• 수산해양기술연구
• /
• 제55권4호
• /
• pp.349-355
• /
• 2019

Reproductive ecology of rabbit fish, Siganus fuscescens were investigated from samples collected monthly in the coastal waters off Jeju Island of Korea from February to December 2014. In male and female of S. fuscescens, the values of GSI were reached high values between July to August in which the water temperature was high, and then decreased until December. The occurrence of individuals which have mature eggs in ovary were higher from July to August. Therefore, a main spawning season was estimated from July to August, with the highest peak in July. Throughout histological observation of the ovary in the spawning period, S. fuscescens belong to an group-synchronous and has a one spawning season a year. Fecundity of ovary ranged from 380,000 to 2,600,000 during the spawning period. Size at 50% sexual maturity, determined from logistic equation, were 25.1 cm TL which is over two years.

• 한국해양바이오학회지
• /
• 제13권1호
• /
• pp.58-65
• /
• 2021

In 2012, fishes caught by three-side fyke net in the coastal waters of Jedo were assessed for species composition and seasonal fluctuation in their abundance. The fish were caught at two research stations (St.) and were found to comprise 53 species, 39 families, and 9 orders. The dominant species were Takifugu niphobles, Lateolabrax maculatus, and Acanthopagrus schlegelii. To gain a measure of their biodiversity, all the species were assessed for their number, richness, diversity, evenness, and dominance. The highest and lowest number of total caught fish individuals was recorded in summer and winter, respectively. The diversity index was the highest in summer and lowest in winter. The evenness index was the highest in summer and lowest in spring. The richness index was highest in summer and lowest in winter. Furthermore, the dominance index was highest in spring and lowest in autumn.

• 한국어병학회지
• /
• 제21권3호
• /
• pp.259-270
• /
• 2008

Disease surveillance was performed to monitor the prevalence of fish pathogens in wild marine fish caught in coastal offshore water in Korea. A total of 333 of fish samples were collected at set net or fish market at landing port in Pohang (East Sea), Taean (Western Sea), Goseong and Tongyeong (Southern Sea) and 21 species of pathogens causing clinical infections to farmed fish were investigated. The detection rates of fish pathogens from Mugili formes, Tetraodontiformes, Pleuroneciformes, Sorpaeniformes, erciformes and Clupeiformes were 90.9, 61.1, 47.6, 43.6, 37.2 and 11.8%, respectively. Comparing with prevalence of diseases seasonally, both the detection rates of bacteria and parasite were higher than those of virus in April but the detection rates of parasites were distinctively higher than those of bacteria in August with high water temperature. Virus were detected in fish samples caught in the Western and Southern Sea in April. The detected parasites were Trichodina, Ichthyophthirius, Dactylogyrus, Microcotyle, Bivagina, Caligus, Alella and Myxobolus. Among the bacterial pathogens, Vibrio, Streptococcus, Photobacterium, Psuedomonas were predominant. Viral nervous necrosis virus (VNNV) and flounder lymphocystis disease virus (FLDV) were detected from the 6 species of fish virus examined in this study.

• 수산해양기술연구
• /
• 제43권2호
• /
• pp.126-139
• /
• 2007

In the autumn of 2000 and spring of 2001, field surveys were conducted to estimate the effectiveness of artificial reefs (type cube, $2{\times}2{\times}2m^3$) that were established in the four islands of Bangnyeong, Socheong, Daeyeonpyeong and Ganghwa in Kyonggi Bay, the west coast of Korea during 1995 and 1996. The condition of reefs was examined through SCUBA diving and a side-scan sonar. Much of the reefs in Daeyeonpyeong and Ganghwa area were buried in bottom sediment. Despite an intensive search in Bangnyeong area, even a cluster of reefs was not found and most of them seemed to be buried by sand waves. Thus an appropriate investigation on the sediment transport should be included in pre-assessment for the expected performance and protection of artificial reefs. Distribution of average CPUE in natural fishing ground (control) was estimated by bootstrapping simulation and possible comparison of CPUE between control and reef areas (treatment) were made in Bangnyeong and Socheong (Experiment I). Positive reef effect was detected in Socheong but CPUE of treatment in Bangnyeong was varied between or lower than the 99% CPUE confidence intervals of the control. Control/treatment abundance and biomass of fishes and invertebrates were tested by paired t-test and sign test (Experiment II). Only four cases among 22 showed significant positive effect. Based on the results, the cube artificial reef in Socheong was inferred as an affirmative one. Floor type was hypothesized to be one of the probable agents in determining the effectiveness of artificial reefs.

• 한국양식학회:학술대회논문집
• /
• 한국양식학회 2004년도 수산관련학회 공동학술대회 발표요지집
• /
• pp.451-452
• /
• 2004

• 한국해안·해양공학회논문집
• /
• 제23권1호
• /
• pp.63-69
• /
• 2011

본 연구에서는 일정한 공극율을 갖는 투과성 그물망으로 이루어진 원통형 양식시설물에 작용하는 파랑하중을 고유함수전개법을 사용하여 해석하였다. 그물망에서의 경계조건식으로 그물망을 통과하는 속도값은 그물망 전후의 압력차에 선형적으로 비례한다는 Darcy의 법칙을 적용하였다. 그물망의 공극율 계수와 양식시설물의 잠긴 위치(부상식, 착저식)를 변화시키면서 양식시설물에 작용하는 파랑하중과 파도응답을 살펴보았다. 착저식 양식시설물에 작용하는 파랑하중이 부상식과 비교하여 크게 감소하며, 그물망의 공극율이 양식시설물의 파랑하중과 양식시설물 주변의 파형을 줄이는데 중요한 역할을 함을 밝혔다.

• 한국수산과학회지
• /
• 제48권4호
• /
• pp.529-541
• /
• 2015

We examined the species composition and community structure of demersal fish in the middle and southern coastal waters of the East Sea of Korea by surveying a commercial Danish seine fishery from 2010 to 2013. We considered the waters north of $37^{\circ}N$ as middle and those south of $37^{\circ}N$ as southern waters. A total of 79 demersal fish species belonging to 18 families were collected. Of these, 59 species (77.6%) inhabited only the East Sea as opposed to the West and South Seas of Korea, and most were resident species. The species and biomass were similar between the two portions of the study area. The sandfish Arctoscopus japonicus (78.0%) and the blackfin flounder Glyptocephalus stelleri (65.1%) were the most common species and accounted for the most biomass in the middle and southern waters, respectively. Fish were most abundant at shallow depths (50-100 m) in the middle portion of the East Sea. Using a cluster analysis, we divided the species composition and community structure at the sampling stations into three groups: middle portion (group A), deep area of the southern portion (group B), and shallow areas of the southern portion (group C). A. japonicas and G. stelleri were dominant in groups A and B, while G. stelleri and Clupea pallasii were dominant in group C.

• 한국수산과학회지
• /
• 제40권1호
• /
• pp.24-30
• /
• 2007

We developed an ecosystem indicator (EI) for the coastal and offshore areas of Korean waters. One of the major scientific challenges of this undertaking was to translate broad policy statements for ecosystem-based fisheries management (EBFM) into practical terms. Fish reproduction potential (FRP) was defined as an EI to describe the reproductive probability of adult fisheries resources in Korean waters. The FRP was estimated as the ratio of adult fish composition to total catch, catches (in metric tons) by species and by ecosystem, and fishery effort (in horse power per metric ton). The FRP indices of the East/japan Sea Ecosystem (EJSE), Yellow Sea Ecosystem (YSE), and East China Sea Ecosystem (ECSE) began to decrease after the mid-1980s, and the current indices have decreased further, at 0.63 (EJSE), 1.22 (YSE), and 0.68 (ECSE) index points compared to the indices of 1975, when similar catch amounts were recorded. Lower FRPs in the Korean marine ecosystems were the result of higher proportion of immature fisheries resources in the total catch. Because this kind of ecosystem-level indicator is thought to reflect scientific approaches to EBFM and to provide an important tool for assessing the current status of marine ecosystems with respect to both quantity and quality, more EIs should be developed for Korean waters.

• 한국수산과학회지
• /
• 제34권4호
• /
• pp.309-314
• /
• 2001

소형 적색육어의 소비기호에 부정적으로 작용하고 있는 잔뼈를 연화시켜 제거하고 비린내를 저감시키기 위하여 대표적인 소형 적색육어인 꽁치, Cololabis saira를 김치양념과 유기산 그리고 미강을 첨가하여 $5\pm0.5^{\circ}C$에서 60일 동안 숙성시키면서 15일 간격으로 숙성 중 화학적 변화를 검토하였다. 마른간이 물간에 비해 염침투도 및 탈수도가 높아 조미양념과의 평형이 15일 정도 빨랐으며, 그로 인해 숙성 중 pH가 높고, 휘발성염기질소함량과 TBA가가 낮아 조미숙성제품 제조시 염 첨가방법은 마른간이 적합하였다. 마른간에 미강을 첨가한 제품은 첨가하지 않은 제품에 비해 미강에 함유되어 있는 아미노산이 제품으로 이행되어 정미성분의 함량을 나타내는 아미노태질소가 높았고, 단백질 산패억제 및 미강의 carotenoid와 tocopherol 둥의 항산화물질에 의한 지질산화 억제효과도 있어 저이용 자원의 활용 증대측면에서 상업적 제품화가 기대된다.

• 한국수산과학회지
• /
• 제21권1호
• /
• pp.30-34
• /
• 1988

본 연구는 1987년 9월 8일, 9일 양일간에 걸쳐 24시간 동안 곤리도 금성수산 방어 가두리 양식장에서 해산어류 양식장${\cdot}$가두리의 방양한도를 산정하는데 기초자료로 쓰일 수 있는 용존산소 수지를 해석해 보기 위하여 실시하였다. 가두리에 수용된 당년생 방어 2,800kg이 1일간 소비하는 산소량은 $3.09g/m^3$였고, 가두리 안의 수체에 의하여 소비되는 산소량은 $1.24g/m^2{\cdot}day$였으며, 수중 식물성 플랑크톤에 의해 생산공급된 산소량과 대기로 부터 해수중으로 녹아 들어간 산소량의 합계는 수중 유기물의 분해와 플랑크톤의 호흡을 포함하는 수조자체의 산소소비량의 $43\%$를 감당하는 수준이었고, 그 나머지 $57\%$와 사육어가 소비하는 다량의 산소는 가두리 안밖으로 교류하는 해수유동에 의하여 공급되고 있었다. 이 어장의 가두리에 수용할 어체량은 해수교환율에 의해 결정되는 듯이 보이며, 어장내의 조류에 대한 가두리 배치방식에 따라 해수교환율이 달라지게 될 것이므로 가두리마다의 해수유통에 따라 수용량을 조정할 필요가 있다 하겠다.