Jinju Bay Research Articles

Chemical recovery of a fish farm in Jinju Bay of South Korea after cessation of long-term fish farming

The development of aquaculture technology has led to significant increases in aquaculture production, which has deteriorated the coastal environment. This study is the first to conduct sedimentary environment recovery monitoring of an aquaculture environment using chemical indicators in a fallow fish farm in South Korea. The total organic carbon concentration in the surface sediments (≤2 cm) decreased to the control level within 1 year; the acid volatile sulfide concentration was not recovered for 3 years and 10 months. Nutrient and sulfide concentrations were high in deep sediments (≤15 cm) because of continuous fish farming for over 20 years and accumulation of organic matter beneath the cages. Complete chemical recovery of this study area may take a longer time than previously anticipated. Overall, this study provides significant insights for implementing coastal management plans and estimating adequate fallowing periods during long-term fish farming.

Distribution Rate of Particles Exiting Jinju Bay in the Namgang Dam Freshwater Discharge

Distribution Rate of Particles Exiting Jinju Bay in the Namgang Dam Freshwater Discharge

Impact of dynamic factors on the exchange flow between two neighboring bays with contrasting topography during summer: A numerical study

A high-resolution, three-dimensional numerical ocean model was employed to understand the exchange flow through Noryang Channel, which connects Gwangyang Bay and Jinju Bay. These two bays exhibit contrasting topographies, with Gwangyang Bay connected to the open ocean through a broad and deep channel, whereas Jinju Bay is relatively isolated from the open ocean by a narrow and shallow channel. Numerical experiments were conducted to determine the contribution of river discharge, wind stress, surface heat flux, and tides to the exchange flow between the two bays during summer. The results suggested that river discharge was the dominant factor affecting the exchange flow along Noryang Channel. Particularly, a high river discharge during summer increased the sea level in Jinju Bay, creating a barotropic flow toward Gwangyang Bay. However, the dense water entering Gwangyang Bay through the wide and deep channel generated a baroclinic flow toward Jinju Bay along the lower layer of Noryang Channel. An analytical model supported the conclusion that river discharge is the main driver of the exchange flow in Noryang Channel.

진주교방문화 콘텐츠 연구

In this paper, focusing on the case of Hanamachi in Kyoto, Japan, we considered how to revitalize Gyobang cultural contents in Jinju-si. Hanamachi in Kyoto is a place where geisha actually exist, and it is a successful example of historical and cultural content where the culture of the Edo period continues to the modern day. Through the case of Hanamachi in Kyoto, which is the most active among the remaining Hanamachi in Japan, we sought ways to revitalize various Gyobang cultural contents owned by Jinju. To this end, Jinju Gyobang cultural contents were classified into person content, place content, and food content. As a result, Jinju's Gyobang Cultural Content is a local specialized resource and has a very high possibility of developing tourism content. Jinju is currently a UNESCO creative city recognized for its historical and traditional characteristics of culture and art. With these points as assets, Jinju City can use Gyobang culture as a traditional cultural tourism resource in Jinju Bay by linking it with various contents of Jinju, just as Kyoto in Japan continues the tradition of geisha culture as a historical and cultural content by utilizing tourist attractions around Hanamachi. To this end, above all, Jinju citizens’ firm will to revitalize the culture of Jinju Gyobang should be the basis.

Variations in food resource usage among eight fish species inhabiting inside and outside Jinju Bay, Korea

Variations in food resource usage among eight fish species inhabiting inside and outside Jinju Bay, Korea

Characteristics of Sea Exchange in Gwangyang Bay and Jinju Bay considering Freshwater from Rivers

Characteristics of Sea Exchange in Gwangyang Bay and Jinju Bay considering Freshwater from Rivers

Phosphorus Dynamics Associated With Organic Carbon Mineralization by Reduction of Sulfate and Iron in Sediment Exposed to Fish Farming

The expansion of the aquaculture industry has resulted in accumulation of phosphorus (P)-rich organic matter via uneaten fish feed. To elucidate the impact of fish farming on P dynamics, P speciation, and benthic P release along with partitioning of organic carbon (Corg) mineralization coupled to sulfate reduction (SR) and iron reduction (FeR) were investigated in the sediments from Jinju Bay, off the southern coast of South Korea, in July 2013. SR in the farm sediment was 6.9-fold higher than the control sediment, and depth-integrated (0–10 cm) concentrations of NH4+, PO43–, and H2S in pore water of the farm sediment were 2.2-, 3.3-, and 7.4-fold higher than that in control sediment, respectively. High biogenic-P that comprised 28% of total P directly reflected the impact of P-rich fish feed, which ultimately enhanced the bioavailability (58% of total P) of P in the surface sediment of the farm site. In the farm sediment where SR dominated Corg mineralization, H2S oxidation coupled to the reduction of FeOOH stimulated release of P bound to iron oxide, which resulted in high regeneration efficiency (85%) of P in farm sediments. Enhanced P desorption from FeOOH was responsible for the increase in authigenic-P and benthic P flux. Authigenic-P comprised 33% of total P, and benthic P flux to the overlying water column accounted for approximately 800% of the P required for primary production. Consequently, excessive benthic P release resulting directly from oversupply of P-rich fish feed was a significant internal source of P for the water column, and may induce undesirable eutrophication and harmful algal blooms in shallow coastal ecosystems.

Effect of freshwater discharge from Namgang Dam on ichthyoplankton assemblage structure in Jinju Bay, Korea

The movement of fish eggs and larvae in bay and estuarine systems is affected by freshwater discharge. In this study, the assemblage structures of ichthyoplankton eggs and larvae were assessed for the first time in Jinju Bay, South Korea, to identify the spawning and nursery functions of the bay. Fish eggs and larvae and several environmental parameters were sampled monthly from April 2015 to March 2016 inside and outside of the bay. Within the bay we collected eggs and larvae from 25 and 35 species, respectively, indicating greater diversity than outside the bay, where we collected eggs and larvae of 20 and 28 species, respectively. Fluctuations in water temperature and salinity were larger inside than outside of the bay, and chlorophyll-a concentration was higher within the bay, likely due to discharge from the Namgang Dam, which causes water to flow from the inside to the outside of the bay. This process influences fish larva abundance, such that more larvae are found outside than inside the bay. We also found that 28 fish species use Jinju Bay as a spawning ground. For some species, the timing of egg and larva appearance differed inside and outside of the bay, suggesting that the timing of spawning may differ between the two environments.

Juvenile fish assemblages in the Jinju Bay region, Korea

Assemblages of juvenile fish and associated abiotic parameters were investigated inside and outside Jinju Bay in southern Korea, on a monthly basis from December 2014 to November 2015. Fluctuations in water temperature and salinity were larger inside than outside the bay. In total, 534,657 individuals per square kilometre from 81 fish species and 47 families were collected during the study period. The most dominant species was Nuchequula nuchalis both inside (25.6%) and outside (26.9%) the bay. The next dominant species were Thryssa kammalensis (17.9%) and Zoarces gillii (16.0%) inside the bay and Liparis tanakae (16.9%) and T. kammalensis (9.0%) outside the bay. Forty species (33% of total number of individuals) of young fish were recorded inside the bay and 47 species (52%) outside the bay. Therefore, it appears that a diversity of fish use nursery grounds inside and outside Jinju Bay. In particular, the following six species appeared: Z. gillii, Pleuronichthys cornutus, L. tanakae, Hemitripterus villosus, Pennahia argentata, and Xenocephalus elongates. Due to assemblage differences for fishes within Jinju Bay and outside the bay, management of both areas is required to maintain current diversity of species in the region.

Pollution Status of Surface Sediment in Jinju Bay, a Spraying Shellfish Farming Area, Korea

Pollution Status of Surface Sediment in Jinju Bay, a Spraying Shellfish Farming Area, Korea

Dietary study using set-nets produces bias in prey choice of fish: A case of three coastal fishes inhabiting southern Korean waters

Prey selection by marine fishes is highly dependent on whether available food resources are abundant or deficient in their feeding grounds. The influence of fishing method on prey choice was analyzed via stomach content analyses of three coastal fishes: Pennahia argentata, Sillago japonica, and Thryssa kammalensis. Fish samples were collected from northern Jinju Bay, Korea, using two types of fishing gear that covered two different fishing layers in the water column: beam-trawl (bottom layer) and set-net (surface layer). When caught via beam-trawl, all three target species were function as bottom-feeding carnivores that consumed mainly benthic crustaceans and other invertebrates. In contrast, when caught via set-net, teleosts were the most abundant prey items in the diets of the three species. Significant differences in the diet composition between beam-trawl and set-net samples were revealed using permutational multivariate analysis of variance. Although seasonal changes in diet composition were also evident, the influence of season was weaker than that of fishing gear. Consequently, in this study, stomach content analysis demonstrated that set-net made a strong effect on prey selection by the co-occurring P. argentata, S. japonica, and T. kammalensis in southern Korean waters.

Seasonal Variation in Residence Times of Two Neighboring Bays with Contrasting Topography

Residence time is an important parameter for evaluating the physical and biochemical characteristics of estuaries and bays. The residence times of two neighboring South Korean bays with contrasting topographies, Gwangyang Bay and Jinju Bay, were calculated for winter and summer using a three-dimensional model. Gwangyang Bay, with considerable industrial development nearby, has a relatively large volume and depth, whereas Jinju Bay is shallow and is primarily used for aquaculture. River discharge in the two bays is high in summer and low in winter, in part due to the influence of the East Asian Monsoon. Temperature and salinity in both bays are vertically homogeneous during winter but stratified in summer. The mean residence time in Gwangyang Bay is more than 20 days in winter due to its large volume, but less than 5 days in summer due to increased gravitational circulation driven by large volumes of river discharge and a horizontal density gradient. However, the mean residence time of Jinju Bay is less than 5 days in both seasons due to its small volume and shallow depth. These results reveal that Gwangyang Bay is vulnerable to industrial pollution during winter, but that it may remove pollutants efficiently in summer. The shallower Jinju Bay is likely to remain free from anthropogenic eutrophication caused by nutrient inputs from aquaculture due to its short residence time throughout the year.

Mixed Aquaculture of Anadara broughtonii and A. kagoshimensis (Bivalvia: Arcidae) in Jinju Bay on the South Coast of the Korean Peninsula

Kim, J.B.; Kim, H.C.; Hong, S., and Park, J.-I., 2018. Mixed Aquaculture of Anadara broughtonii and A. kagoshimensis (Bivalvia: Arcidae) in Jinju Bay on the South Coast of the Korean Peninsula. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 341–345. Coconut Creek (Florida), ISSN 0749-0208.The biological characteristics and potential food resources of Anadara broughtonii and Anadara kagoshimensis were investigated from May 2013 to December 2014 to evaluate the effects of culturing the two species together (mixed aquaculture). There was no difference in sea water temperature between the surface and bottom layers, and salinity decreased after high rainfall. The three sites used as test shellfish farms had high mud contents and similar concentrations of chemical parameters in the sediment. To identify the potential food sources of the two species, carbon and nitrogen isotopes were analyzed using a mixing model. The results revealed that coarse particulate organic matter (CPOM) was the primary food for both species, comprising 88–89% of the total food source for A. broughtonii and 80–82% for A. kagoshimensis. There was no significant relationship between shell length, shell height, total weight, fresh tissue weight, dry tissue weight, or shell weight and A. broughtonii aquaculture type (mono or mixed), nor was there any significant relationship between shell length, shell height, or shell weight and A. kagoshimensis aquaculture type (mono or mixed). However, total weight, fresh tissue weight, and dry tissue weight were significantly higher in mixed aquaculture compared with those in A. kagoshimensis mono-aquaculture. Although A. broughtonii and A. kagoshimensis spats of similar weights were planted, the dry tissue weight of A. broughtonii was twice that of A. kagoshimensis after 5 months, and the difference increased to 3.8-fold upon harvest.

A Study of Variation Characteristics of the Phytoplankton Community by UPLC Located in the Jinju Bay, Korea

A Study of Variation Characteristics of the Phytoplankton Community by UPLC Located in the Jinju Bay, Korea

Temporal and Spatial Variations of Sea Surface Temperature in Jinju Bay in the South Coast of Korea

Temporal and spatial variations of surface water temperature in Jinju Bay for the period of 2010~2011 were studied using the data from temperature monitoring buoys deployed at 17 stations in the south coast of Korea. Water temperature shows the maximum late in January and the minimum early in August. Seasonal variation of water temperatures at the north part of the bay is smaller than the middle and the south. In summer, the lowest and the highest of maximum water temperature are distributed around Jijok Channel which is located at the south of the bay. The fluctuations of water temperatures at Noryang and Daebang Channel are smaller than others because of vertical mixing caused by passage of strong tidal currents. Wind and strong currents affect on the stratification of the surface water layer near Daebang Channel. High temperatures come in frequently around the north area when eastward constant flows appear at neap tide as blowing westerly in the springtime at Noryang Channel. Spectral analyses of temperature records show significant peaks at 7~20 day periods at Noryang Channel, 7~20 day and semidiurnal at the west coast of Changsun Island and Jijok Channel and 7~20 day and diurnal at the middle of the bay. Temperature fluctuation at Noryang Channel shows high coherence and has leading phase with those at other stations in the bay. However, the phase of temperature fluctuation at Noryang Channel falls behind that at Daebang Channel. Daebang Channel has an influence on the temperature fluctuation only at the west and middle part of the bay. Cross-correlation analyses for the temperature fluctuation show that Jinju Bay could be classified into six areas; Noryang Channel, the area of convergence and divergence at the north, Daebang Channel, the west coast of Changsun Island, the mixing area at the middle of the bay and the south inside of the bay, respectively.

Baroclinic two-layer flow induced by extreme discharge from a dam in a narrow channel

Long-term current observations were taken in the narrow Noryang Channel during extreme discharge and small discharge periods from a river dam. The Noryang Channel connects the west Gwangyang and east Jinju bays in southern Korea. Jinju Bay is relatively isolated from the open sea by many islands, whereas Gwangyang Bay is connected to the open sea through a wide, deep channel. Jinju Bay is closer to the river dam than Gwangyang Bay. The residual mean flow in the channel over the observation period showed a baroclinic two-layer flow as in an estuary during the large discharge period, whereas barotropic flow was present during the small discharge period. During the large discharge period, the upper layer of water flowed continuously westward, whereas the lower layer flowed eastward. Hydrographic data observed along the channel showed that Gwangyang Bay water was relatively saline and heavier during the large discharge period. This spatial difference in water density might be the result of a large inflow of discharge into Jinju Bay and relatively strong mixing between the water in Gwangyang Bay and the open sea. The salinity in the more isolated Jinju Bay was lower. Simple analytical model calculations showed that horizontal density difference during the large discharge period could drive the surface current flow westward, whereas that of the dense water of the lower layer in Gwangyang Bay flowed eastward through the Noryang Channel.

진해만과 진주만에서 새우조망으로 어획된 수산자원의 계절변동

진해만과 진주만에서 새우조망을 이용하여 2010년 4월부터 11월까지 총 4회의 어업조사가 이루어졌다. 조사기간 동안, 진해만에서는 총 116종이 어획되었고, 그 중 어류가 62종, 갑각류가 24종을 차지하였다. 진주만에서는 총 105종이 분류되었고, 그 중 어류가 56종, 갑각류가 31종 조사되었다. 진해만에서는 등가시치, 마루자주새우, 갯가재가 우점하였고, 진주만에서는 마루자주새우, 주둥치, 두점박이민꽃게 순으로 우점하였다. SOM을 이용한 군집유형화 결과, 진해만과 진주만의 군집구성이 계절에 따라 다르게 나타났다. 그룹1에 묶여진 진주만 조사정점들은 민새우, 대하 등 갑각류와 주둥치 쥐노래미 등의 어류가 우점하였다. 4월 조사는 해역에 상관없이 모든 정점이 그룹2에 묶였는데 마루자주새우, 검은띠불가사리, 꼼치 등의 밀도가 높았다. 그룹3에 묶여진 진주만의 6월 조사정점들은 두점박이민꽃게를 포함한 다양한 갑각류와 도다리, 돛양태, 쉬쉬망둑 등의 다양한 어류가 우점하였다. 그룹4에 묶인 진해만의 6월~11월 조사정점에서는 등가시치, 흰베도라치 등의 어류가 우점하였다. 우점종인 마루자주새우는 6월까지 포란개체가 많이 어획되었고, 등가시치와 주둥치는 조사기간 동안 대부분 소형개체가 출현하였다. 이는 본 해역이 수산생물의 산란장 및 성육장으로 중요한 역할을 함을 알 수 있다. The species composition and seasonal variation of fisheries resources in Jinhae bay and Jinju bay, were studied using shrimp beam trawl through a year of 2010. During the study period, a total of 117 species were collected in Jinhae bay. Species included were 63 species in Pisces and 24 in Crustacea. And a total of 106 species were collected in Jinju bay. Species included were 57 species in Pisces and 31 in Crustacea. The dominant species were Zoarces gilli, Crangon hakodatei and Oratosquilla oratoria in Jinhae bay, and Crangon hakodatei, Leiognathus nuchalis and Charybdis bimaculata in Jinju bay. The samples were mainly grouped according to the location and season on the SOM. Group 1 with sample sites in Jinju bay, was characterized by high values of Parapenaeopsis tenella, Leiognathus nuchalis and Hexagrammos otakii. Group 2 with sample sites in April, were dominant Crangon hakodatei and Luidia quinaria. The samples in Group 3 were high values of Charybdis bimaculata and Pleuronichthys cornutus. Group 4 with sample sites in Jinhae bay, was characterized by high densities of Zoarces gilli and Pholis fangi. The dominant species, Crangon hakodatei, were catched egg-bearing females until June. Zoarces gilli and Leiognathus nuchalis were presented small size individuals during study period. It represented that study area is an important role in spawning and nursery ground for fisheries resources.

Seasonal features of Heterophyopsis continua metacercariae in perches, Lateolabrax japonicus, and infectivity to the final host

As the second intermediate host, the perch Lateolabrax japonicus provides metacercariae of Heterophyopsis continua to man. Fry of the perch arrive at and grow to mid-sized fish in the brackish water of Jinju Bay, South Korea. The H. continua metacercariae occur in perch as small and mid-sized forms in July and grow to the large form by August. The size distribution of metacercariae shifts dominantly to the large form in September and then remains as it was. Adult H. continua recovery was high from experimental chicks infected with the medium and large metacercariae collected in September and reduced to half from the chicks infected with those of October. Collectively, the H. continua metacercariae grew to the large form in about 20days and achieved infectivity to chicks after 2months in the perches.

광양만과 진주만 해역에서 담수 유입으로 인한 밀도성층 변화

본 연구에서는 EFDC 모델을 이용하여 광양만과 진주만 해역에 대한 조석과 수온, 염분을 고려한 3차원 해수순환 양상을 재현하였다. 수치모델 결과는 관측 자료를 이용하여 검증하였고 그 결과 모델은 관측결과를 잘 재현하였다. 실험 결과, 연구해역의 해수순환은 노량수도와 대방수도 중간 해역에서 해수가 수렴 및 발산되는 양상을 보이고 잔차류는 전형적인 2층 순환구조를 보인다. 모델을 통해 광양만과 진주만 일대의 밀도성층 변화를 분석한 결과, 연구해역은 담수의 영향이 지배적인 해역으로 진주만의 경우 남강댐 방류의 영향을 지배적으로 받는 해역이지만 남강댐에서 방류를 하지 않는 경우에는 섬진강의 영향도 받는 것으로 나타났다. 한편 남강댐 방류시에는 광양만의 성층이 상대적으로 강화되는 결과를 볼 수 있었다. This study simulate three-dimensional ocean circulation patterns using the EFDC model in the Kwangyang Bay and Jinju Bay, considering tide, water temperature and salinity. The numerical model results were verified using observed data. The model results well reproduced the observed data. As a result, ocean circulation patterns in the study area show convergence and divergence in the middle area of Noryang waterway and Daebang waterway, the residual flow patterns show typical two-layer circulation. According to the change of the density stratification in the Kwangyang Bay and Jinju Bay, the effect of fresh water is dominant in study area. In the case of Jinju Bay, although it is strongly influenced by the Namgang fresh water, also it is affected by Seomjin River when there is no discharge by Namgang Dam. On the other hand, the stratification of the Kwangyang Bay is relatively enhanced by the discharge of Namgang Dam.

2003년 3월 대조기 광양만 부유퇴적물의 유 · 출입에 관한 연구

As a preliminary study on the sediment flux, concentrations of suspended particulate matter and current speeds were measured at three inlets of Gwangyang Bay during one tidal cycle of a spring tide of March 2003. The suspended sediment flux rate <TEX>$(g/m^{2}/s)$</TEX> at the mouth of Seomjin River (St. K1) was observed to be higher throughout surface layer during ebb tide <TEX>$(14.3\;g/m^{2}/s)$</TEX> and throughout near-bottom layer during the flood tide <TEX>$(23.2\;g/m^{2}/s),$</TEX> resulting in a net upstream-ward transport of<TEX>$0.9{\times}10^{3}kg/m$</TEX> during 13 period. At the inlet toward Yeosu Bay (St. K2), a relatively low rate (<TEX>$(5.0-6.7\;g/m^{2}/s)$</TEX> of sediment flux occurred throughout the water column compared to St. K1, with a depth-integrated net transport of <TEX>$5.6{\times}10^{3}kg/m$</TEX> toward the outer reaches of Gwangyang Bay inlet. At St. K3 located at Gwangyang Bay-side of Noryang Strait, the outward flux toward the Jinju Bay was observed to be dominant during the flood tide <TEX>$(16.2-23.2\;g/m^{2}/s)$</TEX>, especially through the mid and near bottom layer, compared to the inward flux throughout the whole water column during the ebb tide <TEX>$(13.1-19.7\;g/m^{2}/s).$</TEX> The net transport at St. K3 was calculated to be <TEX>$4.0{\times}10^{3}kg/m$</TEX> toward the outside of Gwangyang Bay. The outward net transport of suspended sediment at all three inlets seems to be consistent with a trend of bottom sediment texture, which suggests a net movement of sediment from a relatively coarse and poorly sorted inner-bay toward a relatively fine and better sorted outer-bay environment.