• 한국수산과학회지
• /
• 제44권6호
• /
• pp.732-739
• /
• 2011

Marine algal flora and community structure were examined at four sites at Tongyeong, Korea, from February to December 2009. Eighty-two algal species were identified, including 10 green, 25 brown, and 47 red algae. During the study period, the number of species was highest at the Dukpo (61 species) site followed by the Gajodo (60 species), Yepo (58 species), and Chilchundo (53 species) sites. Seaweed biomass ranged from 578.11 to 678.26 g, with the maximum and minimum at Chilchundo and Yepo, respectively. Dominant species in term of biomass were Sargassum thunbergii at Yepo, Dukpo, and Gajodo and Gelidium amansii at Chilchundo. The vertical distribution from the high to low intertidal zone was Sargassum thunbergii and Chondria crassicaulis; Sargassum thunbergii and Ulva linza; Ulva pertusa, Sargassum fulvellum, and Gelidium amansii. Two groups clearly segregated in a cluster analysis, a Yepo/Dukpo group (group A) and a Gajodo/Chilchundo (B), indicating relatively strong differences in similarity. The seaweed community structure of group A was characterized by higher biomass and higher species richness of brown algae than were observed in group B. Additionally, the biomass ratio and the species richness of green algae was lower in group A. These differences in seaweed community structure may have been resulted from the effects of cold effluents.

• 한국어병학회지
• /
• 제34권2호
• /
• pp.255-259
• /
• 2021

This is the first report describing acute mass mortality occurred in juvenile olive flounder (Paralichthys olivaceus) caused by gas bubble disease (GBD). A total of 610 fish (average weight = 35 g), which were more than half of the fish acclimated at 17℃ in an aquarium, were killed within two days of acclimation. The dead and moribund fish showed excessively opened opercula and mouths, and occasionally, severe exophthalmia. Through microscopic observation, numerous gas emboli were found in the gills of the dead and live fish, while the fish were not infected with any microbial pathogens. The dissolved oxygen (DO) saturation level of the rearing water and seawater nearby the facility reached 145% and 286%, respectively, whereas other water quality parameters (such as salinity, pH, and chemical oxygen demand) were normal. The extreme saturation rate of seawater in the shore nearby seemed to be due to an enormous algal bloom that occurred there. Through molecular identification based on 18S rDNA sequences, the most dominant algal species was most closely related to Ulva californica (99.87% sequence identity) followed by U. prolifera, U. linza, and U. curvata (99.81%). Therefore, it can be concluded that supersaturated seawater due to mass algal bloom caused gas bubble disease in the olive flounder, leading to mass mortality. After technical adjustment, such as increased aeration, lowered water circulation rate, and inlet water filtration using micro-pore carbon filters, the DO level became normal, no further mortality occurred and the status of the fish was stabilized.

• 한국수산과학회지
• /
• 제12권4호
• /
• pp.225-234
• /
• 1979

자원이 풍부한 해조류 단백질의 효율적인 이용과 이의 영양가를 구명하기 위하여 가장 효과적인 정제방법 및 추출용매를 결정하고 4종 식용해조 즉 둥근 돌김, 구멍갈파래, 미역 및 모자반의 추출 정제단백질의 아미노산 조성과 이의 영양가 및 소화율을 실험한 결과를 요약하면 다음과 같다. 1. 홍조류와 녹조류는 추출단백질을 TCA로 심전시킨 후 ethylether로 TCA를 충분히 제거하면 정제효과가 좋았고, 갈조류는 등전점을 이용한 정제방법의 효과가 좋았다. 2. 각종 용매로 추출한 단백질의 아미노산을 분석한 결과 홍조류와 녹조류는 물 또는 알칼리 추출한 단백질이 좋았고, 갈조류는 알코올-알칼리 혼합용매로 추출한 단백질이 좋았고, 3. 둥근돌김의 정제단백질은 lyeine의 함량이 전시료 중에서 가장 높았으며 구멍갈파래는 threonine의 함량이 월등히 높은 반면, lysine의 함량이 낮았으며 미역과 모자반의 아미노산 분포 양상은 둥근돌김과 구멍갈파래보다 좋지 못했다. 4. 둥근돌김과 구멍갈파래 원조분말의 chemical score는 35정도였으나 정제단백질은 56정도있고, 미역과 모자반은 원조분말이 $10\~16$정도로 극히 낮은 반면에 정제단백질은 $30\~35$ 정도를 나타내었고, protein score는 전시료가 정제단백질의 경우 $62\~73$ 정도를 나타내었다. 5. PPDRI를 이용한 소화율은 원조분말의 $25\~40$ 정도의 낮은 소화율을 보였으나 정제했을 경우에는 $1.3\~2.1$배 증가함을 보였고, 갈조류의 소화율은 일반적으로 극히 낮음을 알 수 있었다.

• ALGAE
• /
• 제23권2호
• /
• pp.151-162
• /
• 2008

Marine algal flora and community structure were seasonally examined at three sites in the vicinity of the Wolseong nuclear power plant in Korea from February to November 2006. A total of 126 seaweeds including 25 green, 31 brown, 70 red algae, and 1 marine plant were identified. The greatest number of species occurred at Jeonchonri (101 species) followed by intake (88 species) and discharge (29 species) during the study period. Of 126 seaweeds, 76 annuals and 13 warm tolerance species were recorded. Dominant species based on important value (IV > 10) were Ulva pertusa and Enteromorpha linza at intake, U. pertusa and Padina arborescens at discharge, and Sargassum horneri and Corallina pilulifera at Jeonchonri shore. Annual average biomass exhibited a wide range of variations, from 40.67g m-2 in dry weight at discharge to 133.69g m-2 at Jeonchonri. Among six functional groups, dominant group was coarsely-branched form at intake and Jeonchonri, but it was different at discharge site as filamentous form. Seaweed community structures of discharge site were distinguishable in decreasing species richness, biomass, species diversity index (H’), richness index (R), and evenness index (J’). Also, the ratios of green algae, warm tolerance species, annual algae, filamentous form and dominance index (DI) remarkably increased. Such phenomenons of discharge site are usually found under environmentally stressful conditions such as high disturbance. Thus, I can conclude that the heated effluents of nuclear power plant act as environmental stress influencing seaweed community structures and it can be detected with various community indices.

• Fisheries and Aquatic Sciences
• /
• 제12권1호
• /
• pp.29-34
• /
• 2009

Fifty seven species of common seaweed from the coast of Korea were screened for antifungal activity against Malassezia species. Seaweeds as a source of bioactive compounds are able to produce a great variety of secondary metabolites with different activities. There are numerous reports on the biological activities of seaweeds against human pathogens, fungi, and yeasts, but only few contain data regarding inhibitory effects against Malassezia sp., a major cause of dandruff and seborrheic dermatitis. To help address this paucity of information, this work was carried out to examine the antifungal effects of seaweed extracts against M. furfur and M. restricta. Of the fifty seven species of marine algae screened for their potential antifungal activity, only 17 species (29.8%) exhibited inhibitory activity. In agar disc diffusion method, the ether extracts of Corallina pilulifera, Enteromorpha linza, Laminaria japonica, Symphyocladia latiuscula and Ulva sp. showed strong antifungal activity. To identify major constituents in seaweed extracts, four selected extracts were analyzed on' a GC-MS equipped with a flame ionization detector, and compared to spectral data from databases WILEY229.LIB and NIST107.LIB. Most constituents in seaweed extracts are fatty acid-related compounds. When we evaluated any acute toxicity, the ether extracts of the selected four species were not toxic in mice. According to these results, it can be suggested that these seaweed extracts are valuable for the development of therapeutic agents in treating dandruff and seborrheic dermatitis. Further investigations to determine its bioactive compound(s) are currently in progress.