Jo, N.; Kang, J.J.; Park, W.G.; Lee, B.R.; Lee, J.H.; Kim, Y.; Ahn, S.H.; Lee, D.; Min, J.-O.; Kang, C.-K., and Lee, S.H., 2018. Carbohydrate-dominant phytoplankton and protein-high zooplankton in the northern part of the southwestern East/Japan Sea in 2015. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 371–375. Coconut Creek (Florida), ISSN 0749-0208.
The biochemical compositions of phytoplankton and zooplankton were monthly investigated in the northern part of the southwestern East/Japan Sea from May to October in 2015 except August. Among the biochemical compositions of phytoplankton, carbohydrate composition (55.5 ± 7.3%) was most dominant during the study period. A significant negative relationship (r = −0.855, p < 0.01, n = 39) was found between the carbohydrate and lipid compositions of phytoplankton in this study, which can be due to a switch from carbohydrate into lipid synthesis under persistent stress conditions. In comparison, proteins were the predominant components (56.1 ± 5.6%) of the zooplankton communities. These high protein contents could be resulted from dominant crustacean zooplankton because copepods have generally high protein contents. Indeed, a positive correlation was found between community composition of copepods and protein composition of zooplankton communities (r = 0.618, p < 0.05, n = 13). In contrast, a lipid content of zooplankton in the northern region (7.3 ± 1.6% DW) was significantly (t-test, p < 0.05) higher than that reported from the southern region (5.5 ± 0.6% DW). This might be due to a higher contribution of cold water species which have generally high lipid contents or/and a low amount of prey in this region. In conclusion, a high protein and relatively lower lipid contents of copepods-dominant zooplankton communities appeared to be regional characteristics in the southwestern East/Japan Sea, which could be a good food source for fish larvae and small fish which have generally high protein requirements.
