Gyeonggi Bay Research Articles

Effects of stepwise tidal flat reclamation on tidal evolution in the East China and Yellow Sea

Abstract Because many coastal developments have been continuously occurred in the Yellow and the East China Sea, it is necessary to analyze the effect of persistent topographic change. This study simulated the tidal change in response to stepwise tidal flat reclamation in East China and the Yellow Sea using the MOdelo HIDrodinâmico (MOHID) ocean model. Based on previous studies and historical coastal information maps, we conducted several numerical experiments with reliable coastal topography changes around two areas (Jiangsu Shoalwater and Gyeonggi Bay) from 1990 to 1994 when the most active development took place. The results show that, unlike other components (S2, O1, and K1), the simulated amplitude of the M2 constituent significantly increased with the disappearance of the tidal flat in the Yellow Sea. At the same time, it decreased in the East China Sea. These results are consistent with the quantile regression analysis using observational data. We also found an accumulating effect of tidal energy flux when the reclamation continued, which does not appear in the previous studies. These results indicate persistent man-made tidal flat reclamation in a specific area can cause more remarkable regional tidal changes through tidal energy redistribution and modification.

Dominant factors responsible for wave modulation in the macro-tidal Gyeonggi Bay of the Yellow Sea

Surface gravity waves, crucial for sediment transport in coastal regions, undergo wave modulation owing to local hydrodynamic conditions. However, the cause of the spatial and temporal distribution of the dominant factors in wave modulation remains vague. This study was aimed at identifying the causes of tidal modulation of waves in Gyeonggi Bay, which exhibits shallow water and macro-tidal environment, and estimating site-specific dominant factors using numerical modeling. The results indicated that tides significantly impact wave dynamics at semidiurnal tidal frequencies, with spatiotemporal variability. The most dominant factor in wave modulation in the nearshore region is the depth change caused by tides, and the most notable impact was found in tidal flats. Depth dependence is mainly evident in surf zones, with a clear distinction at locations where the wave height to water depth ratio reaches 0.2. While idealized studies highlight the significant role of wind in governing incoming waves, it is not the primary cause of modulation. Nevertheless, stronger tidal strength can lead to more pronounced modulation, which is further amplified when accompanied by strong wind conditions. This finding indicates that the spatiotemporal distribution of wave modulation in macro-tidal regions may have a significant impact on various estuarine dynamics including sediment transport.

Variability of Sea Water Characteristics and Sea Levels Due to Climate Change and Appropriate Adaptation Strategies in Gyeonggi Bay

Variability of Sea Water Characteristics and Sea Levels Due to Climate Change and Appropriate Adaptation Strategies in Gyeonggi Bay

Mechanisms of Advective and Tidal Oscillatory Salt Transport in the Hypertidal Estuary: Yeomha Channel in Gyeonggi Bay

Many estuaries have been damaged by such material movements as marine debris, suspended sediment, and pollutants. Understanding the estuarine circulation system is necessary to solve such problems. Salt transport analysis provides an insight into hydrodynamic processes about material circulation in the estuary. In this study, to understand the mechanisms of salt transport, a three-dimensional hydrodynamic model was applied in the hypertidal estuary system—Yeomha Channel in Gyeonggi Bay. The simulation period of the model was a total of 245 days (20 January to 20 September 2020), including the dry and wet seasons. The model results for the temporal variation in tide, current velocity, and salinity were validated by comparing them with the observed in-situ data. The total salt transport (FS) was calculated in three cross sections of the Yeomha Channel and was decomposed into three components (QfS0: advective salt transport; FE: steady shear dispersion; FT: tidal oscillatory salt transport). During the dry season with strong tidal forces, the total salt transport patterns were mainly dominated by QfS0. During the wet season with high river discharge, the total salt transport patterns were determined by the balance between QfS0, FE, and FT. The long-term tidal constituents (MSf and Mm) were the main mechanisms causing QfS0 with the spring–neap variation during the dry season. The tidal trapping effect, caused by a phase difference of less than 90° between tidal current and salinity, generated landward FT in the dry and wet seasons. In addition, the high river discharge during the wet season decreased the phase difference between tidal current and salinity to less than 70°, resulting in a much stronger landward FT. This study suggests that the long-term tidal constituents and tidal trapping effect are unique characteristics that contribute to material circulation in the hypertidal estuary.

Optimization of Influencing Factors in Tidal Current Data Assimilation Modeling in Macro Tidal Estuary, Gyeonggi Bay, South Korea

Gu, B.-H.; Woo, S.-B., and Kim, S., 2021. Optimization of influencing factors in tidal current data assimilation modeling in macro tidal estuary, Gyeonggi Bay, South Korea. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 66–70. Coconut Creek (Florida), ISSN 0749-0208. The study investigates the effect of the model prediction accuracy improvement using data assimilation technique in macro-tidal estuary, such as the Gyeonggi Bay (GGB), South Korea. The observation data used in this study is a tidal current measurement from Acoustic Doppler Current Profiler (ADCP) mooring device. GGB is located at the middle west coast of South Korea, and it is semi-closed estuary that has a tidal range over 6.8 m. To take the irregularity of coastline into account, this study utilized the Finite Volume Coastal Ocean Model (FVCOM), which has the flexible advantage of grid resolution by using unstructured triangular grid system. When applying data assimilation into the coastal model, various parameters, such as scaling factors and correlation lengths are needed to be adjusted to find out the best performance. Total 25 cases used in Taylor diagram showed that different influencing factors are required to be optimized at each observation location. It means that parameters in data assimilation depend on the physical dynamic system via complicated geometry. The optimized parameters not only increase by the tidal range but also it is offset by the effect of river discharge. The horizontal influence range of data assimilation with all observed locations becomes even less than the result applying only one location. It is estimated that the phenomena occurred due to strong tidal currents and interference between the range of influence. The sensitivity of data assimilation parameters in tidally dominated coastal area indicates that a systematic way of choosing the most optimized site-specific parameters are required in macro tidal area.

Cumulative Impact Assessment for Marine Spatial Planning: A Case Study of the Gyeonggi Bay in South Korea

Choi, H.-J.; Cho, S.-J.; Hwang, T.; Nam, J., and Hwang C.S., 2021. Cumulative impact assessment for marine spatial planning: A case study of the Gyeonggi Bay in South Korea. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 360–364. Coconut Creek (Florida), ISSN 0749-0208. Cumulative impact assessment (CIA) techniques for marine spatial planning (MSP) exist in Europe and North America. Effective MSP requires a process for evaluating the effects of human activities on marine ecosystems, that is, a CIA. In Korea, MSP has progressively been developed for waters since the enactment of an MSP law (Act on Marine Spatial Planning and Management) in 2019. This study aims to perform the first CIA for Korea, evaluate its limitations, and assess alternatives for an operational MSP. This study involves an extensive review of the literature, followed by an assessment of the cumulative impact of human activities on the marine ecosystem in Gyeonggi Bay, Korea. Information on the marine ecosystems and influencing activities was collected, and the concept of the activity–pressure–ecosystem relationships adopted. The results reveal high cumulative impact scores along the coast, where human activities are concentrated, with fishing activities accounting for the highest proportion (i.e., 60.3% for gillnet, trap, and stow-net fishing) of the total cumulative impact among the marine activities. The cumulative impact is confirmed to vary by activity depending on whether the weight of the marine ecosystem is applied. This study provides an overview for quantifying the cumulative impacts of marine activities within a spatial context. It also highlights the importance of adequately considering the collection and processing of data before CIA. In addition, the activity–pressure–ecosystem linkage concept must consider the conditions of the study area to improve the accuracy and reliability of CIA. Further, the analysis and mapping techniques for CIA require improvement. This study can be used as a guideline for developing and utilizing the CIA tool in countries and regions planning to adopt MSP.

Numerical Modeling for Region of Freshwater Influence by Han River Discharge in the Yeomha Channel, Gyeonggi Bay

This study estimates the region of freshwater influence (ROFI) by Han River discharge in the Yeomha channel, Gyeonggi Bay. A 3-D numerical model, which is validated for reproducibility of variation in current velocity and salinity, is applied in Gyeonggi Bay. Distance of freshwater influence (DOFI) is defined as the distance from the entrance of Yeomha channel to the point where surface salinity is 28 psu. Model scenarios were constructed by dividing the Han River discharge into 10 categories (200~10,000 m3/s). The relation equation between freshwater discharge and DOFI was calculated based on performing a non-linear regression analysis. ROFI in Yeomha channel expands from the southern sea area of Ganghwa-do to the northern sea area of Yeongheung- do as the intensity of Han River discharge increases. The discharge and DOFI are a proportional relationship, and the increase rate of DOFI gradually decreases as discharge increases. Based on the relation equation calculated in this study, DOFI in the Yeomha channel can be estimated through the monthly mean Han River discharge. Accordingly, it will be possible to respond and predict problems related to damage to water quality and ecology due to rapid freshwater runoff.

Analysis of the Gyeonggi Bay Ecomuseum as a Wide-Area Ecomuseum

This study aims to examine the features of the creation and operation of ecomuseums at wide-area and (metropolitan) local government levels and to analyze their improvements and limitations based on an analysis of a case study on the “Gyeonggi Bay Ecomuseum.” This study also reveals the necessity and direction for ecomuseums led by metropolitan local governments. It attempts to find ways to expand the Gyeonggi Bay Ecomuseum and apply lessons from this ecomuseum to other planned wide-area ecomuseums in South Korea. Overall, this study intends to derive the sustainability of wide-area ecomuseums, and their utility and potential as a means to revitalize the region. 
 The Gyeonggi Bay Ecomuseum is a meaningful case study as it was created in a wide area called the Gyeonggi Bay and was led by a metropolitan local government, along with the official claim as an ecomuseum; the museum creation project also progressed in a phased approach. However, there are issues such as organization problems of the ecomuseum and the absence of resident participation, integrated programs, and an archive center. 
 Therefore, this study presents measures to overcome these obstacles: the establishment of a core ecomuseum and an exhibition center, the development of joint programs, the continuous security of funds and human resources, and measures to generate economic benefits for residents. This study also suggests spatial/functional expansion from being the “Gyeonggi Bay Ecomuseum” to the “Gyeonggi Province Ecomuseum.”
 
 Keywords: Ecomuseum, Wide-area unit, Lead of local governments, Gyeonggi Bay, Regional revitalization 

Mechanisms of Salt Transport in the Han River Estuary, Gyeonggi Bay

본 연구에서는 해수의 ìœ ë™ì— 관한 3차원 수치모델을 사용하여 경기만 한강 하구에서의 염 수송에 대한 메커니즘을 분석하였다. 수치모델의 모의 기간은 갈수기와 홍수기를 포함하는 2020ë „ 1월 20일부터 9월 20일까지 약 245일이며, 모델 결과와 관측 자료의 비교를 통해 해수의 ìœ ë™ 및 염분 변화에 관한 수치모델의 재현성을 ìž ì¦í•˜ì˜€ë‹¤. 한강 하구에서 염의 교환이 활발하게 이루어지는 염하수로의 북단과 남단 지역에 대해서 염 수송량(FS)을 산출하였다. 염 수송에 대한 발생 기작을 ì„¸ë¶€ì ìœ¼ë¡œ 분석하기 위해 FS를 담수 ìœ ìž ì— 의한 염의 이류 수송(QfS0), 수평 및 ìˆ˜ì§ì ì¸ ìœ ì† 차이에 의한 염의 확산 수송(FE), 조석 변동성을 가진 ìœ ì†ê³¼ 염분의 위상 차이에 의한 염의 수송(FT)으로 분해하였다. 갈수기와 홍수기의 월 í‰ê· ì—¼ 수송량에 의하면, 두 기간 모두 외해로부터 한강 하구 지역으로 ìœ ìž ë˜ëŠ” 염의 대부분은 FT에 의하여 강화도 남부 수로를 통해 수송된다. 반면에, 한강 하구로부터 외해로 ìœ ì¶œë˜ëŠ” 염의 대부분은 QfS0에 의하여 ì˜ì¢ ë„ 동부 수로를 통해 수송된다. 한강 하구에서 í‰ê· ì ì¸ 염의 수송은 갈수기 동안 FT에 의하여 한강 하구의 상류 방향으로 수송되며, 홍수기 동안 QfS0에 의하여 외해 방향으로 수송된다. ê²°ê³¼ì ìœ¼ë¡œ, 경기만 한강 하구에서의 염 수송은 외해 방향의 수송을 발생시키는 QfS0와 한강 상류 방향의 수송을 발생시키는 FT의 상호작용에 의하여 ê²°ì •ëœë‹¤. 핵심용어: 염 수송, 한강 하구, 담수 ìœ ìž , 분해 기법

Black-Faced Spoonbill Platalea minor Population Trends, Breeding Success, and Nest Characteristics in the Chilsan Archipelago, South Korea

Long-term population monitoring is very important for the conservation of threatened and endangered species. The Black-faced Spoonbill Platalea minor is a globally endangered species and the majority of its population breed on uninhabited islands off the west coast of the Korean Peninsula. The Chilsan Archipelago in the southwest is the southernmost breeding site for this species in Korea and is expected to help buffer the potential dispersal of Black-faced Spoonbills from breeding populations currently concentrated in the Gyeonggi Bay area. As there has been a lack of information regarding the number of Black-faced Spoonbills, their characteristics, and their recent population trends, the present study investigated the population trends of Black-faced Spoonbills breeding in the Chilsan Archipelago. The study, from 2014 to 2018, examined breeding success in 2015 and 2018, and the size and location of nests in 2018. The number of nests ranged from 43 to 163 (2014, 43; 2015, 93; 2016, 84; 2017, 85; 2018, 163). The percentage of birds that attempted breeding between April and May was 84.9% in 2015 and 87.1% in 2018, while the breeding success rate was 69.9% in 2015 and 81.5% in 2018. The average nest size in 2018 was 55.06±6.09 cm long and 53.44±6.56 cm wide, while the average surface slope below the nest was 25.42±6.95°. In total, nine plant species were used as vegetation for nests. During the present study, the environmental conditions and the presence of anthropogenic disturbances seemed to affect breeding success. Therefore, strictly controlled access to breeding sites and effective management are needed to protect and conserve breeding populations of this endangered species.

Above water remote sensing reflectance dataset on the coastal waters of California and Korea

Remote sensing reflectance (R<sub>rs</sub>) is a fundamental data of ocean color remote sensing that is used as an input data for algorithm development. In this study, the Rrs spectra acquired from the coast of Korea and California, on the opposite side of the Pacific Ocean, were analyzed and compared. The waters of Gyeonggi Bay and Mokpo had a similar spectrum to those of the waters inside of the San Francisco Bay, although the waters of each region had different characteristics. The South Sea in Korea showed similar spectral characteristics on the waters of Monterey Bay and outside of the San Francisco Bay in California. The upward slope of the Rrs spectra in the range of 400 to 600 nm obtained from the inside of the San Francisco Bay was higher than the coastal waters on the Gyeonggi Bay and Mokpo in Korea. The Rrs spectra showing peaks on 580 nm and 680 ~ 700 nm due to chlorophyll were similarly observed in the South and East Seas of Korea, and the coastal waters of Monterey Bay and the outside of the San Francisco Bay in California.

한국 서해 경기만 영흥도 주변 해역의 수질 및 표층 퇴적물 특성

한국 서해 경기만 영흥도 주변 해역의 수질 및 표층 퇴적물 특성

An Update on the Status of Mean Sea Level Rise around the Korean Peninsula

The threat of sea level rise to the heavily populated Korean Peninsula, which contains around 15,000 km of coastline bordering open sea margins, has profound and far reaching implications. This study updates and extends previous detailed studies with the addition of a further 2 years of data to the end of 2019, providing renewed robustness to the identification of emerging threats associated with sea level rise within the warming sea margins around the Korean Peninsula. The study analyzes tide gauge records and satellite altimetry around the Republic of Korea using enhanced time series analysis techniques to detect coastal vertical land motion and current rates of rise in mean sea level to augment planning, design and risk management activities. Despite fluctuations over time at each site, the highest “relative” mean sea level at each of the seven longest tide gauge records occurs in 2019, with weak evidence of an acceleration in the increase in mean sea level around the Republic of Korea. Trends in sea surface height from satellite altimetry across this region note two discreet areas east and west of the Korean Peninsula around 37.5° N (around Ulleungdo Island and in the Gyeonggi Bay region of the Yellow Sea), where rates of rise are well above the global average trend.

Impact of derelict fishing gear on the seafloor integrity and benthic communities in the macrotidal flats from northern Gyeonggi Bay, west coast of Korea

Derelict fishing gear (DFG) is increasingly common in the Korean tidal flats due to intensive fishing activity and the lack of monitoring system to remove the DFG from the tidal flats. Despite the widespread occurrence of DFG in the tidal flats, little is known about DFG in terms of quantity, types, distribution, and the impact on the benthic ecosystem. Unmanned aviation vehicle (UAV)-assisted photogrammetry and high-precision leveling were conducted to characterize DFG in the macrotidal flat, south of Gangwha Island, west coast of Korea. High concentration of DFG occurs preferentially in the channel where nets with stakes were installed for catching fishes. Topographic relief around DFG is more rugged and pronounced in the lower intertidal zone than in the middle intertidal zone, suggesting more dynamic sedimentary processes related to DFG in the lower intertidal zone. The density of benthic species is nearly identical in the middle intertidal zone regardless of the presence of DFG. In contrast, the density of macrofauna in the lower intertidal zone nearly doubles at the area free of DFG compared to the area affected by DFG. The biomass and primary production of the microphytobenthos (MPB) are smaller in the lower intertidal zone than the middle intertidal zone but show no discernible trend related to the presence of DFG. Strong tidal currents in the lower intertidal zone induce larger vortices over DFG and promote rapid deposition and erosion around DFG, resulting in a more hostile condition for the benthic ecosystem. The present study showcased that UAV-assisted mapping provides an effective tool to characterize the distribution and physical disturbance caused by DFG in the macrotidal flats, which will be a breakthrough for the sustainable management of rapidly deteriorating tidal flats with poor accessibility.

Spatiotemporal Distribution of Dissolved Heavy Metals in Gyeonggi Bay, Korea

In this study, we investigated the spatial and temporal distribution of heavy metals and nutrients in Gyeonggi Bay, Korea, to determine their present status and seasonal variability, and to identify their sources. Two surveys (May and August 2017) covering the entire Gyeonggi Bay (15 sites) and twelve surveys over four seasons (February, May, August, and November of 2016–2018) covering the Incheon Special Management Area (7 sites) were carried out to collect surface seawaters. Three surveys (January, April, and August of 2015) were also performed to collect seawater samples at Shihwa Lake (16 sites). Although the concentration gradients of nutrient type heavy metals (e.g. copper, nickel, zinc, and cadmium) corresponded to patterns of salinity in both dry and wet seasons, there was little seasonal variability over the three years studied. However, there was evidence that heavy metals were released during mixing with freshwaters in the wet season, likely from river outflow or direct coastal inputs such as effluents from Shihwa Lake. For nutrients, whereas the conservative mixing of dissolved inorganic nitrogen and the release of dissolved inorganic phosphate and dissolved silica were observed in the wet season, the concentrations of organic particles (e.g., chlorophyll-a, particulate organic carbon, and particulate organic nitrogen) had an inverse relationship with salinity in the dry season (May). Scavenged metals (e.g., manganese and cobalt) had non-freshwater coastal sources, such as benthic remobilization from suboxic sediments, and exhibited seasonal variation; they progressively increased in concentration from winter to spring and summer, and dropped to their minimum levels in the fall, which was presumably related to variation in microbial activity in sediments. Based on their relationship with salinity, heavy metals were deduced to be derived from coastal sources such as effluents from Shihwa Lake and freshwater from the Han River.

A Study on the Activities of the Eco-Museum: Focusing on Gyeonggi Bay Eco-Museum

에코뮤지엄은 지속가능한 지역사회 발전을 위한 역동적인 활동을 의미한다. 이러한 활동을 위해 유산, 참여, 활동을 핵심으로 에코뮤지엄을 실행한다. 경기만에코뮤지엄은 이 원칙에 준하여 2016년부터 사업을 진행해오고 있다. 에코뮤지엄의 이행을 위해 지역사회에 대한 최대한의 이해를 비롯하여 중장기적 관점에서의 단계별 전략을 수행하며, 그 수행과정은 참여의 원칙에 중점을 두고 운영되고 있다. 지난 4년의 경기만에코뮤지엄 활동은 각 현장의 눈높이에 맞추어 지원하고 발굴하는 참여하는 과정을 만들면서 현재에 이르고 있다. 경기만에코뮤지엄은 지역사회의 가치를 주민 스스로 발굴하고 이해하고 학습과정을 통하여 지역사회발전을 모색하는 가치 발굴형 내생적 발전양식이라고 할 수 있다.Eco-Museum means dynamic activities for sustainable community development. For these activities, eco-museums are carried out based on heritage, participation and activities. Gyeonggi Bay Eco Museum has been in business since 2016 according to this principle. For the implementation of the Eco-Museum, we carry out a step-by-step strategy in the mid- to long-term perspective, including the best understanding of the community, and the process is focused on the principle of participation. There is an eco-museum only in the current Gyeonggi-do, creating a participatory process that supports and discovers at the eye level of each site. The Gyeonggi Bay Eco Museum is a value-extracting endogenous development mode that seeks to understand and understand the value of local communities and seek community development through the learning process.

On Robust Multi-Year Tidal Prediction Using T_TIDE

A minimum 19 year tidal prediction dataset covering nodal (satellite) modulation effects is required to determine the Lowest Astronomical Tide (LAT) and Highest Astronomical Tide (HAT) datums. In this study, we explore the ability of a widely used conventional standard harmonic prediction program, T_TIDE ‘t_predic.m’ from Pawlowicz et al. (2002), to produce accurate continuous multi-year predictions. Comparisons are made with the more recent tidal prediction program, UTide ‘ut_reconstr.m’ from Codiga (2011). Tidal height records for two different regimes are employed: for diurnal tides data are employed from Cape Roberts in Antarctica, while for semi-diurnal tides data are used from Incheon, Gyeonggi Bay, Korea. Results demonstrate an issue arises in continuous multi-year tidal predictions made via T_TIDE, due to the program’s single calculation (fixed) of nodal modulation corrections (NMC). We explain a modified NMC update method that successfully solves this problem, rendering the program of use for accurate continuous multi-year tidal predictions.

Improved Estuaries Salinity Stratification at Gyeonggi Bay Using Data Assimilation with Finite Volume Coastal Ocean Model (FVCOM)

Gu, B.-H.; Woo, S.-B., and Kim, S.I., 2019. Improved estuaries salinity stratification at Gyeonggi Bay using data assimilation with Finite Volume Coastal Ocean Model (FVCOM). In: Lee, J.L.; Yoon, J.-S.; Cho, W.C.; Muin, M., and Lee, J. (eds.), The 3rd International Water Safety Symposium. Journal of Coastal Research, Special Issue No. 91, pp. 416-420. Coconut Creek (Florida), ISSN 0749-0208.Assimilating salinity data into coastal models is very important and salinity vertical change is an important component to coastal forecasting. The goal of this study is to represent the salinity stratification at Gyeonggi Bay (GGB) in South Korea and to improve the accuracy of the prediction in hydrodynamics via data assimilation. The GGB area is located in the Yellow Sea between Korea and China and is a semi-closed estuary that has a tidal range above 7 m with a tidal flat where salt water and fresh water is mixed. Salinity stratification appears at Yeomha channel in GGB because it has characteristics of high tide and strong river flow. To represent the tidal flat and creek in the GGB in this study, the unstructured grid numerical model called Finite Volume Coastal Ocean Model (FVCOM) is employed. The performance of the model results is validated against the measured tide, current, and salinity at the Yeomha channel. In order to improve the numerical results, the salinity observations from the surface and bottom Conductivity Temperature Depth (CTD) data in the Yeomha channel are assimilated into the model only for the 4-day middle period out of total simulation days of 15. The direct comparison results show the clear effect of data assimilation for salinity stratification along vertical salinity, and the improvement of salinity profile lasts for 1 day after the end of data assimilation. The salinity stratification in the coastal are also improved as the number of observations and/or data assimilation periods is increased. These results are expected to improve the coastal forecasting system over the GGB area when applied the data assimilation scheme in to the forecasting system.

Uncoupling between Heterotrophic Bacteria and Phytoplankton and Changes in Trophic Balance Associated with Warming of Seawater in Gyeonggi Bay, Yellow Sea

We investigated bacterial production (BP) and respiration (BR), in combination with phytoplankton and environmental parameters, to elucidate major carbon sources regulating heterotrophic bacterial metabolic activity and to evaluate variations of trophic balance associated with seawater warming in Gyeonggi Bay (GB). BP was not significantly correlated with primary production (PP, p > 0.05), but was significantly correlated with dissolved organic carbon (DOC, p 1) implied that trophic balance of GB represented heterotrophic conditions, and ratios showed an inverse relationship with Chl-a concentrations. In comparison to the early 1990s, increasing water temperatures were associated with significant decreases in PP and Chl-a (by a factor of 9 and 2, respectively), whereas changes in BP were insignificant; these changes resulted in a 14-fold increase in the BP/PP ratio. Therefore, our results strongly imply that warming in GB intensified the carbon flux through the microbial loop, which may reduce the efficiency of energy transfer to higher trophic levels.

경기만 해안 및 도서지역 상록활엽수 식재 타당성 연구

경기만 해안 및 도서지역 상록활엽수 식재 타당성 연구