• Journal of Marine Bioscience and Biotechnology
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• v.6 no.1
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• pp.17-25
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• 2014

Periodically, harmful algal blooms (HABs) have occurred, with impacts on various areas including public health, tourism, and aquatic ecosystems, especially aquacultured and caged fisheries. To prevent or manage invasions of HABs into fish farms on an emergency basis, many methods have been proposed. Frequently over the past 30 years in coastal countries, treatments of clay and clay mixed with polyaluminum chloride (PAC) and chitosan have been tested for HAB-removal effectiveness in both the laboratory and the field. In Korea, yellow loess clay (hwangto) has been dispersed using electrolytic clay dispensers, both to decrease the amount of yellow loess clay's usage in containers and enhance HAB-removal efficiency. However, this emergency method has limitations, among which is the requirement for more effective controlling agents for field applications. Thus, in this paper, we review technologies for clay-based red tides prevention and control and their limitations, and, further, introduce next-generation algicidal technologies for the emergency protection of fish farms.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.1
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• pp.1-5
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• 2003

This study was carried out to prepare the depolymerized alginates by physical treatment processing with organic acids. The applied physical treatment methods were autoclaving, microwaving, and ultrasonicating, Among several physical depolymerization methods, autoclaving treatment was the most effective for hydrolyzing the alginate to low molecular compounds such as oligosaccharides. Citrate was most effective catalyst in hydrolyzing alginate to some oligosaccharides among organic acids. An acceptable autoclaving conditions for hydrolyzing alginate to oligosaccharides were to treat at $110^{\circ}C$ for 90 min and $120^{\circ}C$ for 60 min, respectively. The maximum depolymerization percentage produced by autoclaving was $56.8\%$. The depolymerized alginates prepared by autoclaving at $110^{\circ}C\;and\;120^{\circ}C$ has oligosaccharides of $3\~4 $and $7\~8$ species, respectively. The optimum condition for alginate oligosaccarides was autoclaving treatment with $0.5\%$ citrate solution at $120^{\circ}C$ for 90 min.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.834-840
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• 2019

Recently, due to increased tourism and leisure activities, falls by fishers from coastal wave-dissipating blocks (breakwaters) in Korea have been rising. We investigated the optimal mesh size for use in safety nets designed to cover Tetrapod (TTP) breakwaters to prevent casualties from falls. This is a prerequisite for considering the scale and economics of safety net facilities. The optimal mesh size was determined based on the fisher gender and age, and the bodily features of Koreans. The optimal mesh size was found to be 18.6-27.0 cm, derived based on the femoral length and chest circumference.

• Proceedings of the Fisheries Business Administration Society of Korea Conference
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• 2007.06a
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• pp.133-158
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• 2007

This study aims at analyzing the potential of leports-fishing for improving fishing household income. Leports-fishing is a composite concept which is combined with those of leisure, sports and fishing. Korean on-shore resources have also a composite characteristic. The characteristics of the east, west and south coastal waters are quite different in geography, biology and ecology. There is a array of leports-fishing development potentials of utilizing their characteristics. At present, angling forms a main activity of leports-fishing, but coastal seas would be an emerging space for the public. In order for them to be a ground of fun, enjoyment and festivals, there would be necessary to supply a wide range of activities including angling, scuba diving, fish barbecue, ecological experience, fishing experience, cruise, and so forth. As seen in the survey results, the participants have strong desire for fun and enjoyment through leports-fishing activities. The proportion of people participating in one or two times a year amounts to 40 percent. Most coastal places visited are close to medium/large cities and two-days leports-fishing/ tourism accounts for some 77 percent. However, it is shown that conflicts between leports-fishing participants and fishermen are not serious. The results of expenditure function estimation appear that the elasticity of per capita income is very high with 1.2660 and that there are negative relationships between leports-fishing expenditure and transportation/food/lodging costs. Assuming the economic growth rate of 4 percent, it is anticipated that Korean leports-fishing population will increase to 3.18 million in 2010 and 4.07 million in 2015. Korean leports-fishing market potential in 2015, which is calculated based on per capita expenditure on leports-fishing appeared to be 1,400 billion won$\sim$1,600 billion won. The contribution of such market potential is expected to be 62.3$\sim$74.2 percent(934.5 billion won$\sim$111.3 billion won) to the fishing households.

• Fisheries and Aquatic Sciences
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• v.6 no.3
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• pp.140-148
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• 2003

On the basis of factor analysis, stations were grouped according to their similar characteristics of seawater quality. The data for factor analysis were collected from the 15 stations from Dukryang Bay to Ulsan Bay on the southern cost of Korea. The study was based on the data from 1991 to 2000. The 8 water quality items analyzed were temperature, salinity, pH, DO, COD, DIN (dissolved inorganic nitrogen), DIP (dissolved inorganic phosphorus), and SS (suspended solid). Analysis of 6 water quality items including DO with the exception of temperature and salinity showed that 15 stations were grouped into two zones, i.e., the western and the eastern coast, by the axis of Samcheonpo-Jinju Bay-south of Geoje, 3 seawater zones in all. The adjacent stations to the southward or northward but not those to the eastward or westward were classified into the same group. On the analysis of all of the 8 water quality items, the stations of Dukryang Bay and Goheung; and those of Onsan and Ulsan Bay were classified into the same group. Yeosu and Namhae stations were sectioned into 1 group on the all seawater quality items but DIP, Samcheonpo and south of Geoje stations another group on all seawater quality items but water temperature, and Masan and Busan stations in the other group on all seawater quality items but DO. The stations from Dukryang Bay through Goheung to east of Geoje were grouped together on the COD item, and this showed somewhat different tendency in other seawater quality items.

• Journal of Marine Life Science
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• v.8 no.1
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• pp.68-77
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• 2023

In this study, we investigated the quantitative distribution of microplastics in the surface seawater at 8 points near the Taean Peninsula using fluorescence staining. The study revealed a detection range of microplastics from 0 to 360.5 particles/l, with an average of 149.7 ± 46.0 particles/l. When classifying the microplastics by size, it was found that particles smaller than 50 ㎛ were dominant, although there were differences at Site 3. Moreover, it was not possible to identify clear correlations when comparing the number of microplastics based on collection area and particle size. Various physical and chemical factors, including plastic material, dynamic ocean conditions (such as currents, wind, waves, tides), geological characteristics (topography, slope), sediment materials including coastal organisms, human activities (fishing, development, tourism), and weather conditions (floods, rainfall), affect the behavior of microplastics. Therefore, future efforts should focus on standardizing quantitative analysis methods and conducting fundamental research on microplastic monitoring, including the analysis of environmental factors.

• Journal of the Korean association of regional geographers
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• v.10 no.1
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• pp.177-191
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• 2004

Monitoring has been done for the shingle beach in Hagdong Beach in Geojesi, City during the seven month period. The shingle beach has been found to go through the cyclic change according to the tidal schedule. The typhoon Rusa in year 2002 affected whole beach face. Sea wall, constructed to protect the village along the beach, aggravates the situation, since it cut off the supply of shingle from the marine terrace, upon which village was built. Concrete walls along the streams also diminish the supply of shingles from the mountains. To protect the shingle beach and encourage the sustainable eco-tourism long-term monitoring on sediment budget is necessary.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.1
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• pp.6-10
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• 2003

The optimum organic acid and temperature conditions were investigated for the preparation of oligosaccharides from agar. The tested organic acids were acetate, citrate, lactate, malate, and succinate and the conditions for oligosaccharides preparation were $0.3\%,\;0.5%;and\;0.7\%$ organic acid concentrations at $80\~120^{\circ}C.$ The low concentration of organic acid below $0.3\%$ decreased the degrading ratio and the high concentration up $0.5\%$ could not changed the degrading ratio. Conditions below $100^{\circ}C$ was not good for degrading agar. But $100^{\circ}C\;or\;120^{\circ}C$ was optimal temperature conditions for agarooligosaccharides according to the organic acid type and concentration. The organic acid concentration was $0.5\%$ and organic acid was the citrate or malate. The treatment time considered optimum was 120$\~$180 min. The maximal degrading ratio giving optimum conditions such as $100^{\circ}C\;and\;120^{\circ}C\;was\;35.5\%\;and\;38.7\%,$ respectively. The agarooligosaccharides prepared by autoclaving at $100^{\circ}C\;and\;120^{\circ}C$ were 2$\~$7 species oligomer.

• Korean Journal of Ichthyology
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• v.32 no.3
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• pp.160-165
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• 2020

Seasonal fluctuation in abundance and species composition of fish in coastal waters off Samcheonpo were investigated using seasonal samples collected by a beam trawl in 2019 to compare the variation of species composition and dominant species with previous studies. A total of 6,518 fish were sampled and classified into 44 species, 30 families, and 6 orders. The dominant species were Nuchequula nuchalis (1,542 individuals, 23.7%), Platycephalus indicus (529 individuals, 8.1%), Thryssa kammalensis (437 individuals, 6.7%), Argyrosomus argentatus (403 individuals, 6.2%), and Acanthogobius flavimanus (354 individuals, 5.4%). The highest number of individuals was found in July (2,385 individuals), while the lowest number of individuals was found in January (925 individuals). The diversity index was the highest in April (H'=2.733) and the lowest in July (H'=2.546).

• Proceedings of KOSOMES biannual meeting
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• 2004.05b
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• pp.43-48
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• 2004

The development of the traffic system has brought relative reduction in aspect of the cost and time distance on the geographical space. SOC(social overhead capital), an express highway and railroad, has a great and absolute effect on the prosperity of community, As Mokpo is one of the community under the influence q West costal highway express and KTX(Korea Train Express), the number of the tourists visiting city of port like Mokpo has increasing gradually, especially at the high-demand season(in Summer). But the coastal passenger boot can't be capable of customers arriving at the port. As a result of this situation, the 'balking' occurs. No 'balking', means the jam of road. In this thesis, by understanding the concept and property of ARENA and simulating operation of coastal passenger boot at Mokpo port, intends to analyze the truth of 'balking' and finds an effective operation method of coastal passenger boot for the solution to the traffic jam. The solution to the jam in the vicinity of port of Mokpo, which try to develop tourism package commodity now, will present the effect of qualitative analysis in giving an opportunity of economic growth of the community, Mokpo.