본 연구는 패류양식업이 밀집한 남해 강진만 해역에서 수하식 및 살포식 양식해역과 비양식해역을 구분하여 양식활동으로 인한 유기물 축적과 저서다모류군집 변화를 파악하고, 어장환경평가 기법을 활용하여 건강도를 평가하고자 수행되었다. 남해 강진만 해역의 평균 입도, 수온, 염분농도, 총유기탄소 등의 시·공간 분포는 정점간에 큰 차이가 없었던 반면, 출현 종수, 개체밀도와 종다양도 등은 살포식 양식 해역의 정점이 다른 해역의 정점과 비교해 상대적으로 낮은 경향을 보였다. 한편 집괴분석과 주요좌표분석 결과에서도 살포식 양식해역 정 점의 저서다모류군집이 나머지 정점의 군집과 뚜렷하게 구분되었다. 수하식 양식해역의 정점과 비양식해역 정점에서는 오염지시종인 Scolectoma longifolia와 Sigambra tentaculata가 우점종으로 출현하였으나, 수심과 해수 유통 등의 물리적인 요인에 의한 영향을 받는 일부 정점 을 제외하면 점유율이 높지 않았다. 강진만 해역의 저서생태계 건강도는 1~2등급으로 양호한 상태였다. 그러나, 다모류군집구조의 시·공간 분 포와 저서생태계 건강도지수를 고려하면 살포식 양식해역의 퇴적환경은 양식으로 인한 물리적인 교란에 영향을 받는 것으로 보여진다.

River estuaries are dynamic and productive ecosystems with high regional biodiversity. Environmental DNA (eDNA) has become a useful approach to assessing biodiversity in aquatic ecosystems. This study was conducted to investigate fish community characteristics and species diversity in two river estuary ecosystems, the Taehwa River and Changwon Stream. We further compared conventional and eDNA metabarcoding analyses of the fish communities. The conventional survey was performed in May, July, and October 2022, while the eDNA analysis was conducted only in May. We observed various fish species with different life histories, including carp, goby, and marine fish. We also found that migratory fish, such as dace Tribolodon hakonensis, sweetfish Plecoglossus altivelis, and eel Auguilla japonica, occurred in the Taehwa River, suggesting high river connectivity. Marine fish species were predominant in the Changwon Stream, as this river is located close to the sea. The diversity indices showed that the Taehwa River generally had higher species richness, evenness, and diversity values than the Changwon Stream. A total of 9-19 species were detected in the conventional survey for the three sites, whereas 11-18 species were found from eDNA analysis. The findings indicate that the sensitivity of eDNA was similar to or higher than that of the conventional method. Our study findings suggest the efficiency and efficacy of eDNA-based fish community monitoring, although with some shortcomings in applying the genetic marker to Korean fish, including no clear-cut distinction for Korean endemic species and/or genetically closely related species groups.

In this study, changes in the microbial ecosystem of the Yeongheungdo island coastal waters were investigated for five years to collect basic data. To evaluate the influence of distance from the coast on the microbial ecosystem, four sites, coastal Site (S1) and 0.75, 1.5, and 3 km away from the coast, were set up and the changes in physicochemical and biological factors were monitored. The results showed seasonal changes in water temperature, dissolved oxygen, salinity, and pH but with no significant differences between sites. For nutrients, the concentration of dissolved inorganic nitrogen increased from 6.4 μM in April-June to 16.4 μM in July-November, while that of phosphorus and silicon phosphate increased from 0.4 μM and 2.5 μM in April-June to 1.1 μM and 12.0 μM in July-November, respectively. Notably, phosphorus phosphate concentrations were lower in 2014-2015 (up to 0.2 μM) compared to 2016-2018 (up to 2.2 μM), indicating phosphorus limitation during this period. However, there were no differences in nutrients with distance from the coast, indicating that there was no effect of distance on nutrients. Phytoplankton (average 511 cells mL-1) showed relatively high biomass (up to 3,370 cells mL-1) in 2014-2015 when phosphorus phosphate was limited. Notably, at that time, the concentration of dissolved organic carbon was not high, with concentrations ranging from 1.1-2.3 mg L-1. However, no significant differences in biological factors were observed between the sites. Although this study revealed that there was no disturbance of the ecosystem, further research and more basic data on the microecosystem are necessary to understand the ecosystem of the Incheon.

Although the abundance of Metapenaeus joyneri resources with high commercial value was recently confirmed in the outer waters of Gomso Bay, located between Buan-gun and Gochang-gun, Jeollabuk-do, Metapenaeus joyneri resources have not been efficiently utilized due to the absence of fishing gears and methods for a selective Metapenaeus joyneri capture. Therefore, in this study, we adopted shrimp dredge as a trial fishing gear for the Metapenaeus joyneri capture, and analyzed the species composition and cluster community structure of aquatic organisms caught by the shrimp dredge, from May to September 2021 at the coastal waters of Gochang-gun, Jeollabuk-do. During the experimental period, 28 types of marine species of 29,190 individuals and 250,136 g of total biomass were caught. Among them, the population of Metapenaeus joyneri, the target species, dominated by 80.7%, followed by Thrysa chefuensis with 7.1%, and Leiognathus nuchalis with 6.0%, confirming that the fishing ratio of Metapenaeus joyneri was the highest among all species.

The objectives of this study were to analyze the fish community structures and distribution characteristics of fisheries resources in the Osip Stream and Wangpi Stream, fishery resources protection areas. For the study, we conducted fish samplings four times in the two streams from April to October 2019. In Osip Stream and Wangpi Stream, we sampled 31 species and 29 species and the dominant species were Zacco platypus (28.6%) and Squalidus multimaculatus (41.7%), respectively. According to the life type of fish species, primary freshwater species were collected 18 species (58.1%) and 21 species (72.4%), and migration fishes were sampled 4 species (12.9%) and 6 species (20.7%) in Osip Stream and Wangpi Stream, respectively. Fisheries resources species showed high relative abundance in June, and the fish biomass was highest in October. As a results of comparing the previous studies with this study, both rivers showed high biodiversity and were found to maintain stable populations of fishes. According to analysis of tolerance guilds, the proportion of tolerant species, based on the number of individuals, was composed of 14.4% and 1.1% in Osip Stream and Wangpi Stream, respectively. This very low ratio of tolerant species confirmed that both streams have very good physiochemical environment conditions. From the above results, it was judged that the fishery resource protection areas of Osip Stream and Wangpi Stream have high ecological function and preservation value. For sustainable use and management of fishery resource protection areas of Osip Stream and Wangpi Stream, it is suggested that biological disturbance management, fish discharge projects considering environmental capacity, efforts to improve the habitat environment, and establishing a fishery resource protection areas management system were necessary as considerations.

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.

Fish assemblage of total 325 of Korean peninsula estuaries were surveyed to analyze the characteristics of community structure and diversity by sea areas for three years from 2016 to 2018. The scale (stream width) of Korean estuaries were various (14~3,356 m), and 68.9% of all estuaries showed salinity of less than 2 psu. Total 149 species classified into 52 families of fish were identified, and the dominant and sub-dominant species were Tribolodon hakonensis (relative abundance, RA, 12.5%) and Mugil cephalus (RA, 9.5%), respectively. The estuary of the Korean Peninsula had different physical and chemical habitat environments depending on the sea area, and accordingly, fish community structure also showed statistically significant differences (PERMANOVA, Pseudo-F=26.69, P=0.001). In addition, the NMDS (nonmetric multidimensional scaling) results showed the patterns that indicating fish community difference by sea areas, even though low community similarity within sea area (SIMPER, 21.79~26.39%). The estuaries of east sea areas were distinguished from the others in the aspects of which, the higher importance of migratory fishes and endangered species, and that of brackish species were characterized at south sea estuaries. However, the estuaries of west sea showed higher importance of species that have a relation with freshwater (primary freshwater species, exotic species), which is the result that associating with the lower salinity of west sea estuaries because of the high ratio of closed estuaries (78.2%). The SIMPER analysis, scoring the contribution rates of species to community similarity, also showed results corresponding to the tendency of different fish community structures according to each sea area. So far, In Korea, most studies on fish communities in estuaries have been conducted in a single estuary unit, which made it difficult to understand the characteristics of estuaries at the national level, which are prerequisite for policy establishment. In present study, we are providing fish community structure characteristics of Korean estuaries in a national scale, including diversity index, habitat salinity ranges of major species, distribution of migratory species. We are expecting that our results could be utilized as baseline information for establishing management policies or further study of Korean estuaries.

The present study investigated species richness and phytoplankton community structure in lakes in the Geum River Basin during autumn and spring seasons. Surveys were conducted between September and November 2019, and between April and May 2020, which corresponded to the autumn and spring seasons, respectively, to explore the distribution characteristics of the species. A total of 49 species of phytoplankton belonging to 31 genera and seven classes were identified in Cho Pyeong-ji, 51 species belonging to 29 genera and six classes were identified in Song Ak-ji, 49 species belonging to 32 genera and seven classes were identified in Cheong Cheon-ji, 82 species belonging to 45 genera and six classes were identified in Ye Dangji, and 70 species belonging to 40 genera and six classes were identified in Ganwol Lake. A total of 43 species belonging to 74 genera and seven classes were identified. The ranges of phytoplankton standing crop were as follows: 223~3533 cells mL-1 in Cho Pyeong-ji, 881~176018 cells mL-1 in Song Ak-ji, 402~6139 cells mL-1 in Cheong Cheon-ji, 262~10460 cells mL-1 in Ye Dang-ji, and 20413~330695 cells mL-1 in Ganwol Lake. Phytoplankton diversity in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 1.10~2.60, 0.56~2.03, 0.21~2.03, 0.65~2.57, and 0.44~1.12, respectively. Phytoplankton species richness in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 1.91~4.99, 1.82~3.26, 1.26~4.17, 2.07~5.37, and 1.90~2.43, respectively. Phytoplankton evenness indices in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 0.38~0.78, 0.18~0.69, 0.08~0.71, 0.22~0.72, and 0.14~0.38, respectively. Phytoplankton dominance indices in Cho Pyeong-ji, Song Ak-ji, Cheong Cheon-ji, Ye Dang-ji, and Ganwol Lake were 0.40~0.83, 0.55~0.96, 0.44~0.99, 0.42~0.93, and 0.89~0.97, respectively.

본 연구에서는 장기간 운영된 양식장에 휴지기가 주어졌을 때, 양식장 주변 퇴적 환경에서 나타나는 회복상태를 규명하고자 하였으며, 이를 위해 경남 통영의 수하식 굴양식장 일대에서 대형저서다모류 군집을 조사하였다. 2016년 7월부터 2018년 9월까지 20년 간 운영된 후 폐쇄된 양식장(FF), 양식장의 이동으로 새롭게 설치된 양식장(NF), NF와 인접한 비교대상의 굴양식장(CF), 그리고 양식시설이 없는 두 개의 대조지역(Con1, Con2) 등 5개 정점에서 현장조사를 수행하였다. 출현종수와 서식밀도는 여름철에 감소하고 늦가을철 부터 증가하는 계절 변동을 보였으며, 양식장 정점들이 비양식장 정점들에 비해 높았다. 출현종의 상위우점종은 비양식장 정점에서는 Paraprionospio patiens, 양식장 정점에서는 Capitella capitata로 차이를 보였으나, 두 종 모두 유기물이 심한 지역에서 출현하는 잠재적 유기물 오염지시종으로 조사지역 저서환경의 유기물 오염이 상당히 진행되었음을 나타내었다. 다변량분석 결과, FF가 Con1과 군집구조가 유사한 수준으로 변화하였지만 Con1 이상의 상태로 회복을 나타내지 않았다.

본 연구의 목적은 남한 및 백두산일대 분비나무림의 군집구조를 확인하여 보전 및 관리를 위한 기초자료를 구축하는데 있다. 해발 1,000m 이상의 분비나무림 우점지역을 대상으로 총 470개소의 방형구를 설치하여 임분조사를 실시하였다. 조사시기는 2019년 7월부터 2020년 10월까지 수행되었다. 연구결과 군집은 크게 4개의 군집으로 신갈나무-사스래나무 군집, 분비나무 순군집, 주목 군집 그리고 신갈나무 군집으로 분류되었다. 분비나무 개체군의 흉고직경급은 역 J자형의 임분구조로 분석되었다. 국내 및 백두산 일대까지의 분비나무림의 하층식생은 임분이 안정화됨에 따라 낮은 종다양성지수를 나타낼 것으로 판단되었다. 향후 분비나무림의 쇠퇴지역과 유지지역에 대한 모니터링을 통하여 보전과 이용적 측면을 고려한 산림경영이 필요할 것으로 판단된다.

본 연구는 서해안 갯벌의 퇴적물 환경 및 대형저서동물 군집의 특성과 건강도를 파악하기 위해 수행되었다. 조사는 강화도부터 전남 목포까지 2017년 4월(춘계)과 8월(하계), 2018년 4월(춘계)에 실시하였다. 충남 권역의 퇴적물 입도는 조립하였으며, 경기·인천 권역, 전북 권역, 전남 권역의 퇴적물은 세립하였다. 대형저서동물은 총 140종으로, 대형저서동물 군집유사도를 분석한 결과, 대형저서동물 군집은 4개의 그룹으로 나뉘었다. Group2는 바지락 어장 정점이 포함되었으며, 바지락(Ruditapes phillipinarum)과 남방백금갯지렁이(Nephtys polybranchia)와 짧은다리송곳갯지렁이(Lumbrineris nipponica)가 우점했다. Group4에는 퇴적상이 세립한 정점이 포함되었으며, 작은부채발갯 지렁이(Eteone longa)와 유형동물(Nemertea unid.)이 높은 빈도로 출현하였다. 서해안 갯벌의 건강도 분석 결과, ISEP, BHI지수에서 대체로 ‘High (가장 양호)’상태를 나타냈으며, AMBI지수는 ‘Good (양호)’상태인 것으로 확인되었다. 따라서 서해안 갯벌의 건강도는 양호한 것으로 판단된다. 하지만 일부 지역에 오염지시종인 아기반투명조개(Theora lata), 등가시버들갯지렁이(Capitella capitata) 등이 출현하므로 갯벌 환경이 악화되지 않도록 주기적인 관리가 필요하다.