In recent years, macroalgal bloom occurs frequently in coastal oceans worldwide. It might be attributed to accelerating climate change. “Green tide” events caused by proliferation of green macroalgae (Ulva spp.) not only damage the local economy, but also harm coastal environments. These nuisance events have become common across several coastal regions of continents. In Korea, green tide incidences are readily seen throughout the year along the coastlines of Jeju Island, particularly the northeastern coast, since the 2000s. Ulva species are notorious to be difficult for morphology-based species identification due to their high degrees of phenotypic plasticity. In this study, to investigate temporal variation in Ulva community structure on Jeju Island between 2015 and 2020, chloroplast barcode tuf A gene was sequenced and phylogenetically analyzed for 152 specimens from 24 sites. We found that Ulva ohnoi and Ulva pertusa known to be originated from subtropical regions were the most predominant all year round, suggesting that these two species contributed the most to local green tides in this region. While U. pertusa was relatively stable in frequency during 2015 to 2020, U. ohnoi increased 16% in frequency in 2020 (36.84%), which might be associated with rising sea surface temperature from which U. ohnoi could benefit. Two species (Ulva flexuosa, Ulva procera) of origins of Europe should be continuously monitored. The findings of this study provide valuable information and molecular genetic data of genus Ulva occurring in southern coasts of Korea, which will help mitigate negative influences of green tide events on Korea coast.

Abstract
서 론
재료 및 방법
    1. 연구대상 지역
    2. 유전자 분석을 위한 시료 채취 및 전처리
    3. Genomic DNA 추출 및 엽록체 DNA tufA PCR
    4. DNA 염기서열 정렬 및 분자계통수 분석
결과 및 고찰
    1. 분자 계통학적 분석 기반 제주도 연안파래 군집구조 및 주요 종
    2. 제주도 연안 파래 군집구조의 5년간 시간적 변이
적 요
사 사
REFERENCES

• 박혜진(상지대학교 생명과학과 분자생태및진화학연구실) | Hye Jin Park (Molecular Ecology and Evolution Laboratory, Department of Biological Science, Sangji University)
• 변서연(상지대학교 생명과학과 분자생태및진화학연구실) | Seo Yeon Byeon (Molecular Ecology and Evolution Laboratory, Department of Biological Science, Sangji University)
• 박상율(제주대학교 해 양생명과학과 하 구및연안생태학연구실, 제주대학교 기후변화대응센터) | Sang Rul Park (Estuarine and Coastal Ecology Laboratory, Department of Marine Life Sciences, Jeju National University, Center for Climate Change Response, Jeju National University)
• 이혁제(상지대학교 생명과학과 분자생태및진화학연구실) | Hyuk Je Lee (Molecular Ecology and Evolution Laboratory, Department of Biological Science, Sangji University) Corresponding author