• Ocean and Polar Research
• /
• v.32 no.3
• /
• pp.187-201
• /
• 2010

The purpose of this study was to investigate the temporal and spatial variability of taxonomic groups and major species of the mesozooplankton community in Lake Shihwa, Korea. Monthly collections were carried out at five stations in Lake Shihwa for a period of one year. The mesozooplankton community showed distinct seasonal variability with water temperature and salinity. Major mesozooplankton species in each seasonal community were derived from non-metric MDS and SIMPER as follows: winter community (Acartia hongi and Eurytemora pacifica), spring community (Acartia hudsonica and Polychaeta larvae), summer community (Acartia sinjiensis, Pavocalanus crassirostris, Evadne tergestina and Cirripedia nauplii) and fall community (Paracalanus indicus and Podon leuckarti). The succession of the seasonal species, A. hudsonica and A. sinjiensis, was the most remarkable event during the seasonal changes of the mesozooplankton community. The species response curve of these species fitted with the logistic regression in relation to water temperature and salinity. The curve also correctly represented the characteristics of the occurrence of A. hudsonica and A. sinjiensis in Lake Shihwa.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.24 no.4
• /
• pp.255-265
• /
• 1991

The Genus Acartia of calanoid copepod comprises about 50 species from world oceans. Most of them are neritic and very abundant in coastal waters. For the present study samples were collected from ten sites (Garolim Bay, Deukyang Bay, Chinhae Bay, Kyonggi Bay, Kwangyang Bay, Kori, Wolsung, Youngkwang, Uljin and Cheju area) during the period from September 1981 to December 1990 and at selected six stations in Masan Bay during the period from April 1986 to September 1987. As a result, Genus Acartia of Korea was identified as following ten species: Acartia bifilosa, A. danae, A. erythraea, A. hudsonica, A. negligens, A. eomorii, A. pacifica, A. sinjiensis, ,4. spinicauda and A. steueri. The key to the species was suggested and the description of A. sinjiensis was given as the new in Korean waters.

• Korean Journal of Environmental Biology
• /
• v.37 no.3
• /
• pp.299-308
• /
• 2019

The occurrence patterns of Acartia(Copepoda; Calanoida) species, A. erythraea, A. hongi, A. hudsonica, A. ohtsukai, and A. sinjiensis, were examined in the southern coastal waters of Korea in the summer in August 2012. The Acartia species had different spatial distribution according to environmental factors. A. erythraea showed higher density in a semi-closed bay (Gamak, Masan) where the dissolved oxygen was low (<2 mg L^-1). A. sinjiensis showed a high density in a semi-closed bay when the chlorophyll-a concentration was >2 ㎍ L^-1. A. ohtsukai showed a high density at water temperatures >26℃ and low salinity <30. A. hongi and A. hudsonica showed at water temperatures <27℃ and high dissolved oxygen (>5 mg L^-1). These results suggest that environmental factors (temperature, salinity, dissolved oxygen, and chlorophyll-a concentration) may affect the spatial distribution of Acartia species dominant in the southern coasts of Korea in summer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.19 no.4
• /
• pp.265-271
• /
• 2014

We performed dilution experiments together with copepod added incubations to examine the influence of mesozooplankton on the grazing pressure of planktonic ciliates in Sihwa lake during summer when the abundances of phytoplankton and mesozooplankton increased considerably. Planktonic ciliates consumed 104% of primary production in a day on dilution experiments. However, the ciliates consumption on phytoplankton was reduced to 19% in copepod incubations with Acartia sinjiensis added. This was due to selective predation of A. sinjiensis on oligotrich ciliates ($&gt;20{\mu}m$) which were major grazers on nano-phytoplankton. Our experiments show that grazing pressure of planktonic ciliates based on dilution experiments may be overestimated when the abundance of planktonic ciliates is strongly controlled by copepods. We postulate that the role of planktonic ciliates as grazers could diminish in Sihwa lake in spring and summer when abundance of copepods increase considerably. We suggest that the predation of mesozooplankton should be considered to better appraise the role of planktonic ciliates as grazers.