An active stimulating device, such as a fluttering net or canvas attached to the end of a cod end generating a shaking motion, could help to encourage the escape of juvenile fish positioned passively near the net. Field fishing trials using a shrimp beam trawl were carried out to examine the effect on the reduction of juvenile fish or other discard catch by generating a shaking movement of the cod end using an unbiased cap-like round canvas. The mean period of the shaking motion with the round canvas was 〜14 s, and the mean amplitude was 0.4 m as measured by peak event analysis and the global wavelet method. The bycatch of juvenile fish in 14 trials decreased by 〜30% and by 〜25% using a steady cod end for the total bycatch using a shaking cod end in the shrimp beam trawl, while the marketing catch was similar between steady and shaking cod ends. There was no difference in the body size of the shrimp or fish and species composition between the steady and shaking cod ends. Above results demonstrate a new method for bycatch reduction using an active stimulating device, although more detailed studies are needed.

목포해역에서 염분의 농도는 우기인 여름철을 제외한 나머지 계절에서는 30.3%에서 31.1%의 범위를 나타내고 있으나 여름철에는 27.6% 로 낮아져 담수의 유입이 많았다는 것을 알 수 있다. 8월 영산호 하구언 직 하류에서 염분의 농도는 23.6% , 목포항에서는 23.4%이였으며 장좌도와 달리도에서는 28.9%, 30.7%로 나타나 담수의 유입이 영산호에 유입되었으며 목포항에서도 혼합되지 않고 있으며 오히려 염도가 약간 낮아진 것으로 보아 목포항의..

Hydro-acoustic surveys with scientific echo sounder were carried out to estimate the total density and distribution of the juvenile cod in Jinhae bay, Korea. The surveys were conducted 4 times from May to June using 2 frequency method (38kHz and 120kHz) and beam trawl were used to investigate the species composition. Also the catch amounts of juvenile cod were compared with the cod density estimated by the hydro-acoustic method. It was confirmed that the juvenile cod was stayed in Jinhae bay in early June and There was the relationship between catch of juvenile cod and the estimated density by hydro-acoustic survey. The number of juvenile cod was consequently about 365,000 fish (CV 12.9%) in May and 113,000 fish (CV 9.2%) in May based on the hydro-acoustic data.

The age and growth of the Pacific cod, Gadus macrocephalus were investigated using left sagittal otoliths of 682 individuals collected in the West Sea of Korea from January to December 2007. The seasonal changes in the ratio of an opaque zone to interval between annular rings revealed that the narrow translucent parts of the otolith were annual growth rings formed between February and March once a year. The spawning period was December to January and therefore the duration from fertilization to the complete formation of the opaque zone became thirteen months. From the parameters calculated using the average length when the year ring was formed, the estimated von Bertalanffy growth equations were Lt=100.0(1-e-0.1640(t+0.5247)) for females and Lt=64.6(1-e-0.3335 (t+0.3342)) for males when is total length in age t.

본 연구는 압연공정에서 발생하는 폐수 중에 함유되어있는 난분해성 COD 물질을 80μm 두께의 극세사 형태로 제조된 Cu-Zn 금속합금의 산화 작용으로 인하여 발생하는 OH 라디칼을 이용하여 처리하는 방법에 관한 기초 연구이다. OH 라디칼은 유기화합물(RH) 속에 포함된 수소를 수소추출반응(H Abstraction) 또는 탄소와 탄소(C-C)의 불포화 결합에 첨가됨으로써 빠르고 비 선택적인 반응을 수행하는 것으로 알려진 것처럼 난 분해성 유기화합물의 처리에 효과적인 것으로 나타났다. 금속합금 반응 물질은 극세사 형태로 표면적이 넓어서 1회 처리만으로도 수용액의 pH를 평형에 도달하게 하여서 반응 효율성이 높은 것으로 나타났다. COD처리 효율은 중성 pH에 가까운 pH 7, pH 6에서 최고치를 보였으며 산성분위기인 pH 5이하 및 알칼리성 분위기인 pH 8이상에서는 낮은 효율을 보였다. 실제 압연 폐수의 응집 침전을 이용한 COD 처리에서도 redox 반응장치의 유무에 따라 2배 이상의 처리효율의 차이를 보였다.

The purpose of this study is to get basic data for the application of coagulants for treating an industrial wastewater containing NBD COD. The NBD COD concentration of the target wastewater was calculated to be 61 mg/L, which was about 72% of the first stage treated water, and this shows that there must be advanced wastewater treatment process. When Alum(8%) was injected in raw the water, 150ppm was the best dosage and 41% CODmn removal efficiency was obtained. When Alum(8%) was injected in the discharge water, 150ppm was the best dosage, and 19% CODmn removal efficiency was obtained. When powdered activated carbon was injected, 40ppm was the best dosage, 26% CODmn removal efficiency was obtained. The method of injecting Alum(8%) in the discharge water was suitable, when the effluent exceeds the water quality standard by 20%, and the method of injecting the powdered activated carbon was suitable, when the effluent exceeds the water quality standard by 20~40%.

1975년부터 2011년 11월까지 37년간의 한강 본류의 유 기오염물질의 장기변동을 평가하기 위하여 BOD와 COD 항목에 대해 서울시 보건환경연구원 분석 자료와 환경부 의 연간평균자료를 이용하여 비교하였다. 한강본류의 유 기물질 비교지점은 상수원인 팔당댐(PD)을 기점으로 구 의(KU), 잠실(JS), 뚝도(DD), 보광(BK), 노량진(NR), 영 등포(YD), 가양(GY) 등 총 8개 지점을 선정하였다. 한강 본류의 연평균 BOD는 상류인 팔당댐에서 하류인 가양 지점으로 유하하면서 증가하였다. 연도별로는 1984년에 최고치를 나타낸 후 점차 감소하기 시작하여 팔당댐에서 뚝도까지는 하천의 생활환경기준 1b인 ‘좋음’을 유지하고 있었다. 하류인 보광~가양구간은 II등급 수준을 유지하 는 것으로 나타났다. 반면 연평균 COD의 농도는 BOD와 달리 1992년에 최저치를 나타낸 후 1993년부터 증가하 는 경향을 나타내었다. 현재는 팔당댐, 잠실, 뚝도는 1b인 ‘좋음’, 구의, 보광, 영등포는 II등급인 ‘약간좋음’, 노량진과 가양은 III등급인 ‘보통’을 유지하고 있었다. 37년간 생분 해성 유기물의 지표인 BOD의 경우 꾸준히 감소(r2= 0.646)하고 있고 총 유기물을 대표할 수 있는 COD농도 도 감소추세(r2=0.260)를 유지하는 것으로 나타났다. 반 면 팔당댐의 경우 1990년대 이후부터는 BOD는 감소 추 세를 유지하고 있으나 COD농도는 1991년 1.7 mg L-1 이 후 2011년 3.9 mg L-1으로 약 2배 이상 증가추세를 보이 고 있는 것으로 확인되어 팔당댐 수계내의 난분해성 물 질에 대한 체계적인 관리가 필요할 것으로 사료된다. 계 절별 BOD, COD농도는 봄¤겨울¤여름, 가을 순으로 높 았으며 시계열 자료분석을 통해 12개월 주기로 강한 상관관계가 있고 장기간에 걸쳐 주기성이 나타나고 있음을 확인하였다. 팔당댐 방류량이 많을수록 한강본류의 BOD 와 COD농도는 낮아지는 경향을 나타내고 적을수록 높아 지는 경향을 보이고 있다. 따라서 한강수질관리에 있어 팔 당댐 방류량의 유기적 조절이 필요한 것으로 사료된다. 비록 1975년부터 2011년까지의 한강본류의 BOD의 장기 변동만 고려할 때 한강수질이 나아지기는 했으나 팔당댐 COD는 상대적으로 증가하고 있으므로 수질이 개선되었 다고 보기에는 무리가 있다. 따라서 고도하수처리 시설 등 수질개선을 위한 시설 확충과 비점오염원 원인분석 및 저감 대책과 더불어 주변 환경 및 각종 요인을 정확히 분석하고 총체적인 검토가 이루어져야 할 것으로 보이고 앞으로의 수질정책에 있어 중요한 요소라고 생각된다.

2011년 7월부터 2012년 2월에 걸쳐 광양만, 목포 내항, 신안 비금도 주변해역의 퇴적물의 강열감량(IL), COD, 황화수소(H₂S)와 퇴적물 중금속의 함량을 조사하여 해저 퇴적물의 오염도를 평가하였다. 아울러 중금속의 농집지수(Muller, 1979)를 이용하여 퇴적물의 오염도를 평가하였다. COD, H₂S, IL를 이용한 저질의 오염 정도는 신안 비금해역이 I등급, 광양만은 II등급으로 나타났다.

한국 연안에서 해수 유동모델과 입자 추적자 모델을 사용하여 대구 자치어의 이동을 파악하였다. 산란지역인 진해만, 영일만 및 강릉 앞바다에서 산란한 대구 자치어가 주변해역의 조류, 수온 및 염분, TWC(Tsushima Warm Current)에 어떻게 작용하는가를 살펴보았다. 조석잔차류는 동해연안을 따라 남향하고 이 흐름이 부산-쓰시마 북쪽해역에서 일본 연안쪽으로 흐르 는 흐름이 우세하게 나타났다. 조석잔차류에 TWC의 고려한 흐름은 남해 서쪽과 동쪽의 경계역에서 유입하여 서수도의 쓰시마 연안을 거쳐 북동쪽의 흐름과 동수도로 유입하는 흐름이 부산과 일본 서쪽에서 합류하여 일본 연안으로 북상하여 나타났다. 진해만의 산란지점에서, 조석잔차류에 의한 대구 자치어의 이동은 동해쪽으로의 이동은 작게 나타나고 남해쪽으로의 이동이 우 점하였다. 그러나 TWC의 영향을 고려한 자치어의 이동은 서수도를 지나 일본 연안으로 이동하여 나타났다.

대구 자치어의 거동을 파악하기 위해서 해수 유동모델과 자치어 추적자 모델을 통합하여 수행하였다. 먼저 한국 남 해안의 해수 유동 특성을 알기 위해 조류, 취송류, 밀도류를 조사하였다. 외해역에서는 조석잔차류가 대조시 동쪽으로 향하는 흐름을 보였고, 소조시 서쪽으로 향하는 흐름을 보였다. 잔차류의 분포를 보면 표층에서는 연안에서 외해로 나가는 남향류가 우 세하고 중․저층에서는 동향류가 나타났다. 밀도류는 연안에서 보다 외양에서 크게 나타났다. 취송류는 연안역에서 먼 바다보 다 더 강하게 나타났다. 자치어 추적자 모델을 이용하여 대구 자치어의 시간에 따른 공간적 분포를 보면, 진해만 안쪽 보다는 진해만 입구에서 대구 자치어를 방류할 경우 이류에 의해 더 빠르게 확산하는 것으로 판단된다.

본 연구는 황태채, 북어채 및 대구채간의 차이를 MS-전자코를 이용하여 분석하였다. 이들 각 시료의 mass spectrum은 뚜렷한 차이를 보였으며 판별함수분석을 통해 휘발성 성분의 패턴을 분석한 결과 황태채와 북어채, 대구채가 구분되었다(r2= 0.7787, F = 185.2). 이러한 결과는 황태채, 북어채 및 대구채를 러시아산만을 선택하여 비교한 결과 그 차이가 더욱 뚜렷이 구분되었다. 결과적으로 전자코를 이용하여 유사 식품 간의 차이를 충분히 구분 가능하였으며 EMA 식품을 선별하는 데에도 도움이 될 것으로 기대된다.

Maturation and spawning of the Pacific cod, Gadus macrocephalus was investigated based on the samples captured in East Sea of Korea from April 2006 to July 2007. Gonadosomatic index began to increase in November, and reached maximum between December and January. After spawning it began to decrease from March. Reproductive season was estimated to November-February, with peak in January. Fecundity was proportional to the size of the female, with the clutch size varying from 753,985 eggs in the smallest female(TL＝58.6cm) to 9,311,520 eggs in the largest(TL＝101.0cm). Size at 50% sexual maturity(TL50%) determined from mature females was 56.3cm of TL. Annual reproductive cycles of this species could be divided into six successive stages; immature stage(March-September), nucleolus stage(September-October), yolk vesicle stage(October-November), vitellogenic stage (November-December), ripe stage and spent stage(December-February).

Water quality has been deteriorated by the increasing amount of industrial waste water that is due to the better standard of living. In order to lessen the polluted water and substantially reutilize it at factories, a new method is needed. The plasma generator, which uses discharge current below 1,500 voltage and processes at extremely low temperature, has more strong oxidization than current method and an advantage of miniaturizing the apparatus in dealing with waster water by producing carrier gas at room temperature. This study were measured on the 3 kinds of waster water to the plasma generator for 120 minutes. As results, COD was almost decreased and removed in 15 minutes. The results suggest that the plasma generator can be used reduce COD and removal of color for various waster water, which can be reutilized as industrial water, It would be of benefit to the country like Korea in which qualified water is deficient.

본 연구는 자연 식물(미나리)을 이용하여 세제로 오염된 물에서의 정화 효과를 알아보고자 수행되었다. 세제로는 계면활성제 표준액 (linear alkylbenzene sulfonate, LAS)과 주방용 세제 3종을 사용하였으며, 이를 농도별 또는 세제별로 첨가한 수조에 야생의 미나리를 수경 재배하면서 식물체의 성장과 자정 능력을 경시적으로 관찰하였다. 식물체의 성장 변화에 있어서 미나리의 생체 중량은 배양 2일 후부터 유의하게 감소하였으며 (p<0.05) 대조군에 비하여 세제의 농도가 높을수록 감소의 정도가 컸고 시간이 경과할수록 더욱 위축되었다. 미나리 배양액의 pH는 초기의 중성에서 4일 후까지 유의하게 감소하였다가 (p<0.05) 6일 후에는 다시 증가 경향을 보였다. 그러나 초기 수준으로 회복되지는 못하였다. LAS 표준액을 사용한 배양액에서는 다른 세제들보다 초기에 산성의 경향이 짙게 나타났으나 6일 후에 현저히 pH가 증가하여 18일 후에 다른 세제배양액과 비슷하게 중성에 가까워졌다 (p<0.01). 배양액의 화학적 산소요구량 (COD)은 2일 후부터 증가되었으며 4일 후에도 계속 증가하다가 6일 후에 감소 경향을 보였다. 그리고 12일 후부터는 감소 또는 증가하는 등 일정한 경향을 볼 수 없었다. 배양액에 잔류된 세제는 농도별 실험에서는 배양 2일후에 매우 유의하게 감소하였으며 (p<0.01) 이후에는 완만한 감소를 보여 6일 후에는 초기의 12.4∼23.7%만이 잔류하였다. 세제별 실험에서는 6일 후에 세제가 초기의 22.4∼34.2%가 잔류하여 매우 유의한 감소를 보였으며 (p<0.01) 이후에는 이 수준을 유지하였다. 미나리가 비교적 양호하게 성장한 6일 동안의 세제의 감소 효과가 현저하며, 이후 시간이 경과함에 따라 그 효율은 계속 낮아졌다. 이로부터 미나리는 세제로 오염된 물을 수일 정도의 빠른 시간에 정화하는 것이 인정되며, 그 정화 능력은 물의 오염 정도나 생육 환경여건에 따라 달라질 수 있는 것으로 보여진다.

The mesh selectivity of diamond and suare mesh cod-ends at the Southern Korean Sea and the East China Sea were compared for Pampus argenteus, Trachurus japonicus, Trichiurus lepturus. Selection trials were carried out using diamond and square mesh cod-end by trouser type cod-end with cover net. of which the mesh cod-end has four types : A(51.2mm), B(70.2mm), C(77.6mm), D(88.0mm). Selection curves and selection parameters were calculated using a logistic model. The results obained are summarized as follows : 1. Harvest fish : In B. C and D type selection range and fifty percent selection length of the square mesh were about 21mm, 11mm : 12mm, 18mm and 34mm, 5mm higher than those of the diamond mesh, respectively. Selection factor of master curve for the diamond mesh was 1.54 and for the square mesh was 1.68. The optimum mesh size for the diamond mesh was 97.4mm and for the square mesh was 89.3mm, the difference was 8.1mm. 2. Horse mackerel : In A type, selection range was nearly the same for the diamond and the square mesh, but fifty percent selection length of the square mesh was 43mm higher than the diamond mesh. In B. C and D type, selection range and fifty percent selection length of the square mesh were about 6mm, 3mm : 24mm, 21mm and 11mm, 42mm higher than those of the diamond mesh, respectively. Selection factor of master curve for the diamond mesh was 2.37, for the square mesh was 2.77. The optimum mesh size for the diamond mesh was 78.1mm and for the square mesh was 66.8mm, the difference was 11.3mm. 3. Hair tail : In A, B and C type, selection range of the square mesh was about 34mm, 8mm, 60mm higher than those of the diamond mesh. Fifty percent selection length for the diamond mesh was about 5mm, 7mm, 8mm higher than that of the square mesh. Selection factor of master curve for the diamond mesh was 3.11, for the square mesh was 3.48. The optimum mesh size for the diamond mesh was 64.3mm and for the square mesh was 57.5mm, the difference was 6.8mm.

Mesh selection analysis for the trawl net were carried out at the Southern Korean Sea and the East China Sea during the 1992-1994 years by the training ship Seabada of the National Fisheries University of Pusan, using A type (51.2mm), B type (70.2mm), C type (77.6mm), D type (88.0mm) square mesh cod-ends. The fishing trials were made using bottom trawl of the trouser type cod-end with cover net. Selection curves and selection parameters were calculated by a logistic model for Sphyraena pinguis, Pampus argenteus, Trachurus japonicus, Pagrus major, Callanthias japonicus, Trichiurus lepturus. The results obtained are summarized as follows: 1. Red barracuda : Selection range and fifty percent selection length in the A type was 115.8mm, 292.8mm, respectively. 2. Harvest fish : Each selection range and fifty percent selection length in the B. C. and D type was 37.7mm, 113.8mm : 40.1mm, 131.7mm and 64.8mm, 148.6mm, respectively. Selection parameters of master curve were : slope, 3.81 : intercept, -6.4. Optimum mesh size was 89.3mm. 3. Horse mackerel : Each selection range and fifty percent selection length in the A, B, C and D type was 43.0mm, 148.3mm : 60.7mm, 183.2mm, 214.5mm and 91.4mm, 254.9mm, respectively. Selection parameters of master curve were : slope 2.30 : intercept, -6.4. Optimum mesh size was 66.8mm. 4. Red seabrem : Selection range and fifty percent selection length in the D type was 42.7mm, 203.4mm, respectively. 5. Yellowsail red bass : Selection range and fifty percent selection length in the A type was 84.0mm, 110.6mm, respectively. 6. Hair tail : Each selection range and fifty percent selection length in the A, B and C type was 59.7mm, 176.0mm : 100.9mm, 250.7mm and 178.6mm, 307.0mm, respectively. Selection parameters of master curve were : slope, 1.54 : intercept, -5.4. Optimum mesh size was 57.5mm

The fishing experiment was carried out by the training ship Saebada in order to analyse the mesh selectivity for trawl cod-end, in the Southern Korea Sea and the East China Sea from June. 1991 through August, 1992. The trawl cod-end used in this experiment has the trouser type of cod-end with cover net. and the mesh selectivity was examined for the five kinds of the opening of mesh in its cod-end part. A total of 163 hauls, of which having mesh size 51.2mm ; A 89, 70.2mm ; B 54, 77.6mm ; C 55, 88.0mm ; D 52 and 111.3mm ; E 20 were used respectively. Selection curves and selection parameters were calculated by using a logistic function, S=1/(1+exp super(-(aL+b)) ). The mesh election master curves were estimated by S=1/(1+exp super(-[a(L/M)+β]) ). and the optimum mesh size were calculated with (L/M) sub(50) of master curve. In these cases 'a' and 'α' are slope, 'b' and 'β' are intercept. 'L' is body length of the target species of fishes, 'M' is the mesh size, and 'S' denotes mesh selectivity. In this report, the four species of compressed form fishes were taken analized according to fish shape, and 'S' denotes mesh selectivity. In this report, the four species of compressed form fishes were taken analized according to fish shape, and the results obtained are summarized as follows: 1. Red seabream Pagrus major(Temminct et Schlegel) and yellow porgy Dentex tumifrons(Temminct et Schlegel) ; Selection rate in each mesh size of A, B, C, D and E were 99.7%, 97.5%, 91.4%, 76.7% and 57.8% respectively. Selection parameters 'a' and 'b' of mesh sizes C, D and E were 2.65 and -28.62, 4.40 and -77.73, 2.31 and -46.99, and their selection factors were 1.39, 2.10, 1.83 respectively. Selection parameters of master curve 'α' and 'β' were 3.05 and -5.65 respectively, and (L/M) sub(50) was 1.85. The optimum mesh size of Red seabream was 141mm. 2. Filefish Thamnaconus modestus (Gunther) ; Selection rate in each mesh size of A, B, C, D and E were 99.6%, 98.3%, 91.2%, 80.0% and 48.6% respectively. Selection parameters 'a' and 'b' of mesh sizes C, D and E were 5.82 and -55.10, 2.92 and -36.90, 3.91 and -63.09, and their selection factors were 1.35, 1.44, 1.45 respectively. Selection parameters of master curve 'α' and 'β' were 3.02 and -4.32 respectively, and (L/M) sub(50) was 1.43. The optimum mesh size was 129mm. 3. Target dory Zeus faber Valenciennes ; Selection rate in each mesh size of A, B, C, D and E were 99.7%, 100%, 83.2%, 91.6% and 65.0% respectively. Selection parameters 'a' and 'b' of mesh sizes C, D and E were 3.85 and -32.46, 4.19 and -57.38, 2.45 and -40.03, and their selection factors were 1.09, 1.56, 1.47 respectively. Selection parameters of master curve 'α' and 'β' were 2.64 and -3.53 respectively, and (L/M) sub(50) was 1.34. The optimum mesh size was 127mm. 4. Butterfish Psenopsis anomala (Temminct et Schlegel) ; Selection rate in each mesh size of A, B, C, D and E were 99.2%, 34.1%, 46.5%, 14.3% and 2.4% respectively. Selection parameters 'a' and 'b' of mesh sizes B, C and D were 5.35 and -71.70, 5.07 and -69.25, 3.31 and -62.06 and their selection factors were 1.91, 1.75, 2.13 respectively. Selection parameters of master curve 'α' and 'β' were 3.16 and -6.24 respectively, and (L/M) sub(50) was 1.98. The optimum mesh size was 71mm.

The selective response of the sea bass, Lateolabrax japonieus and the gray rock cod, Sebastes inermis to the colored twines was studied in a white tiled aquarium C400LX60WX70H em), by use of Y -maze made of gray plastic plate. Anyone of the different colored twines, white, black, blue, yellow and red, was strung crosswise on a rectangular frame which was mounted to one of the two outlet ends of Y -maze, and another colored twine was used to the other end of the Y -maze. In each trial, a fish was guided toward the inlet of the Y -maze to let the fish select either one of the two different colored twines. The results obtained are aS follows: 1. Sea bass preferably selected the colored twines in a order of white, blue, yellow, black and red with significant difference. 2. Gray rock cod showed little difference in selecting colored twines even though the fish selected white one a little more frequently.