Fine-grained surface sediment provenance in the Hupo Basin, Eastern Coast of Korea

The management for the recreational beach is performed by not only central and local governments but also private organizations for various purposes in Korea. Nevertheless, with the increasing demand for diverse recreational activities based on beaches, a multifaceted and systematic management planning is urgently needed. The purpose of this study is to analysis the environment awareness factors and the importance of the environmental management in accordance with the users of the recreational beach located in the eastern coast of Korea. Likewise, some data was collected through a questionnaire survey targeted on 278 beach users (related business and leisure). Additionally, the characteristics of beach user were analyzed with regard to the environmental management significance by using T-test, ANOVA and multiple regression analysis. As a result of the points of views, it appeared that the user characteristics of the recreational beach in the eastern coast of Korea is highly related to the facility and equipment, natural environment, human resources and user factors. And the environmental awareness of recreational beaches users on the east coast of Korea partially influences the importance of environmental management. These results will be the foundation for the safer and more comfortable operation in Korean recreational beaches surrounded by the other regions as well as east area in Korea.

Lim, H.S.; Lee, H.J.; Kim, D., and Hong, S., 2023. Beach erosion along the eastern coast of Korea: A brief review. Journal of Coastal Research, 39(1), 181–190. Charlotte (North Carolina), ISSN 0749-0208. Most of the beaches on the eastern coast of Korea are eroding at an alarming rate, triggered by combined natural and artificial causes. In this review, each of the major causes of beach erosion is addressed briefly. A few protection measures such as breakwaters and nourishments are also discussed, with the emphasis on the unexpected or undesirable outcomes. Finally, some of the essential requirements for the field measurements in a beach are mentioned. Global warming has induced the chief natural causes of the beach erosion in Korea, including a gradual increase in wave energies and sea level. An estimation in this review suggests the rates of shoreline of 1 m/10 yrs on the eastern coast by sea-level rise alone. By comparison, artificial beach erosion is most likely to occur upon emplacing structures nearby. A variety of the artificially erosional cases by beach developments are described in the review. Storms and typhoons play a critical role in eroding beaches and changing local morphologies in a short period of time and thus should be observed hydrodynamically. However, the diminishing run-off of rivers and streams should be regarded as the primary reason for the nationwide artificial erosion of beaches. The scanty supply of stream sands to the beaches, together with the influence of global warming, would have the beaches eroded continuously without any coastal developments.

Zostera caulescens is an endemic seagrass species in Northeastern Asia. Estimated distributional area of this species is approximately 1–5 km2 on the coasts of Korea. Because Z. caulescens has a very limited distribution, the growth dynamics of Z. caulescens is little known in the coastal waters of Korea. In the present study, we investigated the growth dynamics of Z. caulescens in relation to coincident measurements of environmental factors, such as underwater irradiance, water temperature, and nutrient availability. The study was conducted on a monotypic meadow of Z. caulescens in Uljin on the eastern coast of Korea from September 2011 to September 2012. Shoot density and biomass of Z. caulescens showed distinct seasonal variations, and exhibited strong correlations with water temperature suggesting that the seasonal growth of this species was regulated by water temperature. Shoot density and biomass rapidly decreased during the high water temperature period in summer, and thus Z. caulescens is considered a cold water adapted species like other temperate seagrass species on coasts of Korea. Biomass of photosynthetic leaf tissues on reproductive shoots was approximately 4 times higher than that on vegetative shoots. The height of reproductive shoots ranged from 1.2 m in February 2012 to 3.2 m in August 2012, whereas the height of vegetative shoots was usually less than 1.0 m. Leaf tissues on reproductive shoots probably received much more light for photosynthesis than those on vegetative shoots. Thus, reproductive shoots may play an important role in total production of Z. caulescens.

Effects of water temperature changes on the early life stages (egg and larvae) of walleye Pollock (Gadus chalcogrammus) – Laboratory experiments and field applications

Ha, T.; Park, C.; Yoon, J., and Heo, K.-Y., 2016. Synoptic study on forecasting large swell waves along the eastern coast of Korea using the operational system. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 1102 - 1106. Coconut Creek (Florida), ISSN 0749-0208. In recent years, the eastern coast of Korea has been experiencing frequent large swell waves during winter. These waves, occasionally higher than 3 m, rarely occurred until recently and now cause severe casualties, damage to coastal structures, and extensive beach erosion along the eastern coast of the country. Therefore, the urgency for appropriately predicting large swell waves affecting these areas has increased. A convenient forecasting source is a numerical wave prediction system running in an operational mode. Since 2009, Korea Institute of Ocean Science and Technology (KIOS...

With the results of observations in 2013 and 2014 including ocean buoys, in-situ investigations and wind data, we examined the spatio-temporal variation of cold water masses along the eastern coast of Korea. Usually, a cold water mass first appears along the northern part of the eastern coast from May to July, and then along the southern part of the eastern coast from late June to mid-August. Cold water masses appear 3~5 times a year and remain for 5~20 days in the southwestern part of the East Sea. A distinctive cold water mass appeared usually in mid-July in this area, the surface temperature of which was below 10℃ in some cases. During the appearance of a cold water mass in the southwestern part of the East Sea, the horizontal temperature gradient was large at the surface and a significant low water temperature below 8℃ appeared at the bottom level. This appearance of cold water masses clearly corresponded to southwesterly winds, which generated coastal upwelling.

Korean coastal waters mark the southern distribution limit of Pacific cod (Gadus macrocephalus) in the northwestern Pacific, where climate regime shifts (CRSs) since the late 1980s have driven regional variability in cod catches. Despite the species' ecological and commercial importance, limited research has explored how temperature-dependent physiological traits during early life stages (ELSs; eggs and larvae) interact with local oceanographic conditions to influence recruitment success. This study experimentally assessed cod ELS survival and growth across temperatures representative of Korean spawning seasons and applied these results to estimate a habitat suitability index (HSI: 0-1) across three regions, namely the eastern, western, and southern coasts of Korea, over multiple decades. Hatching rates declined sharply below 3°C and above 10°C (HSI<0.6), while larval survival increased at lower temperatures. Along the eastern coast of Korea, persistent stratification and bottom cooling maintained favourable ELS conditions (HSI≥0.6), coinciding with steadily rising catches. In the western coast of Korea, catches declined in the late 1980s despite favourable spawning conditions, likely due to unfavourable larval-stage environments (HSI<0.6), which improved following the re-expansion of the Yellow Sea Bottom Cold Water. In the southern coast of Korea, broader warming rendered most areas unsuitable for ELS survival, but Jinhae Bay maintained favourable conditions (HSI≥0.6) due to cold-bottom inflow via the Korea Strait. These findings advance our understanding of climate-driven shifts in cod ELS habitats and provide a theoretical basis for predicting regional recruitment dynamics and informing adaptive fishery management.

Eight new species of copepods associated with shallow-water ascidians are described from the eastern coast of Korea. They are Ascidicola secundus n. sp. from a Pyura sp., Enteropsis nudus n. sp. from Pyura sacciformis (Drasche), Mycophilus capillatus n. sp. from a compound ascidian, Bonnierilla yangpoensis n. sp. from Phallusia cf. nigra Savigny, Janstockia truncata n. sp. from Chelyosoma siboja Oka, Pholeterides pilosa n. sp. from a compound ascidian, Pachypygus spinosus n. sp. from a solitary ascidian, and Paranotodelphys unguifer n. sp. from Ascidia samea Oka.

If one tries to imagine the sea level being lowered by only 90 m, the entire Yellow Sea and the adjacent portion of the East China Sea would run dry. Korea would lose its peninsular nature and disappear into the continental mass of Asia. The eastern coast of northern China would move approximately 800 km eastward to coincide with the present eastern coast of Korea. The eastern coast of Korea would be dislocated only minimally by such a lowering of the sea level, however, for the Sea of Japan is relatively deep, its floor dropping to more than 3000 m below sea level not far from the coast of the continent. The steeply sloping coastline continues its sharp decline under the water level for the entire length of the eastern coast of Korea. The 200-m isobath lies less than 4 km from the coast, and the 1000-m isobath lies 8 km from the coast.

The relationships between total length and wet weight and between total length and standard length are presented for six flounder species from the eastern coast of Korea between 2011 and 2012: Paralichthys olivaceus (Temminck & Schlegel, 1846), Cleisthenes pinetorum (Jordan & Starks, 1904), Glyptocephalus stelleri (Schmidt, 1904), Platichthys stellatus (Pallas, 1787), Pseudopleuronectes herzensteini (Jordan & Snyder, 1901), and Pseudopleuronectes yokohamae (Günther, 1877). The values of exponent b, estimated using nonlinear least squares of weight and length data, ranged from 3.076 to 3.469. All relationships between total length and standard length were linear (all r2 > 0.948). Fisheries scientists apply these size conversions (total length calculated from standard length) to understand several aspects of the population dynamics.

The results from the Global Positioning System (GPS) measurements of the Mobile Observation Vehicle (MOVE) on the eastern coast of Korea have been compared with REFerence (REF) values from the fixed GPS sites to assess the performance of Precipitable Water Vapor (PWV) retrievals in a kinematic environment. MOVE-PWV retrievals had comparatively similar trends and fairly good agreements with REF-PWV with a Root-Mean-Square Error (RMSE) of 7.4 mm and <TEX>$R^2$</TEX> of 0.61, indicating statistical significance with a p-value of 0.01. PWV retrievals from the June cases showed better agreement than those of the other month cases, with a mean bias of 2.1 mm and RMSE of 3.8 mm. We further investigated the relationships of the determinant factors of GPS signals with the PWV retrievals for detailed error analysis. As a result, both MultiPath (MP) errors of L1 and L2 pseudo-range had the best indices for the June cases, 0.75-0.99 m. We also found that both Position Dilution Of Precision (PDOP) and Signal to Noise Ratio (SNR) values in the June cases were better than those in other cases. That is, the analytical results of the key factors such as MP errors, PDOP, and SNR that can affect GPS signals should be considered for obtaining more stable performance. The data of MOVE can be used to provide water vapor information with high spatial and temporal resolutions in the case of dramatic changes of severe weather such as those frequently occurring in the Korean Peninsula.

OBJECTIVESIn April 2000, a series of wildfires occurred simultaneously in five adjacent small cities located on the eastern coast of Korea. These wildfires burned approximately 23,794 hectares of forestland over several days. We investigated the effects of prenatal exposure to the by-products generated by wildfire disasters on birth weight.METHODSBirth weight data were obtained for 1999-2001 from the birth registration database of the Korean National Statistical Office and matched with the zip code and exposed/unexposed pregnancy week for days of the wildfires. Generalized linear models were then used to assess the associations between birth weight and exposure to wildfires after adjusting for fetal sex, gestational age, parity, maternal age, maternal education, paternal education, and average exposed atmospheric temperature.RESULTSCompared with unexposed pregnancies before and after the wildfires, mean birth weight decreased by 41.4 g (95% confidence interval [CI], -72.4 to -10.4) after wildfire exposure during the first trimester, 23.2 g (95% CI, -59.3 to 13.0) for exposure during the second trimester, and 27.0 g (95% CI, -63.8 to 9.8) during the third trimester. In the adjusted model for infants exposed in utero during any trimester, the mean birth weight decreased by 32.5 g (95% CI, -53.2 to -11.7).CONCLUSIONSWe observed a 1% reduction in birth weight after wildfire exposure. Thus, exposure to by-products generated during a wildfire disaster during pregnancy may slow fetal growth and cause developmental delays.

Lithologic and geochemical data of a core from the Hwajinpo Lagoon, located on the eastern coast of Korea, provided the evolutionary history of the lagoon related to Holocene sea-level changes of the East Sea (Sea of Japan). Grain size analysis, water content analysis, and soft X-ray analysis of core samples were used to reconstruct sedimentary environments, as were total organic carbon, C/N, S and C/S chemical records. Assemblages of mollusc and diatom remains also provided paleoenvironmental information. The reconstruction of paleoenvironments from these multi-proxy data allows the establishment of an evolutionary model of the Hwajinpo Lagoon. The environmental changes of the Hwajinpo Lagoon can be divided into seven different depositional facies: (l) Exposed basement rock; (2) Estuarine; (3) Stagnant brackish lagoon (isolated); (4) Oxic condition lagoon (organic activity); (5) Fresh water lake; (6) Oxic brackish lagoon (recent condition); (7) Prograding river delta. These environmental changes can be related to sea-level change during the Holocene. The trends of sea-level change in the Hwajinpo Lagoon from this study can be compared to those of the Japanese coastal areas located on the other side of the East Sea such as Lakes Shinji and Nakaumi.

Influence of Tourism Development Impact on Local Resident‘s Satisfaction and Life Satisfaction - Focused on the residents of regions where have been promoted tourism development in Eastern Coast of Korea -

Internal waves and internal tides occur frequently along the eastern coast of Korea. During the spring-tide period in April 2003, the East Korean Warm Current (EKWC) flowed near the Korean East Coast Farming Forecast System (KECFFS; a moored oceanographic measurement system), creating a strong thermocline at the intermediate layer. Weakened stratification and well-mixed water appeared frequently around the KECFFS, with duration of approximately 1 day. The results suggest the following scenario. Baroclinic motion related to the internal tide generated high frequency internal waves around the thermocline. The breaking of those waves then created turbulence around the thermocline. After well-mixed water appeared, a current component with perpendicular direction to the EKWC appeared within the inertial period. The change in stratification around the KECFFS locally broke the geostrophic balance as a transient state. This local vertical mixing formed an ageostrophic current within the inertial period.