• 한국어류학회지
• /
• 제21권3호
• /
• pp.167-176
• /
• 2009

제주도 서부 연안에서 출현하는 어종들의 군집구조와 계절변동을 알아보기 위해 2008년에 홑자망, 삼중자망 그리고 통발을 이용하여 어획물의 종조성 및 계절변동을 분석하였다. 조사기간 동안 총 13목 45과 81종이 출현하였으며 농어목과 쏨뱅이목 어종이 전체 출현종수의 69.1%를 차지하고 있었다. 시기별 출현종수는 고수온기인 7월에 54종으로 가장 많이 출현하였고 저수온기인 4월 42종으로 가장 적게 출현하였다. 시기별 출현개체수와 생체량은 9월에 895 개체, 135 kg으로 가장 높았으며 12월에 450 개체, 52 kg로 낮았다. 조사어구 중 어획량이 가장 빈약했던 홑자망을 제외한 삼중자망과 통발의 다양도 지수를 구한 결과 각각 2.88~3.22, 1.31~1.87의 범위로 변화하였고 두 어구 모두 9월에 가장 높은 값을 나타냈다. 주요 우점종은 쏨뱅이, 쥐치, 호박돔, 황놀래기 등으로서 이 어종들은 계절에 상관없이 조사해역 내에서 우점 출현하고 있었다.

• 한국수산과학회지
• /
• 제46권6호
• /
• pp.948-956
• /
• 2013

Seasonal variations in species composition and abundance of the fish assemblages in the coastal waters off Gadeok-do were determined using monthly sample collection by a small otter trawl in 2010-2011. Of a total of 65 fishes collected, the dominant species were Leiognathus nuchalis, Clupea pallasii, Thryssa kammalensis, Engraulis japonicus, Repomucenus valenciennei, Sillago japonica, Trachurus japonicus, Pennahia argentatus, Okamejei kenojei, Cynoglossus joyneri, Pholis fangi, Pleuronectes yokohamae, and Zoarces gillii. These 13 fishes accounted for 92.8% of the total number of individuals collected. The number of fish species, number of individuals, biomass, and species diversity indices fluctuated with the seasons. The peak number of fishes occurred in April, whereas the biomass of fishes was highest in August. The numbers and biomass of fishes were lower in February corresponding with the low temperatures, and diversity indices were lower in January than in any other month.

• ALGAE
• /
• 제30권1호
• /
• pp.67-79
• /
• 2015

Planktivorous fish which limit zooplankton grazing have been predicted to increase algal biodiesel production in wastewater fed open reactors. In addition, tanks with higher algal diversity have been predicted to be more stable, more productive, and to more fully remove nutrients from wastewater. To test these predictions, we conducted a 14-week experiment in Houston, TX using twelve 2,270-L open tanks continuously supplied with wastewater. Tanks received algal composition (monocultures or diverse assemblage) and trophic (fish or no fish) treatments in a full-factorial design. Monocultures produced more algal and fatty acid methyl ester (FAME) mass than diverse tanks. More than 80% of lipids were converted to FAME indicating potentially high production for conversion to biodiesel (up to $0.9T\;ha^{-1}y^{-1}$). Prolific algal growth lowered temperature and levels of total dissolved solids in the tanks and increased pH and dissolved oxygen compared to supply water. Algae in the tanks removed 91% of nitrate-N and 53% of phosphorus from wastewater. Monocultures were not invaded by other algal species. Fish did not affect any variables. Our results indicated that algae can be grown in open tank bioreactors using wastewater as a nutrient source. The stable productivity of monocultures suggests that this may be a viable production method to procure algal biomass for biodiesel production.

• 한국수산과학회지
• /
• 제50권6호
• /
• pp.829-836
• /
• 2017

This study investigated the species composition and abundance of floating fish eggs to determine the timing and location of spawning of fish inhabiting the coastal waters of Sagye, Jejudo Island. Eggs were collected with a Bongo net bimonthly from May 2009 to February 2010. Identifications were based on nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Eggs were determined to belong to 43 distinct taxa, 35 of which were identified to the species level. The assemblage spanned eight orders, 23 families, and 32 genera. The number of taxa collected varied from month to month, with 14 taxa (12 species) found in June 2009, 11 taxa (10 species) in October 2009, 10 taxa (nine species) each in August 2009 and February 2010, eight taxa (six species) in April 2009, and five taxa (four species) in December 2009. Five abundant species (Branchiostegus japonicus, Engraulis japonicus, Pseudolabrus sieboldi, Goniistius zonatus, and Halichoeres tenuispinis) together represented 52.8% of the total number of eggs collected during the study.

• 한국수산과학회지
• /
• 제36권6호
• /
• pp.686-694
• /
• 2003

Monthly fish samples were collected using bottom gill nets and analyzed to study species composition and seasonal variation of fish assemblages in the coastal waters off Gadeok-do, Korea in 1998. During the study period, a total of 49 fish species representing 30 families were collected. The fish assemblages predominantly consisted of Limanda yokohamae, which accounted for $53.3\%$ of the number of individuals and $42.2\%$ in the biomass. The fish species, which had over 100 individuals, included Cynoglossus abbreviatus, Ditrema temmincki, Hexagrammos otakii, and Stephanolepis cirrhifer. These four species accounted for $24.1\%$ of the number of individuals and $24.3\%$ of the biomass. More fish species were collected in May and June than in any other months. The number of individuals and the amount of biomass peaked in April and May and reached a low in August. While the predominance of L. yokohamae caused the lowest species diversity by number of individuals in April, the predominance of Platycephalus indicus caused the lowest species diversity by biomass in July. Although gill nets show a strong selectivity for the target species or for size, gill nets can be used as an alternative fishing gear to collect fish in waters with rough bottoms, like rocky reefs, where other kinds of fishing gear such as trawls can not be used.

• 수산해양교육연구
• /
• 제27권2호
• /
• pp.319-344
• /
• 2015

A seasonal characteristic of marine environment and fish assemblages in the coastal waters of Jeju Island were determined using samples collected by a trammel net in from 2012 to 2013. Annual mean temperature and salinity were $18.8^{\circ}C$, 33.7psu (2012) and $18.8^{\circ}C$, 33.8psu (2013) which shows stable water mass. nutrient concentrations represent that dissolved inorganic nitrogen (DIN) ranged from 0.030 to 0.217mg/L, dissolved inorganic phosphorus (DIP) from 0.002 to 0.010mg/L, and silicate ($SiO_2$) from 0.096 to 0.292mg/L. Chlorophyll a concentrations of phytoplankton ranged from 0.905 to $1.125{\mu}g/L$ were appeared the highest in summer and the lowest in winter. Suspended Solid(SS) concentrations ranged from 1.200 to 2.100mg/L (mean, 1.634mg/L) were appeared the highest in autumn and the lowest in spring. During the survey period, a total of 83 species (48 families and 12 orders) of fishes were identified, Perciformes and Scorpaeniformes accounted for 63.9% of the total number. The number of species was higher in summer than in winter, showing a peak in summer at 57 species and a low in winter at 47 species. The number of individuals and the biomass peaked in summer at 694 individuals and 151.9kg, and were the lowest in autumn at 466 individuals and 106.5kg. The diversity index, evenness index and richness index were appeared 2.92~3.14, 0.75~0.83 and 7.06~8.56 at each stations. the dominance index were appeared highest in spring and summer, were appeared the lowest in winter and autumn. The Filefish (Stephanolepis cirrhifer), Bluestriped angelfish (Chaetodontoplus septentrionalis), Marbled rockfish (Sebastiscus marmoratus), Rabbit fish (Siganus fuscescens), Blackfin sweeper (Pempheris japonica) were dominant species, which occurred abundantly during the entire survey period. The subtropical fishes were identified total of 41 species (49.4%) and the number of species was higher in summer at 29 (50.9%) species and a low in winter at 20 (42.6%) species. The dominant species of subtropical fishes were appeared Bluestriped angelfish, Blackfin sweeper, Rabbit fish, Scarbreast tuskfish (Choerodon azurio), Ballonfish (Diodon holocanthus), Flagfish (Goniistius zonatus), Blue-spotted boxfish (Ostracion immaculatus) in study sites. The subtropical fishes of species, individual and biomass showed significant correlation with environmental factors (Chlorophyll a, DIN, DIP, $SiO_2$) in almost all sampling sites.

• 한국어류학회지
• /
• 제33권2호
• /
• pp.95-106
• /
• 2021

본 연구에서는 남한측 동해 최북단인 강원도 고성군에서 2년간(2018~2019년) 매월 정치망을 이용하여 어류 종조성을 확인하였으며, 과거 연구와의 비교를 통해 동해 해양환경과 어류상 간의 관계를 확인하고자 하였다. 조사기간 동안 총 77개 분류군이 어획되었으며, 이 중에서 75개 분류군이 종 수준까지 확인되었다. 우점하는 분류군은 참복과, 가자미과 등이었으며, 우점종은 도루묵, 전어, 쥐치, 말쥐치, 전갱이 등이었다. 표층수온은 과거에 비해 겨울철 및 봄철에는 지속적으로 상승하였고, 봄철 어류 종조성은 과거 한류성 어종에서 최근 난류성 어종으로 변화한 것으로 확인되었다. 본 연구에서는 이전 연구보다 참복과 어류의 종 다양성이 매우 높았는데, 이는 수온 상승과 함께 동해안으로 유입되는 참복과 어류의 양적인 증가와 관계가 있는 것으로 추정된다. 어류 종조성에서는 과거 남부해역(삼척, 강릉)의 종조성과 유사해졌으며, 월별 군집분석 결과에서는 한류성 어종이 우점하는 1~4월 그룹과 방어, 고등어가 우점하는 7~10월 그룹, 그리고 난류성 어종이 우점하는 5~6월, 11~12월 그룹으로 나뉘어져서 1년 중 8개월이 동해안으로 회유하는 난류성 어종들이 우점하는 것을 확인할 수 있었다. 장기간 난류성 어종들의 우점하는 경향은 북방한계선의 확장, 서식적수온대의 장기간 형성, 그리고 풍부한 먹이에 따른 결과로 생각된다. 따라서, 동해안으로 회유하는 난류성 어종들의 상업적인 이용방법 모색과 동시에 효율적인 자원관리 정책의 마련이 필요할 것으로 생각된다.

• Journal of Ecology and Environment
• /
• 제38권3호
• /
• pp.383-388
• /
• 2015

Reservoirs consist of two different environments, the littoral and the pelagic zone, and different fishing gear is commonly used in each zone-gill nets in the pelagic zone and electrofishing in the littoral zone. However, an active fishing gear, the cast net, is normally used instead of electrofishing for scientific studies in South Korea. In order to estimate cast net effectiveness for determining fish status in reservoirs, the study was conducted at 15 reservoirs with two different fishing gears: a cast net in the littoral zone and gill nets in the pelagic zone. When combining catches of both gears, species richness increased substantially compared to using one gear only. There was a size difference in fish caught by each net, and small fish were predominantly caught with the cast net due to its small mesh size (7 mm). The combined length of six species, used for length-weight relationship analysis, collected with the cast net was smaller than that collected with gill nets (independent t-test, P < 0.05). In this study, cast net sampling provided sufficient data for the littoral zone, but not enough to identify the overall fish assemblage in studied reservoirs. Utilization of only one gear can therefore lead to substantial underestimation of fish status, and a combination of both gears is recommended for determining more reliable estimates of fish status in reservoirs.

• Ocean and Polar Research
• /
• 제35권4호
• /
• pp.441-452
• /
• 2013

The fish species composition of seagrass bed in Chuuk Lagoon, Micronesia, was investigated every month from August 2009 to July 2011, using a seine net for fish caught. A total of 32 fish species belonging to 18 families under 6 orders were identified during the study period. Of these fish, Atherinomrus lacunosus, and Strongylura incise were the major dominant species representing 85.0% in total number of individuals. The number of species and individuals were high from August to December 2009, 2010. The biomass was highest in September 2010 and the diversity index was higher in September 2009, April, August 2010 and July 2011. The 14 dominant species could be divided into 2 groups of 3 individuals based on appearance patterns; (1) resident species and temporal species (9 species, e.g. Atherinomrus lacunosus), juvenile and adults living in seagrass beds and juveniles living only in seagrass beds; (2) temporal species (2 species, e.g. Hemiramphus lutkei), juveniles living only in seagrass beds; (3) temporal species (3 individuals, e.g. Caranx sexfasiatus). For some species, the appearance patterns were affected by water temperature. However, the relationships between sea currents, salinity, tide, and structure of fish assemblage remain unclear. Further studies that regularly monitor sea grass habitats are necessary to clearly understand the correlation between environmental factors and sea grass habitat use patterns in fish assemblages.

• 한국어류학회지
• /
• 제27권2호
• /
• pp.104-115
• /
• 2015

2010년 9월부터 2011년 8월까지 매월 소조기에 낙동강 하구역의 안쪽과 바깥쪽 두 개 정점에서 자치어를 채집하여 종조성의 시공간 분포를 밝혔다. 연구기간 동안 출현한 자치어는 총 7목 26과에 속하는 43개 분류군이 출현하였으며, 망둑어과 자치어가 전체 개체수의 63.1%를 차지하여 가장 우점하였다. 그중 하계 출현 망둑어과 자치어가 개체수비 55.5%로 가장 많이 채집되었다. 그 다음으로 청어 (13.2%), 멸치 (13.0%), 그리고 춘계 출현 망둑어과 자치어 (4.6%), 전어 (3.8%), 동계 출현 망둑어과 자치어 (3.1%), 정어리 (1.2%), 웅어 (0.7%) 순으로 채집되었고, 이들 8개 분류군이 전체 자치어 출현량의 95.0%를 차지하였다. 본 연구에서 출현한 자치어 군집은 총 5개의 그룹으로 구분되었으며, 시기적으로 봄, 여름 및 가을, 그리고 겨울 그룹으로 분리되었다. 특히 여름 및 가을에 자치어 군집의 공간적 분리가 나타났다. 하구역의 안쪽 정점에서는 하계 출현 망둑어과 자치어가 우점하였으며, 바깥 정점에서는 망둑어류 외에 멸치가 우점하였고, 기타 다양한 해수어종의 자치어가 출현하였다.