본 연구는 유용 냉수성 어류 등의 종묘생산 시 초기의 성장과 생존률을 향상시키기 위하여, 저온에서 증식할 수 있는 저온내성을 가진 로티퍼(Brachionus plicatilis)를 배양하여, 수온 및 시간에 따른 영양강화 실험을 실시하였다. 로티퍼의 저온 배양은 20℃에서 배양하던 로티퍼의 수온을 점차적으로 낮추면서 활력이 있는 개체의 선별 배양을 반복하여 최종적으로 10℃에서 사육하였다. 영양강화는 상업적으로 이용되는 영양강화제인 A, S, SCV 및 SCP의 4종류를 사용하여 10, 15 및 20℃의 수온에서 6, 12 및 24시간 실시하였다. 수온 10℃에서 50일간 로티퍼의 증식률 실험을 한 결과 접종 밀도 350±7.9개체/ml에서 최종 배양 밀도는 1,064±5.7개체/ml로 약 3배 개체수가 증가하였다. 영양강화제에 포함된 지방산을 분석한 결과, n3계 고도불포화 지방산인 eicosapentaenoic acid (EPA, C20:5n-3) 및 docosahexaenoic acid(DHA, C22:6n-3)는 SCP에서 각각 15.49%, 35.03 %로 높게 나타났다. 영양강화한 로티퍼의 지방산 조성은 영양강화제에 따라 영향을 받았다. EPA는 SCP가 영양강화 수온 및 시간에 관계없이 2 % 이상을 차지하여 다른 영양강화제보다 높은 비율을 나타냈다. DHA는 S가 15℃, 24시간 실험구에서 12.40 %로 높게 나타났다. 영양강화 로티퍼의 EPA와 DHA의 비율을 고려하면 S를 20℃에서 12시간 영양강화한 실험구가 각각 3.09, 11.65 %로 높게 나타났다.

In this study, we investigated the growth of striped mullet (Mugil cephalus), Yesso scallop (Patinopecten yessoensis) and kelp (Saccharina japonica) farmed under the IMTA (integrated multi-trophic aquaculture) system developed by national institute of fisheries science (NIFS). The farmed striped mullets grew from an initial length and weight of 152.5±12.1 and 41.6±7.8 g in October 2013 to 154.2±5.6 and 47.5±8.6 g in November, 160.2±8.7 and 55.9±9.1 g in December and 168.4±9.6 and 58.4±8.7 g in January. The fish continued to grow and reached 190.2±9.4 in length and 87.5±8.9 g in weight in April and 256.4±9.7 and 156.7±6.7 g in October 2014. The daily growth rate (DGR) for total fish length was 0.015 0.1 /day during the periods of fast growth and attained 0.038 0.1 /day during February March. The kelp grew from an initial blade length and wet weight of 1.19±0.2 and 0.0028±0.0012 g in January 2014 to 3.3±0.8 and 2.5±0.9 g in February and 126.5±11.6 and 107.4±22.6 g in March, after which, erosion occurred and slowed the growth. The DGRs for kelp length ranged 0.03 1.9 /day in January 2014 and increased to 0.88 1.9 /day during March April. Increasing water temperatures beginning in April lowered the DGR to 0.03 /day. Yesso scallops grew from an initial shell length, shell height and wet weight of 11.83±0.6 , 12.68±0.7 and in September 2013 to 19.9±2.5 , 20.8±2.6 and 0.9±0.04 g in November 2013. They continued to grow to 45.91±0.71 in shell length, 42.55±0.8 in shell height and 12.7±1.3 g in wet weight by May 2014 and 60.2±2.51 , 554.6±2.61 and 24±2.70 g by October 2014. The DGRs for shell length of Yesso scallop ranged from 0.02 to 0.256 /day with higher values of 0.256 0.27 /day during November December 2013 and March April 2014.

We constructed marine forest to restore barren grounds which are expanding in the east coast of Korea using 2 methods of (1)seedlings transplantation method and (2)underwater floating ropes method. We transplanted 3 macroalgae species, Ecklonia cava, Undaria pinnatifida, and Saccharina. japonica to construct marine forest. Blade length of Undaria pinnatifida on underwater floating ropes was 56.70±8.69㎜ in April and grew 68.75±22.30㎜ in May and 70.75±14.36㎜ in July. Blade length of S. japonica was shown 97.95-143.00㎜ in April to June. Blade length of Ecklonia cava was 30.50±1.91㎜ in May, 41.55±1.84㎜ in August, 45.30±2.57㎜ in November, 2009 and 45.30±1.99㎜ in February, 2010. The survey on Dangsa area, Ulsan-city in January, 2009 found a total number of 15 algal species(1 brown algae, 14 red algae species) with the highest variety at 5m depth of A station and the lowest at 8m depth of A and B stations. The March survey showed a total of 24 species (1 green algae, 1 brown algae, 22 red algae species) with the highest variety of 11 at depths of 3m and 5m of B station and the lowest of 6 at 10m of B station. In May, total biomass was 3,755.4g (green algae 1.2g, brown algae 199.0g, red algae 3,555.2g). From January, 2009, we found that E. cava was dominant at the depths of 3m and 5m of A and B stations while Peyssonnelia capensis was dominant at the depth of 8m of A station. The 8m depth of B station was dominated by Acrosorium polyneurum. In May, Grateloupia lanceolata was dominant at 8m depth of A station while other depths were dominated by Phycodrys fimbriata. In June, the dominant species were G. lanceolata at the 3m depth, E. cava at the 5m and P. fimbriata at the depths of 8m and 10m of A station. Under B station, G. lanceolata was dominant at the depths of 3m and 5m while P. fimbriata was dominant at the depths of 8m and 10m.

Eco-physiological research and the control of Cochlodinium polykrikoides was carried out to elucidate eco-physiological characteristics of red tide organism through culture experiment depending on the condition of photon irradiance. Oxygen consumption of C. polykrikoides was high with a value of 1.12mg/L/hr in the dark compared with that of 0.13mg/L/hr at 100μEm-2s-1. DO values in a circular chamber with the lapse of time in seawater containing C. polykrikoides were declined in the dark period. DO values of seawater containing C. polykrikoides in the dark were declined from 7.01mg/L to 2.65mg/L in 30cm depth and from 7.01mg/L to 6.63mg/L in 5cm depth depending on the depth of circular culture vessel. Olive flounder, Paralichthys olivaceus and file fish, Stephanolepis cirrhifer exposed to Cochlodinium showed the separation of the lamella epithelium from gill filament, which disrupted the respiratory process at the gill level.

The solitary ascidian, Halocynthia aurantium, which is commonly called the sea peach because of its coloration and general shape, is a valuable organism of benthic marine population in the northern region of the East Sea, Korea. It is seldom found at a depth of less than 10 meters and the sea peach is frequently observed in large populations between 20 and 100 meters. It appears to prefer attachment to vertical rocks faces and artificial cement blocks exposed to the currents. Mass mortality and reduction of resources in sea peach, H. aurantium, were occurred in the benthic area of the northern region of the East Sea because of the rapid fluctuation of environmental factors such as temperature and salinity due to mass rainfall in summer and going up north of a strong warm current in winter. Therefore, we examined the effects of temperature and salinity on embryonic development of fertilized eggs, tadpole larva to metamorphosis, and attachment to siphon development. Laboratory-raised larvae were studied using a two-factorial experimental design with four levels of temperature(8, 12, 16 and 20℃) and four levels of salinity(20, 25, 30 and 34 psu). The ascidian larvae of H. aurantium survived environmental conditions between temperature of 8～20℃ and salinity of 25～34 psu and exhibited positive growth at 8～16℃ and 30～34 psu. Fertilized eggs have not developed at lower salinity of 20 psu irrespective of temperature range tested and have showed an abnormal development at the salinity of 25 psu between higher temperatures of 20 and 24℃. This result suggests that temperature increase and salinity reduction depending on environmental fluctuation may have significant impacts on population variation of H. aurantium in the northern region of the East Sea.

The clam, Gomphina melanaegis, which is commonly called the sandy beach clam because of its habitat, is a valuable organism in the sandy coast of East Sea, Korea. It is frequently observed in large populations between 0.5 and 5 meters. We have released 50,000 seedling, ranging from the diameter of approximately 3 mm, 2007, and 1,000,000 seedling, ranging from the diameter of approximately 0.2 mm, plus 100,000 adult individuals, ranging from the shell length of approximately 20～40 mm, 2008 at Jinha beach. The spawning period of G. melanaegis, was from June to August, and the main spawning occurred in July. This investigation was carried out to elucidate population distribution on the stocking area of sandy beach clam, G. melanaegis. The relationship between shell length and ring radius in each ring was investigated as a regression line. The relationship between the shell length and shell height of released young clam was SH=1.0105SL-4.7764 (R2=0.7905). The relationship between the shell length and total weight of released young clam was TW=0.0013SL2.3966(R2=0.71). It draws a deduction that the ring of this clam was produced once a year during the duration between June and August.