• Journal of Korea Port Economic Association
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• v.31 no.4
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• pp.53-73
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• 2015

This study analyzes the economic impact of the shipping and port logistics industry in Gwangyang Bay Area on the regional economy. For this purpose, the study constructs an input-output table of 29 sectors for 2010 in the area. The main findings are as follows. In terms of production, value added, and share of employment, the regional shipping and port logistics industry accounts for approximately 10.8 percent, 6.0 percent, and 2.9 percent of the national shipping and port logistics industry, respectively. Moreover, the economic impact of the industry on the regional economy is estimated to be an increase in terms of production of about 6 trillion Korean won), to be an increase in value added of about 2.5 million Korean won, and an increase of about 16,000 in employment. Furthermore, the industry is found to have strong inter-industry linkages with the main manufacturing as well as the main producer service industries.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.3
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• pp.113-123
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• 2008

We have analyzed a long term data of marine environments, red tide information and meteorology acquired by NFRDI and KMA, in order to understand the characteristics of marine environments in the Narodo coastal waters which is known to be the first outbreak region of Cochlodinium polykrikoides blooms. During the period of from 1992 to 2007, Cochlodinium polykrikoides blooms have first occurred more often in August. However, the outbreak time of the blooms tended to be earlier annually, and in addition, the surface salinity also had a tendency to increase. Consequently, it suggested that there might be a relationship between the transition of the outbreak time of the blooms and salinity. On the other hand, insolation was relatively rich but precipitation was relatively scarce in Gohung Province, compared to Yeosu or Tongyeong, when Cochlodinium polykrikoides blooms first occur in Narodo coastal waters. Average water temperature and salinity in August in Narodo coastal waters were all higher than those in Gamak and Jinhae bays, suggesting that Narodo coastal waters are a region of relatively high water temperature and high salinity. Also, concentrations of nutrients and chlorophyll- a were significantly low than those in Jinhae Bay, which is known to be a eutrophicated region, while the overall water quality seemed to be similar to Gamak Bay. The results of PCA(Principal Component Analysis) proved that insolation and water temperature are the most important factors for the outbreak of Cochlodinium polykrikoides blooms in Narodo coastal waters while concentrations of COD and dissolved oxygen are secondly important. Furthermore, typhoons also appeared to be one of most important factors for the outbreak of Cochlodinium polykrikoides blooms.

• The Korean Journal of Malacology
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• v.28 no.1
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• pp.73-79
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• 2012

Seasonal changes in biochemical composition of muscle, gonad-viceral, mass and whole body of the cultured ark shell, Scapharca broughtonii in the Gamag bay of Yeosu city were studied from December 2008 to November 2009 in relation to environmental condition and reproductive cycles. Average monthly water temperature in the winter was in the range of $7-12^{\circ}C$ and $20-25^{\circ}C$ in the summer, while the salinity fluctuated in the range of 30.1%-33.8‰ on the average. Seasonal fluctuation of the concentration of nutrient salt was the highest in September ($13.04{\mu}g/L$) with average annual concentration of $4.6{\mu}g/L$. The main spawning season of the ark shell was during the months of July and August, and the gonads were in inactive stage during the winter. The gonad-visceral mass contained lower amounts of proteins than the other body parts. The most marked changes in body composition were lipids and carbohydrates within the gonad-visceral mass, and protein for each of the organs was relatively consistent throughout the year. All the parts in the visceral sac displayed the highest changes during the gametogenic cycle while the contents of moisture and lipid within the visceral act displayed somewhat inverse relations with each other. Moisture content was the lowest during the inactive stage during which the lipid content is the highest. The lipid content was the lowest immediately following spawning with increase in the moisture content as the lipid is being consumed. Protein mass within the visceral sac was low in comparison to the muscle mass. It is deemed that carbohydrates, lipids and proteins in the visceral sac play the major role as the source of energy during the development process of the gonads, and used for maintenance of base metabolism when available food is scarce.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.3
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• pp.785-798
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• 2017

This study was conducted to evaluated the surface(10 variables) and bottom(10 variables) water quality, and sediment(3 variables) in the cage fish farm off Baegyado in Gamak Bay using a multivariate analysis from January 2013 to November 2014. Generally, the environmental data did not show a certain tendency by months during two years investigated. The pairwise simple correlation matrices among variables were also shown. The first four principal components of the surface water in 2013 explain 93% of the total sample variance; the first principal component($z_1$) showed the freshwater inflow and/or precipitation, $z_2$, $z_3$ and $z_4$ related to freshwater inflow and/or precipitation, organic matters and eutrophy, respectively; the first four principal components of the bottom water in 2013 explain 93% of the total sample variance; the $z_1$, $z_2$ and $z_4$ related to freshwater inflow and/or precipitation, and $z_3$ water temperature. In 2014, at the surface water the first three principal components explain 87%; the $z_1$, $z_2$ and $z_3$ related to water temperature, eutrophy and freshwater inflow and/or precipitation, respectively; at the bottom water the first three principal components explain 93%; $z_1$, $z_2$ and $z_3$ related to water temperature, freshwater inflow and/or precipitation and eutrophy. Half of the principal components related to freshwater inflow and/or precipitation.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.3
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• pp.58-66
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• 2006

Environmental Sensitivity Index Map(ESI Map) is useful information for efficient and prompt contolling of oil spill accident. Environmental sensitivity information relating to oil spill is very various, so efficient access and utilization for environmental sensitivity information at control field is required. In order to improve the efficiency of controlling accident at the field, it is necessary to building digital ESI Map and GIS program. In this study, GIS database was built to utilize environmental sensitivity information at Yeosu and Gyunggi bay. And the ESI Map program which is focused on the control job was developed. IMO/IPIECA's guide to make the ESI Map and Korea Coast Guard's guide to collect information for the control information map were referenced to capture environmental sensitivity data and build GIS database. The symbology of environmental sensitivity layers was defined and functions for supporting control job were implemented in ESI Map program. For the future works, the program in this study could be applied to ESI Map program for the whole coastal area of Korea and it could be the essential element technology in marine pollution control supporting system.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.3
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• pp.225-231
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• 2004

The power and scale of 950 hPa typhoon "Maemi" which struck the shore of Gosung in Kyungnam Province was same as that of 951 hPa typhoon "Saraho" in 1959. For the purpose of getting the safety of training ship "KAYA", we anchored at Jinhae Bay with riding at two anchors paid out 8 shackles of cable respectively. By the way when wind force being over 30m/s, we could not keep the safety of the ship "KAYA" by means of the holding power of an anchor only. Just by using the main engine moderately, we were able to maintain the security of the ship. The holding the main engine moderately, we were able to maintain the security of the ship. The holding power of an anchor according to the way of anchoring, the quality of sea bottom, the direction and speed of wind and current, and the length of an anchor cable were analyzed. The obtained results are summarized as follows : 1. When riding at two anchors rather than lying at single anchor we could get a good holding power. 2. There was a big difference in holding power according to the quality of the bottom. 3. It would be best anchoring in a soft mud area than in any other place as possible. 4. It would also be desirable to set anchor shackles much more than equipment number prescribed in regulation in order to get safety of a ship providing against typhoon.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.691-696
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• 2001

The first bloom of Cochlodinium polykrikoides was observed in the estuary of Nak-dong river near Pusan in Korea in 1982. Since then, there have been irregular blooms, sometimes spread over the adjoining .to Jinhae Bay even though it was confined to the bay and its vicinites until 1988. It had been outbroken frequently in the adjacent to Tongyeong, Geoje, Namhae and Yeosu coast since 1989. It became widespread along the coast of the South Sea to the East Sea of Korea in 1995. And in October in 1998 and 1999, the bloom had been taken place in Kunsan coast of Yellow Sea. According to the observations in situ, the frequency of occurrence has been increased year by year. The prevailing bloom season was from July to October with peak in September. The duration of the bloom became longer with the year, and sometimes lasted more than one month. The density of the bloom did not exceed 5,000 cells $mL^{-1}$until 1991, but it increased year by year to the highest of 43,000 cells $mL^{-1}$ in 1999. With respect to the assembleges of species in dinoflagellate blooms, C. polykrikoides was one of the important species with diatoms and the other dinoflagellates in 1980s. But since then, C. polykrikoides made an almost monospecific bloom. Based on two decadal observations of C. polykrikoides blooms, it became widespread throughout whole coast of the Korea, persistent for about one or two month long in some year, and monospecisc high density blooms. It was reported that significant fish mortalities were caused by this harmful dinoflagellate blooms especially in the fishfarms accomodating intensive fish cages such as Tongyeong, Namhae-do, Geoje, Yeosu and Geomun-do fishfarming yards. This widespread and persistent harmful algal blooms impede the development of marine aquaculture industries.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.1 s.28
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• pp.9-20
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• 2007

PAHs(Polycyclic Aromatic Hydrocarbons) are widespread contaminants in the marine environment. They are of mainly anthropogenic origin from urban runoff, oil spill and combustion of fossil fuels. Some PAHs are potentially carcinogenic and mutagenic to aquatic organism The contamination of PAHs in the coastal environments has not been well known yet in Korea. This study was carried out to survey the contamination of PAHs in sediments around Gwangyang bay. The Yeosu petrochemical industrial complex, POSCO(Pohang steel company) and Gwangyang container harbor are located around the bay. PAHs in sediment samples were extracted in soxhlet extractor and were identified and quantified by GC-MS(Gas Chromatography-Mass Spectrometry) TOC(Total Organic carbon) and textural parameters in sediment samples were also analyzed 13 species of PAHs were detected at all of the surface sediments. Total PAHs concentrations in the surface sediments ranged from 171.40 to $1013.54{\mu}g/kg$ dry wt.. In most of the surface sediments, Naphthalene was the highest in the range of 14.08 to $691.39{\mu}g/kg$ dry wt. and Anthracene was the lowest in the range of 0.49 to $22.66{\mu}g/kg$ dry wt.. The correlation coefficients between individual PAHs and Total PAHs in the surface sediments were relatively higher in the low molecular compounds such as Naphthalene and Phenanthrene. In the relationship of the P/A(Phenanthrene/Anthracene) ratio and F/P(Fluoranthene/Pyrene) ratio, P/A ratio was generally above 10 and F/P ratio was shown to be above 1 in all sediment samples. These data indicate that PAHs in sediments around Gwangyang bay seem to be of both pyrolytic and petrogenic origin. Total PAHs in the surface sediments were correlated with TOC and textural parameters. The values of PAHs in the surface and core sediments were lower than the biological effect guidelines.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.1
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• pp.1-8
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• 2005

In order to find out the environmental factors influencing movement of common grey mullet, Mugil cephalus in funnel net fishing ground of the Dolsan-do, Yeosu southern sea area, the oceanographic factor such as the water temperature, isobath and tidal current were observed respectively, the water temperature was compared with the amount of common grey mullet caught by funnel net. Also, to investigate the movement direction of common grey mullet in same sea area, 160 common grey mullets of body length 22 to 51cm caught at funnel nets of the Dolsan-do southern sea area were marked and then released at 5 positions in 5 times. The results obtained are summarized as follows : 1. The water temperature at the funnel net fishing ground of Dolsan-do in 2002 was ranged from 6.9 to 27.4$^{\circ}C$. The water temperature was displayed a maximum value in August to increase from March and a minimum value in February of the ensuing year to decrease from September. The catches of gray mullet caught by funnel net were generally abundant from March to September, but decreased sharply from October. The optimum range of water temperature for the funnel nets fishing was situated between 15.0 to 25.0$^{\circ}C$. 2. The isobath from 6m to 13m in coast sea set up funnel nets were densely distributed and the depth more than 14m of isobath were widely spreaded to the open sea at Dolsan-do southern sea area. 3. The tidal current of the coast sea set up funnel nets flowed southward and northward along the coast ato ebb and flood tide respectively. The direction of tidal current to the open sea was southeast at ebb tide with the mean speed 43cm/sec, but northwest at flood with the mean speed 25cm/sec. 4. The recapture rate through the experiment duration showed 9.4%. The recapture rate in Gyedong area was very high value with 33.3% as compared with others. The movement of common grey mullet in Dolsan-do southern sea area trended toward a inner bay and north bound mainly.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.5
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• pp.523-530
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• 2020

Based on the results of harmful algal blooms (HABs) monitoring by the National Institute of Fisheries Science and local governments, the effects of changes in the marine environment on HABs are described. Since the beginning of HABs monitoring in 1972, they continued to increase from the 1980s to the 1990s. After the largest number of HAB incidents (109) in 1998; the trend declined until the 2010s. Most HABs in the 1970s were caused by diatoms. In the 1980s, coastal dinoflagellates caused HABs; Cochlodinium polykrikoides blooms have been occurring continuously since 1993. There are three HAB species that cause damage to fisheries in Korea. The high-density bloom of Karenia mikimotoi caused mass mortality in shellfish in Jinhae Bay in 1981. Karenia sp. blooms occurring around Tongyeong in 1992 killed aquaculture fish. Since the occurrence of the largest fisheries damage of KRW 76.6 billion in 1995 caused by C. polykrikoides blooms, they have been occurring continuously. The concentration of nutrients in coastal waters was the highest in the 1980s and has declined since the mid-1990s. This reduction in nutrient concentration is a good explanation for the decreasing number of HABs. Since 2016, a summer high water temperature of 30℃ or more has appeared, and the range and scale of C. polykrikoides blooms have been greatly reduced. In 2016, K. mikimotoi blooms occurred around Wando, Jangheung and Goheung and small scale blooms of C. polykrikoides occurred around Yeosu. There were no C. polykrikoides blooms in 2017; however, Alexandrium affine blooms occurred from Yeosu to Tongyeong. There was a small-scale blooms of C. polykrikoides in 2018 compared to those in the previous years. Our results show that reduction in nutrients and the high water temperature owing to climate change are a good explanation for variation in HABs in Korean coastal waters.