• Korean Journal of Environmental Biology
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• v.31 no.3
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• pp.225-231
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• 2013

To study the characteristics of rocky intertidal invertebrate fauna on the coastal areas of the East Sea, seven regions including Dokdo, Ulleungdo, Gyeongju, Pohang, Yeongdeok, Uljin, and Gangwondo, the common species ratio (%) and similarity index using Bray-Curtis similarity matrix were calculated. The contributed species for dissimilarity between Dokdo and the other East Sea's coastal areas were selected by using SIMPER. The common species ratio and the cluster analysis showed that Ulleungdo presented the highest similarity. However, Yeongdeok showed the highest similarity in the eastern costal areas, and Gangwondo showed the lowest one. However the cluster analysis revealed the discrimination of the rocky intertidal invertebrate community on Dokdo with others region caused by the particularity of rocky shores exposed to strong wave action and by the particular distribution of rocky intertidal invertebrate fauna in Dokdo.

• Korean Journal of Environmental Biology
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• v.23 no.3 s.59
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• pp.250-256
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• 2005

A benthic faunal survey of the Hangang Estuary located in the northwestern part of South Korea was performed in October 2004. A total of 11 species identified, which were comprised of two species of molluscs bivalves (Limnoperna fortunei and Corbicula felnouilliana) in two families, two species of annelids polychaetes (Neanthes japonica and Nephtys caeca) in two families, and seven species of decapods (Palaemon carinicauda, P. annandalei, P. modestus, Ilyoplax deschampsi, Eriocheir sinensis, Eriocheir leptognathus and Sesarma dehaani) in four families. Four of the 11 species in six families, Limnoperna fortunei, Neanthes japonica, Nephtys caeca and Palaemon modestus, were newly found in this study area. Eleven species were presently listed with brief ecological remarks.

• Korean Journal of Environmental Biology
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• v.17 no.2
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• pp.175-182
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• 1999

An unprecedented mass mortality of commercially important macrobenthic animals, including Haliotis discus discus, H. diversicolor, Batilus cornutus, Sticopus japonious and Hemicentrotus puzoherrimus, occurred off the west coast of Cheju Island in summer of 1996. Phytoplankton blooms were absent along the coast. The appearances of the surface low-salinity water (SLSW) off the coast of Cheju Island preceded the mass mortality, leading to speculation that the low-salinity stress may have a crucial role in the mass mortality. Since there was no heavy rain for the same period, the precipitation was not a possible explanation for the decrease of salinity. Physical oceanographic data taken by NFRDI (1997) clearly indicated that the SLSW was present in the area between China and Cheju Island in August 1996. This is most likely due to a freshwater supply resulting from the existence of large river runoff. Evidence of the current and the distance between the Yangtz River and Cheju Island also supports the hypothesis that source of the SLSW was the freshwater originated from the Yangtz River runoff.[macrobenthic animals, mass mortality, surface low-salinity water].

• Korean Journal of Environment and Ecology
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• v.19 no.1
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• pp.46-54
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• 2005

The change of fish community in the Wonju-stream was investigated from May to November, 2004. During the period,24 species belonging to 6 families were collected. There were 10 Korean endemic species$(41.7\%)$, including Pseudopungtungia tenuicorpa, Coreoleuciscus spiendidus, Squalidus gracitis majimae, Squalidus japonicus coreanus, Microphysogobio yaluensis, Microphysogobio longidorsalis, Iksookimia koreensis, Koreocobitis rotundicaudata, Liobagus andersoni and Odontobutis interrupts. The dominant species was Zacco Platypus$(54.7\%)$, and the subdominant species was Rhynchocypris oxycephalus$(16.7\%)$. Also, Carassius auratus$(5.4\%)$, I. koreensis$(3.4\%)$, Orthrias toni$(3.3\%)$, and Pungtungia herzi$(3.0\%)$ appeared. According to the fish species compositions, the fish community was divided into 2 groups by an unweighted pair group method using arithmetic averages(UPGMA). The comparison of the fish community showed that benthic fish species were decreased, while, the number of water-column species, resistant 1,o substrate changes and water pollution were increased.

• Journal of Wetlands Research
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• v.8 no.3
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• pp.51-65
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• 2006

Surface sediments for sedimentary analyses were sampled at 199 stations in the study area in August 2003. The surface sediments consisted of six sedimentary facies. Generally, sandy mud sediments dominated in the southern tidal flat of Ganghwa Island and sand sediments dominated in channel and subtidal zones of the western part of Ganghwa Island. The area of sandy mud sediment extended to eastward tidal flat compared to sedimentary facies in August 1997. In 30 surface sediment samples from the Ganghwa tidal flat and subtidal zone, 61 species were recorded in total assemblages, including 34 species of living population. Ammonia beccarii and Elphidium etigoense in living population and Ammonia beccarii, Elphidium etigoense, Jadammina sp. and Textularia earlandi in total assemblage were widely distributed. Generally, relatively large numbers of species and high values of species diversity occurred in the area of western part of tidal flat. Cluster analysis of total assemblages discriminates four biofacies. Biofacies 1 indicated eastern part of the tidal flat and biofacies 4 indicated western part of the tidal flat. Biofacies 3 were transitional zone between biofacies 1 and 4.

• Korean Journal of Environmental Biology
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• v.27 no.3
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• pp.297-305
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• 2009

The Asian paddle crab, Charybdis japonica (A. Milne-Edwards) is an important fishery resource in Korea. Despite its common occurrence and commercial importance, few studies have been carried out on the life cycle and trophic ecology of these populations inhabiting on the tidal flat. Food habits of C. japonica populations were investigated on the Jangbong tidal flat, Incheon, Korea. Monthly samples were taken using a modified otter trawl from November 1999 to January 2001. Based on the examination of stomach contents from 257 individuals, the frequencies of occurrence and the relative volumes of food items were analysed. As a result, the crustaceans (the brachyura, the cirripedia and the harpacticoid copepoda), the echinoderms (the ophiuroidea) and the molluscs (the cephalopoda Loligo beka, the bivalves Bivalvia unid. and Mytilus galloprovincialis) were important food for this species. To examine ontogenetic shifts in diets, individuals of C. japonica were categorized into 2 different size classes (${\leq}60mm$ and ${\geq}61mm$ in carapace width) representing sexually premature and mature stages. The food items of the small crabs (${\leq}60mm$) were dominated by the crustaceans with the harpacticoid copepods constituting 84.6% of total prey number. The next group was the bivalves and the brachyurans. On the other hand, the large crabs (${\geq}61mm$) mainly feed on the bivalvia (Mytilus galloprovincialis and Bivalvia unid.), the brachyurans (Crab unid.) and occasionally the cephalopods and fishes. The difference in proportions of the main prey items among these two size classes was statistically significant. Therefore, the feeding habits of the portunid crab, C. japonica changed with growth.

• Korean Journal of Environmental Biology
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• v.17 no.4
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• pp.379-387
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• 1999

During the past several decades, electricity generating plant increased with remarkable rapidity in Korea. Recently the increase has been much more rapid as the rate of industrialization has accelerated. Construction of nuclear power plants in coastal areas inevitably caused the perturbation of critical coastal habitats and thus influenced marine algal species composition. Particularly, an increase in the building of nuclear power plants led the amounts of heat discharged to increase exponentially. As far as the effects of cooling water and thermal discharges are concerned, benthic marine algae are likely to be vulnerable to a discharge. Heated effluents from nuclear power plants, with the temperature rises of 7~12$^{\circ}C$ under normal operating and design conditions, are discharged through the discharge canal and into natural water bodies. It is clear that the characteristic marine algal community is developed in the area affected by the thermal discharges; i.e. low species richness and low species diversity. Nevertheless, it is worthwhile to note that elevated temperatures exert differential effects depending on the algal populations. Benthic marine algae grown at the discharge canal can be regarded as warm tolerant species. 35 species (4 blue-green, 9 green, 8 brown and 14 red algae) of marine algae occurred more than 20eye frequency at discharge canal of three nuclear power plants in the east coast during 1992 ~ 1998 and thus can be categorized as warm tolerant species in Korea. To minimize the ecological impacts of waste heat on benthic marine algae, it is recommended that, in the future, nuclear power plants will have to employ some form of closed-cycle cooling for the condensers.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.4
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• pp.331-337
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• 2017

This study was carried out to analyze the community structure and distribution of macrobenthos at the intertidal zone of Jukbyeon in Uljin-gun during 2015-2016. The number of species were total 41 from 5 phyla. The species composition of Cnidaria 4, Mollusca 19, Annelida 3, Arthropoda 13, Echinodermata 2 and the individuals was $1,642inds./m^2$ and the weight was $1,959.42gWWt./m^2$ in the study area. The dominant species of the upper zones were Chthamalus challengeri and Nodilittorina radiata. Those of the lower zones were Mytilus galloprovincialis, Nipponacmaea schrenckii and Chlorostoma turbinata. The dominant species of the upper zones of winter and spring were C. challengeri, the summer and autumn of the N. radiata. Those of the lower zones were all seasonal of M. galloprovincialis. As a result of cluster analysis, those regions were divided in three groups, which were a group A of December 2015, August 2015 and February to August 2016 of intertidal zone lower, group B of December 2016 and May 2015 of intertidal zone lower, group C of intertidal zone upper.

• Korean Journal of Ecology and Environment
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• v.53 no.2
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• pp.173-184
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• 2020

Irrigation ponds, 'dumbeong', which are artificially constructed water resources for traditional farming, serve as a biological shelter connecting seasonally created rice paddy fields to local freshwater ecosystems. This 2018 study surveyed 143 irrigation ponds in the western Civilian Control Zone (CCZ) area from August to September, revealing species diversity and community characteristics of benthic macroinvertebrates. A total of 13,454 individuals of macroinvertebrates were captured and classified into 3 phyla, 5 classes, 17 orders, 59 families, 192 species. Among Insecta, the most frequently recorded order was Odonata, 55 spp.(33.7%), followed by Coleoptera, 52 spp. (31.9%), Hemiptera, 34 spp. (20.8%), Diptera, 17 spp. (9.8%), Ephemeroptera, 3 spp. (2.4%), Trichoptera, 1 spp. (0.6%) and Lepidoptera, 1 spp. (0.6%). Taxon of non-Insecta consisted of Mollusca, 14 spp. (48.2%), Annelida, 11 spp. (37.9%) and Arthropoda, 4 spp. (3.4%). The analysis of Diversity Index (H'), Species Richness Index (RI), Dominance Index (DI) and Evenness Index (J') revealed the general stability of communities in the study sites. A total of 28 rare species were found in 98 study sites, including three endangered species designated by the Ministry of Environment. These results showed that the species diversity and rarity of macroinvertebrates in the study area were greater than those of previous research on lentic wetlands (lake, etc.) and national conserved wetlands(Upo-swamp, etc.) in Korea. A conservation planning of aquatic ecosystems in the western CCZ area, therefore, should focus on conservation of irrigation ponds.

• Korean Journal of Environmental Biology
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• v.30 no.4
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• pp.355-361
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• 2012

Genus of Gambierdiscus, Ostrepsis, Prorocentrum, Coolia and Amphidinium are epiphytic ciguatoxin-producing armored dinoflagellate, often attached on macroalgae. These organisms are the primary causative agent of ciguatera fish poisoning which occurs in tropical and subtropical regions. However, regardless of the fact that population of epiphytic dinoflagellates have expanded to such temperate areas from sub-trophic and trophic areas, monitoring of the epiphytic dinoflagellates was greatly lacked in coastal water of Korean Peninsula. This study was performed in the Korean Peninsula in November, 2011. Cell densities of Gambierdiscus spp. on macroalgae ranged from zero to 10 cells $g^{-1}$ and the maximum density was recorded at St.18 (Pohang guryongpo). The abundance of Ostreopsis spp. was highest on macro-algaes Chondrus ocellatus, Lomentaria catenata and Plocamium telfairiae (140 cells $g^{-1}$). The maximum abundance of Prorocentrum, Coolia and Amphidinium were 52, 3 and 1 cells $g^{-1}$, respectively. Of these, Prorocentrum lima was observed at most stations of East Sea. Therefore, our results suggest that the epiphytic armored dinoflagellates may have adapted to Korean coastal water of temperate areas (i.e., East Sea) and those abundances may be related to the macroalgal species.