Abstract ▼

Ⅳ. Research Results
Section 1. Pacific cod culture
1. Basic study in seed production
This report carried out the artificial seed production from January 17 to February 18, 2009.
Fertilization rate was reached about 80%, the size of fertilized eggs were about 1.1 mm, the range of total l

Ⅳ. Research Results
Section 1. Pacific cod culture
1. Basic study in seed production
This report carried out the artificial seed production from January 17 to February 18, 2009.
Fertilization rate was reached about 80%, the size of fertilized eggs were about 1.1 mm, the range of total length in the newly hatched larvae were 4.1~4.3 mm, which were not opened moth and have the yolk. The hatching was occurred during the 3 days. We have fed the rotifer with 5 individuals/ml for larvae, also formated the green water by chlorella. Larvae were opened mouth on 4 days after hatching. And we could observed larvae with fed rotifer.
The amount of larvae were dead from 10 days after hatching, total length of larvae were reached 5.1~5.6 mm on 11 days, 7.0~7.4 mm on 22 days after hatching. We have fed the mixed rotifer and artificial feed on 30 days after hatching. Larvae were grew to 7.6~7.9 m in total length on 33 days after hatching, daily grow rate were 1.84 %.
2. Physiological characteristic in juvenile
A. Oxygen consumption rate
A study was conducted to investigate the effect of water temperature and photoperiod on the oxygen consumption of the fasted juvenile Pacific cod, Gadus macrocephalus (mean body weight 79.9±2.0 g) in order to quantify metabolic response of this species at given conditions. The oxygen consumption rate (OCR) of G. macrocephalus was measured under the combination of four different water temperatures (7, 10, 13 and 16℃) and three different photoperiods (24L:0D, 12L:12D and 0L:24D) with an interval of 5 minutes for 24 hours using a closed recirculating respirometer. In each treatment three replicates were set up. The OCRs increased with increase in water temperature under all photoperiod conditions (P<0.001). Mean OCRs at 7, 10, 13 and 16℃ ranged 793.7~1108.4, 1145.7~1570.3, 1352.8~1742.5 and 1458.2~1818.6 mg O2 kg^-1 h^-1 respectively. Mean OCRs of G. macrocephalus were the highest in continuous light (24L:0D) followed 12L:12D and 0L:24D photoperiod under all water temperature conditions except 7℃ (P<0.001). Mean OCRs of fish exposed to the 12L:12D photoperiod was significantly higher during the light phase than during the dark phase under all temperature conditions (P<0.001). Q₁₀ values ranged 3.19~5.13 between 7 and 10℃, 1.41~1.70 between 10 and 13℃ and 1.15~1.35 between 13 and 16℃, respectively. Based on overall results, water temperature, photoperiod and their combinations exert a significant influence on the metabolic rate of juvenile cod. This study provides empirical data for estimating the amount of oxygen demand and managing the culture of cod under the given water temperatures and photoperiod.
B. Total ammonia nitrogen excretion rate
A study was carried out to examine the effect of water temperature on daily pattern and rate of total ammonia nitrogen (TAN) excretion in juvenile Pacific cod Gadus macrocephalus (mean body weigh: 36.5±0.3 g) under fasting and feeding conditions. Fish were acclimated over 10 days under three different water temperatures (9, 11 and 13℃). After 72 hours of fasting, endogenous TAN excretion was measured at each temperature. And then, to investigate post-prandial TAN excretion, fish were hand-fed with a commercial diet containing 40.6% crude protein over 7 days, two times daily 08:00 and 16:00 h. Water was sampled for both the inlet and outlet of chamber every 2 h over a 24 h period. Both of endogenous and post-prandial TAN excretion increased with the increase of water temperature (P<0.05). Mean endogenous TAN excretion rates at 9, 11 and 13℃ were 9.3, 11.0 and 11.9 mg TAN kg fish^-1 h^-1, respectively. The value of 9℃ was lower than those of 11 and 13℃ (P<0.05), but there was no significant difference between 11℃ and 1 3℃. Mean post-prandial TAN excretion rates at 9, 11 and 13℃ were 23.0, 31.6 and 45.4 mg TAN kg fish^-1 h^-1, respectively. A peak value of post-prandial TAN excretion rate occurred after 2 hours from each feeding, and second value is always higher than first value. Maximum post-prandial TAN excretion rate occurred after 10 hours from the first feeding at 9℃ (mean 38.0 mg TAN kg fish^-1 h^-1), 11℃ (52.9 mg TAN kg fish-1 h-1) and 13℃ (77.5 mg TAN kg fish^-1 h^-1), respectively. The TAN loss for ingested nitrogen at 9℃ (43.9%) was lower than that of 11℃ (46.4%) and 13℃ (48.4%). As overall results, water temperature exhibits a significant effect on the nitrogen excretion of juvenile Pacific cod.
3. Rearing the juveniles from wild
This research investigated that the growth of cod juvenile from wild reared by fed krill and growth of cod juvenile with the different feed types in Deep Seawater Center, Goseong, Gangwon. In the first experiment, the size of experiment fishes with collected on January 2009 were 18.4±1.2 cm in mean total length (MTL) (56.8±13.5 g in mean body weight (MDW)). Its were grow 21.6±1.2 cm in MTL, 95.9±20.8 g in MDW after 47 days, 26.6±2.8 cm in MTL, 154.3±57.5 g in MDW after 130 days. Daily growth rate was 0.81%/day during the 130 days. On March 2009, juveniles (initial total length, 19.5±1.1 cm; initial body weight, 63.6±12.5 g) were grow 21.7±1.45 cm in MTL and 76.8±20.5 g in MBW after 74 days, respectively. Daily growth rate was 0.25%/days during the 74 days. In the second experiment, there was investigated the grow of cod juvenile by fed the different diet with EP-1 (be made by extruded pellet 85% and moisture 15 %), EP-2 (extruded pellet 85%, krill concentrate 15%), MP-1 (frozen mackerel 65%, powder pellet 35%) and MP-1 (frozen mackerel 50%, powder pellet 35%, and krill concentrate 15%), respectively. Cod juvenile were grow from 143～147 g in rang of initial body weight to 152～159 g in final body weight. Survivial were 99.1, 96.1, 98.0 and 96.0% in EP-1, EP-2, MP-1 and MP-2. feed efficiency were higher 26.7, 40.3% in MP-1, MP-2 than 12.8, 12.3% in EP-1, EP-2. Feed intake were highest 7,035 g in EP-1 and lowest 3,803 g in MP-2, total weight gains were 900.5 g, 747.0 g in EP-1, EP-2 and 1,062.5 g, 1,536 g in MP-1, MP-2. Daily growth rate were high 0.23, 0.34 % in
MP-1, MP-2 and low 0.17, 0.16% in EP-1, EP-2. Daily feed intake were high 1.34, 1.33% in EP-1, EP-2 and low 0.88, 0.83% in MP-1, MP-2.
4. Optimal stocking density and feeding frequency
Growth patterns of Pacific cod with 178.9 g in mean weight on the stocking densities (4, 8 and 12 kg m³) and feeding frequency (3 and 5 times in a week) were investigated from October 2009 to February 2010. Total weight gain increased from 17.8% in stocked at 4 kg/m3 to 35.9% in stocked at 12 kg/m3. Specific growth rates, survival rates and feed efficiency increased as density increase, but there were not significantly different. Daily feed intake decreased as stocking density increased, whereas condition factors increased as stocking density increased (P<0.05). Growth rates of Pacific cod with fed to satiation increased as feeding frequency increased, but were not significantly different (P>0.05). Survival rates, daily feed intake, feed efficiency and condition factors of pacific cod were not significantly different (P>0.05). Based upon these results, it is recommended that the optimum stocking density at juvenile stage in cod is hold above 12 kg/m³, feeding frequency is three times a week
5. Application to offshore submergible cage on cod culture
A. Status of offshore cage in Korea
Fish culture applying to offshore cage have carried by government funding from 2005 in Korea. Firstly, they candidated to the owner for pilot business per each regional government, also invested to the funds. Already Jeju province, Kyungsangnam-do and Jeonranam-do tried to that since 2006, in addition, the legal base for offshore culture on the fishery law administrated by project. The offshore culture have to be combined with currents of fisheries condition, preferentially, and special skills, infra-structure of these system will be prepared before it trying to that.
B. Application and fixation of offshore cage
Offshore cage for cod culture were fixed the ball type cage produced by Aqua-pod in 2008, and about six month later, assembled and installed in Yangyang province in Gangwon-do. Nevertheless, had suffered to the assemble it by language problem and so on, it finished the fixation about 24m depth. After supplimentary measures of air tanker, put into the fin fish for pilot survey. But in Jan. 2010, by water temperature drop abruptly, all of fin fish died and founded out that some of the steel sheet also tear off that the plan which put juvenile cod into the cage were canceled. It was impossible to processing the cod culture applying to offshore cage in coldwater area.
6. Economical Analysis
This study was carried out the economical analysis of pacific cod culture applying to offshore submerged cage system according to 3 scenario in shipment (A, shipping the cod with reared 170 g fish in mean wight for 8 months; B, shipping the cod with reared 170 g fish to 1.5 kg fish; C, first shipping: about the cod with reared 170g to 600g; Second shipping: about the cod with reared to 1 kg; third shipping: about the cod with reared to 1.5 kg) and 2 scenario in seed obtain (1, often purchase the seed during the business period; 2, only one purchase the seed on initial time in culture, for the rest, obtain the seed by seed production). In case of scenario A-1, net present value (NPV) was -15,092.73, benefit-cost ratio (B/C-ratio) was 0.422. On B-1, NPV was -1,013.03, B/C-ratio was 0.901, and -4,661.19 in NPV and 0.767 in B/C-ratio on C-1. And its were -6,721,74 (NPV), 0.640 (B/C-ratio) on A-2, -69.08 (NPV), 0.99 (B/C-ratio) on B-2, -1,877.75 (NPV), 0.89 (B/C-ratio) on C-2, respectively. This results recommended that the business of cod culture applying to offshore cage system is no economically viable from NPV were smaller than "1" and B/C-ratio were smaller than "0" in all scenario.
Section 2. Bluefin tuna culture
1. Feasibility of Offshore Cage Culture
Pacific bluefin tuna is evaluated as the optimal tuna species of offshore cage culture as it is priced high, grows fast and migrates to the Korean coastal waters, making it easy to obtain juveniles needed for farming. Its fast growth and dynamic swimming pattern requires a large-scaled farming system. Also to be the optimal farming site, it should have well flowing of tide and currents and be free of red-tide. It can be concluded that offshore cage culture is practicable for tuna if the site is optimally selected based on tuna's biological and ecological traits.
2. Optimal Site Selection and Environment Assessment
The waters of Pyosun and Hanrim, Jeju was selected as the optimal farming site as it was assessed to have more favorable farming conditions like warm water temperature of 14℃ in winter, high transparency, less suspended solid and high DO. As for other candidate sites, Yokji-island of Tongyoung and Gujora of Geoje were assessed to be vulnerable to redtide, Guryongpo of Pohang city vulnerable to hypoxic water mass and Geomoon-island of Yeosu to be less accessible.
3. Selection of Offshore Cage
Safety of facility and reared tuna comes first to consider the location of offshore cage. Considering that tuna swim in a large radiation, round cage is the most appropriate. Rearing conditions should be also taken into account to decide the cage.
4. Supply Channels of Seeds (Juveniles) Used for Tuna Aquaculture
We reviewed on the supply channel of juveniles needed for farming. Juveniles can be obtained through trolling, purse seine and import, though trolling is the most preferred as it costs less while offers a very high change for success. As such, trolling was evaluated as the most effective channel of seed supply with a potential to boost the income of fishing community.
5. Capturing Juveniles for Tuna Aquaculture
We captured 833 juveniles aged less than 1 year through trolling and 371 among which were contained in the offshore cage. It was judged that securing a large amount of young tuna is practicable. As for the seed import from Japan, it is technologically possible but with diplomatic issues and a possible ban on the trade due to the more intense competition for the tuna stock. Those issues are needed to be resolved through the long-term cooperation between the two countries.
6. Development of Rearing Technology for Offshore Cage Culture
The tuna juveniles captive in the offshore cage were caught in 2009 and fed by raw fish-based moist pellet. As of June 2010. the survival rate was 91%. The growth investigation was conduced by the dual-frequency identification sonar and stereo camera, which enabled effective growth investigations with no direct contact to the body of fish and no stress on it. The duel-frequency identification sonar also showed that tuna swim in a small radiation and in the bottom depth at night time while swim in a large radiation and in the shallow depth at day time. It was also found that young tuna weighed 3kg accumulated the fat as fast as adults while slowly accumulated the mercury as the weight increased. Genetic analysis on tuna and its growth hormone helped to lay a foundation for genetics resources industry.
7. Environment Assessment of Offshore Cage
The open-type offshore cage is evaluated as eco-friendly as it is not affected by sea currents, being free of land-based pollution and dealing with pollutants in a very fast way. Meanwhile, the coastal cage is not only susceptible to land-based pollution but has less capacity to handle the pollutants, leaving the land-based wastes accumulated around the farming cages.
8. Economic Assessment of Offshore Cage
Though costing high in terms of regular maintenance and early investment, the offshore farming of tuna is evaluated as competitive based on its high survival rate. For cost reduction, juveniles are needed to be domestically supplied and for stable supply of juveniles, hatchery-reared juvenile culture is urgently needed to be completed. The offshore culture is judged to be more competitive than the coastal culture based on the fact that the former has higher survival rate and less vulnerability to red-tide, typhoon, low water temperature, and other natural abnormalities.

목차 Contents

• 표지 ... 1
• 제 출 문 ... 2
• 요 약 문 ... 3
• SUMMARY ... 14
• CONTENTS ... 22
• 목 차 ... 24
• 제 1 장 연구개발과제의 개요 ... 27
• 제 2 장 국내외 기술개발 현황 ... 30
• 제 1 절 국외의 기술개발 현황 ... 30
• 제 2 절 국내의 기술개발 현황 ... 37
• 제 3 장 연구수행 내용 및 결과 ... 40
• 제 1 절 대구양식분야 ... 40
• 1. 종묘생산을 위한 기초연구 ... 41
• 가. 재료 및 방법 ... 41
• 나. 결과 ... 43
• 다. 고찰 ... 46
• 2. 대구 치어의 생리적 특성 ... 47
• 가. 재료 및 방법 ... 47
• 나. 결과 ... 52
• 다. 고찰 ... 60
• 3. 자연산 대구종묘의 인공사육 ... 64
• 가. 재료 및 방법 ... 64
• 나. 결과 ... 68
• 다. 고찰 ... 72
• 4. 대구의 적정사육밀도와 먹이공급횟수 ... 73
• 가. 재료 및 방법 ... 73
• 나. 결과 ... 76
• 다. 고찰 ... 82
• 4. 외해가두리 적용 ... 85
• 가. 외해가두리 현황 ... 85
• 나. 외해가두리 선정 및 적용 ... 88
• 6. 경제성 분석 ... 99
• 가. 대구양식 경제성 검토 ... 99
• 나. 대구 외해양식 경제성 분석 ... 116
• 제 2 절 참치양식분야 ... 141
• 1. 외해수중가두리 타당성 검토 ... 141
• 가. 분류 ... 141
• 나. 태평양 참다랑어 (Thunnus orientails)의 생리, 생태적 특성 ... 143
• 다. 성숙 및 산란 ... 143
• 라. 성장 ... 145
• 마. 산소소비량 ... 147
• 바. 염분 내성 ... 147
• 사. 충돌사 ... 148
• 아. 사료 ... 149
• 자. 기타 생리적 특성 ... 151
• 차. 결론 ... 152
• 2. 적지선정 및 양식시험지 환경영향 분석 ... 152
• 가. 조사지역 ... 152
• 나. 조사 내용 및 항목 ... 153
• 다. 조사 결과 ... 153
• 라. 종합 분석 ... 166
• 3. 참치용 실용화 외해가두리 선정 검토 ... 167
• 가. 국외의 외해양식 및 가두리 개발 현황 ... 167
• 나. 외해가두리에서 참치양식 성공을 위한 요건 ... 167
• 다. 세계 각국의 외해양식 추진 현황 및 계획 ... 168
• 라. 세계 각국의 외해가두리 개발 현황 ... 169
• 4. 양식용 참치종묘 확보방안 마련 ... 170
• 가. 국외 어획현황 ... 170
• 나. 조사방법 ... 171
• 다. 결과 ... 172
• 라. 문제점 및 대책 ... 176
• 마. 종합결론 ... 177
• 5. 양식용 참치종묘 확보 ... 177
• 가. 채낚기를 이용한 참치종묘 어획시험 ... 177
• 나. 수입에 의한 참치종묘 확보 ... 185
• 6. 참치 외해가두리 사육관리기술 개발 ... 190
• 가. 참다랑어 종묘의 수송 및 수용 ... 190
• 나. 외해 수중가두리 사육시험 ... 193
• 다. 성장조사 기법 개발 ... 195
• 라. 가두리내 유영특성 ... 201
• 마. 어체 영양축적 특성 ... 206
• 바. 유전학적 특성 ... 210
• 7. 참치양식장 어장환경 영향 분석 ... 226
• 가. 외해가두리 어장환경 평가 ... 226
• 나. 외해가두리와 내만가두리 어장환경 특성비교 ... 230
• 8. 외해 참치양식 경제성 분석 ... 233
• 가. 현황 ... 233
• 나. 양식경제성 비교 ... 240
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 244
• 제 1 절 목표 달성도 ... 244
• 제 2 절 기여도 ... 245
• 제 5 장 연구개발 성과 및 성과활용 계획 ... 247
• 제 6 장 연구개발과정에서 수집한 해외과학기술정보 ... 248
• 제 7 장 참고문헌 ... 249
• 끝페이지 ... 256