• 한국수자원학회논문집
• /
• 제55권12호
• /
• pp.1041-1052
• /
• 2022

본 연구는 낙동강 본류의 안동댐 하류(4,565.7 km²) 하천을 대상으로 1차원 물리적 서식처 모형인 PHABSIM과 2차원 물리적 서식처 모형인 River2D를 활용하여 대상어종에 대해 환경생태유량을 산정하고 어류서식처에 대한 2차원 공간분석을 수행하였다. 서식처 모형의 구축을 위해 낙동강유역의 하천기본계획보고서를 활용하여 하천단면정보와 수리학적 입력자료를 수집하였다. PHABSIM 구축범위는 구담수위관측소(GD)로부터 약 410.0 m, River2D의 경우 GD를 포함한 약 6.0 km에 대해 구축하였다. 대상어종 선정 및 HSI 구축을 위해 대상하천의 하류에 위치한 풍지교에서 어류 현장조사를 수행하였다. 어류 현장조사 결과, 피라미가 우점종으로 나타나 피라미(Zacco platypus)를 대상어종으로 선정하였고 피라미의 물리적 서식처 특성을 활용하여 HSI를 구축하였다. 피라미의 최적 HSI 범위는 유속에서 0.3~0.5 m/s, 수심에서 0.4~0.6 m, 그리고 하상재료는 모래에서 잔자갈로 나타났다. HSI를 PHABSIM에 적용하여 환경생태유량을 산정한 결과, 대상하천의 최적 환경생태유량은 20.0 m³/sec로 산정되었다. River2D를 활용하여 어류서식처의 2차원 공간분석을 수행한 결과 WUA는 환경생태유량 조건에서 107,392.0 m₂/1000 m으로 산정되었고, Q₃₅₅ 조건과 비교하여 하천 전반적으로 어류서식처가 확보되는 것을 확인하였다.

• 수산해양기술연구
• /
• 제54권2호
• /
• pp.146-156
• /
• 2018

Acoustic surveys were conducted in the seas surround the South Korea (South Sea A, South Sea B (waters around the Jeju Island), West Sea and East Sea) in spring and autumn in 2016. First, the vertical and horizontal distributions of fisheries resources animals were examined. In most cases vertical acoustic biomass was high in surface water and mid-water layers other than South Sea A in autumn and West Sea. The highest vertical acoustic biomass showed at the depth of 70-80 m in the South Sea A in spring ($274.4m^2/nmi^2$) and the lowest one was 10-20 m in the West Sea in autumn ($0.4m^2/nmi^2$). With regard to the horizontal distributions of fisheries resources animals, in the South Sea A, the acoustic biomass was high in eastern and central part of the South Sea and the northeast of Jeju Island ($505.4-4099.1m^2/nmi^2$) in spring while it was high in eastern South Sea and the coastal water of Yeosu in autumn ($1046.9-2958.3m^2/nmi^2$). In the South Sea B, the acoustic biomass was occurred high in the southern and western seas of Jeju Island in spring ($201.0-1444.9m^2/nmi^2$) and in the southern of Jeju Island in autumn ($203.7-1440.9m^2/nmi^2$). On the other hand, the West Sea showed very low acoustic biomass in spring (average NASC of $1.1m^2/nmi^2$), yet high acoustic biomass in the vicinity of 37 N in autumn ($562.6-3764.2m^2/nmi^2$). The East Sea had high acoustic biomass in the coastal seas of Busan, Ulsan and Pohang in spring ($258.7{\sim}976.4m^2/nmi^2$) and of Goseong, Gangneung, Donghae, Pohang and Busan in autumn ($267.3-1196.3m^2/nmi^2$). During survey periods, fish schools were observed only in the South Sea A and the East Sea in spring and the West Sea in autumn. Fish schools in the South Sea A in spring were small size ($333.2{\pm}763.2m^2$) but had a strong $S_V$ ($-49.5{\pm}5.3dB$). In the East Sea, fish schools in spring had low $S_V$ ($-60.5{\pm}14.5dB$) yet had large sizes ($537.9{\pm}1111.5m^2$) and were distributed in the deep water depth ($83.5{\pm}33.5m$). Fish schools in the West Sea in autumn had strong $S_V$ ($-49.6{\pm}7.4dB$) and large sizes ($507.1{\pm}941.8m^2$). It was the first time for three seas surrounded South Korea to be conducted by acoustic surveys to understand the distribution and aggregation characteristics of fisheries resources animals. The results of this study would be beneficially used for planning a future survey combined acoustic method and mid-water trawling, particularly deciding a survey location, a time period, and a targeting water depth.

• 한국환경보건학회지
• /
• 제42권1호
• /
• pp.10-18
• /
• 2016

Objectives: Microcystin (MC) produced during cyanobacterial blooms is a worldwide problem presenting a serious health threats to humans and ecosystems. During July through October of 2013, the Ilwol Reservoir experienced a high biomass of phytoplankton (maximum $211.7mg/m^3$ of Chlorophyll-a) containing the toxigenic cyanobacterium Oscillatoria sp. The aim of this study is to analyze MC concentration in the reservoir water, as well as in representative fish species (Carassius cuvieri, Carassius auratus, Channa argus). We also evaluated the human health risk of exposure to MCs accumulated in the fish. Methods: Concentrations of MCs in the water and fish samples were analyzed by liquid chromatography with a triple quadrupole tandem mass spectrometer (LC/MS/MS) and enzyme-linked immunosorbent assay (ELISA). Results: The total levels of four MC variants, including MC-LR, MC-RR, MC-YR and MC-LA were below the WHO drinking water guideline limit (1 ug MC-LR per liter) both for the dissolved and particulate fraction present in the water samples. The mean MC concentrations in the livers of all species were significantly higher than in the gills (p < 0.01) and muscles (p < 0.05). The values of estimated daily intake of MCs in muscles, the edible part of the fish, would be only $0.005-0.015{\mu}g/kg{\cdot}day$, much lower than WHO's provisional tolerable daily intake of $0.04{\mu}g/kg{\cdot}day$. Conclusion: This study suggests that, owing to the spatial distribution or temporal variation of MC, there is a need for careful monitoring of cyanotoxin in reservoir water and aquatic animals to protect public health.

• 수산해양기술연구
• /
• 제52권1호
• /
• pp.24-35
• /
• 2016

An acoustic and trawl pilot survey using a small vessel was conducted in Jinhae bay of the South Sea of South Korea on April 13~14, May 11~13 and June 8~10, 2015. During the survey, acoustic data was collected and bottom trawls were conducted at the same time. First, various noises were eliminated by using the Park method based on the Wang method (Wang et al., 2015; Park et al., 2015), the species compositions and catch rate from each bottom trawl were observed, and spatial distribution of fishery resources in the water column and their nautical area scattering coefficient (NASC) were investigated through acoustic data. During the entire survey period, 12 orders, 33 families and 41 species were caught. The most caught species in April, May and June were Okamejei kenojei, Zoarces gilli and Pholis nebulosa, respectively. Fish schools were observed near the line of net mouth height in April. Numerous weak scatters were presented on the echograms in May and June. Many fish schools appeared in between the water surface and 20 m deep in May. The NASC value from entire water columns was the lowest in April ($35.9m^2/n{\cdot}mile^2$) and highest in June ($1541.3m^2/n{\cdot}mile^2$).

• Fisheries and Aquatic Sciences
• /
• 제18권2호
• /
• pp.183-193
• /
• 2015

Several transgenic marine medaka Oryzias dancena strains harboring a green fluorescent protein (GFP) reporter construct regulated by an endogenous ${\beta}$-actin promoter were established and their expression characteristics in relation to transgene copy numbers were examined in 21 transgene genotypes. Most of the transgenic strains displayed transgene insertion patterns typical of microinjection-mediated introduction of foreign DNA into fish embryos, characterized by the random integration of multiple transgene copies (ranging from 1 - 282 copies per cell), often accompanied by the formation of concatemer(s), as assessed by genomic Southern blot hybridization analysis and qPCR. Transgenic strains showed ubiquitous and continued temporal and spatial expression patterns of the transgenic GFP during most of their life cycle, from the embryonic stage to adulthood, enabling assessment of the expression pattern of the endogenous ${\beta}$-actin gene. However, a comparative evaluation of transgene copy numbers and expression levels showed that copy number-dependent expression, the stability of the ubiquitous distribution and expression efficiency per transgene copy varied among the transgenic strains. Fluorescence expression levels were positively correlated with absolute transgene copy numbers, whereas the expression efficiency per transgene copy was inversely related to the number of transgene integrant copies. Data from this study will guide the selection of potentially desirable transgenic strains with ubiquitous expression of a fluorescent transgene, not only in this marine medaka species but also in other related model fish species.

• 생태와환경
• /
• 제51권4호
• /
• pp.354-364
• /
• 2018

본 연구는 2008년부터 2016년까지 한강 지류 중랑천을 대상으로 수환경 변화에 따른 어류 군집 양상을 파악하고자 실시하였다. 조사결과, 중랑천에서 서식하는 어류는 총 9과 37종 8,421개체로 나타났으며 과별 출현 종수는 잉어과에서 23종(62.2%)으로 가장 많은 종이 출현하였고, 생태계교란종 및 외래종은 모두 강우기 후 출현하는 특성을 보였다. 수질변화에 따르면, BOD, EC, TN, TP의 변화는 강우량의 증가에 따라 감소하는 양상을 보이는 반면, SS 변화는 증가하는 양상을 보였다. 지점간 CA결과 한강 본류와 인접한 St. 7과 St. 1, 3, 5가 어류의 출현양상 차이를 보였으며, PCA 분석결과 상류에서 하류, 강우기 전과 후의 어류출현양상과 유기오염지표의 변화 양상을 보였다.

• 수산해양기술연구
• /
• 제55권2호
• /
• pp.121-128
• /
• 2019

Various artificial reefs provide the fish habitat and nursery, and contribute the improvement of fisheries productivity. The evaluation methods of fishery resources in the artificial reefs have been done by fishing, scuba diving, underwater camera, and scientific echo sounder/sonar. There are a number of studies using echosounders on the quantitative and qualitative evaluations of artificial reefs in various seas around the world. This study focused on the spatial distribution of fishes around artificial reefs and the influential area of reefs off Bukchon, Jeju Island. Not only acoustic data but also various properties of artificial reefs were used in the geographic information system to extract relevant results. As a result, the major material of reefs on this study site was concrete and the number of reefs with that material was the most. The volume of reefs consisted of steel only and steel with riprap was considerably large compared to other reefs. The average NASC in the vertical distribution of fishes in artificial reefs was $31.6m^2/nm^2$ in April, and that was $61.3m^2/nm^2$ in June. The distance between the fish school and their nearest reef in June morning had a wide range from 750 to 3250 m. On the basis of the influence ray of artificial reefs, it had a tendancy of NASC to decrease with distance from the reef in the June morning. It is a preliminary study to present the geospatial analysis example to understand a better way of comprehensive artificial reef environments.

• ALGAE
• /
• 제23권1호
• /
• pp.83-90
• /
• 2008

Eelgrass beds are very productive and provide nursery functions for a variety of fish and shellfish species. Management for the conservation of eelgrass beds along the Korean coasts is critical, and requires comprehensive strategies such as vegetation mapping. We suggest a mapping method to spatial distribution and quantify of eelgrass beds using a digital echosounder. Echosounding data were collected from the northeast part of Kwangyang Bay, on the south of Korea, in March, 2007. A transducer was attached to a boat equipped with a DGPS. The boat completed a transect survey scanning whole eelgrass beds of 11.7 km2 with a speed of 1.5-2 m s-1 (3-4 knot). The acoustic reflectivity of eelgrass allowed for detection and explicit measurements of canopy cover and height. The results showed that eelgrass bed was distributed in depth from 1.19 to 3.6 m (below MSL) and total dry weight biomass of 4.1 ton with a vegetation area of 4.05 km2. This technique was found to be an effective way to undertake the patch size and biomass of eelgrass over large areas as nondestructive sampling.

• 생태와환경
• /
• 제55권2호
• /
• pp.99-110
• /
• 2022

본 연구에서는 어류 양식장 퇴적 유기물의 기원 및 기여도 평가를 위해 어류(숭어) 가두리 양식장이 이동된 후 수층 및 퇴적물 내 물리/화학적 인자들의 변화와 함께 안정 동위원소 비의 특성을 조사했다. 이를 토대로 과거 양식장 퇴적물 내 축적된 유기물의 거동을 구체적으로 파악함으로써 효과적인 어장환경평가 기법을 검토하였다. 연구정점(OFF 및 control)에서 입자성 및 침강물질은 정점 간 차이보다는 계절적 강수량 변동에 따라 차별적 분포를 보였다. 하지만 퇴적물 내 분석된 δ¹⁵N 결과는 수층 기원 질소원과는 유의한 차이를 보였으며, 과거 외부기원의 유기물 (예: 어류 배설물)의 다량 유입이 주된 요인이라 판단된다. 실제로 과거 어류 가두리 양식활동으로 인해 OFF 정점 내 어류 배설물의 우점적 기여(>50%)를 확인할 수 있었다. 따라서 본 연구정점 내 분해되지 않은 어장 양식기인 유기물의 농도가 높은 수준으로 존재할 것이라 판단되며, 어장 회복력의 체계적인 진단을 위한 중요한 고려요인이라 판단된다.

• 한국수산과학회지
• /
• 제27권2호
• /
• pp.183-192
• /
• 1994

대서양 남빙양 새우의 주된 분포역은 South George Island, Laurie/Coronation Islands와 Livingston/King George Islands 지역으로 공간적인 구분을 뚜렷이 하였다. 어획 수심은 층에서 150 m층까지 달했고, 10 m층으로 구분한 단위노력당어획량의 수직 분포는 층간에 큰 차이가 없었으나 수심이 깊어 질수록 낮아지는 경향을 보였다. 수온과 단위노력당 어획량의 관계로 부터 남빙양 새우는 주로 $0.8{\sim}l.0^{\circ}C$ 범위에서 높은 밀도를 나타내었다. 남빙양 새우의 암수별 체장 조성은 큰 차이를 보여 숫컷의 비율은 작은 체장에서, 암컷의 비율은 큰 체장에서 각각 높았다. 두흉갑장과 체장관계, 체장과 체중관계가 암수별로 추정되었다. 암수별 성비조성은 숫컷이 $60.3\%$, 암컷이 $39.7\%$로서 유의한 차이를 나타내었다.