, 후포, 부산, 그리고 울산 순으로 나타나며 남풍에 비해 남서풍의 조건에서 용승 유량이 약 1.5배 크게 나타났다. 남서풍 9 m/s에 의한 용승역은 약 17 22 km/day의 수평적 확산 속도로 바람이 1주일 이상 지속된다면 포항 남쪽 연안에서 발생된 용승현상에 의해 발생된 냉수대는 울릉도 근해까지 확장한다.