• 수산해양기술연구
• /
• 제46권4호
• /
• pp.346-357
• /
• 2010

Characteristics of age and growth of the black rockfish, Sebastes inermis sampled in the Jeonnam Marine Ranching Area (JMRA) around Geumo Islands south of Yeosu were investigated using 642 otoliths from March 2009 to February 2010. The opaque zone was formed in September once a year and hence it was used as an annulus. The parturient period was December to January, and therefore the duration from fertilization to the complete formation of the opaque zone was nineteen months. From the parameters calculated using the average length when the year ring was formed, growth of S. inermis were expressed by von Bertalanffy growth equation as $L_t$=23.267 ($1-e^{-0.4406(t+1.1971)}$) for females and $L_t$=22.030 ($1-e^{-0.5312(t+0.6834)}$) for males when is total length in age t. Through the growth equations, the maximum length was determined as 23.27cm for females and 22.03cm for males and the growth factor as 0.4406/yr and 0.5312/yr, respectively. Finally, the growth of female S. inermis is larger than the one of male S. inermis.

• 환경생물
• /
• 제25권3호
• /
• pp.205-214
• /
• 2007

Marine environmental characteristics on the dinoflagellate cysts distribution in surface sediment of the southwest sea of Korea were investigated from 21 stations in September 2003, and 36 stations in June, 2004. The water mass characteristics indicated that the southwest sea of Korea is characterized by various oceanographic conditions due to coastal waters of Korea and China. The Tsushima warm currents and the cold bottom water of the Yellow Sea. Mud contents and chlorophyll a concentrations were higher in central region such as, Namhaedo, Yeosu and Goheung coast than in western region such as, Wando, Haenam and Jindo coast in the South Sea of Korea. A total of 35 taxa of dinoflagellate cysts were identified representing 21 genera, 33 species, 2 unidentified species. Cyst abundance ranged from 13 to 527 cysts $g-dry^{-1}$, showing higher abundance in the coastal areas than in western region of the South Sea of Korea. From the result of the PCA analysis, the distribution of dinoflagellate cysts was not only related to the different water masses which appeared in the southwestern sea but also to physical and biological parameters such as water temperature, light, surface sediment faces and phytoplankton biomass.

• 수산해양기술연구
• /
• 제47권1호
• /
• pp.18-26
• /
• 2011

This study is to contribute to income growth of fishermen by the common octopus fishery characterized in the Tando Bay on the southwest coast of Korea. This area is engaged in Longline fishing (301 persons), Shovel fishing (196 persons), Trap fishing (14 persons) and Torch light fishing (40 persons) in 2008. Population who is joined in the spring becomes main fishery target population of longline fishery in the fall because entering fishing ground in August, and is joined in the fall becomes main fishery target population of longline fishery in the spring because entering fishing ground in December. Average size of common octopus examined by longline 6.26cm, 5.82cm for Shovel fishing, 8.09cm for trap, and expressed big difference by fishery. It needs necessary various kinds of Octopus resource management actions and methods in continuous use. Specially, Fishing force increased by fishing automation system, so the reduction of fishing force is needed to increased by fishing force. Government support and fishermen's self-conscious of resource management is needed.

• 한국패류학회지
• /
• 제27권4호
• /
• pp.331-336
• /
• 2011

2011년 4월 20일부터 7월 15일까지 전복배합사료와 건다시마를 먹이원으로 한 북방전복과 해삼의 실내 복합사육에서 생존율과 성장에 어떠한 영향을 받는지 관찰하였다. 실험에 사용된 북방전복의 크기는 각장 $28.54{\pm}1.23mm$, 전중량 $2.92{\pm}0.26g$ 이었고, 해삼은 습중량 $3.0{\pm}0.2g$ 이었다. 먹이는 전복배합사료 실험구, 건다시마 실험구 및 전복배합사료와 건다시마 혼합 실험구로 설정하였다. 북방전복과 해삼의 생존율은 모든 실험구에서 각각 97.0%, 87.0% 이상을 보였다. 북방전복의 생존율은 건다시마 실험구에서 가장 높은 반면 해삼은 가장 낮았지만 유의적인 차이는 보이지 않았다. 성장은 북방전복의 경우 전복배합사료 실험구에서, 해삼의 경우 전복배합사료와 건다시마를 동시에 공급한 실험구에서 가장 빨랐다.

• 한국해양공학회지
• /
• 제21권6호
• /
• pp.72-80
• /
• 2007

The tsunami that resulted from the Central East sea Earthquake, which registered 7.7 on the Richter scale, that occurred over the entire water region in Akita on May. 26, 1983 and the tsunami that was triggered by the Southwest off Hokkaido Earthquake (7.8 on the Richter scale) that occurred in Southwest off Hokkaido on July 12, 1993 are representative cases that led to considerable damage in life and property, not only in Japan but also in Korea. In this study, multi-grid method was used in order to reproduce sufficiently the shoaling effect that occurs as water depth becomes shallow in the shallow water region and moving boundary condition was introduced to consider the runup in the coastal region. For the tsunamis that exerted considerable effect on the East Sea coast of Korea that were caused by the Central East Sea Earthquake in 1983 and the Southwest off Hokkaido Earthquake in 1993, characteristics like water level rise and propagation in the East Sea coast will be examined using numerical simulations. At the same time, these values will be compared with observed values. In addition, maximum water level rise and change in the water level with respect to time that were caused by the tsunamis were examined at each location along the East sea coast. Usefulness of numerical analysis was verified by comparing with observed values.

• 한국발생생물학회지:발생과생식
• /
• 제18권1호
• /
• pp.13-23
• /
• 2014

This study is conducted to monitor the morphological developmental features of the egg development, larvae and juvenile of Epinephelus septemfasciatus, the fertilized eggs were gotton using artificial insemination. Matured parents are collected from marine caged fish farms in Geomun-ri, Samsan-myeon, Yeosu-si, Jeollanamdo Korea in June 2012. The fertilized eggs were pelagic eggs containing one oil globule, and measured 0.81~0.89 mm ($0.85{\pm}0.04mm$, n=50) in diameter. In regard to rearing environment, the water temperature is $21.0{\sim}23.0^{\circ}C$ and the salinity is 32.0~33.2‰. Hatching was observed from 48 hours after fertilization, the mouth and anus of prelarvae was not opened but had egg yolk at newly hatched. 4 days after hatching, the mouth and anus of postlarvae was opened and began to eat Rotifer and was measured 2.40~2.49 mm ($2.45{\pm}0.03mm$ n=10) in total length. 12 days after hatching, postlarvae was measured 3.77~4.67 mm ($4.27{\pm}0.33mm$) in total length, its the second pole tide of dorsal fin and the first pole tide of pelvic fin was extended longitudinally. 71 days after hatching, juvenile was measured 40.5~45.4 mm ($42.6{\pm}2.04mm$) in total length. Seven bands were observed in body, and pole tides of dorsal and pelvic fins were shortened.

• 한국패류학회지
• /
• 제27권3호
• /
• pp.199-204
• /
• 2011

급감하는 개조개의 자원량을 회복하기 위한 방안으로 치패를 중간육성 후 씨뿌림하는 방식이 생존과 성장에 어떠한 영향을 미치는지 관찰하였다. 개조개 평균 각장 15.81 mm (평균 전중 0.90 g) 의 치패를 4월에 채롱에 수하하여 10월까지 중간육성한 결과 각장 22.9 mm 내외 (전중 3.88 g 내외) 로 성장하였고 생존율은 73% 이상으로 자연에 초기 치패를 씨뿌림하였을 때 보다 생존율이 높은 것으로 나타났다. 이를 다음해 1월까지 다시 씨뿌림한 결과 각장 27.6 mm (전중 6.6 g) 으로 성장하였고 생존율은 약 74%를 나타내었다. 이는 중간육성 후 씨뿌림 방식이 종묘 방류 후 나타나는 대량폐사의 문제점을 해결할 수 있는 하나의 대안으로 충분히 가능성이 있다는 사실을 보여준다.

• Journal of Species Research
• /
• 제8권4호
• /
• pp.365-372
• /
• 2019

We have conducted faunistic study of sea lice collected from marine plankton samples of western and southern coasts of Korea. These specimens were identified as Caligus undulatus Shen and Li, 1959, belonging to family Caligidae and order Siphonostomatoida with worldwide distribution. The range extension of C. undulatus is reported in addition to the previously known distributional range from the Northwest Pacific (China, Japan, and Korea), India, Brazil, and Mexico. This species can be distinguished from all previous reports with characteristics such as overall body proportions of both sexes, structure details of mouth appendages, armature of legs, and some variation in body size. The distributional range of C. undulatus is now given with its northern and south hemisphere limit being 40 to $10^{\circ}N$ in the Indo-Pacific and $30^{\circ}S$ in the Southwest Atlantic. This is the first record of its female occurring in Korea.

• 한국어병학회지
• /
• 제26권3호
• /
• pp.139-148
• /
• 2013

패각 및 석회기질을 천공하는 것으로 잘 알려져 있는 Polydora 속(Polychaeta, Spionidae) 다모류는 종종 전복을 포함한, 상업적으로 중요한 패류에 침입하여 성장률 및 육중량 감소와 상품가치를 하락시키다. 2012년 우리나라 전복 가두리 양식장 10개소를 대상으로 패각 천공성 다모류의 감염현황을 조사한 결과, 활전복에서는 5~99%, 죽은 전복 패각에서는 5.3~70.3%의 감염률을 보였다. 이들 전복은 진주층으로 덮힌 blister 및 패각변형이 일어났으며 패각 표면에는 Polydora가 서식하는 도관(burrow)으로 연결된 2개의 구멍이 확인되었다. 여기에서 분리된 Polydora는 성체의 길이가 40mm 이상으로 검은 띠가 있는 두드러진 palps, 꼬리 말단부위의 원반형 pygidium 및 4개의 eyespots을 가지는 것이 특징적이었다. 본 연구는 우리나라 전복 가두리 양식장의 패각 천공성 다모류 감염현황에 대한 첫 보고이다.

• 한국해양공학회지
• /
• 제29권2호
• /
• pp.175-185
• /
• 2015

Jack-up type WTIV(Wind Turbine Installation Vessel) is used to avoid the effects of waves when installing wind turbines in the Southwest Sea of South Korea. During the preloading procedure, unexpected penetration may cause some risks such as excessive penetration or punch-through failure. To ensure the safety of the WTIV during preloading, the bearing capacities should be evaluated based on the soil data at each borehole. Eight boreholes (OW-1 to -8) have been drilled in the Southwest Sea of South Korea. The bearing capacities of a spudcan designed to be used in this district are calculated using both a conventional analysis and finite element analysis with the soil properties of OW-1 to -8. A finite element analysis is carried out for OW-1, -3, and -4 to gain an in-depth understanding of the soil behavior during the penetration. OW-1, -3, and -4 are representative boreholes for a strong layer overlying a soft layer, a general soft layer, and a soft layer overlying a strong layer, respectively. The resultant bearing capacity curves versus the depth of the numerical analysis are compared with the conventional method. The results show that the conventional analysis is conservative. Case studies for different spudcan areas and shapes are also conducted to seek an appropriate spudcan type for the Southwest Sea of South Korea. Finally, a spudcan with a rectangular shape and a bearing area of $112.8m^2$ is selected.