• 한국수산과학회지
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• 제39권spc1호
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• pp.142-150
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• 2006

We examined the effect of predation by observing the changes in macrobenthic communities in a tidal flat at Seonjae, Korea, following the exclusion of large predators such as birds, fishes and crustaceans using protective screens. We conducted two interference experiments in the field from April to November 2004: (1) Experiment 1 was conducted at a mid-tidal flat in the western part of Seonjae-do, Incheon, Korea, (2) Experiment 2 was set up at a low tidal flat in the eastern part of Seonjae-do. predator exclusion showed different effects in the two experiments. Both the number of species and density were reduced by 20% in Experiment 1. Whereas in Experiment 2, they increased by up to 13% and 69%, respectively. In Experiment 1, a high density of brachyuran crabs observed in the treatment may have caused the difference in community composition between the treatment and the control, and this probably resulted from active predation of macrofauna (e.g., small crabs) under protection from megafaunal predators such as birds and fishes. However, in Experiment 2, as typically observed in other predator exclusion experiments, a lower density of benthic predators and the subsequent reduction of over predation probably resulted in a more diverse and abundant benthic community in the treatment. We confirmed that predation was a contributing factor in the formation of the macrobenthic community. We also demonstrated relationships that exist among different trophic groups (large predators, macrobenthic predators and prey) and what effects and responses occur in each component of the tidal flats.

• 대한수의학회지
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• 제30권2호
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• pp.203-214
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• 1990

A total of 166 strains of Salmonella (S) typhimurium var copenhagen isolated from pigeons (164 strains) and aquatic birds (2 strains) were examined for the biochemical characteristics and plasmid profiles. All the strains were sensitive to ampicillin, chloramphenicol, gentamicin, kanamycin and sulfadimethoxine. But 13 strains(7.8%) were resistant to streptomycin (Sm), 2 (1.2%) to tetracycline, 2 (1.2%) to rifampicin, and 1 (0.6%) to nalidixic acid. Among drug resistant strains, only one strain resistant to Sm contained conjugative R plasmid which was fertility inhibition and incompatibility group $I_{\alpha}$. All the strains were sensitive to cobalt chloride, cupric sulfate, lead nitrate, mercuric chloride and silver nitrate. Of 166 isolates, 6 (3.6%) were resistant to sodium arsenate and 1 (0.6%) to potassium tellurite. Among 166 isolates, 1 (0.6%) was colicinogenic, 12 (7.2%) sucrose fermenters, and 166 (100%) maltose fermenters. Plasmid profiles were confirmed as being 4 or 5 plasmids, and their molecular weight ranged 3.2 to 60 megadalton (MD). All the strains harbored 60 Md plasmid. There are three patterns by the plasmid profile, 150 isolates (90.4%) were pattern I (3.2, 3.5, 33, 60Md), 14 (8.4%) pattern II (3.2, 3.5, 29, 60Md), and 2 (1.2%) pattern III (4.2, 7.8, 8.5, 15, 60Md). S typhimurium var copenhagen strains containing 60Md plasmid were resistant to killing by 90% normal guinea pig serum.

• 한국수산과학회지
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• 제47권6호
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• pp.973-977
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• 2014

We studied distribution of seabirds using strip transect counts from May $2^{nd}$ to $30^{th}$, 2011. we observed 322 individuals from nine seabird species. Black-tailed gulls (Larus crassirostris, 48.4%) were numerically dominant. Ancient murrelets (Synthliboramphus antiques, 18.6%), Vega gulls (Larus vegae, 17.7%), red-throated divers (Gavia stellata, 4.7%), Pacific divers (Gavia pacifica, 4.3%), streaked shearwaters (Calonectris leucomelas, 1.9%), and common terns (Sterna hirundo, 1.6%), were also frequently observed. The overall seabird density was 0.55 birds $km^{-2}$, lower that of the East Sea.

• 한국잡초학회지
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• 제18권2호
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• pp.85-94
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• 1998

Herbicides play a very important role in modern agriculture. However, the herbicide applied to the agricultural field may accumulate in the field, converting the advantages to environment pollution. Many small animals in the ecosystem such as alderfly, earthworm, butterfly, loach, frog, firefly, some birds and aquatic organisms have been known to disappear gradually. In addition, several behavior of herbicides including adsorption by soil, movement by water, photodecomposition, volatilization to air, absorption by plant, metabolism by soil microorganisms and so on, are proceeded while the herbicide remained in the environment. In this review, fate and behavior of herbicides in the environment and their effect on ecosystem after their application are focused on four aspects : the first is the absorption and metabolism of herbicides by plant; the second is the residues of herbicides in soil and water environments: the third is the accumulation and release of herbicides in aquatic organisms and the fourth is the translocation of herbicides in model agricultural ecosystem. Many factors may affect the behavior and fate of herbicides after their application, climatic conditions and soil properties seem to be the most important. Therefore, the fate and behavior of herbicide in Taiwan, located on subtropical region, may differ from those in Korea.

• 한국습지학회지
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• 제19권4호
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• pp.409-422
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• 2017

월동수조류의 군집에 영향을 미치는 환경요인을 파악하기 위하여 원주천을 6구간으로 나누어 조류의 군집 및 하천의 크기, 기온, 수질, 저서성무척추동물, 어류를 조사하였다. 원주천에서 수조류의 군집에 영향을 미치는 요인은 하천의 구조 및 기온, 수질이었다. 하천의 구조 중 월동수조류의 군집에 가장 큰 영향을 미치는 요인은 저수로의 폭과 흐르는 물의 넓이인 유폭으로 그 넓이가 넓을수록 월동수조류의 종수와 개체수가 많았으며, 둔치의 폭이 넓어서 저수로의 폭과 유폭이 좁아질수록 개체수는 적었다. 월동기의 기온 변화는 하천의 결빙으로 이어지므로 수조류의 군집에 영향을 미쳤으며 결빙되지 않는 구간은 기온의 하강과 상승에 뚜렷한 증가와 감소를 보였다. 수질조사 항목 중 pH, 수온, COD, BOD, T-N, T-P, 총대장균의 수치는 하류로 갈수록 증가하여 월동수조류의 개체수 증가와 높은 상관성을 보였는데 하류에 위치한 하수처리장의 영향으로 S6의 수질검사 항목의 수치가 높게 나타났으며 월동수조류의 개체수 또한 가장 많이 관찰되었다. 하수처리장 배출수는 수질에 상당한 영향을 미치는 것으로 보이는데 T-N을 비롯하여 여러 항목 수치의 증가는 하천의 영양화를 촉진시키고 이로 인해 유기물질의 축적과 수서생물의 증식을 가져옴으로 이를 먹이원으로 하는 월동수조류의 증가 원인이 될 수 있을 것으로도 여겨진다. 저서성 대형무척추동물의 군집과 어류의 군집은 원주천 모든 구간에서 대체적으로 양호한 것으로 나타났으나 월동수조류의 군집과의 상관성을 보이지 않았다.

• Journal of Veterinary Science
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• 제22권4호
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• pp.43.1-43.10
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• 2021

Background: The H5 avian influenza viruses (AIVs) of clade 2.3.4.4 circulate in wild and domestic birds worldwide. In 2017, nine strains of H5N6 AIVs were isolated from aquatic poultry in Xinjiang, Northwest China. Objectives: This study aimed to analyze the origin, reassortment, and mutations of the AIV isolates. Methods: AIVs were isolated from oropharyngeal and cloacal swabs of poultry. Identification was accomplished by inoculating isolates into embryonated chicken eggs and performing hemagglutination tests and reverse transcription polymerase chain reaction (RT-PCR). The viral genomes were amplified with RT-PCR and then sequenced. The sequence alignment, phylogenetic, and molecular characteristic analyses were performed by using bioinformatic software. Results: Nine isolates originated from the same ancestor. The viral HA gene belonged to clade 2.3.4.4B, while the NA gene had a close phylogenetic relationship with the 2.3.4.4C H5N6 highly pathogenic avian influenza viruses (HPAIVs) isolated from shoveler ducks in Ningxia in 2015. The NP gene was grouped into an independent subcluster within the 2.3.4.4B H5N8 AIVs, and the remaining six genes all had close phylogenetic relationships with the 2.3.4.4B H5N8 HPAIVs isolated from the wild birds in China, Egypt, Uganda, Cameroon, and India in 2016-2017, Multiple basic amino acid residues associated with HPAIVs were located adjacent to the cleavage site of the HA protein. The nine isolates comprised reassortant 2.3.4.4B HPAIVs originating from 2.3.4.4B H5N8 and 2.3.4.4C H5N6 viruses in wild birds. Conclusions: These results suggest that the Northern Tianshan Mountain wetlands in Xinjiang may have a key role in AIVs disseminating from Central China to the Eurasian continent and East African.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.236-240
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• 2001

When we make on irrigation and drainage canals, the environment should be preferentially taken into consideration. The purpose of this study is to test Close-to-nature Consolidation Techniques in the drainage canals of Samsungri, Kanam-myun, Yeoju-gun, Kyunggi-do. The monitoring and assessment of these techniques has been conducted during two years, focuesed the drainage canals ecological habitat and landscape. As the result of this study, the embankment covered with Close-to-nature Consolidation Techniques played an important role as a habitat for aquatic animal, fish and birds as well as the groth emergement plant.

• 농촌계획
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• 제27권2호
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• pp.49-58
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• 2021

Rural and agricultural landscapes are important forms of land use in maintaining biodiversity. In addition humans are provided with various public functions from ecosystems and agricultural ecosystems. But the creation of a facility horticultural complex can be a space that can undermine the public interest function of the agricultural ecosystem. Therefore, this study aims to quantify the function of ecosystem services that land use changes affect biodiversity in Korea's rice paddy fields. The area subject to the study was selected as the largest agricultural complex in Korea due to rice paddy fields and land use changes, and field agriculture was also carried out simultaneously. The survey was conducted only in the fields of vegetation, insects, amphibians, and birds, four areas of biodiversity that are believed to have a high impact on changes in land use in agricultural landscapes. The valuation of ecosystem services in four areas of biodiversity derived from this study was evaluated as non-market value. As a result of quantitative evaluation, about 25 species of vegetation were reduced due to changes in land use. The diversity of about 40 species of aquatic insects that inhabit rice paddies among insects has disappeared due to the creation of a horticultural complex. Birds and amphibian reptiles were also found to have decreased diversity and populations. This research is expected to be used in various ways to develop policies to enhance ecosystem service functions.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권2호
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• pp.77-83
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• 2022

This study was conducted from March 2018 to December 2019 to identify bird diversity and environmental correlates within the Mulchat-oream wetlands in the Jeju Islands of South Korea. A total of 255 individual belonging to 37 species were recorded form Mulchat-oream. The observation produced a species diversity of 3.14, species richness of 6.54 and species evenness of 0.88 in 2018, and in 2019, the observed species diversity was 3.02, species richness was 6.56 and species evenness was 0.84. The highly dominant species are composed of Passeriformes. The absence of diverse submerged plants, deep water depth and isolated geographical locations makes difficult for aquatic birds to prefer this area, and this has resulted in the dominance of Passeriformes. The appearance of the birds was the lowest in the winter and highest during the summer. The analysis showed that the species richness and evenness increased with an increase in temperature and precipitation. However, the number of species appearing during Mulchat-oream significantly dependent on the temperature (P<0.001, df=2). To date, there has been little research on bird diversity together with environmental factors for the Hallasan National Park. This study shows the environmental factors and seasonal patterns that affect bird population.

• 한국수산과학회지
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• 제17권1호
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• pp.47-54
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• 1984

태평양 서부 적도해역에서 조업하는 다랑어 선망어선 4척으로 부터 다랑어 어군 370개의 어군속성, 어군에 대한 선망조업의 경과, 어획물등에 관한 자료를 얻어 이것을 통계학적으로 해석하여 다음의 결과를 얻었다. 1. 이 해역에서 발견되는 다랑어 표층역어군은 보편적으로 해오, 소형어류 및 부류물체와 함께 발견되었다. 2. 부류물체에 모인 어군에 대한 선망조업에서는 일출전시각에 투망되는 회수가 많고, 해조가 따르는 어군에 대한 조업에서는 일출후시각에 투망되는 회수가 많다. 3. 부류물체에 모인 어군에 대한 선망조업에서는 조업당어획량이 중위치이상인, 성공적조업의 회수가 많다. 4. 부류물체에 모인 어군에 대한 선망조업에서는한 어군에 대하여 한 번 투망한 다음 추가하여 제2차 이상 투망하는 수가 있다. 5. 부류물체에 모인 다랑어 어군의 크기는 물체의 길이와는 상관관계가 낮고, 물체의 구조와는 상관관계가 높다. 즉 통나무, 나무 판자등 단순한 구조의 물체보다는 뿌리나 가지가 달린 나무 줄기, 대나무 덤불 등이 뿌리 뽑힌 것과 같이 복잡한 구조의 물체의 어군유인효과가 크다.