• Parasites, Hosts and Diseases
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• v.36 no.3
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• pp.163-170
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• 1998

An epidemiological survey was performed to know the infection status of oysters with Gwmnophclloides seoi metacercariae in 7 islands of the West Sea known as the habitat of paleartic oystercatchers . Hcemntopus ostralegus osculans, in Korea. The surveyed areas were Aphaedo (Shinan-gun. Chollanam-do) Jangiado, Sonyudo and Munyodo (Okdo-myon, Kunsan-shi, Chollabuk-do), Yubudo (Changhang-up, Sochon-gun Chungchongnam-do), and Polumdo and Chumoondo (Sodo-myon, Kangwha-gup, Inchon ski). The oysters collected from Aphaedo, the known endemic focus, were examined monthly from August 1995 to October 1996 for observation of any seasonal variation of the metacercarial density. The average metacercarial burden was 761-2,077 by month, but the seasonal variation of the metacercarial density was not obvious. A total of 54 metacercariae was detected in 63 oysters collected from Yubudo. Out of 30 oysters from Sonyudo, 25 (83.3%) were infected with 1-66 metacercariae (12.6 in average). All of 50 oysters (100%) from Munyodo were infected with 3-162 metacercariae (53.5 in average), Only 4 metacercariae were detected in 100 oysters from Chumoondo. However, no metacercariae were found in 55 oysters from .Tangjado and 50 oysters from Polumdo. From the above results, it was confirmed that G. seoi is still highly prevalent in oysters from Aphaedo, and several islands of the West Sea known as the habitats of paleartic oystercatchers are new endemic areas of this fluke.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.160-169
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• 2019

The migration status of waterbirds inhabiting the 10 coastal wetlands in the south and west coasts (Jangbongdo, Muuido, Daecheoncheon estuary, Seocheon tidal flat, Yubudo, Gomso bay, Hauido, Jeungdo, Doam bay, Gangjin bay) was examined from May 2008 to March 2013. For the most dominant taxonomical group, shorebirds accounted for 37.5% of the number of species and 67.1% of the total population, followed in the order of dabbling ducks, herons, and seagulls. The dominate species were Calidris alpina, Larus crassirostris, Limosa lapponica, Charadrius alexandrinus, and Calidris tenuirostris. Shorebirds were observed most at Seocheon Tidal Flats and Yubudo Island, and dabbling ducks were found most in Doam Bay. Diving ducks were observed most at Gangjin Bay and seagulls were seen most frequently at Seocheon Tidal Flats. The ten coastal wetlands of the western and southern coasts were divided into three groups according to the similarity index of waterbirds (Ro). Group 1 was the area where dabbling ducks and diving ducks were dominant, group 2 was the area where shorebirds were dominant, and group 3 was the area where seagulls were dominant. It was evident that there were differences in species composition depending on the regional environments.

• Journal of Wetlands Research
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• v.21 no.1
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• pp.84-94
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• 2019

The Seocheon and Yubu Island mudflats in Geum Estuary are important stopover sites for migratory birds as energy supplementation area in the East Asia-Australasian Flyway. Benthic invertebrates in the tidal flats are important food resources for the migratory birds. In other words, benthic invertebrates in the tidal flats play an important ecological role in energy flow. This study was conducted to investigate the relationship between benthic invertebrate assemblages and environmental factors in Seocheon and Yubudo tidal flats in the Geum Estuary. As a result of the benthic invertebrate assemblage during the fall migration season, the total species number was 147, density and biomass were $1,772{\pm}1,342individuals/m^2$ and $445.1{\pm}807.6g/m^2$, respectively. Based on the appearance species and the density data, the result of analysis of mutual similarity among sampling sites was divided into two groups. Group A was the Macrophthalmus-Heteromastus community and Group B was the Spio-Urothoe-Mandibulophoxus community. Group B showed higher mean species number, density and biomass than Group A. The BIO-ENV analysis showed that the benthic invertebrate assemblages were most affected by the combination of sand content % and sediment sorting (${\rho}=0.500$). The variables of significant relationship with species number and biomass were sediment sorting (p=0.015) and the pore water DO(Dissolved Oxygen, p=0.003) in sediment, respectively.