• Journal of Ecology and Environment
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• v.42 no.4
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• pp.285-291
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• 2018

The impact of climate change on animals has been globally documented. Especially, migration of birds has been extensively monitored as migratory birds are susceptible to any changes occurring both on breeding grounds and on wintering grounds. However, in contrast to spring migration, the patterns and the factors for autumn migration have not been well documented. In this study, we investigated the relationship with climate condition and the first arrival dates (FADs) of bean geese (Anser fabalis) and white-fronted geese (A. albifrons), the representative group of wintering birds in South Korea, using the data collected by Korean Meteorological Association during 1995-2016. Average temperature of September in wintering grounds has increased, and the FADs of the geese have advanced over the 22 years. Even when the influence of autumn temperature was statistically controlled for, the FADs of the geese have significantly advanced. This suggests that warming has hastened the completion of breeding, which speeded up the arrival of the geese at the wintering grounds. In order to assess the effect of climate condition on the arrival of the wintering migratory birds such as the geese in more detail, extensive data collection over many sampling sites and with long-term monitoring is needed.

• Ocean Science Journal
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• v.42 no.1
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• pp.41-48
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• 2007

We investigated the temperature and salinity effects on the major fish species in the wintering grounds based on trawl surveys and oceanographic observations in the southwestern waters of Korea during March-early April in 2002-2003. The influence area of warm Kuroshio water was limited to the southwestern area of Korea in 2003 with a range of $7.7-16.3^{\circ}C$, 32.54-34.70 of salinity, wider than that of 2002. The number of fish species and density of major fish species in 2003 were higher than in 2002. Geographical estimation showed high proportions of species number and catches in the areas around Jeju Islands, southwestern waters and the southeastern coast of Korea. Five species; silver pomfret (Pam pus echinogaster), hairtail (Trichiurus lepturus), anchovy (Engraulis japonicus), Small yellow croaker (Larimichthys polyactis) and yellow goosefish (Lophius litulon) were most abundant, composing above 60% of the total catch in 2002 and 2003. More than 50% of catch in the major fish species were mostly distributed in the range of $9.5-11.0^{\circ}C$ of temperature and 33.1-33.9 of salinity. Non-parametric estimation for the major species showed the 1st mode around $10^{\circ}C$ and the 2nd mode at $8-9^{\circ}C$ in 2002 and $11-14^{\circ}C$ in 2003. Among major fish species, hairtail was principally composed of juveniles, and larger individuals were caught in southeastern waters. These results are considered to be helpful for the area-based fishery management strategy for the wintering grounds of the Yellow Sea and coastal waters of Korea.

• Korean Journal of Environment and Ecology
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• v.30 no.5
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• pp.848-856
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• 2016

The purpose of this study is to determine the impact on settlement pattern of wintering swans by distribution of rapidly spreading lotus in Junam reservoir. When we investigated the relationship between the spreading lotus and population variation of the wintering swans in all around Nakdong-river estuary, the spreading lotus did not affect the number of swans in Junam reservoir. The occupation ratio of lotus distribution continuously increased from 13.2%(2013) to 19.0%(2014). Before we begin with the investigation, we compared two particular groups: inside of lotus community and far (>100 m) water area from the border of lotus community. At the first survey(2013.12.17), we observed 3.1 times more swan population in the inside, comparing with far water area. The third(2014.01.29.) and fourth(2014.12.03) inquiries also showed respectively 5.5 and 7.5 times higher swan population in the inside and near water area. The second observation was conducted during visitors were increased so these phenomenon was not observed. This result might be explained as the similar environmental condition of habitate for swan and lotus such as less than 1 m water depth. However, we considered that lotus and swan were not relation of conflict due to increasing both lotus community and swan population at the same time. According to the observation that inhabitation density of wintering swans is significantly high in near lotus communities area, at least spread of lotus did not negatively affect the wintering swans.

• The Korean Journal of Ecology
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• v.14 no.1
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• pp.63-73
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• 1991

Nakdong estuary provides the largest wintering grounds for migrating waterfowls in Korea, and was designated Natural Monument No. 179 in 1966. Nakdong barrage and related construction-projects finished in 1987 to increase freshwater-supply to nearby Pusan metropolitan area and to reclaim the vast intertidal areas for land development. Changes on distribution, primary productivity, and standing crop of Schoenopluctus triqueter, the dominant species in this intertidal flats, were investigated after the construciton, during the 1988-1990, and were compared to those before the construction. Total standing crop. tuber biomass and net primary productivity of S. triqueter increased in 1988 and 1989, but decreased slightly in 1990. Increase of tuber biomass means an increase in available food, thus the carrying capacity, for swans wintering in this area. Habitat environment of this estuary should be protected and managed as a wintering ground for migrating waterfowls, inspite of the construction of the barrage.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2007.04a
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• pp.176-177
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• 2007

We determined how presence of heterospecific individuals in the vicinity of a focal individual affects the behavior of two critically endangered species of cranes on their wintering grounds at Cheolwon in the Korean Demilitarized Zone(DMZ). The Red-crowned crane, Grus japonensis, is larger than the White-naped crane, Grus vipio, and it dominates the White-naped crane in aggressive interactions. We showed that the dominant species increases foraging activity in the presence of the subordinate species presumably because of scrounging of the food from the subordinate. Because interspecific interactions may affect avian endangerments this behavioral findings should be taken into account when managing winter refuges for the two engendered crane species.

• Journal of Aquaculture
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• v.1 no.1
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• pp.85-102
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• 1988

An experimental study on seedling production and wintering to develop pearl oyster, Pinctada fucata culture in Korea was carried out. from December 1986 to November 1988 in waters of Kori and of Seogwipo as wintering and of Eogu as culturing grounds. All pearl oysters as the sample were imported from Japan. The highest water temperature at Eogu was $23.6^{\circ}C$ in August and the lowest at Kori and Seogwipo were $13.2^{\circ}C$ and $14.0^{\circ}C$c in February, respectively, Phytoplankton was relatively plentiful but mortality of pearl oysters was $20.5\%$, which was twice at Seogwipo, due to high amount of suspended muds. It shows that Seogwipo is better wintering ground even though the amount of phytoplankton is lower than Kori. Average rates of pearl production after 6-months and 15-months period were $58.2\%$ and $48.3\%$ respecitively. Thickness of pearl layer and coating rate were also satisfactory. More than half of the pearls produced was so-called the pink-pearl, the best colour. About $10\%$ of them was the best quality. There were three peaks of D-shape larvae from July to September and it took about one month for D-shape larvae to become seed-shells. Settling was satisfactory and most of them settled at 1$\~$3 m layer and the best was 2 m-layer. Success of settling was supposed due to high water temperature and low precipitation than the normal year.

• Journal of Veterinary Clinics
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• v.31 no.3
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• pp.206-211
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• 2014

Anaplasmosis is a rickettsial zoonosis mediated by blood-sucking arthropods, such as ticks, flies, and mosquitos. Migratory birds are common hosts of ticks that are mediators of anaplasmosis, in particular, the tick infection rate in thrushes (family Turdidae) has been known to be high. The main purpose of this study is to survey the occurrence and prevalence of Anaplasma spp. from the migratory thrushes in Jeju island. We collected blood samples from 6 thrushes rescued at the Jeju Wildlife Rescue Center and from 34 wild-caught thrushes on Mara island which is a satellite island of Jeju. As a result, the nested PCR confirmed that seven out of 40 individuals (17.5%) were infected by Anaplasma spp. and all of them were identified as A. phagocytophilum based on sequences obtained from partial 16S rRNA. All the infected birds were on their northward migration in spring, our results suggest that the Turdidae family, which is a common and abundant migrant group passing through Jeju island, may act a role as active reservoir and disperser of A. phagocytophilum causing potential influx of the zoonotic pathogens from its wintering grounds in lower latitude to the mainland Korea as well as Jeju.

• The Korean Journal of Ecology
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• v.28 no.4
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• pp.199-206
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• 2005

Estuary islets should be managed systematically because they are important places for birds to rest and breed. This paper investigates the environmental properties of islets where the sand banks are located from east to west on the southernmost of Nakdong estuary during a year (September 2003 $\sim$ August 2004). The research showed that 59 species and 19,148 individuals were found in the area A (Jangja Shinja-Do) and 61 species and 28,394 individuals in the area B (Saja-Do; Beakhapdeung Doyodeung). Totally, 74 species and 47,539 individuals were observed in both of this estuary. Shorebirds are the most observed species in both areas. In area, most of individuals were especially observed in the spring when Shorebirds migrate northward for breeding. In B area, various species were also observed in the fall when they migrate southward for wintering. Therefore, many groups of birds are observed around Shinja-Do in the spring. They passed the winter in Doyodueng, associated with feeding in the main stream of Nakdong river mainly. Although the southernmost sand bar is the breeding place to access to outside without interception, invasion by human beings and predators (mice, weasels and etc.) gives a fatal blow for birds to breed or rest. The reed which is a tall herbaceous plant is flourished according to the process of ecological succession. Therefore, the sand bar becomes a land. It results in reduction of habitats and breeding grounds for birds. In conclusion, these areas where birds can use the islets as habits and breeding places must be preserved by restraining luxuriance of reeds and systematic management of human beings and predators is necessary.

• Korean Journal of Remote Sensing
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• v.32 no.6
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• pp.639-645
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• 2016

Yeongjong-do is seventh largest island in the west coast of Korea which is 4.8 km away in the direction of south-west from Incheon. The mudflat area around the Yeongjong-do has variable dimension according to tide level. In addition, Yeongjong-do is important area with high environmental value as wintering sites for migratory birds. The mudflat of Yeongjong-do is also meaningful region because it is used as place of education and tourist attraction. But, there are increasing concerns about preservation of mudflat area caused by artificial development such as land reclamation project and Incheon airport construction. In this paper, mudflat area was detected using Landsat 7 ETM+ images that United States Geological Survey (USGS) is providing the data in 16 days period. The false color composite was made from band 7, 5, and 3 that could dividing boundary between water and land for the purpose of appearance of boundary line in mudflat region. This area was calculated using results of classification based on false color composite images and was digitized through repetitive algorithm during research of period. Therefore, the change of northeastern area in Yeongjong-do was detected according to tide level during 16 years from 2000 to 2015 on the basis of providing period at tide station. This paper will expect as indicator for range of area in same tide level prior to the start of the research for preservation of mudflat. It will be also scientific grounds about change of mudflat area caused by artificial development.

• Korean Journal of Environment and Ecology
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• v.32 no.3
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• pp.256-260
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• 2018

Cannibalism is a widely observed phenomenon in the animal kingdom. However, it is rarely found among birds outside nests in the wild because it occurs irregularly and it is almost impossible to monitor animal behavior constantly. On 17 January 2017, this behavior was directly observed from a group of vultures feeding on a conspecific in a paddy field near Lake Geumho in Haenam-gun ($34^{\circ}35^{\prime}58.25^{{\prime}{\prime}}N$, $126^{\circ}26^{\prime}57.64^{{\prime}{\prime}}E$). It was observed and recorded with the binoculars and a camera with a telephoto lens in a car approximately 20 m (or 60 m) away from the site. The observer approached the feeding site after the last vulture had finished feeding and flown away and found remains of a vulture, including body feathers, skull, sterna keel, and both legs. It was the first report of cannibalism in Cinereous vulture Aegypius monachus in its overwintering grounds. The remaining skeleton was very fleshy, and the surrounding grass was wet with the blood of vulture. No other traces of a mammal or bird that could have been the vultures' prey were found. This report provides a detailed account of the events related to this rare observation and the causes that might have led to it.