• Journal of Aquaculture
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• v.10 no.2
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• pp.199-211
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• 1997

Effects of light and temperature on the early growth of Hizikia fusiformis were investigated for establishment of artificial seed production. Young germlings were cultured for 70 days under different culutre conditions : light intensities (500, 1, 000, 2, 000, 4, 000, 8, 000 lux), photoperiods (8 : 16, 12 : 12, 16 : 8, (L : D)) and temperatue (10, 15, 20, 25, $30^{\circ}C$). Growth of the germlings was facilitated in 2, 000~4, 000 lux of light intensities, 16 : 8 (L:D) of photoperiods and 15~$20^{\circ}C$ of temperature. Culture conditions were revealed for the mass culture of artificial seeds of effective early growth in Hizikia cultivation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.3
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• pp.231-238
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• 2010

The Induction of regeneration and maturation in the free-living gametophytes of Ecklonia stolonifera Okamura was studied at four temperatures (5, 10, 15, and $20^{\circ}C$), four levels of irradiance (5, 10, 20, and 40 ${\mu}mol\;m^{-2}s^{-1}$) and three photoperiods (14:10, 12:12, and 10:14 h L:D). Female gametophyte fragments were maintained in active regeneration without reaching sexual maturity under $5{\sim}10^{\circ}C$, 10 ${\mu}mol\;m^{-2}s^{-1}$, 10:14 h (L:D), whereas the conditions for male gametophytes were slightly different at $20^{\circ}C$, 40 ${\mu}mol\;m^{-2}s^{-1}$, 10:14 h (L:D). The sexual maturation of female and male gametophytes was facilitated at $15^{\circ}C$, 20 ${\mu}mol\;m^{-2}s^{-1}$, 14:10 h (L:D). These results provide basic information for controlling the regeneration and maturation of the free-living gametophytes for artificial seed production of E. stolonifera.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.3
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• pp.246-253
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• 2010

The marine algal flora and community structure were investigated at three sites in Ulsan on the southeast coast of Korea between August 2005 and July 2006. Ninety-one benthic algae species were identified, including 14 Chlorophyta, 21 Phaeophyta, and 56 Rhodophyta species. Of the 91 seaweeds, 19 species were found throughout the survey period. The wet weight biomass ranged from 310.8 to 2,960.4 g $m^{-2}$ during the study period. The maximum biomass was recorded at Sinri, and the minimum was recorded at Daesong. The R/P, C/P and (R+C)/P values reflecting flora characteristics were 2.67, 0.67, and 3.33, respectively. The flora investigated could be classified into six functional groups: coarsely branched (46.2%), thick leathery (22.0%), filamentous (16.5%), Sheet (7.7%), jointed calcareous (4.4%), and crustose (3.3%) forms. A cluster analysis produced two groups that differed meaningfully: one included the site Sinri-summer and the other included the sites Daesong and Jinha.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1293-1296
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• 2005

Nitrite plays an important role in the formation of carcinogenic nitrosamine. In order to effectively inhibit the formation of carcinogenic nitrosamine in food and biological systems, scavenging of residual nitrite is necessary. In screening test of nitrite-scavenging effect of seaweed, The methanol extract from Phaeophyta was more effective than those from Rhodophyta and Chlorophyta. Among the brown algae family, Laminariaceae, A. cribrosum (90.4$\%$) and E. cava (80.1$\%$), E. stolonifera (79.0$\%$) that belong to genus Ecklonia showed marked nitrite-scavenging effect at pH 1.2. Furthermore, these algae showed potent reducing power and radical scavenging activity. The nitrite-scavenging effect was correlated with level of reducing power.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.6
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• pp.920-933
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• 2012

Marine algal flora and community structure were investigated seasonally at four stations in Busan, in which coastal area and estuary affected by Nakdong river are involved, from February 2011 to October 2011. Total 78 species including 9 of cholophyta, 17 of phaeophyta and 52 of rhodophyta were found during the study period. Maximum and minimum species number were recorded at station 1(57 species) and at 3(32 species). As based on the cluster analysis, grouping pattern between the four stations was significantly affected by season and Nakdong river run off. At station 3 directly exposured on Nakdong river run off, species diversity was relatively low and dominant species were similar throughout four seasons. However, coverage at the station was relatively high because of Ulva bloom. This difference results from salinity and nitrates concentrations closely related with river runoff controlled according to precipitation. Marine algal coverage was high at lower salinity and higher nitrate concentration. In conclusion, the spatio-temporal distribution of benthic marine algae in estuary of Nakdong river was mainly determined by the precipitation and river run off with the seasons, whereas that in coastal area was seasonally affected by general physical, chemical, biological and dynamic factors.

• The Korean Journal of Food And Nutrition
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• v.31 no.6
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• pp.821-827
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• 2018

Ecklonia cava which is a kind of phaeophyta and belongs to Laminariales Alariaceae is a perennial seaweed distributed over Jeju and Dokdo islands. The purpose of this study evaluate antioxidant activities of Ecklonia cava crackers. Crackers were prepared with different measurements (0, 2, 4, 6, 8 g) of Ecklonia cava; indicated as S1, S2, S3, S4 and S5, and are used to examine and compare antioxidant activities, and quality characteristics. Ecklonia cava powder was used, after being extracted with 70% ethanol in hot water and done in freeze dehydration. To examine antioxidant activities of Ecklonia cava and cracker, DPPH radical scavenging activity, total phenolic and reducing power were tested. Total phenolic content was 36.86 mg GAE/g. DPPH radical scavenging activity and reducing power showed good vitality as amounts of Ecklonia cava powder increased (p<0.001). pH level decreased as amounts of power increased. L (lightness) values and b (yellowness) values decreased with an increased concentration of Ecklonia cava powder (p<0.001), whereas (redness) values didn't show tendency. S5 indicated the lowest spreadness. According to sensory evaluation, S4 (6 g) was preferred the most in terms of color, flavor, taste, appearance, texture, and overall palatability. Results suggest that Ecklonia cava powder has antioxidant effect and is useful as a functional food resource.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.3
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• pp.278-291
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• 2024

This study performed three research methods (destructive, non-destructive, and panoramic image analysis) to determine the most useful for identifying seaweed habitat characteristics. Panoramic images are suitable for understanding the overall seaweed distribution. The composition of the main dominant seaweed species showed a significant difference between the destructive and non-destructive methods using Quadrat. The destructive method showed Rhodophyta dominance, whereas the non-destructive was showed Phaeophyta as dominant. Destructive methods are disadvantageous because they destroy natural communities in sea areas where bleaching is severe. Non-destructive methods are disadvantageous because of the difficulty in analyzing small species. Performing 10 surveys using a non-destructive method was found to explain up to 80% of the species identified by the destructive method. However, considering the difficulty of field investigation, repeating the investigation with non-destructive methods at least 6-7 times is necessary to ensure that more than 60% of the destructive methods can be interpreted. To understand the distribution of oceanic marine algae, performing both destructive and non-destructive surveys are necessary, as each has its own merits and demerits.

• The Korean Journal of Ecology
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• v.19 no.1
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• pp.21-29
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• 1996

Variation in triacylglycerols(TGs) and fatty acids in Fucus serratus was analyzed for a period of one year. TGs were more concentrated during the summer(2.8mg/g dw)and autumn(2.6mg/g dw) than during the spring (0,7mg/g dw)and winter (0.5mg/g dw). The dominant fatty acides in total liqid were palmitic acid ($C_{16:0}$, 24.1%), oleic acid (($C_{18:1}$, 22.4%) and arachidonic acid (($C_{20:4}$, 14.4%) but the dominant ones in TG were $C_{16:0}$(22.8%), $C_{18:1}$(36.4%) and $C_{18:2}$(linoleic acid, 16.4%). The levels of $C_16$ fatty acids were high in winter while $C_18$ in summer and autumn. The polyunsaturated fatty acids (UFAs) were more abundant in the $C_20$ series, while the UFAs of the $C_16$ were low. Especially, the amount of arachidonic acid ($C_{20:4}$, 14.4% of total fatty acids (TFA) was more abundant than that of eicosapentaenoic acid ($C_{20:5}$, 10.4% of TFA). The amount of $C_{20:4}$ and $C_{20:5}$,in TG was 9.2% and 4.8%, respectively. These UFAs in total lipid were thus higher than TG. Therefore, the synthesis of TG and fatty acid was stimulated by the alternation of emersion and submersion of thalli from sea water and eco-physiological conditions during summer: high temperature and light, and low concentration of nitrogen.

• ALGAE
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• v.20 no.2
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• pp.151-155
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• 2005

To obtain basic data, we investigated the effect of blade length on transplants, the transplanting method of Laminaria japonica for creating L. japonica resources and the number of transplanting plates with surviving L. japonica. The survival rate of L. japonica, blade length of transplants and drag force of transplanting plates were also researched. The number of transplanting plates with surviving L. japonica, the survival rate and blade length of 20 cm long-initial transplants were greater than those of 1.5, 5 and 10 cm long-initial transplants in an outdoor aquarium. At the depth of 4 m in the coastal waters, the number of transplanting plates with surviving transplants, the survival rate and the blade length of 30 cm long-initial transplants were higher than those of 10 and 20 cm longinitial transplants. The drag force is calculated by cording up sporophytes of L. japonica into the transplanting plates under water. The drag force in the case of a 2.18 kg-weight transplanting plate and in a current speed of 0.5 m${\cdot}s^{-1}$ for considering stability of the plate was 631.50 g to a concrete substratum on the seabed, 703.92 g to a shingle substratum, 788.00 g to a sand substratum, and 1018.30 g to a silt substratum. If we consider the stability and economic efficiency of the transplanting plate, the proper weight of the plate per one individual of 18.11 cm in blade width and 190.20 cm in total blade length is regarded as 508.2 g when it is calculated with the concrete substratum that shows the lowest drag force.

• ALGAE
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• v.25 no.3
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• pp.141-153
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• 2010

Seagrass epiphyte blooms potentially have important economic and ecological consequences in Tampa Bay, one of the Gulf of Mexico's largest estuaries. As part of a Tampa Bay pilot study to monitor the impact of environmental stresses, precise characterization of epiphyte diversity is required for efficient management of affected resources. Thus, epiphyte diversity may be used as a rational basis for assessment of ecosystem health. In May 2001, epiphytic species encompassing green, brown and red macroalgae were manually collected from dense and sparse seagrass beds of Thalassia testudinum and Syringodium filiforme. A total of 20 macroalgal epiphytes, 2 Chlorophyta, 2 Phaeophyta, and 16 Rhodophyta, were found on T. testudinum and S. filiforme seagrass at the four sampling sites (Bishop Harbor, Cockroach Bay, Feather Sound, and Mariposa Key). The Rhodophyta, represented by 16 species, dominated the numbers of species. Among them, the thin-crusted Hydrolithon farinosum was the most commonly found epiphyte on seagrass leaves. Species number, as well as species frequency of epiphytes, is higher at dense seagrass sites than sparse seagrass sites. Four attachment patterns of epiphytes can be classified according to cortex and rhizoid development: 1) creeping, 2) erect, 3) creeping & erect, and 4) erect & holding. The creeping type is characterized by an encrusting thallus without a rhizoid or holdfast base. Characteristics of the erect type include a filamentous thallus with or without a cortex, and a rhizoid or holdfast base. The creeping and erect type is characterized by a filamentous thallus with a cortex and rhizoid. A filamentous thallus with a cortex, holdfast base, and host holding branch is characteristics of the erect and holdfast attachment type. This study characterized each species found on the seagrass for epiphyte identification.