Species Composition and Distributional Patterns of Marine Benthic Algae at Intertidal Zone in Masan Bay

곽석남,허성회,Kwak, Seok-Nam,Huh, Sung-Hoi The Korean Society of Marine Environment and safet 2009 해양환경안전학회지 Vol.15 No.3

The species composition and distributional patterns in marine benthic algae at intertidal zone in Masan Bay were investigated seasonally throughout 2007. A total of 42 species, 5 Chlorophyta 8 Phaeophyta and 29 Rhodophyta were recorded, and dominant species were Enteromorpha linza, Ulva pertusa, Sargassum thunbergii, Gelidium amansii, G. divaricatum, Corallina pilulifera, Gracilaria textorii, and Polysiphonia morrowii during study periods. Especially the vertical distribution of dominant algal species was remarkable: U. pertusa and G. divaricatum were dominated in the upper part, E. intestinalis, E. linza, S. thunbergii and G. divaricatum were in the middle part, and U. pertusa, Undaria pinnatiffda, S. thunbergii, G. amansii, G. divaricatum and C. pilulifera mainly occurred in the low part of tidal zone. The numbers of species were different with seasons and stations; Higher number of species was 38 species in winter, whereas 28 species were the lowest in fall. The number of species was higher at stations 4 and 6 Mile the lower value was at stations 1 and 2 than other stations. The spatial distributional patterns of marine benthic algal composition at each station in dendrogram and MDS ordination were due to the differences of local topography and physical characteristics such as currents and water movements.

Seasonal Variations in Species Composition and Biomass of Epiphytic Algal Community in an Eelgrass (Zostera marina) Bed

곽석남,Kwak, Seok-Nam The Korean Society of Marine Environment and safet 2009 해양환경안전학회지 Vol.15 No.3

A total of 3 epiphytic macroalgae were collected from eelgrass bed in Jindong Bay, and Scytosiphon lomentaria and Colpomenia sp. in Phaephyta, Gracilaria sp. in Rhodophyta occurred during study periods. For epiphytic microalgae (diatoms), Cocconeis scutellum and Cocconeis placentula were common species. Seasonal variations of epiphytic algal biomass were marked: the higher epiphytic macroalgae was 3.3 g $DW/m^2$ in November 2003; whereas epiphytic diatoms were 43,153 $cells/m^2$ in June 2003. Diversity and number of epiphytic macroalgae species were the lowest in the study area, compared with those of in other areas such as Koongyang Bay, Dongdae Bay, and Aenggang Bay. These results were therefore likely due to the severe physical characteristics of the intertidal mudflat eelgrass biological characteristics, and the deterioration of water quality.

Marine Benthic Algal Community at Intertidal Zone in Jinhae Bay

곽석남,Kwak, Seok-Nam The Korean Society of Marine Environment and safet 2009 해양환경안전학회지 Vol.15 No.2

The species composition and seasonal patterns in marine benthic algal community at intertidal zone in Jinhae Bay were investigated seasonally throughout 2007. A total of 45 species, 6 Chlorophyta, 10 Phaeophyta, and 29 Rhodophyta, were recorded, and dominant species were Ulva pertusa, U. conglobata, Sargassum horneri, Gelidium divaricatum, Gracilaria textorii, and Polysiphonia morrowii during study periods. The number of species were differed with seasons and stations; Higher number of algal species was 42 species in winter, whereas 33 species was lower in summer. The number of algal species were higher at station 1,7,8, while the lower value was at station 2, 3 than other stations. The differences of marine benthic algal composition at each station in MDS ordination due to the physical characteristics and local topography.

인공용승류 해역에서 채집한 난자치어의 종조성 및 시공간 변동

곽석남,허성회,김하원,Kwak, Seok-Nam,Huh, Sung-Hoi,Kim, Ha-Won 해양환경안전학회 2013 해양환경안전학회지 Vol.19 No.4

Temporal and spatial variations and species composition of ichthyoplanktons were investigated by Bongo net in a sea area with the construction of artificial upwelling structure at 13, June, 21 September, and 23 September in 2012. A total of fish eggs was 4,849 ind./$1,000m^3$, and fish larvaes was 641 ind./$1,000m^3$ in the study area. The common fish eggs was Engraulis japonicus which was composed of 57.5%, and unidentified I, II, III and IV were occurred with decreased number of individuals order. For fish larvaes, Pictiblennius yatabei, Repomucenus sp.A, sp.B and Scomber japonicus were dominated, however, other species were Engraulis japonicus, Konosirus puntatus, and unidentified I, II. Temporal variations of fish eggs and larvae were remarkable differed. Higher numbers of fish eggs and larvaes were July 2012, whereas those were lower at August 2012. Spatial variations of those were also significantly differed with higher numbers were at station 2 and 3 during study periods. The total number of fish eggs and larvae was about 4 fold against numbers of those in the compared area far from study area. These results indicated that higher numbers of fish eggs and larvaes were due to influx much more nutrients and food organisms with artificial upwelling.

Change in Fish Assemblage Inhabiting Around Dae Island in Gwangyang Bay, Korea

곽석남,허성회,김하원,Kwak, Seok-Nam,Huh, Sung-Hoi,Kim, Ha-Won The Korean Society of Marine Environment and safet 2012 해양환경안전학회지 Vol.18 No.3

Changes of fish assemblage inhabiting around Dae Island in Gwangyang Bay, Korea were investigated using a small beam trawl monthly from March 2009 to February 2010. These data were compared with those obtained in previous studies(1990~1991 and 1995~1996) at our study sites. A total of 8,133 fish belonging to 74 species in 38 families were collected. Leiognathus nuchalis, Argyrosomus argentatus, Acentrogobius pellidebilis, Sillago japonica, Apogon lineatus, Thryssa hamiltoni, Repomucenus richardsonii, Pholis nebulosa, Pleuronichthys cornutus, Hexagrammos otakii, and Limanda yokohamae dominated, and these were responsible for 89.5% and 58.9% in the number of individuals and in biomass, respectively. These were primarily small species or early juveniles of larger species. Seasonal variation in both species composition and abundance was large: the peak number of fish species occurred in May and October 2009, whilst both number of individuals and biomass were the highest in May 2009. Fish numbers as well as biomass was lowest in January and February 2010. Seasonal changes in the abundance of fishes corresponded with temperature. Compared with the previous studies, the total number of individuals and biomass per unit area($m^2$) were higher, and the predominance of L. nuchalis occurred while abundances of Liparis tanakai were significant decreased. These results seemed to be change of species composition in fish assemblage which was due to variation of annual environmental characteristics in Gwangyang Bay.

전남 갯벌 조간대의 환경특성 및 서식 생물의 종조성

곽석남(Seok-Nam Kwak), 김성수(Sung-Soo Kim), 이광섭(Kwang-Sup Lee), 정승민(Seung-Min Jung), 강진묵(Jin-Muk Kang) 전남대학교 수산과학연구소 2020 수산과학연구소 논문집 Vol.29 No.1

전남 무안군 갯벌 조간대의 수온은 13.54~24.80℃의 범위로 나타났으며, 염분은 30.23~32.00 psu, pH는 7.85~7.98, 용존산소는 7.38~8.26 mg/L의 범위로 나타났다. 퇴적물의 입도조성은 3개 지역 모두 모래가 50.0% 이상으로 나타났다. 갯벌조간대에서 출현한 식물플랑크톤은 규조류가 종조성의 90% 이상으로 나타났으며, 주요 우점종은 Paralia sulcata로 나타났다. 동물플랑크톤은 절지동물문이 종조성의 90% 이상으로 나타났으며, 주요 우점종은 게류 유생 (brachyura larvae)으로 나타났다. 식물 및 동물플랑크톤의 종조성은 우리나라 연안의 전형적인 출현양상이었다. 대형저서동물은 환형동물문이 80% 이상으로 나타났으며, 주요 우점종은 털보집갯지렁이 (Diopatra sugokai)로 나타났다. 칠게와 낙지의 출현량은 정점 2에서 가장 높게 나타났으며, 낙지의 주 먹이 생물인 칠게의 출현량이 높은 곳에서 낙지의 출현량이 높게 나타난 것으로 판단되었다. Our results showed the temperature of tidal flat intertidal zone in Muan-gun, Jeonnam ranged from 13.54 to 24.80°C. The sediment particles was composed by sand more than 50.0% in all study sites. Phytoplankton composition of tidal flat intertidal zone was diatoms more than 90%, and the dominant species was Paralia sulcata. In zooplankton, arthropods was dominant group more than 90%, and the dominant species was brachyura larvae. Species composition of phytoplankton and zooplankton was a typical tendency of the coastal area of Korea. Macro-invertebrate composed annulus more than 80% and the dominant species was Diopatra sugokai. The lacquer and octopus was sampled the highest at site 2, and we believe that the occurrence of octopus was high at the high occurrence of crab which is major prey for octopus.

마산만 해역에서 서식하는 어류군집의 종조성 및 출현량 변동

곽석남 ( Seok Nam Kwak ),허성회 ( Sung Hoi Huh ) 한국어류학회 2007 한국어류학회지 Vol.19 No.2

전남 갯벌 해역 낙지 인공 산란장 조성 및 적지 기준에 관한 연구

곽석남(Seok-Nam KWAK),김성수(Sung Soo KIM),강진묵(Jin Muk KANG),최옥인(Ok In CHOI),진지웅(Ji Woong JIN),김기동(Gi Dong KIM) 한국수산해양교육학회 2021 수산해양교육연구 Vol.33 No.3

The Suitable criterion of construction of artificial spawning area for Octopus minor in muddy tidal flat, Chonnam Area was temperature 10∼20℃, salinity 27.0∼35.0psu, dissolved oxygen above 5.0mg/L, sand and mud in sediment composition, maximum 7 hours in exposure periods. The construction period of artificial spawning area for Octopus minor was from May to June, October to November, and minimum 7.0cm ML for Octopus minor with considering actual spawning periods of Octopus minor. The 1,000 individuals each sex ratio were copulation for 3 days with supply food, and then female with eggs were in artificial spawning area with boundary. signal. The series was systematic for construction of artificial spawning area for Octopus minor in muddy tidal flat. Higher 40 percent caught Octopus minor individuals in construction of artificial spawning area than those of non-construction area. Therefore construction of artificial spawning area for Octopus minor in muddy tidal flat were higher effect for Octopus minor catch rate in Chonnam Area.

울산지역 해삼 종자방류사업의 경제적 효과 분석

곽석남(Seok-Nam KWAK),한지성(Ji Sung HAN),김두호(Do Ho KIM),최종국(Jong-kuk CHOI),신우철(Woo-Chur SHIN) 한국수산해양교육학회 2025 수산해양교육연구 Vol.37 No.4

This study aims to analyze the economic effect of sea cucumber seed releasing program in two fishing villages in Ulsan region. The economic effect of sea cucumber seed releasing program using the benefit/cost ratio method from 2020 to 2023, based on the data from field survey and recapture rate. The result showed benefit/cost ratio of 2.27 and 1.42, indicating that the seed releasing program was evaluated to be economically feasible. The sensitivity analysis results showed that higher market prices and recapture rates, as well as lower seed prices, lead to greater economic effect of sea cucumber seed releasing program in Ulsan.

남해도 연안해역에서 서식하는 어류군집의 종조성 및 계절변동

곽석남 ( Seok Nam Kwak ),허성회 ( Sung Hoi Huh ),김하원 ( Ha Won Kim ) 한국어류학회 2008 한국어류학회지 Vol.20 No.4

Seasonal variation in species composition and abundance of fishes was determined using monthly samples collected by a fyke net in coastal waters off Namhae Island in 2006. The sampling gear, both-side fyke net, is a widely used commercial fishing gear in shallow waters of the region. A total of 89 fish species was collected, the dominant species were Konosirus unctatus, Mugil cephalus, Lateolabrax japonicus, Acanthopagrus schlegeli, Sebastes inermis, Nibea mitsukurii, Clupeapallasii, Pampus echinogaster, Sebastes schlegeli and Limanda yokohamae. They accounted for 61.1% of the total number of individuals and 80.3% of the biomass. The dominant species were primarily composed of small individuals or juveniles of large-sized fishes. Abundance in the number of individuals and biomass showed peaks in April, May and September, and was lowest in January. Temporal change in fish abundance was related to the temperature and related factors.