• Journal of Food Hygiene and Safety
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• v.16 no.4
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• pp.315-323
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• 2001

This study was concentrated that the contents of heavy metals were estimated from 782 samples of sold fisheries in Seoul(33 species in fishes, 15 in bivalves, 12 in crustaceans and 10 in others) by Atomic Absorption Spectrometer. The contents of As, Cd and Pb [minimum~maximum (mean)] were N.D.~0.162 mg/kg(0.021),0.001~0.120 mg/kg(0.014) and 0.015~0.499 mg/kg(0.111) in fishes, 0.003~0.311 mg/kg(0.052), N.D.~1.905 mg/kg(0.182) and 0.013~0.462 mg/kg(0.138) in bivalves, N.D.~0.328 mg/kg(0.042), 0.002~1.113mg/kg(0.079) and 0.006~-.510 mg/kg(0.109) in crustaceans, N.D. ~0.181 mg/kg(0.024), 0.001~0.214 mg/kg(0.033) and 0.010~0.877 mg/kg(0.118) in others respectively, bivalves were the highest than others. The average weekly intakes of three metals from sold fisheries took about 1.4~26.4% of PTWI (provisional tolerable weekly intakes) that FAO/WHO Joint Food Additive and Contaminants Committee had set to evaluate their safety.

• Korean Journal of Environmental Biology
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• v.22
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• pp.30-37
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• 2004

Peysistent oyganochlorine compounds (OCs) weve determined in sediments and bivalves from Gwangyang Bay. The concentrations of ∑PCB, ∑DDT, ∑HCH and ∑CHL in sediments were in the range of f 2.25∼11.4 ng g$\^$-1/, 0.16∼1.16 ng g$\^$-1/, nd∼0.51 ng g$\^$-1/, and 0.05∼0.79 ng g$\^$-1/, respectively. The overall OCs concentrations in sediments were below the effect range -median (ER-M) values toy benthic organisms suggested by NOAA (1991). Levels of PCB compounds a re relatively lower than other industrialized bays (Pusan Bay, Ulsan Bay, and Youngil Bay). OCs accumulated in bivalves were higher than those in sediments. In bivalves, the concentration ranges of ∑PCB, ∑DDT, ∑HCH and ∑CHL were 9.97∼31.7 ng g$\^$-1/, 7.54∼22.6 ng g$\^$-1/, 0.49∼2.0 ng g$\^$-1/, and 0.82∼7.32 ng g$\^$-1/, respectively. Relatively high PCB concentrations in both environmental matrices are found at the inner bay than the outer part, indicating that the sources of PCBs were located inside the bay. DDT compound showed relatively high concentrations in the vicinity of the mouth of river and urban area, whereas other organochlorine pesticides show homogeneous distributions over the bay. Homologue profile of PCB compounds shows that low-chlorinated congeners (especially, di-, tyi- and tetra-) are abundant in Gwangynng Bay, which is diferent from other areas in Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.1
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• pp.11-16
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• 2012

In coastal areas that are affected by continuous, seasonal or occasional pollution sources, bivalves accumulate biological contaminants such as pathogenic bacteria. We investigated the effect of natural seawater relaying and electrolyzed seawater depuration on the bacteriological quality of artificially contaminated oysters Crassostrea gigas and short-necked clams Ruditapes philippinarum to suggest an alternative method of shellfish sanitation control.When artificially contaminated oysters and short-necked clams (fecal coliform level 1,700 MPN/100 g) were relayed into a sea area of safe bacteriological water quality, the fecal coliform level dropped to below 110 MPN/100 g after 1 day. The bacteriological quality of oysters and short-necked clams that are contaminated at a fecal coliform level of 1,700 MPN/100 g could be improved, and become appropriate for raw consumption by a single day relay under proper environmental conditions. When artificially contaminated oysters (fecal coliform level 330 MPN/100 g) were depurated with electrolyzed seawater, 94% of fecal coliform was eliminated after 12 h and fecal coliform was undetectable after 24 h. After 24 h depuration with electrolyzed seawater, the fecal coliform level of short-necked clams with initial fecal coliform of 2,400 MPN/100 g was below 20 MPN/100 g. However, the fecal coliform level of short-necked clams with initial fecal coliform of 17,000 MPN/100 g was relatively high, at 790 MPN/100 g, even after 24 h of depuration with electrolyzed seawater, because of the repeated cycle of excretion and accumulation of fecal coliform in shellfish tissue under the closed depuration environment. Such natural seawater relaying and electrolyzed seawater depuration can be restrictively applied to improve or secure the bacteriological quality of oysters and short-necked clams in accordance with safety levels for bivalves for raw consumption.

• The Korean Journal of Malacology
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• v.21 no.1
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• pp.25-31
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• 2005

The embryos of marine bivalves have been commonly used in bioassays for the quality assessment of marine environments. Although several standard protocols for developmental bioassay with bivalves have been already proposed, there have been few trials for applying these protocols in environmental assessment, or for developing new protocol with Korean species. So, there is a strong need to establish the standard bioassay protocols using bivalves commonly found in Korean waters. Prior to developing a new protocol, it is essential to know the optimum conditions for the reliable bioassay procedures. Here, we established the purpose of this study to determine the optimum bioassay conditions for successful development of a common mussel, Mytilus galloprovincialis. The conditions considered as critical for developmental bioassay, and determined in this study were; (1) temperature, (2) salinity, and (3) initial density of embryo. The optimal temperature for developmental bioassay of M. galloprovincialis was determined as $15^{\circ}C$. At this temperature, the required time for the embryo to become veliger larva was 48 hr. The acceptable range of salinity for the embryotoxicity test using M. galloprivincialis was from 30 to 35 psu, which was narrower than that of the natural habitat of adult populations. The optimum density of embryo at the beginning of bioassay was 100 embryos/ml. Over this density, the proportion of normally developed larvae decreased significantly. The results obtained in this study will serve as a basis for preparation of the standard bioassay protocol using embryo of M. galloprovincialis.

• Journal of Aquaculture
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• v.17 no.2
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• pp.115-121
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• 2004

In a series of feeding experiments using the newly established the first laboratory strain of a temperate photosynthetic ciliate, Mesodinium rubrum MR-MAL01, direct evidence was obtained for ingestion of the cultured M. rubrum cells by the bivalves like the Korean scallop, Chlamys farreri and Manila clam. Ruditapes phil-ippinarum. Each experimental Korean scallop and Manila clam removed up to 9,590 and 23,200 cells min-1, respectively. Small particles almost identical to the ruptured cells of MR-MAL01 culture were observed in the gut of the experimental bivalves, although no intact M. rubrum cell was found. In a 28 days rearing experiment, Isoshrysis galbana (KMCC H-2), a microalga, supported better growth of small Manila clam spat (0.46 mm in shell length) than MR-MAL01 strain. For the large Manila clam spat (0.84 mm in shell length), however. MR-MAL01 strain was a better prey item. Mass culture methods for this photosynthetic marine ciliate may be developed for use as live feed in aquaculture of the spat and broodstock of bivalve and small-mouthed fish larvae.

• The Korean Journal of Malacology
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• v.15 no.2
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• pp.105-113
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• 1999

This study was measured environmental factors of flat oyster habitats and biomass of flat oyster to improve the productivity of flat oyster. Water temperature and salinity of the flat oyster habitat ranged from 5.5 to 27.4$^{\circ}C$ and from 31.2 to 33.4 , respectively. Average concentrations of DO, COD, DIN and PO$\_$4/$\^$3/ -P were 7.11 mg/l, 4.55 $\mu\textrm{g}$-at./l and 0.36 $\mu\textrm{g}$-at./l respectively. Surface sediments at the sampling area were composed of coarse sand, sandy silt and silty sand. Average level of IL, COD and AVS in the surface sediments were 2.6%, 13.70 mg/g dry and 0.33 mg/g dry respectively. In each sampling station, total standing crops of phytoplankton showed peaks twice in February and August. Dominant species of phytoplankton occurred in Haechang Bay throughout the year were Skeletonema costatum, Paralia sulcata, Eucampia zodiacus, Chaetoceros curvicetus, C. affinis, C. debilis, C. decipiens, Asterionella glacialis, Pseudonitzschia longissima, Pseudonitzschia seriata, Ceratium furca and C. fusus. Ten species of the bivalves were collected at the flat oyster habitat. Most of bivalves were the eutrophic species Ostrea denselamellosa, Crassostrea gigas, Ruditapes philippinarum, Scaphraca subcrenata, Scapharca broughtonii, Atrina pectinata, Fulvia mutica, Mytilus edulis, Protothaca jedoensis and Megacardita ferruginosa. The mean density of them was 21 inds./㎡ (479.14 g/㎡), while that of the flat oyster was at 0.25 inds./㎡ (231.25 g/㎡).

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.483-492
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• 2019

During the breeding season, both adults and immature Eurasian Oystercatchers (Haematopus ostralegus osculans) were observed to feed on prey, such as gastropods (Umbonium thomasi) and bivalves, at the tide water line around Yubu island in Korea. To determine differences in the foraging efficiency between the adult and immature birds, we recorded the feeding behavior using digiscoping with a telescope and a smartphone. We compared the pace, the prey search rate, the proportion of prey search techniques, the feeding success rate, the handling time, and the heads-up rate between the adult and immature birds. There were significant differences in the proportion of prey search techniques when gastropods were consumed and in the prey search rate and heads-up rate when bivalves were consumed but there were no significant differences in feeding success rates. Therefore, although the immature birds on Yubu Island were inferior to adults during the breeding season and they lacked the proficiency to locate prey, their overall foraging efficiency was similar to adults. This was considered to be due to the continuous eating of bivalves during the wintering season, which requires a high level of foraging efficiency.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.463-468
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• 2002

Influence of increased temperature on the standard metabolism in three species of marine bivalves, Crassostrea gigas, Ruditapes philippinarum and Mytilus edulis, acclimated to seasonal water temperatures and collected from the south coast of Korea, were examined in the laboratory. The standard oxygen consumption and filtration rates in the 3 species were measured respectively at the experimental temperature, 4, 7 and 10$^{\circ}C$ or 3, 6 and 9$^{\circ}C$ higher than the mean seasonal water temperature. When the experimental temperatures were higher than the seasonal water temperature, the rates of C. gigas decreased in autumn and spring, and increased In winter, while there was thermal stress in summer. The rates of R. philippinarum increased in spring when the experimental temperatures were 3$^{\circ}C$ and 6$^{\circ}C$ higher than the seasonal water temperature, but the rates increased in autumn and winter when the experimental temperature was even 9$^{\circ}C$ higher than the seasonal water temperature. In summer. metabolic activities of R. philippinarum decreased significantly at temperature higher than acclimation temperature. The rates of M. edulis increased in spring when the experimental temperatures were 3$^{\circ}C$ higher than the seasonal water temperature but the rates were stressed by the increased temperature above 3$^{\circ}C$. In winter, increased temperature did not affect the metabolic activities of M. edulis. These results suggested that the standard metabolism of the three marine bivalves in summer was stressed by the increased temperature, whereas the metabolism was activated in winter.

• The Korean Journal of Malacology
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• v.30 no.2
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• pp.135-138
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• 2014

We report two new records Korean marine bivalves. The new record species are Siliqua albida (Adams & Reeve, 1850) and Macoma (Macoma) middendorffi Dall, 1884. As a result, the family Pharidae in Korea turned out to be 8 species of 4 genera and Tellinidae are 37 species of 15 genera.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2001.11a
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• pp.87-87
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• 2001