빔 직경에 따른 다중모드 광섬유의 대역폭 변화

오철웅,문석배,김덕영 한국통신학회 2004 한국통신학회 기타 간행물 Vol.2004 No.11

다중모드 광섬유의 대역폭 향상을 위한 경사각 입사 방법

오철웅,문석배,김덕영 한국통신학회 2004 한국통신학회 기타 간행물 Vol.2004 No.11

Variations in Species Composition, Biomass, and Density in Shrimp Trawl Bycatch Across Seasons and Tidal Phases in Southern Korean Waters: Developing a Fisheries Risk Management Approach

오철웅,김성태,나종헌 한국수산과학회 2009 Fisheries and Aquatic Sciences Vol.12 No.2

We quantitatively investigated compositions of fish and invertebrate bycatch in Korean shrimp fisheries. We sampled shrimp trawl bycatch from 48 commercial trawls over 1 year. These samples contained 108 taxa from 50 families, with 60 fish taxa contributing 51.2% of the total biomass and 48 invertebrate taxa 48.8%. However, 86.32% of the total individual organism density comprised invertebrates, while individual fishes made up the remainder. Within the bycatch, two fish species varied in population size structure by season, suggesting recruitment is seasonal in these taxa. Overall general catch characteristics (total bycatch biomass and organism density) varied significantly by season and tide, and a significant interaction effect was observed (season×tide) on total density, but not on total biomass. The data collected will be used in designing a program of long-term bycatch monitoring

다중모드 스펙트럼 광원을 이용한 광섬유의 색분산 측정

오철웅,문석배,김덕영 한국통신학회 2004 한국통신학회 기타 간행물 Vol.2004 No.11

Growth Pattern of Pandalus gracilis (Decapoda: Pandalidae) in the Southern Coastal Waters of Korea

오철웅 한국수산과학회 2011 Fisheries and Aquatic Sciences Vol.14 No.2

The population dynamics of Pandalus gracilis was investigated in the southeastern coastal area of Korea between May 1998 and April 2000. Of the 4,127 specimens, 57% were identified as females, 39% as males, and 4% as transitional hermaphrodites. The number of females was greater than that of males and transexuals. A significant correlation was observed between the number of transitional hermaphrodites and ambient seawater temperature. Growth parameters were estimated using the modified von Bertalanffy growth function model incorporating seasonal variation in growth using the program ELEFAN. Females grew faster and reached a larger size-at-age than males (K=0.65/y and L_∞=17.86 mm carapace length [CL] for females; K=0.51/y and L_∞=14.70 mm CL for males). Mean size and age (95% confidence limits) at sex transition, calculated from growth parameters, were 7.07 mm carapace length and 1.05 years, respectively. The reproductive strategies of pandalid shrimps are discussed in terms of the type of sex transition.

Population Biology of Korean Pomfret Pampus echinogaster (Basilewsky, 1855) (Perciformes: Stromateidae) on the Western Coast of Korea, Yellow Sea

오철웅,나종헌,김진구 한국통합생물학회 2009 Animal cells and systems Vol.13 No.1

Investigations were made on population biology of Pampus echinogaster (Basilewsky, 1855) in the coastal areas of Korea, Yellow Sea, between August 2005 and July 2006. Population structure was not significantly different between male and females. Monthly variation of gonadosomatic index (GSI) of both sexes defined spawning period extending from March through July. A similar pattern was also observed in change at maturity stages. For males and females GSI was positively correlated with hepatosomatic index (HSI). Fecundity, ranging from 41,250 to 103,610 eggs, was related to body size, indicating that body size is the useful determinant of fecundity. The sexual maturity (L50) was estimated as 14.98 cm TL for males and 19.32 cm TL for females. Parameters of growth estimated by the modified von Bertalanffy growth function model showed that the values of L∞ and K for combined data were 39.12 cm TL and 0.65 yr−1. The growth performance index of this study (2.75) was higher than that of the previous study (2.45). This difference could be attributed to sampling method. The recruitment patterns indicated one normally distributed group. Percentage of the recruitment was 51.04% in the spawning season and the highest in August (19.78%). Investigations were made on population biology of Pampus echinogaster (Basilewsky, 1855) in the coastal areas of Korea, Yellow Sea, between August 2005 and July 2006. Population structure was not significantly different between male and females. Monthly variation of gonadosomatic index (GSI) of both sexes defined spawning period extending from March through July. A similar pattern was also observed in change at maturity stages. For males and females GSI was positively correlated with hepatosomatic index (HSI). Fecundity, ranging from 41,250 to 103,610 eggs, was related to body size, indicating that body size is the useful determinant of fecundity. The sexual maturity (L50) was estimated as 14.98 cm TL for males and 19.32 cm TL for females. Parameters of growth estimated by the modified von Bertalanffy growth function model showed that the values of L∞ and K for combined data were 39.12 cm TL and 0.65 yr−1. The growth performance index of this study (2.75) was higher than that of the previous study (2.45). This difference could be attributed to sampling method. The recruitment patterns indicated one normally distributed group. Percentage of the recruitment was 51.04% in the spawning season and the highest in August (19.78%).

새우류 어업에서 어구의 망목 크기가 부수어획량에 미치는 영향

오철웅(Chul Woong OH) 한국생태공학회 2012 한국생태공학회지 Vol.3 No.1

The composition of shrimp and bycatch species caught by two fishing gears (shrimp beam trawl and single-walled tangle net) in the shrimp fisheries of Korea was examined from the major fishing ground during two years between October 2002 and September 2004. A total of 127 species was observed in shrimp trawl and a total of 70 species in single-walled tangle net. These samples were occupied by 74.2% of shrimps, 11.6% of fishes, 7.5% of other crustacens and 4.2% of shellfishes in shrimp trawl, and 88.9% of shrimps and 10.4 % of fishes in single-walled tangle net in terms of total numbers. These samples were occupied by 36.1% of fishes, 25.8% of shellfishes and 14.4% of shrimps in shrimp trawl and by 64.5% of shrimps, 32.7% of fishes in single-walled tangle net in terms of total catch weight. Main bycatch calculated by biomass was Chaeturichthys stigmatias (21.6%), Rapana venosa (21.1%) and Charybdis japonica (12.5%) in beam trawl, and Collichthys lucidus (14.7%), Thryssa kammalensis(11.4%) and Setipinna taty (10.0%) in single-walled tangle net. During the study period, the bycatch-to-shrimp ratio of shrimp beam trawl and single-walled tangle net were 0.87 and 0.24, respectively. Experiment of gear selectivity with increasing mesh size from mesh size in present use to 50% and 100% increase of its mesh size, showed that 50% selectivity size increased and bycatch-to-shrimp ratio are reduced. Measures to reduce the bycatch proportion in the shrimp fisheries are discussed with various management options.

한국 서해남부 해역에 분포하는 넓적뿔꼬마새우 (Latreutes planirostris) 의 생식생태 및 개체군 동태

오철웅 ( Chul Woong Oh ),마채우 ( Chae Woo Ma ),나종헌 ( Jong Hun Na ) 한국수산과학회 2003 한국수산과학회지 Vol.36 No.2

N/A Reproductive biology and population dynamics of Latreutes planirotris were investigated on the south western waters of Korea, from June 2001 to May 2002. This paper describes sex ratio, population growth, and reproductive aspects of Latreutes planirostris. Brood size was an isometric function of female carapace length. Based on dry weight, reproduction effort (mass of eggs/mass of female) averaged 0.23 Ovarian examination showed that there was significantly higher gonadosomatic index from May to September, with a peak in June. Statistical analysis revealed that the ovarian dry weight of females with eyed eggs was significantly higher than that of those with non-eyed eggs. This suggests that females were potentially consecutive breeders. Sex ratio showed that female is more numerous than male. Growth parameters, mortality, and recruitment were estimated by monthly length-frequency data. Growth parameters were estimated, using the seasonalized von Bertalanffy growth function model (L_∞ = 12.70 mm CL, K=0.87yr^-1, C = 0.96, WP = 0.59). The recruitment pattern was twice a year.

우리나라 서해남부해역의 새우류 어획물에 대한 자원생물학적 연구 1 . 어획물조성과 젓새우류의 산란시기

오철웅(Chul Woong Oh),정인주(In Ju Jeong) 한국수산과학회 2002 한국수산과학회지 Vol.35 No.3

우리나라 새우류 생산의 45% 이상을 차지하는 서해남부해역의 새우어업에 대한 어획물 조성 뿐만 아니라 주요 어획대상종인 젓새우류 (A. japonicus, A. chinensis)의 자원생물학적 특성치로서 성비, 체장과 체중 및 포란수와의 상관관계와 그들의 산란시기를 조사하였다. 어장에서 이용되는 주머니얽애그물의 어획물을 2000년 3월부터 2001년 2월까지 매월 채집하였다. 총 59종이 출현하였으며 새우류 14종, 어류 34종, 기타 갑각류 8종 및 두족류 3종으로 나타났다. 조사기간동안 새우류에 대한 부수어획물의 비는 2000년 4월에 2.42로 가장 높게 나타났으며, 2000년 8월과 2001년 2월을 제외하고 전 기간동안 1 미만으로 나타났다. 이러한 결과는 다른 지역이나 다른 국가에서 행해지는 새우어업과 비교해 볼 때 본 어법은 새우류에 대한 어구선택성이 탁월하고 다른 어종에 미치는 영향이 작다는 것을 지적해 주고 있다. 본 연구지역에서 출현량이 가장 많은 분류군은 젓새우류 (Acetes japonicus, A. chinensis)로 나타났다. 이들의 평균 성비는 젓새우의 경우 1.44±0.42, 중국젓새우의 경우 1.44±0.43으로 나타나 두 종 모두 암컷이 더 많이 출현하는 경향을 보여주었으며, 특히 8월에 암컷의 비율이 가장 높게 나타났다. 젓새우의 평균 포란수는 4,812±1,511개로 나타났으며, 중국젓새우의 평균 포란수는 5,561±1,900개로 나타났다. 두 종에 있어서 성숙한 암컷개체는 5월에서 8월까지 나타났다. 또한 생식소 숙도지수 (GSI)는 7월과 8월에 높게 나타났으며, 7월에 가장 높은 것으로 나타났다. 이러한 결과는 그들의 산란시기가 여름이라는 것을 지적해 주고 있다. Investigations were made on catch composition, sex ratio, relationships between carapace length, body weight and fecundity and spawning season of major target shrimps (Acetes chinensis, A. japonicus) in the shrimp fishing areas of south-western coastal waters, accounting for about 45% of annual shrimp landings in Korea. Catches were collected monthly in the fishing areas from March 2000 to February 2001, using single pocket-walled fishing gear. Total 59 species (shrimps 14, fishes 34, other crustaceans 8 and cephalopods 3 species) occurred. During the study period the bycatch-to-shrimp ratio of shrimp fishery was 2.42 in April 2000 and less than 1 for all months except for August 2000 and Febuary 2001. Compared with shrimp fishery of other areas and nations, these results indicate that effect of the fishing gear on catches of other species is minor, suggesting higher gear selectivity for shrimps. Of shrimps, there were two dominant species (A. chinensis, A. japonicus). Average sex ratio was 1.44±0.42 for A. japonicus and 1.44±0.43 for A. chinensis, which are dominant females in August. Average fecundity was 4,812±1,511 for A. japonicus and 5,561±1,900 for A. chinensis. In the two species mature females were found in the period from May to August. Similarly, the gonadosomatic index (GSI) was higher in July and August, with a peak in July. These results indicate that their main spawning season was summer.

우리나라 서해남부 해역에 출현하는 둥근돗대기새우 (Leptochela sydniensis)의 개체군 동태 및 생식생태

오철웅 ( O Cheol Ung ),최정화 ( Choe Jeong Hwa ) 한국수산과학회 2003 한국수산과학회지 Vol.36 No.6

N/A Investigations were made on the population structure, sex ratio, growth, and recruitment patterns of Leptochela sydniensis in the southwestern coastal areas of Korea, between May 2000 and December 2001. Spawning period, fecundity, brood loss, reproductive output, and size at sexual maturity also were examined. The results of the sex ratio showed that females were more numerous than males during the overall study period. Parameters of growth were estimated using the modified von Bertalanffy growth function (VBGF) model incorporating seasonal variation into growth. Females grew somewhat faster and reached a larger size than males (L_(∞)=12.80 mm CL and K=0.70 yr^(-1) for females, and L_(∞)=12.08 mm CL and K=0.69 yr^(-1) for males). The structure of recruitment patterns obtained by the FiSAT program indicated one normally distributed group. Based on the occurrence of ovigerous females and the gonadosomatic index (GSI), the main spawning season was from June to August. Analysis of covariance indicated that brood loss was not observed during the incubation period. The size at which 50% of females are mature is estimated as 5.48mm CL.