• Animal Systematics, Evolution and Diversity
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• v.27 no.1
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• pp.53-58
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• 2011

The zoeal stages of Pisidia serratifrons are described and illustrated for the first time and its morphological characteristics are compared with those of three known Pisidia species of the family Porcellanidae. The zoea of P. serratifrons differs from those of other Pisidia (P. brasiliensis, P. dispar, and P. dehaanii), by having 11 spinules on the exopod of the antenna. In order to facilitate the study of plankton-collected material, a provisional key is provided for identification of the Korean porcellanid zoeae.

• Korean Journal of Ecology and Environment
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• v.44 no.4
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• pp.407-410
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• 2011

Aquatic Oligochaeta is a notable animal group in freshwater environment such as streams, rivers and lakes in view of its biomass and species richness. Taxonomic studies of this group, however, have hardly been performed in Korea. Here five naidid oligochaete species are reported - Slavina appendiculata, Pristina longiseta, Pristina biserrata, Chaetogaster diaphanus and Nais variabilis - from the Seokhyeoncheon Stream in Yangju and from the Changreungcheon Stream in Goyang, Gyeonggi-do. Aquatic oligochaetes attaching on aquatic vegetations were collected with a plankton hand net. An image and description on Nais variabilis new to Korea are provided.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.11 no.3
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• pp.123-127
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• 1978

Distributions of microplankton in two different regions of the East China Sea were studied based on the plankton samples collected by R. V. Umitaka Maru of Fisheries University of Tokyo, Japan in September, 1975. The abundance distribution and species composition of the two areas were interpreted with their temperature-salinity properties. The two areas aye characterized by differences in the depth of thermocline, the nature of surface and bottom waters, and the abundance and species composition of microplankton.

• Journal of Plant Biology
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• v.3 no.2
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• pp.26-28
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• 1960

Electron-Microscopical Observalion on Fine Structure of Diatom Frustules which is collected in the East Coast of Kyung-Pook Province. Kor. Jour. Bot. 3(2) 26-28 lllus. 1960 The fine structure of Diatom frustules which is collected in the east coast of Yungil and Wul Sung, Kyung-Pook Province, is ovserved by the light microscope and hte electron-microscope, and the materials collected by auther are 1 family, 2 genus and 2 species. Coscinodiscus elegans. Greville Actinoptychus undulatus Rals Those were havitated in sea water as the plankton which were found in diatomite.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.15 no.1
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• pp.23-33
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• 1979

This paper was analysed based on the oceanographic and meteorological data complied from 1971 to 1977 for that search relationships among the fluctuation of sea condition and weather condition, and the catch of anchovy. In the year when heat loss from the sea surface in winter was maximum(in 1974, 658 Iy), temperature of midwater in summer was lower 2~4\ulcornerC than normal year. While heat loss was minimum (in1973, 487 Iy), temperature of mid water was higher 2\ulcornerC. When temperature of mid water of southern coast from June to August was higher than normal year, anchovy was caught good deal, but that was lower than normal year was bad fishing. When it had much precipitation (in 1973, 256mm), plankton was checked maximum (12cc) and also the catch of anchovy too (11, OOOm/t). While precipitation was minimum (in 1976, 123mm), plankton (3cc) and anchovy (2, 800m/t) was a litle. If we calcalate heat budget in winter, we can forecast temperature of mid-water in summer of following year. Therefore we may be able to forecast catch anchovy.

• Journal of Korean Society on Water Environment
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• v.26 no.6
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• pp.976-985
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• 2010

In this study, characteristics of dissolved organic matter (DOM) from Lake Paldang and seven other DOM sources (lake plankton, plants, soil, composite, treated sewage) were studied using XAD resin fractionation and 28-day microbial incubation experiment. Distribution patterns of DOM-fractions, which include hydrophilic acids (HiA), hydrophilic bases (HiB), hydrophilic neutrals (HiN), hydrophobic acids (HoA), hydrophobic neutrals (HoN) and the extent of DOM biodegradation (i.e., biodegradability) were different depending on the origins of the DOM samples. The DOM distribution pattern and the biodegradability were found to be effective for distinguishing the different DOM sources. The biodegradability (%) had negative correlations with the content (%) of hydrophobic fractions (Ho) and specific UV absorbance of DOM, which indicate that the Ho fractions contain more aromatic carbon structures and relatively stable during biodegradation, irrespective of the sources. To gain additional insight into the microbial transformation of the DOM, we also investigated the changes in the fraction's distribution for plankton, leaf litter and composite samples after the incubation. The results showed that biodegradation of hydrophilic fraction (Hi) causes an increase in the proportion of Ho (HoA, HoN), while biodegradation of HoA increases the HoN production.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.2
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• pp.118-128
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• 2005

Surface sediment samples from 31 stations in Jinhae Bay were analyzed to evaluate the pollution by sewage from the spatial distribution of the fecal sterol, coprostanol. The sums of eight sterols (coprostanol, epicholestanol, epicoprostanol, cholesterol, cholestanol, brassicasterol, stigmasterol and $\beta$-sitosterol) were in the range of $2,703-27,154{\cal}ng/{\cal}g$ dry weight. The concentrations of the coprostanol in the sediments, which is a good tracer of sewage-derived organic contamination, were in the range of $76-3,964{\cal}ng/{\cal}g$ dry weight. The levels of coprostanol were much higher (almost one order of magnitude) at stations close to the big cities such as Masan and Jinhae. However, those levels were comparable to or lower than those previously reported in other foreign locations. Some ratios of coprostanol to other sterols and multivariate analysis could provide us with the information on the origin of the sterols being from sewage, plankton, and/or benthos. Those showed sewage dominance at the stations near the cities Masan and Jinhae, plankton dominance at the center of Jinhae Bay and mainly marine fauna origin at the mouth of Jinhae Bay. These results suggest that the contents of sterols and some ratios of these components are quite powerful tracer for the detection of the origin of the organic contaminants in the coastal environments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.437-444
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• 2013

Eight fecal sterols were analyzed in surface sediments collected from shellfish farming areas in Yeoja Bay and Gangjin Bay, Korea, to evaluate sewage-derived fecal pollution. The concentrations of coprostanol, a good marker of sewage-derived organic contamination, in sediments were in the range of 10-530 ng/g-dry in Yeoja Bay, and 10-190 ng/g-dry in Gangjin Bay. Coprostanol levels were markedly higher in the inner bay than in the outer bay. These levels were lower than those reported in urbanized bays in Korea, however, they were comparable to levels in other shellfish farming areas including Gamak Bay. A multivariate analysis of the ratios of other sterols suggested that the sterols originated from sewage and plankton/benthos. Sewage was the dominant source at stations located close to the river mouth and wastewater treatment plant (WWTP) outfalls, and plankton/benthos was the primary source in the outer bay. These results suggest that management of point sources, e.g., WWTP as well as non-point sources, e.g., riverine inputs is important for improving the water quality in Yeoja Bay and Gangjin Bay.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.165-173
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• 1996

Large amounts (300 grams) of natural red tide plankton, Cochlodinium polykrikoides, was collected at the Yokji island coastal waters, Kyeongnam, Korea, on October, 1993. Using the bioassay systems, bioactive materials were screened from methanol extracts of C. polykrikoides. Live C. polykrykoides was toxic to fishes, however, the water soluble and chloroform soluble fraction of their methanol extracts did not shown ichthyotoxicity (5 mg/ml), and toxicity to mice (50 mg, i.p,). These fractions did not show any peaks corresponding to paralytic shellfish toxins or diarryhetic shellfish toxins on the fluorometric HPIC chromatograms. Neither fractions did not show antibiotic activities by paper disk (10 mg/disc) test and chloroform soluble fraction showed only $20\%$ growth inhibition activity on the Lymphoid P-388 at the concentration of $180\;{\mu}g/ml$. Hemolytic activity was detected by both fractions. Fatty acid analysis by GC, GC/MS and proton NMR showed that the chloroform soluble fraction composed of $25.3\%$ of DHA (dorosahexaenoic acid) and $15.3\%$ of IPA (eicosapentaenoic acid) as the hemolytic components.

• KSBB Journal
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• v.26 no.1
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• pp.7-12
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• 2011

In order to perform an acute toxicity assessment of a new algicide, thiazolidinedione derivative (TD53) with enhanced solubility and lower toxicity to marine ecosystem, representative 3 organisms: plant plankton (Skeletonema costatum), animal plankton (Daphnia magna), fish (Paralichthys olivaceus) related in the food chain of marine ecosystem according to OECD standard methods were employed in the exposure experiment. The exposure assessment showed that $EC_50$ of S. costatum in 96-hour, $EC_50$ of D. magna in 48-hour and $LC_50$ of P. olivaceus in 72-hour for TD53 were $1.53\;{\mu}M$, $0.61\;{\mu}M$ and $2.14\;{\mu}M$ respectively. NOEC (No Observed Effect Concentration) and PNEC (Predicted No Effect Concentration) were calculated to be $0.25\;{\mu}M$ and 6.10 nM, respectively from $EC_50$ of most sensitive strain, D. magna. Comparing with the results of toxicity assessment previously performed by using Ulva pertusa Kjellman accepted as an ISO standard method, the values of PNEC showed 3.7 times lower toxicity in case of this study employing 3 organisms, indicating that if the organisms which are more representative and sensitive in marine ecosystem are further investigated, more accurately and validly predicted toxicity of TD53 could be applied in field.