• 한국수산과학회지
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• 제52권6호
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• pp.685-695
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• 2019

To assess the state of Todarodes pacificus fisheries, we examined changes in major fishing and ecological characteristics by comparing jigging fishery data between high (HCLP, 1996-2000) and low (LCLP, 2013-2017) catch level periods. The peak catch occurred in October during the HCLP compared with December during the LCLP. The average catch per unit effort was higher during the HCLP (1.3 tons/jigging vessel) than LCLP (1.0 ton/jigging vessel). During the HCLP, fishing grounds were highly concentrated in the southwestern East Sea and Yamato bank, whereas during the LCLP, the distribution of grounds extended to the South Sea, West Sea, and northern East Sea (near Russian waters) at a low density. Water temperatures in the main fishing ground in the southwestern East Sea were higher at 0, 50, and 100 m depths during the LCLP than HCLP. Meanwhile, the average mantle length of catches decreased from 23.5 cm during the HCLP to 22.21 cm during the LCLP. The mantle length at 50% maturity also decreased between the two periods from 22.06 (HCLP) to 18.77 cm (LCLP). These findings will help guide future management strategies for T. pacificus.

• 한국수산과학회지
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• 제45권2호
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• pp.173-179
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• 2012

The common squid $Todarodes$ $pacificus$ is a dominant species in Korean waters, where it is captured preponderantly by the angling fishery. The spawning and nursery grounds of $T.$ $pacificus$ extend from the southern East Sea to the northern East China Sea. Consequently, the environmental conditions in this area during the spawning and nursery seasons might affect the abundance of $T.$ $pacificus$. This study, analyzed the relationship between the distribution of zooplankton and the abundance of $T.$ $pacificus$ and variation in the squid angling fishing grounds in Korean waters. There was a positive relationship between the fluctuations in zooplankton and the catch per unit effort (CPUE; $kg{\cdot}day^{-1}{\cdot}person^{-1}$) of the angling fishery in the East Sea of Korea. The main fishing season is from July to December and the CPUE was closely related to the zooplankton biomass in April in the East Sea. Recently, the center of the squid jigging ground has moved drastically from the area around Ulleung Island to the northern East Sea. We postulate that the fishing grounds of the squid angling fishery will move farther north with climate change.

• 한국수산과학회지
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• 제53권6호
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• pp.925-933
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• 2020

This study is aimed to compare stock assessment models which are effective in assessing red snow crab Chinonoecetes japonicus resources and to select and apply an effective stock assessment model in the future. In order to select an effective stock assessment model, a process-error model, observation-error model, and a Bayesian state-space model were estimated. Analytical results show that the least error is observed between the estimated CPUE (catch per unit effort) and the observed CPUE when using the Bayesian state-space model. For the Bayesian state-space model, the 95% credible interval(CI) ranges for the maximum sustainable yield (MSY), carrying capacity (K), catchability coefficient (q), and intrinsic growth (r) are estimated to be 10,420-47,200 tons, 185,200-444,800 tons, 3.81E-06-9.02E-06, and 0.14-0.66, respectively. The results show that the Bayesian state-space model was most reliable among models.

• 수산해양기술연구
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• 제48권4호
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• pp.401-414
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• 2012

Distribution pattern and fishing conditions of sandfish, Arctoscopus japonicus in the East Sae were explored using catch and catch per unit effort (CPUE) by eastern sea Danish seine and coastal gill net fisheries from 2004 to 2008. A. japonicus was one of major target species for the eastern sea Danish seine and coastal gill net fisheries in the East Sea, which were caught from April to October for the eastern Danish seine, and from October to December for the coastal gill net, respectively. In recent, the distribution and centroid of fishing ground moved northward, as seawater temperature increased. The species spawned in the coastal areas of Gangwon, northern East Sea, during winter, started to move to deeper water after spawning from spring, extended widely from Gangwon to Ulsan, southern East Sea, during summer, and migrated back to the spawning ground off Gangwon during autumn.

• 수산해양기술연구
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• 제55권2호
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• pp.95-104
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• 2019

This study is aimed to take a stock assessment of blackthroat seaperch Doederleinia seaperch regarding the fishing effort of large-powered Danish Seine Fishery and Southwest Sea Danish Seine Fishery. For the assessment, the state-space model was implemented and the standardized catch per unit effort (CPUE) of large powered Danish Seine Fishery and Southwest Sea Danish Seine Fishery which is necessary for the model was estimated with generalized linear model (GLM). The model was adequate for stock assessment because its r-square value was 0.99 and root mean square error (RMSE) value was 0.003. According to the model with 95% confidence interval, maximum sustainable yield (MSY) of Blackthroat seaperch is from 2,634 to 6,765 ton and carrying capacity (K) is between 33,180 and 62,820. Also, the catchability coefficient (q) is between 2.14E-06 and 3.95E-06 and intrinsic growth rate (r) is between 0.31 and 0.72.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.174-179
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• 2006

Information on the distribution characteristics of tuna resources in Kiribati EEZ waters in three zones (Zone 1: west Gilbert region, Zone 2: central Phoenix region, and Zone 3: east Line region) as well as their relationship with the ocean environment is critical for sustainable managing the migratory tuna resource and fishing practices in this region. Therefore, this study is designed to investigate the spatial and temporal distribution and concentration of bigeye (BET) and yellowfin tuna (YFT) in Kiribati EEZ waters in relation to sea surface temperature (SST) and thermocline depth so as to better understand the tuna resources management basis in Kiribati waters. The geographic and temporal distribution and concentration were first displayed. Paired t-test was utilized to compare the distribution between the two tuna species based on Catch per Unit Effort (CPUE) derived from the Korean longliners during 1996 to 2004, and also among the three zones of Kiribati EEZ waters. Environmental conditions of the three zones were then compared and correlated with the CPUE of YFT and BET. In addition, the effect of ENSO phenomena on the environmental conditions and the distribution of YFT and BET within the three zones were also examined. The BET was relatively higher in the Zone 3 whereas YFT predominate in the Zone 1 and the Zone 2 due to oceanographic differences among the three zones and the ecological habitats of the two tuna species. It was suggested that El Ni?o/Southern Oscillation (ENSO) phenomena altered the oceanographic conditions of the three zones that in turn change the distribution of the two tuna species. During El Ni?o, the warm phase of ENSO, resulted in having more BET in all the three zones and the opposite observed during La Ni?a (cold phase) replacing by having relatively higher catch rate for YFT, particularly in the Zone 2. Although the results of the study are from short periods (1996 to 2004) in considering oceanographic anomality, these environmental variations should be considered into sustainable fisheries management of tuna fisheries in Kiribati EEZ waters.

• 수산해양기술연구
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• 제40권4호
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• pp.295-303
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• 2004

한국 거문도 연안에서 시설된 세라믹 어초의 시설 효과를 구명하기 위하여 2001년부터 2003년까지 어초 시설구, 자연초구 및 비시설구 어장에서 삼중자망에 의한 어획량과 어획종을 조사하였다. 어초 시설구에서의 폭당 어획량은 1,621.9g으로 자연초구와 비시설구에 비해 각각 67.9%, 333.3%많았는데, 이를 Tukey test로 검정한 결과, 어초 시설구와 자연초구에서는 유의차가 없었으며, 어초 시설구와 비시설구와는 유의차가 인정되었다.(p<0.05). 어초 시설구에서 어획된 월 평균 종수는 7.2종으로 자연초구에 비해 7.1% 적었던 반면 비시설구보다 97% 많았는데, ANOVA 분석결과 유의차가 없었다. 어초 시설구의 어획률은 11월에 최대, 5월에 최소치를 보였으며, 이러한 현상은 자연초구, 비시설구에서도 나타났다. 어초 시설구의 우점종은 참동, 말쥐치, 쥐치, 도다리, 거북복 등 암초성이 강한 저서어종이었고, 자연구와 비시설구에서는 저서성 및 회유성 어종이 혼재하였다.

• 수산해양기술연구
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• 제31권2호
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• pp.153-165
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• 1995

경북 연안 정치망어업의 어획량 변동에 관한 연구를 위하여 1985~1989 연간 총 11통의 표본어장의 어획자료로부터 연도별, 월별, 지역별, 어종별, CPUE(1양망당 어획량), 어종조성 및 각 어장별 주요어종의 출현시기 및 해황 특징 등에 관한 연구 결과를 요약하면 다음과 같다. CPUE 변동은 연도별로 보면, 변동폭이 매우 크고 대체적으로 감소하는 경향이고, 지역별로는 죽변 지역이 높고 나머지 지역은 낮았다. 월별로 보면, 전체적으로는 8~11월이 높게 나타났고, 지역별로는 주변, 강구는 8~11월, 축산, 감포는 9~11월, 후포는 8~12월이 높게 나타났다. 연도별 CPUE 변동은 연도별로는 쥐치, 고등어, 참다랭이, 조피볼락, 방어는 감소 추세에 있고, 정어리, 전갱이, 청어는 증가 추세에 있으며, 오징어는 안정을 유지하면서 증가하는 경향에 있고, 갑오징어는 1987년 이후 낮은 수준에서 안정된 경향을 보였다. 월별로는 고등어, 전갱이, 참다랭이, 방어, 조피볼락은 9~10월, 쥐치와 오징어는 11~1월, 정어리는 4~5월, 청어는 3월, 갑오징어는 4월이 높게 나타났다. 연도별로 출현하는 주요어종의 어군크기는 1985년~1989년 전체적으로 볼 때 쥐치, 정어리, 전갱이, 고등어, 오징어, 참다랭이, 방어의 순 이였고, 연도별로는 1985년 쥐치, 1986년 정어리, 1987년에는 전갱이, 1988년에는 쥐치, 1989년에는 정어리가, 월별로는 1~7월까지는 정어리가, 8~10월에는 정어리, 고등어가, 그리고 11~12월에는 쥐치가 수위를 차지하고 있었다. 어종별 출현시기를 감포와 죽변 지역을 비교해 볼 때, 쥐치, 고등어, 오징어, 참다랭이, 갑오징어는 죽변 지역이 다소 빠르게 나타나고, 고등어와 방어는 감포 지역이 빠르게 나타났다. 특히 정어리의 경우는 출현시기가 약 3개월 차이를 보인 반면, 전갱이와 삼치는 동일한 시기에 출현하였다. 또한 경북 연안 정치망어업에서는 평년에 비해 난류세력이 강하고 수온전선이 연안을 따라 남북으로 길게 형성되는 해에 해황이 좋은 것으로 나타났다.

• Journal of Ecology and Environment
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• 제38권4호
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• pp.505-515
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• 2015

The objectives of this study were to determine the effects of stream nutrient regime, N:P ratios and suspended solids on fish tolerance/trophic compositions and stream ecosystem health, based on multi-metric model, during 2008-2013. Also, stream ecosystem health was evaluated in relation to chlorophyll-a (CHL) as a measure of algal productivity or indicators of trophic state to water chemical parameters. Total number of sampled fish species were 50 and showed a decreasing trend from 2008 to 2013. The minnow of Zacco platypus, based on the catch per unit effort (CPUE), was the most dominant species (25.9%) among the all species. Spatial heterogeneity was evident in the fish tolerance guilds that showed the dominance of sensitive species (89%) in the headwaters (S1) and the dominance of tolerant species (57%) in the urban. These conditions were directly influenced by concentrations of nutrients and organic matter (COD). The N:P ratios, as a barometer of water pollution, had a negative linear function (R² = 0.40, P < 0.01) with CHL, and the ratios had an important role in changes of COD concentration (R² = 0.40, P < 0.01). Under the circumstances, the N:P ratio directly influenced the relative proportions of fish trophic/tolerance compositions. According to the regression analysis of omnivore (O_m) and insectivore sp. (I_n) on total nitrogen and total phosphorus, nitrogen had no significant influences (P > 0.05) to the two compositions, but phosphorus influenced directly the two guilds [slope (a) = -32.3, R² = 0.25, P < 0.01 in the I_n; a = 40.7, R² = 0.19, P < 0.01 in the O_m]. Such water chemistry and fish trophic guilds determined the stream ecosystem health, based on the multi-metric fish model.

• 한국수산과학회지
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• 제30권5호
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• pp.719-729
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• 1997

눈다랑어와 황다랑어의 먹이의 종류와 섭이 습성을 비교하기 위하여 서부 열대 태평양에서 연승어업으로 어획된 이들 다랑어의 위내용물을 조사하였다. 눈다랑어와 황다랑어의 먹이는 주로 어류, 두족류, 갑각류이었다. 이들 두 종의 다랑어에서 동정된 먹이생물의 총 종수는 어류가 15종, 갑각류 6종 그리고 두족류가 1종이었으며 그 중 가장 중요한 먹이는 샛비늘치류인 Myctophum sp였다. 황다랑어와 눈다랑어의 먹이를 분석해본 결과 먹이의 종류에 있어서는 두 종간에 큰 차이가 없었으며 이것으로 보아 같은 해역에 서식하는 다랑어류는 먹이 습성이 유사함을 알 수 있었다. 그러나, 먹이 가운데 몇몇 종 (Myctophidae, Alepisauridae, Oplophoridae, Gammaridae, and Onychoteuthidae)의 경우 그 중요도에 있어서 두 다랑어간에 현저한 차이를 보였다.