• ALGAE
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• v.17 no.3
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• pp.187-194
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• 2002

A seaweed biofilter/production system of being developed to reduce the environmental impact of marine fish farm effluent in coastal ecosystems as a part of an integrated aquaculture system. Several known seaweed taxa and their cultivars have been considered as candidate biofilter organisms based on their species-specific physiological properties such as nutrient uptake kinetics and their economic value. Porphyra is an excellent cadidate and shows efficient nutrient extraction properties. Rates of ammonium uptake were maintained at around 3 ${\mu}moles{\cdot}g{\cdot}dw^{-1}{\cdot}min^{-1}$ at 150 ${\mu}M$ inorganic nitrogen at $10^{\circ}C$. Ulva is another possible biofilter candidate with an uptake rate of 1.9 ${\mu}moles{\cdot}g{\cdot}dw^{-1}{\cdot}min^{-1}$ under same conditions. A simple uptake/growth and harvest model was applied to estimate the efficiency of the biofilter/production system. The model was deterministic and used a compartment model structure based on difference equations. The efficiency of Porpyra filter was estimated over 17% of ${NH_4}^+$ removal from the contimuous supply of 100 ${\mu}mole{\cdot}l^{-1}\;{NH_4}^+\;at\;100l{\cdot}sec^{-1}$ flow rate.

• The Journal of Fisheries Business Administration
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• v.50 no.4
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• pp.1-9
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• 2019

Seaweed by-products have been dumped into the sea and induced marine pollution. However, they can be recycled as a valuable natural resources. Approximately 240,000 tons of sea mustard and kelp by-products were estimated to be producted during the last three years. The estimate corresponds 6.7% of the total production of marine aquaculture and 14.9% of the total production of seaweeds. When adding up the by-products from fish and mollusks, approximately 1,000,000 tons of fisheries by-products were thrown out into the sea every year. A three-step strategy is required for the industralization of fisheries by-products. The first step is the construction of the processing foundation of by-products, the second is its food industralization, and the third is its recycling as raw biomaterials. The stable supply of raw materials is the prerequisite for the industralization. Thus, it is necessary to construct the refuse logistics around chief production districts and to build the processing facility and frozen storage of by-products. Cooperation among private enterprises and government investment for research and development is required the second and third steps.

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.193-199
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• 2012

We performed qualitative and quantitative surveys on the distribution of seaweed species and dominant species with their standing crop and temporal variations in Hauido tidal flats in order to understand the role of seaweeds in a coastal wetland ecological system that may be used for conservation and management of coastal wetland ecological system. A total of 9 species were found at 7 stations of the study area; 4 species of Chlorophyta (Ulva compressa, U. prolifera, U. pertusa and Ulothrix flacca), 3 species of Phaeophyta (Ectocarpus arctus, Scytosiphon lomentaria and Myelophycus simplex) and 2 species of Rhodophyta (Gracilaria verrucosa and Caulacanthus okamurae). Major dominant species were U. compressa, U. prolifera and U. pertusa (Chlorophyta), Scytosiphon lomentaria (Phaeophyta) and Gracilaria verrucosa (Rhodophyta). Standing crops of U. compressa and U. prolifera were $2.94{\sim}45.25g{\cdot}dw{\cdot}m^{-2}$ and $6.19{\sim}91.9g{\cdot}dw{\cdot}m^{-2}$, respectively, in spring. Seaweed habitat was characterized by textural differences that the percentage of coarse particles and organic material were a little higher in seaweed flourishing areas than in seaweed barren areas.

• ALGAE
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• v.21 no.3
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• pp.305-310
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• 2006

Succession of artificial seaweed communities in an artificial iron reef at Ikata, southern Japan was studied based on monthly or bimonthly observations from February 1999 to August 2000. Communities were associated with different substrata (40 cm x 60 cm: steel, concrete, wood and stone) as the cover on artificial iron reefs (4.5 m x 4.1 m x 2.5 m, 45.38 m3 and 3.2 ton), which were placed on a sandy substratum at 8 m depth. Within one month diatoms dominated on all substrata with cover of approximately 100%. Enteromorpha intestinalis and Colpomenia sinuosa dominated on the reef within three months after the placement in the spring. Seaweed communities on the reef decreased during the summer. In the winter, the seaweeds on the reef recovered. Sargassum spp., Ecklonia kurome and Padina arborescens dominated on each substratum after one year. Seaweed communities on the artificial reef were similar to those on the rocky substratum around the artificial reef and also similar on different substrata covering the iron artificial reef. These results indicate that seaweed succession was impacted by season and the recruitment of spores and propagules from mature algae around the artificial reefs.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.272-272
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• 2017

• ALGAE
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• v.32 no.1
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• pp.1-13
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• 2017

Seaweed aquaculture technologies have developed dramatically over the past 70 years mostly in Asia and more recently in Americas and Europe. However, there are still many challenges to overcome with respect to the science and to social acceptability. The challenges include the development of strains with thermo-tolerance, disease resistance, fast growth, high concentration of desired molecules, the reduction of fouling organisms and the development of more robust and cost efficient farm systems that can withstand storm events in offshore environments. It is also important to note that seaweed aquaculture provides ecosystem services, which improve conditions of the coastal waters for the benefit of other living organisms and the environment. The ecosystem services role of seaweed aquaculture and its economic value will also be quantitatively estimated in this review.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.5
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• pp.571-578
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• 2018

Seasonal variability in algal community structure of the subtidal zone was examined at four study sites on the southeastern coast of Korea from February to November 2016. A total of 81 species of algae (8 green, 12 brown, and 61 red) were indentified. During the study period, the greatest number of species was observed at Sinamri (57 species) followed by Daesongri (50 species), Dongbaekri (47 species) and Gangyangri (42 species). Of the six functional seaweed forms, the coarsely-branched form was the most dominant, accounting for about 43% of the total species at Daesongri. The annual average biomass in wet weight varied from $700.59g/m^2$ at Sinamri to $1,712.45g/m^2$ at Daesongri. The parameters of seaweed community structures were as follows: dominance index (DI), 0.30-0.54; richness index (R), 4.92-7.05; evenness index (J'), 0.54-0.72; and diversity index (H'), 2.05-2.91.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.232-233
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• 2002

In recent years devastation on coasts worldwide has led to barren grounds resulting in the loss of the natural population of many marine organisms and macrophytes. Furthermore, fishery resources such as abalone, fish and seaweeds have been depleted (Serisawa and Ohno, 1995). Since 1980, many fishery scientists and phycologists have tried to create artificial seaweed beds using various technique in order to recover lost seaweed beds (Ohno, 1993; Choi et al., 2000). (omitted)

• ALGAE
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• v.20 no.2
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• pp.121-125
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• 2005

The modern integrated fish-seaweed mariculture has been tested to reduce the environmental impacts of an intensive fed culture. To obtain the best seaweed bioremediation performance, the effects of therapeutants used for fish disease control on the selected seaweed species should be considered. As a selected seaweed, Porphyra yezoensis was tested with six commercial antibiotics including erythromycin thiocyanate_A, erythromycin thiocyanate_B, oxytetracycline, doxycycline, pefloxacin, and amoxicillin trihydrate under the batch incubation at a photon flux density of 10 $\mu$mol ${\cdot}m^{-2}\;{\cdot}\;s^{-1}$ at 15$^{\circ}C$. Among the tested commercial antibiotics, erythromycin thiocyanate_A, erythromycin thiocyanate_B, oxytetracycline, and doxycycline showed decreases in Fv/Fm, the photochemical efficiency of photosystem II, with a dose-dependant and time-dependant manner. From the quenching analysis of chlorophyll fluorescence, three differential patterns were observed in the antibiotics-treated Porphyra: (1) high nonphotochemical quenching (NPQ) and low photochemical quenching (qP) in the cases of Erythromycin thiocyanate_B and amoxicillin trihydrate, (2) high NPQ and high qP in the case of pefloxacin and (3) low NPQ and low qP in the case of oxytetracycline. These results indicated that antibiotics affected in various ways on the photosynthetic apparatus, reflecting differential lesion sites of antibiotics. In addition, the rates of ammonium uptake also decreased with a decrease of Fv/Fm in P. yezoensis thalli treated with erythromycin thiocyanate_B and oxytetracycline. Therefore, the four antibiotics mentioned could affect the bioremediation capacity of the selected seaweed species in the integrated fish-seaweed mariculture system due to the decrease of photosynthetic activity and the simultaneous decrease of ammonium uptake.

• ALGAE
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• v.27 no.3
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• pp.205-213
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• 2012

The thermostability of antioxidant activity of dieckol, a phlorotannin isolated from brown seaweed Ecklonia cava was investigated. The thermostable antioxidant properties of dieckol were evaluated at 30, 60, and $90^{\circ}C$ for 7 days using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical scavenging activities, and comparing its performance to that of ascorbic acid. The intracellular reactive oxygen species (ROS) scavenging activity and apoptotic body formation were investigated using DCF-DA assay and nuclear staining with Hoechst 33342, propidium iodide and flow cytometry. Dieckol treated at different temperatures during 7 days showed stable scavenging activities on towards DPPH and hydroxyl radicals. In addition, dieckol showed a stable protective effect against $H_2O_2$-induced apoptotic body formation in Vero cells. On the other hand, the radical scavenging activities and intracellular ROS scavenging activities of ascorbic acid, used as a positive control, were significantly decreased at $60^{\circ}C$ and $90^{\circ}C$ from on the 4th day and 3rd days, respectively. In conclusion, the results indicated that food grade antioxidant extracts containing dieckol derived from E. cava remain a stable during the temperatures encountered during the processing of food and cosmetics.