This study investigated the species composition and community structure of aquatic organisms captured using coastal beam trawling in Gomso Bay, Jeollabuk-do, from January to December 2022. Throughout the experimental period, a total of 20,246 individuals belonging to 94 marine species were captured, with a combined biomass of 602,828 g. Fish exhibited the highest abundance, comprising 56 species, followed by crustacea (21 species), bivalvia (8 species), cephalopoda (5 species), gastropoda (3 species), and holothuroidea (1 species). The dominant species was Leiognathus nuchalis, constituting 14.0% of the total individuals, followed by Portunus trituberculatus at 12.1%, Oratosquilla oratoria at 10.4%, Crangon hakodatei at 9.9%, and Metapenaeus joyneri at 7.9%. The diversity index ranged from 1.72 to 2.55, with the lowest diversity observed in March and the highest in July. Cluster analysis based on species composition of the 27 most common species showed that aquatic organisms were divided into three groups: spring and summer organisms (Group A) and summer organisms (Group B) and autumn and winter organisms (Group C).
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.
To assess the characteristics of meiofaunal community fluctuations related to environmental factors, seasonal surveys were conducted in the subtidal zone of Hallyeohaesang National Park. The average depth of the study area was about 20 m, and the average water temperature at the bottom was low in winter (11.33°C) and high in summer (17.95°C). The sedimentary particles mainly comprised silt and clay at most stations. The abundance of meiofauna ranged from 81.7 to 1,296.5 Inds. 10 cm-2, and the average abundance was 589.3 Inds. 10 cm-2. The average abundance of meiofauna in each season was the lowest at 416.5 Inds. 10 cm-2 in winter and the highest at 704.5 Inds. 10 cm-2 in spring. The dominant taxa were nematodes (about 92%) and harpacticoids (about 5%). In the cluster analysis of meiofaunal communities, they were divided into four significant groups. The largest group mainly contained spring and summer samples, and contained stations with a high nematode density of over 500 Inds. 10 cm-2 and harpacticoids below 50 Inds. 10 cm-2 with a high composition ratio of nematodes. In the cluster analysis, no regional division was found between the stations, and it was thought to be divided by the seasons with high abundance according to seasonal variation and the composition ratio of nematodes and harpacticoids. In the Spearman rank correlation analysis, the density of total meiofauna and the most dominant taxa, nematodes, was not significantly related to environmental factors. However, the density of harpacticoids had a significant positive correlation with water depth and a negative correlation with sediment particle size.
To assess the influence of environmental factors on the phytoplankton community structure and total phytoplankton biomass during four seasons in 2014, we investigated the abiotic and biotic factors at 25 stations in the Busan coastal region. The phytoplankton community and total phytoplankton biomass were strongly dependent on the discharge from the Nakdong River, and the high density of phytoplankton was related with the introduction of the Tsushima Warm Current (TWC), particularly in the thermohaline fronts of the fall season. The relationship between the salinity and nutrient (Dissolved inorganic nitrogen=DIN: R 2=0.72, p<0.001 and Dissolved inorganic silicon=DSi: R 2=0.78, p<0.001) highly correlated with the river discharge, implying that those nutrients have played a crucial role in the growth of diatom and cryptophyta. The total phytoplankton biomass was highest in the summer followed by autumn, spring, and winter. Diatom and cryptophyta species were dominant species during the four seasons. Additionally, there were strong positive correlations between Chlorophyll a and total phytoplankton biomass (R 2=0.84, p<0.001), cryptophyta (R 2=0.76, p<0.001) and diatom (R 2=0.50, p<0.001), respectively. In particular, we found that there were significant differences in the nutrients, phytoplankton community compositions, and total phytoplankton biomass between the inner and the outer coastal region of Busan, depending on the amount of river discharge from the Nakdong River, particularly during rainy seasons. Therefore, the seasonal change of TWC and river discharge from the Nakdong River serve an important role in determining phytoplankton population dynamics in the Busan coastal region.
Species composition and seasonal variations of fish in the Five West Sea Islands in Korea, were investigated by using otter trawls and bongo nets from 2014 to 2015. During the surveyed period using an otter trawl, a total of 53 species, 147,253 ind./km2 and 2,721,296 g/km2 of fish were collected by otter trawls. The individual dominant species were Chaeturichthys stigmatias (30.3%), Coilia nasus (18.2%), Engraulis japonicus (12.3%), and Setipinna tenuifilis (12.2%). Moreover, the biomass dominant species in biomass were Liparis tanakae (21.3%), Beringraja pulchra (18.5%), Engraulis japonicus (8.3%) and Okamejei kenojei (8.1%). Eggs by bongo nets included 1,748 ind./1,000 m3 of Engraulis japonicus and 64,691 ind./1,000 m3 of unidentified species. A total of 15 species and 2,015 ind./1,000 m3 of fish larvae were collected, and the dominant species were Johnius belengerii and Pholis fangi.
본 연구는 부산광역시 해안림 곰솔군락의 식생구조 및 생태적 특성을 파악하여 해안림의 식생구조를 파악하고 향후 부산광역시 해안림 관리방안을 위한 기초자료를 구축하고자 수행하였다. 부산광역시 해안림 지역에 100m² 크기의 조사구 97개를 설치하여 조사·분석하였다. TWINSPAN과 DAC기법을 사용하여 군락을 분리한 결과, 곰솔-졸참나무 군락, 곰솔-사스레피나 무(1)군락, 곰솔-사스레피나무(2)군락, 곰솔-갈참나무군락, 곰솔-동백나무(1)군락, 곰솔-동백나무(2)군락, 곰솔-사스레피나무- 동백나무군락으로 분리되었다. 조사결과 부산광역시 해안림 곰솔군락의 교목층에서는 곰솔이 주요 우점종으로 나타났으며, 하층식생에서 사스레피나무와 동백나무가 우점하였다. 곰솔-졸참나무군락에서 졸참나무가 일부 교목층과 아교목층에서 곰솔과 경쟁관계를 이루고 있으며 변화를 살피기 위해서는 지속적인 모니터링이 필요할 것이다. 해안림의 환경 특성상 곰솔을 비롯한 내염성이 강한 수종들이 군락을 이루고 있기 때문에 곰솔-졸참나무 군락을 제외한 군락들은 급격한 환경변화가 발생하지 않으면 현 상태의 군락 구조를 당분간 유지할 것으로 예상된다.
본 연구는 제주 연안에 서식하는 중형저서동물 군집의 특성과 계적적 변동을 알아보고자 수행되었다. 제주도 조간대 지역에서 20개의 조사지점을 선정하였으며, 2017년 4월부터 2019년 2월까지 총 8회의 조사를 수행하였다. 조사결과, 조사지점 당 중형저서동물의 밀도는 733~2,505 inds. 10 cm-2였으며, 2017년 4월에 밀도가 가장 높았고 2019년 2월에 가장 낮았다. 모든 조사지점에서 Nematode 가 우점하고 있는 것으로 나타났으며, copepod와 nauplius가 그 다음 우점 분류군으로 조사되었다. 생태계 건강성을 나타내는 Nematods/Copepods ratio (N/C ratio)는 2017년 4월에 가장 낮은 값인 0.02, 2019년 2월에 가장 높은 값인 87.40으로 산출되었으며, 이는 조사지점의 건강성이 악화 되었음을 의미한다. Multi-Dimensional Scaling (MDS) 분석 결과는 제주 연안의 중형저서동물 군집구조는 지역적 차이보다는 계절적 변동에 의해 더 크게 영향을 받고 있음을 나타냈다. 제주도의 중형저서동물 군집의 계절적 변동 특성을 보다 명확히 이해하기 위해서, 추가적인 군집조사와 환경 인자와의 상관관계 분석이 후속 연구로 필요할 것으로 판단된다.
It was turned out by shrimp beam trawl monthly survey from March, 2015 to February, 2016 that different species composition and abundance of the fish assemblages in Sacheon Bay and coastal waters off Namhae, Korea were compared. As a result of monthly measured sea temperature and salinity of Sacheon Bay and coastal waters off Namhae, sea temperature of both areas was changed seasonally; however, differences in sea temperature occurred during certain periods depending on the region. Salinity was generally low in Sacheon Bay affected by fresh water, and both areas was low in summer and high in winter. A total of 73 species representing 37 families were collected in Sacheon Bay. The dominant fish species in terms of numbers and biomass were Liparis tanakae, 23,077 inds./km2, 332.1 kg/km2. A total of 91 fish species representing 49 families were collected in coastal waters off Namhae. The dominant fish species in terms of numbers were Leiognathus nuchalis, 139,683 inds./km2 and biomass were Chelidonichthys spinosus, 1,078.6 kg/km2. Analysis of dendrogram of the clustering showed that Sacheon Bay and coastal waters off Namhae were distinctive featured (global R = 0.691, p = 0.017). And except of summer season (July-October), there was a distinctive feature seasonally (global R = 0.844, p = 0.001). The fish species that appeared in common in both areas, where fish species caught in Sacheon Bay, an important inner bay,were smaller than those caught in coastal waters off Namhae appeared. It presented that Sacheon Bay plays a more important role in spawning and nursery ground for fisheries resource than coastal waters off Namhae, Korea.
남해 연안해역에서 이른 여름 식물플랑크톤 군집의 분포특성을 파악하기 위해 2018년 6월말에서 7월 중순까지 11개 해역을 대상으로 실시하였다. 결과 출현한 식물플랑크톤 출현 종은 56속 105종으로 규조류가 52.4%, 와편모조류가 40.0%, 기타 편모조류가 7.6%였다. 현존량은 표층에서 5.5~593.2 cells mL-1로 변화하여, 출현종과 현존량 모두 동부해역에서 높고, 서부 해역에서 낮은 특정을 나타내었다. 식물플랑크톤 군집은 남해 금포, 여수 오천동 및 고흥 외나로도 해역을 제외하면 규조류에 지배되는 특성을 보였으며, 우점종은 여수 오천동과 완도 충도를 제외하면 중심규조 Skeletonema costatum-like species (ls)에 의해 우점되었다. 그러나 오천동 해역은 유독와편모조류 Gymnodinium catenatum에 의해 극우점되었고, 남해 금포 및 외나로도 해역은 와편모조류 Tripos fusus에 의해 12% 이상의 우점율을 나타내었다. 이른 여름 남해 연안해역의 식물플랑크톤 군집의 공간분포는 강수량 등 영양염류 공급에 크게 지배되고 있는 것으로 판단할 수 있었다.
This present study investigated characteristics of distribution and community structure of macrobenthic invertebrates through the survey of commercial Danish seine fisheries from 2011 to 2013. In this study, a total of 28 species were sampled with a mean density of 32,568 ind./km2 and mean biomass of 1,649.5 kg/km2. The dominant species, comprising over 1.0% of the total number of individuals, were Chionoecetes opilio (11,203 ind./km2, 34.4%), Pandalus eous (9,247 ind./km2, 28.4%), Ophiuridae spp. (5,750 ind./km2, 17.7%), Argis lar (2,631 ind./km2, 8.1%), Neocrangon communis (994 ind./km2, 3.1%), Berryteuthis magister (612 ind./km2, 1.9%), Sepiola birostrata (499 ind./km2, 1.5%) and Strongylocentrotidae sp. (424 ind./km2, 1.3%). The dominant species, in terms of biomass, comprising over 1.0% of the total biomass, were C. opilio (1,167.2 kg/km2, 70.8%), B. magister (130.3 kg/km2, 7.9%), P. eous (102.4 kg/km2, 6.2%), Ophiuridae spp. (84.6 kg/km2, 5.1%), Enteroctopus dofleini (45.5 kg/km2, 2.8%), A. lar (35.7 kg/km2, 2.2%), Strongylocentrotidae sp. (25.0 kg/km2, 1.5%) and S. birostrata (22.1 kg/km2, 1.3%). Among them, S. birostrata, E. dofleini, Strongylocentrotidae sp. and Ophiuridae spp. were higher abundance and biomass in the shallow water (<200 meters in depth), whereas C. opilio, P. eous, A. lar, N. communis and B. magister were higher in the deep water (301 ~ 500 meters in depth).As the results of cluster analysis and non-metric multidimensional scaling (nMDS) analysis based on the Bray-Curtis similarity of fourth root transformed data for number of species and individuals, the macrobenthic invertebrates community by Danish seine survey was divided into two groups of station in the shallow water (<200 meters in depth, Group A) and the deep water (201 ~ 500 meters in depth, Group B). The major individual-dominant species was S. birostrata, Ophiuridae spp. and immature C. opilio in group A. But Group B was P. eous, A. lar, B. magister and mature C. opilio.
Coastal areas across the globe and people who live in them are vulnerable to a host of natural disasters including hurricanes, typhoons, and tsunamis. During the past several decades, coastal communities of the world have also been seriously affected by man-made disasters resulting in severe social, economic, and environmental damages. The 2010 Deepwater Horizon oil spill (DWH) was the worst man-made disaster for the Gulf coast communities of the US. Community residents and resource organizations in the Florida Gulf coast responded quickly to address social, economic, and environmental needs after this disaster. The purpose of this single case study is to determine these community responses. The research uses documents from community organizations and in-depth interviews with community leaders. Constant comparative analysis method was used to determine major and sub categories of community efforts. Results show that community efforts centered on collaboration, outreach, and grassroots mobilization for resiliency after the disaster.
본 연구는 2012년 3월 저수온기 동해연안의 10개 정 점에서 식물플랑크톤의 군집구조를 세포의 크기에 따라 구분하여 조사하였다. 식물플랑크톤의 총 개체수는 3.4 ×106~7.6×106 cells L-1, 탄소량은 0.08×108~6.3×108 pg L-1로 나타났다. 개체수를 기반으로 생물량을 보았을 때, 극미소플랑크톤의 비율이 미세∙미소 플랑크톤보다 높았다. 그러나 탄소량을 기반으로 하는 생물량을 보았 을 때, 극미소플랑크톤은 세포 크기가 작아 기여도가 미 미하였고, Coscinodiscus속과 같이 크기가 큰 종들은 기 여도가 높았다. 이와 같이 식물플랑크톤의 생물량을 정 확하게 파악하기 위해서는 다양한 관점으로 여러 항목 을 조사할 필요성이 있는 것으로 나타났다. 식물플랑크 톤의 군집 구조를 확인한 결과, 총 10개 정점 중에 8 정 점에서 극미소플랑크톤이 우점하였다. 또한 8개 정점에 서 미소플랑크톤의 개체수가 미세플랑크톤보다 높은 비 율을 나타냈다. 미세∙미소플랑크톤 중에서는 규조류의 비율이 95% 이상이었다. 극미소플랑크톤의 군집구조를 살펴보면, 5가지의 형태학적 특성이 다른 군집이 확인되 었으며, 7개 정점에서 S type이 가장 우점한 것으로 나 타났다. 본 연구를 통해 확인된 극미소플랑크톤이 차지 하는 생태학적 기여도가 커 이들에 대한 연구가 꾸준히 수행되어야 하며, 이를 위하여 그들의 분류학적 체계 구 축과 생리학적 특성 연구가 선행되어야 할 것으로 판단 된다. 이와 같은 연구를 기반으로 향후, 변화하고 있는 동해연안에서 생물 군집 변화 현상을 규명할 수 있을 것이다.