• Korean Journal of Environment and Ecology
• /
• v.31 no.2
• /
• pp.166-173
• /
• 2017

Morphological and population characteristics of the Cottus koreanus were investigated at Hoam stream from October 2015 and April 2016. This is the first record on C. koreanus not only from Hoam stream (the upstream region of Daejong stream, Gyeongsangbuk-do Gyeongju-si Yangbuk-myeon Hoam-ri) but also from the stream flowing into the Samcheogosip stream, in the southern part of East Sea, Korea. The distribution of C. koreanus ranged from Girim temple to Yongyeon waterfall, about 1.2 km, and the water surface were about $3,600m^2$. The population size was assumed to 1,656 individual number, 46 object per $100m^2$. The morphometric characteristics of C. koreanus in the Hoam stream and the Han river are very similar except that the population at Hoam stream shorter head length, ventral fin ray length, pectoral fin ray length and mouth width when compared with the population at Han river. Other than that, the two populations showed the same meristic characters. Frequency analysis of total length indicated that the group with 40~59 mm in total length was one year old, the 60~79 mm was two years old, and the group over 80 mm was three years old. The average number of eggs in the ovaries was estimated as 361 (239~468) per matured female. The number of matured eggs size in ovaries was $2.6{\pm}0.21$ (23.~3.1) mm and this species was large eggs type. Calculation of the length-weight relation of C. koreanus showed the value of constant a as 0.00001 and b as 3.01, and the Condition factor (K) was 1.26 an on average.

• Korean Journal of Plant Resources
• /
• v.25 no.1
• /
• pp.105-122
• /
• 2012

This study was carried out to illuminate the flora of vascular plants of islands at Chungnam. This study was conducted from March to November, 2010. Based on the voucher, vascular plants of in investigated islands were 105 families 326 genera 454 species 4 subspecies 45 varieties 9 forms, totally 512 taxa. Korean endemic plants were 6 species such as Aster koraiensis, Salix koriyanagi, Indigofera koreana, Hemerocallis taeanensis, Hepatica insularis, Philadelphus schrenckii, rare and endangered plants of designated by Korea Forest Service were 4 taxa, such as Magnolia kobus (planted), Koelreuteria paniculata, Berchemia racemosa var. magna, Glehnia littoralis respectively. Phytogeographical special plants were totally 69 taxa, which were grade I of 50 taxa, grade II of 1 axon, grade III of 11 taxa, grade IV of 4 taxa, and grade V of 3 taxa. 14 southern plants and 4 northern plant by criterion from climate change study were found in this area. Naturalized plants were 17 families 46 taxa, that was 9.1% of total vascular plants in this area. Even naturalized plants has not influence on the islands vegetation. However, regular passenger ferry between islands and increasing of visiter will be affecting vegetation.

• Journal of Environmental Science International
• /
• v.12 no.11
• /
• pp.1181-1187
• /
• 2003

Hibiscus hamabo, called "Hwang-geun", growing about 3m in height is a deciduous shrub or subtree of Malvaceae. Because the number of these species is very limited in the world, the Ministry of Environment has designated H. hamabo as a preserved plant. The Korea Forest Service also protects it strictly by law since H. hamabo is an out-of-the-way plant and possibly may be exterminated soon in Korea. Investigation for distribution and ecological characteristics of the habitat for H. hamabo was carried out on Soan Island. Two wild H. hamabo were found at the forest edge (equation omitted) along the sea coast located in the southern part of Soan Island and this was the first report in the Korean academic world. These two wild H. hamabos were growing in a naturally inhibited area. The diameters at the base were 12cm and 15cm. The Tree heights were 150cm and 210cm and the number of branches of each wild H. hamabo was 4 and 7. However, the present condition of these plants was not good. Environmental conditions of the naturally inhibited area of H. hamabo were very mild because it is located at the edge of the forest and is always sunny during the daytime since the slope of the inhibited area is facing South. The ground drained very well since the soil was made of gravels and sand. Because the percent of vegetation of the subtree layer where H. hamabo was growing was 40%, the cover degree and sociability of flex crenata trees and Eurya japonica were found to be high. In the naturally inhibited area of H. hamabo, a dominant value of Rubus parvifolius in the lower part of the herb layer was very high and many plants in Compositae, such as Artemisia princeps var. orientalis and Erigeron annuus, were also present. A dominant value of liana, such as Vitis thunbergii var. sinuata, Rosa multiflora, Clematis terniflora and Hedera rhombea, and Gramineae plants that rhizomes were well developed and aggressively propagated, such as Miscanthus sinensis var. purpurascens, Phragmites communis, Spodiopogon cotulifer and Oplismenus undulatifolius which were surveyed as high, too. These results imply that H. hamabo might be exterminated soon through a natural selection if the proper management of the naturally inhibited area of H. hamabo is not conducted continually.

• The Korean Journal of Quaternary Research
• /
• v.24 no.2
• /
• pp.35-48
• /
• 2010

The purpose of this study is to investigate paleoenvironmental conditions of the shallow sea around Jeju Island during the Late Holocene using geochemical contents of the bivalve (Glycymeris albolineata) collected from the Sangmori Shell Mound. The bivalve shell used shows the archaeological age of 2,300 yr BP. Stable carbon and oxygen isotope compositions show that growth rates decreased with aging. Coeval trends of both isotope compositions can be observed: heavier values during winters and lighter values summers except for their young and old growth stages. The seasonality of bivalve shell appear to reflect seasonal variations of paleotemperature as well as paleosalinity. Especially China Coastal Water with low salinity was transported into the southern Jeju Strait from Changjiang River during summer periods. Heavier carbon isotope values during winter indicate higher productivity, and this is supported by high density of phytoplanktons and higher chlorophyll contents during winter time. For accurate interpretation, monitoring of present-day conditions of shallow marine water as well as additional geochemical analysis of the same Recent bivalve may be necessary.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.32 no.1
• /
• pp.39-47
• /
• 2020

In order to investigate current characteristics at the Gungpyung beach, which is a macrotidal flat, field measurements were carried out in the summer and winter at the intertidal and the subtidal zones. The distribution of residual current at intertidal flat was dominant in the northward direction in the summer and dominant in the northward and southwestern directions in the winter. The direction and speed of the residual current in the winter are highly correlated with the significant wave height, and the turbidity is also highly correlated with the significant wave height. Therefore, in the winter, high sediment rates are suspended by high waves, and sediments are transporting due to the residual current in the southwest direction. On the other hand, it is expected that the northward residual current is predominant due to the small wave in the summer, and sediment transport does not occur largely due to less suspended sediments. In addition, sediment transport in the southern direction is blocked by the dock, which is the artificial structure, and the erosion occurs in the south side of the dock. The erosion pattern in the macrotidal zone of Yellow sea is dominated by seasonal waves, and blocking of sediments by artificial structure is very important.

• Korean Journal of Environmental Biology
• /
• v.31 no.4
• /
• pp.353-361
• /
• 2013

An in situ mesocosm experiment was designed to investigate how exposure to ocean acidification by increased carbon dioxide affected the growth of juvenile oliver flounder (Paralichthys olivaceus). A total of 447 individuals were reared in the mesocosm experimental devices deployed at sandy-muddy bottom in the southern coast of East Sea for 43 days and divided into two groups: treatment group (223 individuals, $6.32{\pm}0.75$ cm, high-$CO_2$ environment) and control group (224 individuals, $6.34{\pm}0.84$ cm, natural $CO_2$ environment). The average values of pH and $CO_2$ concentration in the treatment device were $7.63{\pm}0.13$ and $1660{\pm}540$ ${\mu}atm$, respectively, while those in the control device were $8.07{\pm}0.05$ and $514{\pm}65$ ${\mu}atm$, respectively. There was no significant difference in mortality rate between treatment and control group, and the mortalities in two groups gradually decreased during the study period. But, the increase of size and weight of juvenile oliver flounder was higher in control group than treatment group, i.e., weight gain or growth rate was higher in control group. These results suggested that high $CO_2$ environments could have a significant negative influence on the early growth of juvenile oliver flounder.

• Journal of the Korean Geographical Society
• /
• v.41 no.4 s.115
• /
• pp.457-469
• /
• 2006

This study aims to understand the characteristics of spatial distribution of snowfall and to analyze its development mechanism in Honam province in Korea. The areas of snowfall in Honan area can be divided into the seven sub-area by snowfall pattern. In the west coastal area of heavy snowfall and the southwest coastal area of heavy snowfall, snowfall develops over reason of ocean by Siberian High while in the northern inland area of heavy snowfall and the southern inland area of heavy snowfall, it develops when a strong Siberian High affects to inland. Then, much snowfall is by a forced ascending due to topography in Namwon, Imsil and Gwangju of the northwestward of the Noryung and Sobaek mountain ranges while it is weak in Jeonju and Suncheon of the low plains and the southeastward. In the mountainous area of heavy snowfall and the south coastal area of light snowfall, cyclone is also one of causes of snowfall. In the southwest coastal area, snowfall is meager than the southwest coastal area of heavy snowfall because this area is far from the west coast. It is confirmed that the snowfall difference of the coast, inland and mountainous area appears by temperature difference of sea surface and 850hPa temperature, wind speed of Siberian High.

• Animal Systematics, Evolution and Diversity
• /
• v.14 no.3
• /
• pp.173-192
• /
• 1998

This study was made as a part of the benethic fauna of Geojedo Island. The material was obtained from 17 localities (Fig. 1) along the coastal sea of Geojedo Island and it's adjacent waters during the years 1995-1998. This paper includes 38 species from a limited area of the southern part of Korea and includes 13 previously known species by Rho(1975-1991). Of these Didemnum (D.) pardum, Symplegma oceania, and Styela coriacea, are new to the Korean fauna, and 22 species are newly added to the fauna of Geojedo Island. We provided taxonomic notes and brief notes on the ascidian fauna, and the biogeographical distribution of Geojedo island. Its ascidian fauna are characterized by a high percentage of 18(47.4%) warm-water species and the extreme scarcity of eight(21.1%) boreal-water forms. This result may be attributable to the fact that Geojedo island and its adajacent waters are located under the influence of the warm Kuroshio Current.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.7 no.4
• /
• pp.257-266
• /
• 2002

To estimate the nitrogen budget and assess the purification function of a tidal flat ecosystem, a field survey was carried out at Hajeon tidal flat in Gomso Bay, the southern part of Byeonsan Peninsula, Chollabuk-do, Korea. A study area of 3.0$\times$4.5 ㎢ was established on the tidal flat and the concentrations of chlorophyll-a, DIN, DON, and TN were measured in the water column during the period of April 17-18, 1999: From the budget analysis, the loss rate of Chl-a was estimated to be -0.05 mg Chl/㎡/hr, which is approximately 7% of that at Issiki tidal flat in Aichi Prefecture, Japan. The lower loss rate of Chl-a in the study area was attributable to the lower standing crop of phytoplankton, the lower temperature that may reduce metabolic rates of biotic components and the lower biomass of macrobenthos in the study area. Over the 13.5 ㎢ of study area, Hajeon tidal flat removed 8.36$\times$10$\^$2/ kg N/day of TN, 5.36$\times$10$\^$3/ kg N/day of PON and 1.62$\times$10$\^$2/ kg N/day of phytoplankton-related PON, showing that the tidal flats may play an important role in removing nitrogen in coastal waters. The removal rate of PON, compared to the removal cost of the existing waste water treatment facilities, indicates that the economic value of the purification function of Hajeon tidal flat (13.5㎢) may be more than that of two large facilities.

• 한국해양학회지
• /
• v.23 no.2
• /
• pp.76-88
• /
• 1988

Size distribution of suspended particulate materials (SPM) in the coastal waters of eastern Korea was studied using a laser particle size analyzer. Mean particle size (MPS) ranges from 3.69 to 8.40 ${\mu}m$ in surface waters, from 3.38 to 6.43 ${\mu}m$ in mid-depth waters, and from 3.88 to 8.30 ${\mu}m$ in near-bottom waters. For smaller MPS, the size distribution is unimodal, whereas it becomes polymodal as the MPS increases. Particle concentrations increased with the increases in MPS, suggesting that processes of adding larger particles in the waters such as resuspension of bottom sediments are more important in controlling MPS in the area than processes of removing smaller particles such as flocculation of fine particles. Observations of higher MPS near the coast in mid-depth waters, and at the continental slope in near-bottom waters appear to support the above idea. For surface waters with high MPS, mean particle density was noticably low, indicating the importance of biological activities in the formation of suspended particles.