완도 해역의 새우조망어업에서 발생한 부수어획물의 계절적 변동

오철웅 한국수산과학회 2010 한국수산과학회지 Vol.43 No.1

We examined shrimp and bycatch species composition in the shrimp beam trawl fishery off Wan-do, Korea (in the major fishing ground) from December 2004 to November 2005. We observed a total of 103,072 individuals in 96 taxa. By densities of individuals, 96.97% were shrimps, 1.20% decapods, 1.10% fish, 0.30% cephalopods and 0.43% other species. By catch weight, 57.29% were shrimps, 26.33% fish, 6.82% decapods, 4.64% cephalopods and 4.92% other species. In spring, the dominant bycatch species by biomass were Okamejei kenojei, Lophiomus setigerus, and Charybdis bimaculata. In summer, the dominant species were Charybdis bimaculata, Muraenesox cinereus, and Paralichthys olivaceus. In autumn, dominants were Okamejei kenojei, Conger myriaster, and Setipinna tenuifilis,and in winter they were Okamejei kenojei, Chaeturichthys stigmatias, and Sillago japonica. Bycatch species composition and individual species abundances differed significantly among seasons, probably indicating that variations were related to the life history characteristics of bycatch species. The diversity index was highest in October (2.797) and lowest in July (1.012). The July dominance index (0.569) was much higher than in other months; evenness was highest in September (0.856) and lowest in July (0.374). During the study period, the bycatch-to-shrimp ratio of this fishery varied from 0.063 in February 2005 to 11.031 in May 2005, with a mean of 3.363. These temporal variations may be linked to variations in reproductive behaviors and migration patterns of the marine animals sampled.

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

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%).

다중모드 광섬유의 대역폭 향상을 위한 경사각 입사 방법

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

빔 직경에 따른 다중모드 광섬유의 대역폭 변화

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

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.

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

오철웅,정인주 한국수산과학회 2002 한국수산과학회지 Vol.35 No.3

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. japonirus). 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 새우류 생산의 45% 이상을 차지하는 서해남부해역의 새우어업에 대한 어획물 조성뿐만 아니라 주요 어획대상종인 젓새우류 (Acetes 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 (A.ja-ponicus, 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. 명태와 옥수수 단백질을 이용하여 제조한 이중필름이 명태 단백질 단독으로 제조한 필름에 비하여 L값과 a값은 낮고 b값과 ΔE값은 높았다19\~l.27gC/m^{2}/day$</TEX> 범위에 평균 $0.62gC/m^{2}/day$로 나타났다 9월에 1.12gC/m^{2}/day$의 높은 값을 나타낸 이후 점차 감소하기 시작하여 2월에 0.19gC/m^{2}/day$의 최소 값을 나타내었으며, 봄철로 접어들면서 점차 증가하는 양상을 보였고, 5월에 $1.27gC/m^{2}/day$의 최대 값을 나타내었다. (P<0.05). 헤마토그리트과 비만도는 모든 사료구에서 유의적인 차이가 없었다 (P<0.05). 따라서, 치어기 잉어에 있어서 Iysine 부산물은 어분단백질의 100% $FM; LCM_20$, 80% $FM+20\%$ $LCM; LCM_40$, 60% $FM+40\%$ $LCM; LCM_60$, 40% $FM+60\%$ $LCM; LCM_100$, 100% $LCM; LCM_20$l, 80% $FM+20\%$ $LCM+0.07\%$ $Lysine; LCM_40$l, 60% $FM+40\%$ $LCM+0.14\%$ $Lysine; LCM_60$l 40% <TEX>$FM+60\%$</T

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

오철웅,나종헌,마채우 한국수산과학회 2003 한국수산과학회지 Vol.36 No.2

영암댐의 어도를 이용하는 회유성 어류 자원의 계절적 변화 연구

오철웅,황종서,박경양,송태곤 木浦大學校 沿岸環境硏究所 1999 沿岸環境硏究 Vol.16 No.1

영암호 통선겸용 갑문식 어도에서 총 30회의 어류 조사 결과 줄공치, 웅어, 숭어, 빙어, 전어 등 총 25종이 출현하였다. 어도의 출현 종은 계절별로 종조성, 개체수, 생체량에 있어서 크게 변동하는 것을 보여 주었다. 월별 총출현 종수는 6월에 12종으로 가장 많은 종이 출현하였으며, 다음으로 7, 8, 9월에 11종, 10월에 10종이었으며, 11월에 6종, 4월과 5월에 각각 5종으로 가장 적은 종수의 출현하였다. 종다양도지수 또한 6월에 1.048로 가장 높았으며, 11월에 0.346으로 가장 낮게 나타났다. 출현종의 개체수는 봄철이후로 전반적인 감소 경향을 보여 주었으며, 주요 우점종의 전체 개체수는 줄공치, 웅어, 빙어, 숭어의 순으로 나타났다. 생체량도 개체수의 변화와 마찬가지로 봄철이후로 전반적인 감소 경향을 보여 주었으며, 주요 우점종에 대한 전체 비율를 보면 웅어, 줄공치, 빙어, 숭어의 순으로 나타났다. 이러한 영암호 통선겸용 갑문식 어도에서 어도 이용 생물의 종조성, 개체수 및 생체량의 뚜렷한 계절적인 변화 (temporal variation)를 관찰 할 수 있었다. 이러한 결과는 계절별로 다양한 종들이 그들의 생활사의 일부 기간에 어도를 효과적으로 이용하고 있다는 것을 반영해 주었다. 우점종의 한종인 줄공치의 체장빈도분포 분석결과 줄공치는 두개의 연급군으로 이루어져 있으며, 두번째 연급군이 탁월 연급군이었다. 가입은 주로 여름철 (8월과 9월)에 일어났다. 이러한 결과는 줄공치가 치어기부터 성어기까지 어도를 이용하고 있다는 것을 지적해 주고 있다. Investigations were made on the temporal changes in species composition and species diversity, number of individuals and biomass of fishes in the fish way constructed at Young-am Dam. During the sampling period total 25 species were observed. Of these, dominant species were Hemiramphus kurumaeus, Coilia ectenes, Mugil cephalus, and Hypomesus olidus. Number of species was the most numerous in June (12) and the least in April and May (5). Similar results were found in the species diversity index (H'), which was 1.048 in June and 0.346 in November. There were variations in number of Individuals and biomass of fishes in the fish way, showing a gradual decline from summer to Autumn. This suggests that a variety of adult and larval fishes utilized in the fish way as a channel of migration in relation to their life history. Number of individuals (percentage of total number) was in the order of Hemiramphus kurumaeus (63%), Coilia ectenes (17%), Hypomesus olidus (15%), Mugil cephalus (5%) and biomass (percentage of total biomass) in the order of Coilia ectenes (51%), Hemiramphus kurumaeus (35%), Hypomesus olidus (7%), Mugil cephalus (4%). For one of the dominant species, Hemiramphus kurumaeus, length-frequency distribution showed that it consisted of two cohorts, with predominance in the 2nd cohort and recruitment occurred mainly in August and September, indicating utilization of fish way at various stages during its life history.