• Fisheries and Aquatic Sciences
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• 제24권5호
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• pp.197-206
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• 2021

Marine brown seaweeds are a source of functional ingredients with various biological properties. They have been used in the food and functional food industries. Brown seaweeds are divided into three parts of blades, stipe, and root. Normally seaweed blades were used as raw materials for biological research. However, there are limited uses on stipes of Ecklonia maxima (E. maxima) depending on the physicochemical, nutritional, and biological properties. Besides, the comparative studies of two structures of E. maxima, blades and stipe didn't discover previously. This study aimed to compare the potent antioxidant and anti-inflammatory activities of the two structures of E. maxima, blades and stipe in vitro studies to increase the utilization of the two structures of E. maxima. The enzyme-assisted hydrolysate from E. maxima showed significant antioxidant and anti-inflammatory activities. Among them, celluclast-assisted hydrolysate from E. maxima blades (EMBC) and viscozyme-assisted hydrolysate from E. maxima stipe (EMSV) expressed significant protection on hydrogen peroxide-induced oxidative stress. Moreover, EMBC and EMSV treatment remarkably reduced nitric oxide production by downregulation of pro-inflammatory cytokine expressions in lipopolysaccharide-stimulated Raw 264.7 cells. Especially EMBC showed strong inhibition on pro-inflammatory cytokine production compared to EMSV. Taken together research findings suggest that EMBC and EMSV possessed potent antioxidant and anti-inflammatory properties and may be utilized as functional ingredients in the food and functional food sectors.

• 한국수산과학회지
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• 제42권4호
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• pp.354-359
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• 2009

The productivity of ultra-small rotifer, Synchaeta kitina was investigated at the exchange rate of culture water (10, 20, 30, 40 and 50%) and initial inoculation densities (250, 600 and 900 inds. per mL) in semi-continuous culture. Also, the possibility of mass culture was investigated in a 100 L culture tank. Tetraselmis suecica was used as the feed for S. kitina in all experiments. The production of S. kitina increased with an increase in exchange rate of culture water. The highest production ($82.0{\times}10^5$ inds.) was achieved at 40% exchange rate of culture water. The production of S. kitina increased with an increase of initial inoculation density during the first week and the highest total production ($17.4{\times}10^6$ inds.) was achieved at 900 inds. per mL of initial inoculation density. However, on the second week, all treatments were not significantly different in total production (P>0.05). During the two weeks, total production of S. kitina at 900 inds. per mL of initial inoculation density was higher than at 600 inds. of initial inoculation density, but there was no significant difference (P>0.05). In the 100 L culture tank, density of S. kitina was kept from 516 to 890 inds. per mL and S. kitina was daily harvested $15.5{\times}10^6$ to $26.7{\times}10^6$ during the experimental period. The production cost for 100 million rotifers in semi-continuous culture was 63,656 won. The results from this study indicate that the optimal exchange rate of culture water and initial inoculation density for the semi-continuous culture of ultra-small rotifer, S. kitina are 40% and 600 inds. per mL, respectively.

• Fisheries and Aquatic Sciences
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• 제17권1호
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• pp.1-11
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• 2014

The Kenyan aquaculture sector is broadly categorized into freshwater aquaculture and mariculture. Whereas freshwater aquaculture has recorded significant progress over the last decade, the mariculture sector has yet to be fully exploited. The Kenyan aquaculture industry has seen slow growth for decades until recently, when the government-funded Economic Stimulus Program increased fish farming nationwide. Thus far, the program has facilitated the alleviation of poverty, spurred regional development, and led to increased commercial thinking among Kenyan fish farmers. Indeed, national aquaculture production grew from 1,000 MT/y in 2000 (equivalent to 1% of national fish production) to 12,000 MT/y, representing 7% of the national harvest, in 2010. The production is projected to hit 20,000 MT/y, representing 10% of total production and valued at USD 22.5 million over the next 5 years. The dominant aquaculture systems in Kenya include earthen and lined ponds, dams, and tanks distributed across the country. The most commonly farmed fish species are Nile tilapia Oreochromis niloticus, which accounts for about 75% of production, followed by African catfish Clarias gariepinus, which contributes about 21% of aquaculture production. Other species include common carp Cyprinus carpio, rainbow trout Oncorhynchus mykiss, koi carp Cyprinus carpio carpio, and goldfish Carassius auratus. Recently, Kenyan researchers have begun culturing native fish species such as Labeo victorianus and Labeo cylindricus at the National Aquaculture Research Development and Training Centre in Sagana. Apart from limited knowledge of modern aquaculture technology, the Kenyan aquaculture sector still suffers from an inadequate supply of certified quality seed fish and feed, incomprehensive aquaculture policy, and low funding for research. Glaring opportunities in the Kenyan aquaculture industry include the production of live fish food, e.g., Artemia, daphnia and rotifers, marine fish and shellfish larviculture; seaweed farming; cage culture; integrated fish farming; culture of indigenous fish species; and investment in the fish feed industry.

• 한국수소및신에너지학회논문집
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• 제24권1호
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• pp.20-28
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• 2013

Photobiological hydrogen production by nitrogen-fixing unicellular cyanobacteria has long been considered to be an environmentally sound and very promising method for the future supply of renewable clean energy. Using six Korean nitrogen-fixing unicellular cyanobacterial strains and the Synechococcus sp. strain Miami BG043511 we performed cultivation experiments to find out the strain-specific optimal temperature for population growth and $H_2$ production. Under $20^{\circ}C$ the population growth of all the tested strains was significantly retarded in contrasts to the faster and higher growth under 25, 30 or $35^{\circ}C$. The highest growth rates in all the 7 strains were measured under $30^{\circ}C$ while the maximal biomass yields were under $30^{\circ}C$ (strains CB-MAL 026, 054, and 055) or $35^{\circ}C$ (strains 002, 031, 058, and Miami BG043511). The difference between the maximal biomass yields at $30^{\circ}C$ and $35^{\circ}C$ was not greater than 10%. The quantity of photobiologically produced $H_2$ was only slight larger under $35^{\circ}C$ than that under $20^{\circ}C$. Our result may suggest a two-step process of $H_2$ production which includes rapid and sizable production of biomass at $30^{\circ}C$ and the following high $H_2$ production at $20^{\circ}C$ by the test strains of marine nitrogen-fixing unicellular cyanobacteria.

• Fisheries and Aquatic Sciences
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• 제2권1호
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• pp.105-111
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• 1999

In order to produce functional chitin oligosaccharides, a chitinolytic bacterium was newly screened from the viscera of Korean bony fishes, and identified as Bacillus sp. LJ-25. For the production of chitinolytic enzymes, $1.0\%$ nutrient broth and $0.3\%$ colloidal chitin were used as nitrogen and carbon source, respectively. The optimal temperature, initial pH and concentration of NaCl for the enzyme production by Bacillus sp. LJ-25 were $30^{\circ}C$ 6.5-7.0 and $1.0\%$, respectively. The enzyme activity of Bacillus sp. LJ-25 increased until the incubation time of 168 hr, followed by a decrease in activity.

• KSBB Journal
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• 제13권3호
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• pp.303-307
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• 1998

The fermentation conditions for the maximal production of the useful polysaccharides(water soluble polysaccharide and cell bound polysaccharide) from marine bacterium Zoogloea sp.(KCCM 10036) were investigated with a 5 L jar fermentor. The maximal production of these polysaccharides was obtained under the conditions of initial pH 7.8, 30$^{\circ}C$, 400 rpm of agitation speed, 2 Wm of aeration rate, 10%(w/v) of inoculum size and 2.5%(w/v) of glucose substrate and 10.38 g/L of total polysaccharide was produced. Apparent viscosity of the culture broth was increased with the production of these polysaccharides and the maximum value was reached to 22,500 cp.

• 수산해양교육연구
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• 제17권1호
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• pp.115-131
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• 2005

The fishery buy-back programs were studied to analyze fishery production and CPUE. The results from this study during the concerned period can be derived as follows: 1. In total offshore fisheries, CPUE for each boat increased 8.7%, and 8 fishing categories were increased in CPUE for each boat. CPUE for tonnage increased 4.2% in total offshore fisheries field, and 7 fishing categories increased in CPUE for tonnage. In total offshore fisheries, CPUE for HP increased 6.8%, and 8 fishing categories increased in CPUE for HP. 2. The correlation coefficient of the number of fishing boats vs. production and that of the tonnage vs. production were 0.91. This means that there is a strong relation between them. The correlation coefficient of the number of fishing boats vs. CPUE for each boat and that of the tonnage vs. CPUE for tonnage were -0.73 and -0.88 respectively. This reveals that there is a relatively strong reverse relation between them.

• 수산해양교육연구
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• 제28권5호
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• pp.1365-1377
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• 2016

The purpose of this study is to find out by comparing the ability of comprehension and production of causative and passive sentences and grammatical morphemes between multicultural family children and normal children. Fifteen multicultural family children and fifteen normal children aged 7-9 years participated in this study. The results of this study are as follows; First, the children of multicultural family showed significantly a lower ability to comprehension and production of causative and passive sentences compared to normal children. Second, the children of multicultural family showed the difference about the acquisition of grammatical morpheme of causative and passive compared to normal children. Third, multicultural family children and normal children were not statistically significant differences in comprehension and production abilities of causative and passive in accordance with the increase of age.

• 수산경영론집
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• 제44권1호
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• pp.15-24
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• 2013

Recently the Korean court accepts two typies of fisheries damages caused by oil pollution.. One is the direct loss of fisheries production originated from pollution of oil spillover. The other is the indirect loss of fisheries production originated from governmental measure of restricting fishing activities because of safety of marine product of oil spillover areas. The paper tries to suggest the appropriated measure of oil pollution damages of hanging and floating netcage aquaculture fisheries using the court judgement for responsibility restriction on Herbei Spirit Case. The paper tries to compare the damge estimation method of floating netcage aquaculture fisheries with that of natural aquaculture fisheries using conventional theory of the population biology of living resources characterized with age distribution.

• 수산해양교육연구
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• 제27권1호
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• pp.308-318
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• 2015

In order to improve the competitiveness of Korean large purse seine fishery, the purpose of this study is to find out the problems and present the improvement of the production structure of Korean large purse seine fishery by comparing to the production structure of Norwegian purse seine fishery. Norwegian purse seine fishery has been operating labor and energy-saving systems through a single wire operation and avoiding fishing competition through the introduction of IVQ system with different types of fishing vessel and obtaining benefits from Leading fishery management integrated with fish pumps and cooling water systems. In contrast, our country has a large purse seine fishery issues such as high cost and low efficiency of production structures, the volatility of mackerel resources, the lack of leading fishery management after catching fishes, the reduction of fishing ground in accordance with the North East Asia EEZ system. To solve these problems, initiatives to improve the structure of our large purse seine fishery are as follows: First, Implementing the promotion of the effective immature fishes management and establishing Korea-China-Japan resource management system. Second, the promotion of reduction of fleet size, the review of possible single fishing operation, leading out to strengthen its competitiveness by switching to energy-efficient production systems through enhanced efforts at fisheries catches steps. Third, it is necessary to realize corporate through the diversification of business areas and the large-scale commercialization of production structure.