• Title/Summary/Keyword: Sea algae

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The Macroalgal Community of Bagryoungdo Island in Korea (백령도 해조군집의 종조성과 생물량)

  • Baek, Jae-Min;Hwang, Mi-Sook;Lee, Jae-Wan;Lee, Wook-Jae;Kim, Jong-In
    • ALGAE
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    • v.22 no.2
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    • pp.117-123
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    • 2007
  • The seasonal change of algal flora and intertidal community structures of Bagryoungdo Island was investigated at Dumujin from February to November 2006. The description of subtidal algal community was made in October by Scientific SCUBA-diving. The total of 43 species, including 6 Chlorophytes, 6 Phaeophytes, 29 Rhodophytes and 2 sea grasses were identified in this survey. The occurrence of species according to season, listed as follows, 26 species in winter, 34 in spring, 18 in summer and 18 in autumn. Three species, Laminaria japonica, Neorhodomela aculeata and Ulva pertusa were dominant. The algal zonation of intertidal zone was figured out by Porphyra spp., Gloiopeltis furcata, Caulacanthus okamurae, Gelidium divaricatum - Neorhodomela aculeata, Enteromorpha compressa - Ulva pertusa, Dumontia simplex, Laminaria japonica from upper to lower zone. The zonation of subtidal zone was figured out by Ulva pertusa - Laminaria japonica - Zostera marina (sea grass), crustacean red algal population in autumn. The average of biomass of macroalgae was measured as 119.4 g∙dry wt/m2.

Biological environmental characteristics in Habitats of an abalone Haliotis diversicolor in the eastern coast of jeju-do, Korea

  • Yoo, Joon-Taek;Choi, Young-Min;Yang, Moon-Ho;Im, Yang-Jae;Ko, Joon-Chul;Chang, Dae-Soo
    • The Korean Journal of Malacology
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    • v.25 no.3
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    • pp.231-236
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    • 2009
  • This study describes biological environmental characteristics in natural habitats of Haliotis diversicolor in the coastal area of Sungsanpo located in the eastern coast of Jeju-do, Korea. The field survey was monthly conducted from May 2006 to February 2007. H. diversicolor, sea urchin, turban shell and marine algae were collected by two divers using SCUBA. The species composition of demersal fishes were seasonally investigated by fish traps in 2007. During the study period, more than 67% of H. diversicolor and sea urchin were found in the depth shallower than 5 m, and more than 64% of turban shell were found in the depth deeper than 3 m. The dominant algal species in May were generally Undaria pinnatifida, Ecklonia cava, Sargassum. spp. and coralline algae. Most of demersal fishes collected by the fish traps were wrasses which have been reported as a major predator of young abalone.

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Feeding behaviors of a sea urchin, Mesocentrotus nudus, on six common seaweeds from the east coast of Korea

  • Yang, Kwon Mo;Jeon, Byung Hee;Kim, Hyung Geun;Kim, Jeong Ha
    • ALGAE
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    • v.36 no.1
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    • pp.51-60
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    • 2021
  • The sea urchin, Mesocentrotus nudus, is widely distributed in North West Pacific regions. It has a substantial impact on macroalgal communities as a generalist herbivore. This study examined various aspects of its feeding ecology, including algal preference, foraging behaviors, and possible effects of past feeding history on its algal preference. We used six common algal species (Ulva australis, Undaria pinnatifida, Sargassum confusum, Dictyopteris divaricata, Grateloupia elliptica, and Grateloupia angusta) from the east coast of Korea as food choice in a series of indoor aquarium experiments. The first choice of starved M. nudus was exclusively U. pinnatifida, followed by G. elliptica and S. confusum. Unlike large urchins, small urchins equally preferred U. pinnatifida and G. elliptica. On the other hand, Undaria-fed urchins preferred to feed only G. elliptica, although its preference slightly differed over time. We then grouped sea urchins into three categories (starved, Undaria-fed, mixed species-fed) to observe 12-days feeding preference as well as early foraging movements. Foraging behaviors of the three groups were distinctively different, although they could not completely reflect the actual consumption. For example, U. australis was highly attractive, but rarely eaten. Undaria-fed urchins seemed to stay with only S. confusum and U. australis. This study demonstrates that M. nudus shows high flexibility in food preference depending on past feeding history and body size. Its foraging behaviors are also affected by past feeding conditions, exhibiting active chemoreceptive movements.

Enhancing Red Tide Image Recognition using NMF and Image Revision (NMF와 이미지 보정을 이용한 적조 이미지 인식 향상)

  • Park, Sun;Lee, Seong-Ro
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.2
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    • pp.331-336
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    • 2012
  • Red tide is a temporary natural phenomenon involving harmful algal blooms (HABs) in company with a changing sea color from normal to red or reddish brown, and which has a bad influence on coast environments and sea ecosystems. The HABs have inflicted massive mortality on fin fish and shellfish, damaging the economies of fisheries for almost every year from 1990 in South Korea. There have been many studies on red tide due to increasing damage from red tide on fishing and aquaculture industry. However, internal study of automatic red tide image classification is not enough. Especially, extraction of matching center features for recognizing algae image object is difficult because over 200 species of algae in the world have a different size and features. Previously studies used a few type of red tide algae for image classification. In this paper, we proposed the red tide image recognition method using NMF and revison of rotation angle for enhancing of recognition of red tide algae image.

Development of The Automation System for Seaweed Biomass Mass Production (바이오매스용 해조류 대량 양식을 위한 자동화 시스템 개발)

  • Choi, Kook-Jin
    • Journal of the Korean Society of Industry Convergence
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    • v.23 no.2_2
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    • pp.351-359
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    • 2020
  • The algae biomass is considered as one of the potential sources of ocean renewable energy because it can be easily mass-produced with abundant sunshine in the vast ocean space. However, the practical use of the biomass has been hindered by the lack of efficient and cost-effective harvesting and maintenance system so far. The algae biomass aquaculture systems are installed in far offshore locations in much larger scales compared to the conventional aquaculture systems so that the automatic seaweed planting and harvesting system needs to operate in heavy sea conditions in far offshore location. In this research, we develop a concept design of a mega-scaled aquaculture system and an automatic seaweed planting and harvesting system, which can operate in heavy seas and mass-produce the algae biomass.

Use of New Fibers for the Development of Security Paper (특수섬유를 이용한 보안용지의 개발)

  • Jung, Sun-Young;Gil, Sang-Hyuk;Kim, Young-Wook;Seo, Yung-Bum
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.44 no.1
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    • pp.16-23
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    • 2012
  • Use of security papers for monetary papers, gift certificates, and lottery tickets increases every year. As the use of security papers increase, there are more possibility of counterfeits. In this study, we used unique fibers from the sea to increase the difficulties against counterfeiting. The red algae fibers give opacity as much as calcium carbonates, and have unique shape in length ($500{\sim}900\;{\mu}m$) and width ($1{\sim}4\;{\mu}m$) to be discerned from other natural fibers such as wood and cotton fibers. We mixed red algae fibers to wood fibers in a series of fixed ratios to make single and multiply papers for making security papers. Paper with dyed red algae fibers were also used. Paper made without fillers gave enough opacity for printing when red algae fibers were used more than 20% of the fiber furnish. Those properties may allow red algae fibers to be a potential candidate for fiber raw materials of security paper.

Marine Algal Flora and Grazing Effect of Sea Urchins in the Coastal Waters of Cheju Island (제주연안의 해조상과 성게의 섭식효과)

  • 이기완;손철현;정상철
    • Journal of Aquaculture
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    • v.11 no.3
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    • pp.401-419
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    • 1998
  • The structure of benthic algal flora and feeding behavior of sea urchins (Anthocidaris crassispina and Hemicentrotus pulcherrimus), were investigated from the eight different locations along the coast of Cheju Island, Korea. Biomass distribution and dominance of the algal communities were studied in relation to the gut contents and population parameters of the sea urchins. As a result, although the largest algal biomass and biological characteristics of sea urchins, such as test diameter, test hight, body weight, gonad weight, etc. This inhdicated that sea urchins would not be dependednt sorely on the abundance of algal foods, and they might feed on other food items. In order to know such a trend with regard to food selectivity, the diets consumed by sea urchins were analyzed, and it was found that they were composed of benthic and drifted algae, various animal components (sponges, bryozoans, crustaceans, and various unidentified capsulated eggs, etc.) and biets turned out to be smaller than might be expected, and it is postulated that sea urchins were not likely to be the major grazing animals for the formation of algal bed and also canopy deterioration, so-called "white incrustation."

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Studies on the Isolation of Vibrio vulnificus from Sea Water and Marine Products in the Southern Sea of Korea (한국 남해안 일대의 해수 및 해산물에서 Vibrio vulnificus의 분리연구)

  • Ju, Jin-Woo;Kim, Il
    • The Journal of the Korean Society for Microbiology
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    • v.21 no.1
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    • pp.97-106
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    • 1986
  • Authors studies on the isolation of V. vulnificus from sea water, sea mud fishes, shellfishes and algae at the seasides of Pusan, Masan, Chungmu and Ulsan in Korea in 1985. Authors carried out test for isolated strains to bacteriological test, hemolysis test about erythrocytes of various animal, sensitivity test of various chemotherapeutic agents and serological test with antiserum of V. vulnificus. The resultls obtained were as follows: 1. V. vulnificus was isolated 15 strains from 399 total specimens: 110 cases of sea water, 40 cases of sea mud, 90 cases of fishes, 60 cases of shellfishes and 79 cases of various algae, respectively. 2. Nine strains were isolalted from sea water, 4 strains were isolated from sea mud and 2 strains were isolated from fishes, respectively. 3. Two strains among 15 strains isolated were lactose positive reaction. 4. All strains isolated were grown in concentration of $0.5%{\sim}7.0%$ NaCl, but were not grown 0% and 8.0% NaCl. 5. Hemolysis reaction about various erythrocytes was sensitived to guinea pig, human and rabbit erythrocytes, but was not sensitived to sheep erythrocytes. 6. Sensitivity test using with chemotherapeutic agents of "BioLab" Microbial Sensitivity Test Discs were generally sensitived to amikacin, ampicillin, clindamycin, erythromycin, gentamycin, kanamycin, streptomycin, tetracyclin and tobramycin, and were moderate to penicillin, but were resistant to methicillin and lincomycin, respectively. 7. The distribution of serotypes of V. vulnificus isolated were on antiserum of $0.1{\sim}07$ of V. vulnificus: 1 case of 01 and 2 cases of 07, respectively.

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Summer Marine Algal Communities at Dokdo, Korea (독도의 하계 해조 군집)

  • Choi, Chang-Geun;Kwon, Chun-Jung;Kim, Mi-Kyong
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.5
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    • pp.1037-1043
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    • 2014
  • We extensively observed macroalgal assemblages of species composition and biomass of summer benthic marine algae at Dokdo in the East sea of Korea. A total of 102 species (12 Chlorophyta, 36 Phaeophyta, and 54 Rhodophyta) were identified in quadrats and were analysed qualitatively to define the variation patterns. Biomass in dry weight according to various depths ranged between 146.0 to 764.2 g m-2 at study sites. Mean biomass at the investigated sites was greater in the 10m depth range than in the 5 and 15m depths at Dongdo. The flora could be classified into six functional groups: coarsely branched form (51.0%), filamentous form (17.7%), thick leather form (15.7%), sheet form (5.9%), jointed calcareous form (4.9%) and crustose form (4.9%). The R/P, C/P and (R+C)/P value were 1.67, 0.50 and 2.17, respectively. The number of marine algae species and the biomass in Dokdo area were markedly reduced as compared with those in the previous studies. This result suggests possible future changes in the algal vegetation, considering coastal marine environment of this area.

Free-living Heterotrophic Stramenopile Flagellates from Gippsland Basin, South-eastern Australia

  • Lee, Won-Je
    • ALGAE
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    • v.22 no.1
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    • pp.23-29
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    • 2007
  • Free-living heterotrophic stramenopile flagellates, which lack chloroplasts, were encountered in deep-sea sediments of Gippsland Basin (Australia) and classified into 10 species (8 genera, 5 families, 3 orders). Their descriptions were based on living specimens by light microscopy. Those species rarely found in this study were Bicosoeca gracilipes, Caecitellus parvulus, Cafeteria minuta, Cafeteria roenbergensis, Pseudobodo tremulans, Spumella sp., Paraphysomonas sp., Actinomonas mirabilis, Ciliophrys infusionum and Developayella elegans. Their morphological characters and geographic distribution are presented.