We investigated the spatial distribution of heterotrophic bacteria associated with different water masses in the northern East China Sea (ECS) in summer. The surface water masses were divided into the Changjiang Diluted Water (CDW) and high salinity water (HSW). In the CDW region, the concentrations of dissolved inorganic nitrogen (DIN) and chlorophyll-a (Chl-a), and micro Chl-a contribution were high; and bacterial abundance (BA) and ciliate abundance (CA) were also high. In the HSW region with relatively low DIN concentrations, Chl-a concentration and micro Chl-a contribution were low, but pico Chl-a contribution was increased compared to those in the CDW region. BA did not show any significant difference from the CDW region, but CA was decreased. BA showed a positive correlation with Chl-a concentration in the CDW region; however, it did not show a significant correlation with Chl-a concentration in the HSW region. The ratio of bacterial carbon biomass/phytoplankton carbon biomass was exponentially increased with a decrease in the Chl-a concentration. Compared to the past (1990-2000s), the surface phosphate concentrations and the size of dominant phytoplankton have recently decreased in the ECS. Considering this trend of nutrient decrease and miniaturization of the phytoplankton, our results indicate that changes in the strength of the oligotrophic water mass could alter the function of the microbial food web.

본 연구는 2019년 8월 한반도 주변해역(동해, 서해, 남해, 동중국해)에서 탄소 및 질소 안정동위원소 기법을 활용하여 하위영양 단계에서의 먹이망 구조를 파악하였다. 입자성 유기물(POM)의 δ13C 범위는 -26.18 ~ 20.61 ‰, δ15N 범위는 5.36 ~ 15.20 ‰의 넓은 범위를 보였다. POM과 각 생물별 개체군 사이의 δ13C 분별작용의 결과는 대부분 micro-POM을 섭식하는 것으로 확인하였으나 해역 간 차이를 보였 다. 각 생물별 영양단계는 chaetognaths (3.40±0.61)가 가장 높은 영양단계에 있음을 확인하였다. 동위원소 혼합모델을 적용한 결과에서 chaetognaths의 먹이원으로 copepods (13 ~ 48 %)와 euphausiids (20 ~ 51 %)가 가장 높은 기여도를 나타냈다. 본 연구결과 각 해역별 먹이원의 제한적 공급 및 다양성의 차이가 먹이망 구조 및 각 생물별 동위원소 비에 영향을 미친 것으로 판단된다.

The food components of red sea bream(Pagrus major) cultured in copper alloy(brass) net(BN) and nylon net(NN) cages for nine months were investigated. The body weight was 234.9g at the beginning of the culture(the young fish), and then 692.1g(BN group) and 549.3g(NN group) at the fish cultured for nine months(the nine-month culture fish). The moisture content of the edible portion of the fish was higher in the young fish than in the nine-month culture fish. On the contrary, the lipid content was higher in the latter (9.1-10.6%) than in the former (7.6%).　 The lipid content in the nine-month culture fish was slightly higher in the BN group compared to the NN group. There was little difference in protein content between the young fish and the nine-month culture fish, or between the BN and NN groups. There was a slightly higher level of copper content in the liver (5ppm in the young fish and 5-6ppm in the nine-month culture fish) compared to the edible portions (1ppm in the young fish and 3-4ppm in the nine-month culture fish), but no difference was evident between the BN and NN groups. The prominent fatty acids were 16:0, 18:1n-9, 22:6n-3, 16:1n-7, 18:2n-6, 20:5n-3, and 18:0 in the edible portions of the young and cultured fish. The n-3 fatty acid content was slightly richer in the BN group.

This study is to analyze the efficiency of Korean sea food manufacturing using Data Envelopment Analysis. Firstly, based on an output oriented traditional CCR, BCC model, the study estimated the efficiency scores. The average estimates of technical, pure technical, and scale efficiency turned out 0.6517, 0.7184, 0.9074 respectively, which are separated for 50 marine corporations. The 10 DMUs were efficient under CCR model while the 17 DMUs under BCC model. Also, the study suggested that the operating profit of the two output factors should be more increased relatively and averagely from the viewpoint of efficiency improvement. Secondly, super efficiency scores are estimated under super efficiency and SBM model. As a result, it came to be possible to distinguish and rank the efficiency of the efficient DMUs. The highest score was 4.2975 under Super-CCR, was 2.4947 under Super-BCC, was 2.7160 under SBM-Super- CCR, and was 1.5319 under SBM-Super-BCC model. The average estimates of super efficiency were 0.76 and 0.82 under Super-CCR and Super-BCC model respectively, and were 0.61 and 0.67 under SBM-Super- CCR and SBM-Super-BCC model. Finally, the study conducted a rank-sum test, Wilcoxon-Mann-Whitney test, to find a statistical significance of heterogeneity existing in efficiencies among the sample corporations. The result showed that there was a significant difference in average efficiency between Dried, Salted product manufacturing and Frozen product manufacturing under BCC-Super efficiency model at 10% level of significance. Furthermore, TOBIT model was applied to find out the potential factors that might influence the efficiency, Wilcoxonand the results showed debt and sales cost influenced all of the technical, pure technical, and scale efficiency, while net profit influenced only the technical efficiency.

국내 양식산 진주담치 Mytilus edulis 의 가치증진 및 향후 효율적인 활용을 위한 식품학적 자료를 얻기 위해 연안에서 생산되는 진주담치의 식품성분 조성을 분석하였고, 아울러 복합추출법으로 추출한 진주담치 추출물의 품질특성에 대하여 분석 검토하였다. 진주담치 육의 수분, 조단백질과 탄수화물 함량은 각각 79.0%, 15.2% 및 1.9% 이었고, 진주담치 총지질의 주요 지방산은 16:0, 16:1n-7, 20:5n-3 및 22:6n-3 등으로, 20:5n-3 및 22:6n-3을 위주로 하는 고도불포화지방산의 조성비가 매우 높았다. 총아미노산의 함량은 15,344.8 mg/100 g 으로 glutamic acid, aspartic acid, glycine, alanine, leucine, lysine 및 arginine의 함량이 많았다. 유리아미노산 총함량은 961.8 mg/100 g 으로, taurine이 전체 유리아미노산의 14.3%를 차지하고 있었으며, glutamic acid, glycine, alanine 및 arginine도 비교적 많이 함유되어 있었다. 진주담치 열수추출물, 잔사 효소분해물 및 복합추출물(Brix 20°)의 조단백질 함량은 각각 6.6, 8.6 및 7.4%, 염도는 1.8, 0.9 및 1.6%, 아미노질소량은 264.6, 358.4 및 323.0 mg/100 g 이었다. 추출수율은 진주담치 1 kg 당 열수추출물 689 mL, 잔사 효소분해물이 323mL 로서 복합추출을 통해 약 47%의 수율이 증가하였다. 진주담치 복합추출물은 열수추출물과 관능적인 면에서 유의적 차이가 없었으며, 시판 굴자숙농축액과 비교하여 전혀 손색이 없었다. 열수추출물과 복합추출물의 유리아미노산의 총함량은 각각 5,733.5 및 7,210.5 mg/100 g 으로 glutamic acid가 함량 및 taste value로 보아 지배적이었으며, 다음이 aspartic acid, alanine, glycine, arginine, lysine 및 histidine 순으로 맛에 영향을 미칠 것으로 추정되었다.

The crude lipid contents of dried sea food products varied remarkably from 1.2 to 29.9% for dried fish products, from 2.8 to 12.3％ for dried mollusk ones, and from 0.1 to 2.3％ for dried seaweed ones. In fatty acid composition of dried fish products, the saturated acid was the most predominant component for dried anchovies, hair tail, Kstsuobushi, the monoenoic acid was the most predominant one for dried yellow corvenia, flat head, common carp, sea eel and conger eel. And the polyenoic acid was the most abundant one for dried cod. Allaska pollack, flounder, sole fish, ray, smelt and sardine. The major fatty acids of these dried fish products were 16:0, 16:1, 18:0, 18:1, 20:5 and 22:6. Fatty acid composition of dried mollusk products were mainly consisted of polyenoic acid, and followed by saturated acid, monoenoic aced. The major fatty acids of these products were similiar to those of dried fish products. And in case of dried seaweed products, saturated acid such as 14:0, 16:0 was the most predominant component, while polyenoic acid was abundant one in dried laver and sea mustard. The main fatty acids of dried seaweed products were 14:0, 16:0, 18:1, 20:1, 20:4, and 20:5. Judging from the results, dried sea food products were abundant of the highly unsaturated fatty acids in spite of the drying processing and storage.