• Korean Journal of Ecology and Environment
• /
• v.53 no.3
• /
• pp.229-240
• /
• 2020

In this study, the results of fish assemblage survey for 16 reservoirs in the Yeongsan·Seomjin-River watershed were presented with fish assemblage characteristics analysis in relation to reservoir size. The survey method including number of sampling sites was followed the "Biomonitoring survey and assessment manual" of the Ministry of Environment/National Institute of Environmental Research (MOE/NIER), and the reservoirs were categorized as three size groups, small, medium or large reservoirs, based on the MOE/NIER as well. Total 13 family classified into 44 species were collected from 2018 (7 reservoirs) to 2019 (9 reservoirs), and the dominant and subdominant species were Hemiculter eigenmanni (Relative abundance, RA, 32.9%) and Lepomis macrochirus (RA, 31.4%), respectively. As a result of the analysis in relation to the reservoir size, the average (±standard deviation) number of species of the small, medium and large reservoirs were 11±2.9, 14.3±2.1, 22.7±0.6, respectively, which showed positive correlation with the reservoir size. Total 6 fish assemblage characteristics(number of species, number of individuals, richness index, herbivorous fish ratio, carnivorous fish ratio, exotic fish ratio) showed significant differences between the each reservoir size groups (P<0.05). As a result of cluster analysis, 16 reservoirs were clustered into 5 groups with 60% similarity, and the each reservoirs seems to be clustered depends on the distance from each other, watershed and their historical geology rather than size. These results are baseline information for the understanding of fish assemblage in Korean reservoirs, important for establishing management policy of reservoirs in the Yeongsan·Seomjin-River watershed.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.11
• /
• pp.1653-1663
• /
• 2016

Meat quality is a complex trait influenced by many factors, including genetics, nutrition, feeding environment, animal handling, and their interactions. To elucidate relevant factors affecting pork quality associated with oxidative stress and muscle development, we analyzed protein expression in high quality longissimus dorsi muscles (HQLD) and low quality longissimus dorsi muscles (LQLD) from Duroc pigs by liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomic analysis. Between HQLD (n = 20) and LQLD (n = 20) Duroc pigs, 24 differentially expressed proteins were identified by LC-MS/MS. A total of 10 and 14 proteins were highly expressed in HQLD and LQLD, respectively. The 24 proteins have putative functions in the following seven categories: catalytic activity (31%), ATPase activity (19%), oxidoreductase activity (13%), cytoskeletal protein binding (13%), actin binding (12%), calcium ion binding (6%), and structural constituent of muscle (6%). Silver-stained image analysis revealed significant differential expression of lactate dehydrogenase A (LDHA) between HQLD and LQLD Duroc pigs. LDHA was subjected to in vitro study of myogenesis under oxidative stress conditions and LDH activity assay to verification its role in oxidative stress. No significant difference of mRNA expression level of LDHA was found between normal and oxidative stress condition. However, LDH activity was significantly higher under oxidative stress condition than at normal condition using in vitro model of myogenesis. The highly expressed LDHA was positively correlated with LQLD. Moreover, LDHA activity increased by oxidative stress was reduced by antioxidant resveratrol. This paper emphasizes the importance of differential expression patterns of proteins and their interaction for the development of meat quality traits. Our proteome data provides valuable information on important factors which might aid in the regulation of muscle development and the improvement of meat quality in longissimus dorsi muscles of Duroc pigs under oxidative stress conditions.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.29 no.5
• /
• pp.727-743
• /
• 1996

To know the floristic composition, vortical distribution and community structure of marine benthic algae inhabiting in the intertidal and subtidal zones of Yongil Bay, east coast of Korea, the study has performed using the quadrat method along a transect line from July, 1995 to June, 1996. In this area, a total of 144 species including 2 new red algae to Korea was found: 5 blue-green, 18 green, 20 brown and 101 red algae. The representative species throughout the year were Ulva pertusa, Gelidium amansii and Symphyocladia latiuscula. Dominant species were Sargassum thunbergii in spring, U. pertusa in summer and autumn. In winter, Chondrus ocellatus and Monostroma grevillei occurred dominantly. The standing crop exhibited mean value as $185.8g/m^2$ dry weight. Maximum value was recorded in spring $(267.3g/m^2)$ and minimum was observed in winter $(93.7g/m^2)$. Shannon's species diversity (H') and evenness (J') as maximum value were recorded in spring, whereas minimum values were shown in winter. Vertical distribution, rerognized by cluster analysis based on relative coverage of the species, could be divided into two or three algal groups except spring. In general, green algae (M. grevillei, Capsosiphon fulvescens, U. pefusa, Enteromorpha compressa) and brown algae (Sargassum fulvellum, S. thunbergii) were represented in the upper and middle zone and red algae (G. amansii, C. ocellatus, S. latiuscula, Crateloupia okamurae, Pachymeniopsis eilliptica) in the lower zone. The algal community varied according to season and environmental conditions. Particularly, seasonal variation of vortical distribution seemed to be affected primarily by water temperature. Also seasonal tidal level and tolerance of algal species to desiccation appeared to be associated with it in this area.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.6
• /
• pp.789-796
• /
• 2016

The anti-lipogenic effect of cereal samples on high sucrose diet (HSD)-induced non-alcoholic fatty liver disease (NAFLD) in mice was studied. We divided C57BL/6 mice into various groups based on 8 weeks of treatment with three types of cereal samples (HSD+WR, HSD diet containing 40% white rice; HSD+MCG, HSD diet containing 40% mixed cereal grain; HSD+AO-MCG, HSD diet containing 40% mixed antiobesity-cereal grain). After the experimental period, body weight changes, liver weights, serum lipid profiles, and hepatic fatty acid metabolism-related gene expression levels were determined. We found that HSD+WR, HSD+MCG, and HSD+AO-MCG treatments reduced body weight and liver weight, especially HSD+MCG and HSD+AO-MCG effectively reduced levels of serum triglycerides, total cholesterol, and low-density lipoprotein cholesterol. However, high density lipoprotein cholesterol levels increased compared to the control group. Furthermore, expression of hepatic lipogenic genes such as sterol regulatory element-binding protein-1c, acetyl-coenzyme A carboxylase, fatty acid synthase, stearoyl-coenzyme A desaturase-1, cluster of differentiation, and $PPAR-{\gamma}$ (peroxisome proliferator activated receptor ${\gamma}$) decreased, whereas expression of ${\beta}-oxidation$ genes such as $PPAR-{\alpha}$ and carnitine palmitoyl transferase-1 increased following HSD+MCG and HSD+AO-MCG treatment compared with levels in HSD+WR and control groups. These results suggest that the functional cereal samples, especially HSD+AO-MCG treatment, improved hepatic steatosis triggered by an HSD-induced imbalance in hepatic lipid metabolism.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.3
• /
• pp.265-273
• /
• 1986

The marine algal communities of Yonhwa-do at the southern coast of Korea were investigated in aspects to quantitative analysis of their structure and dynamics. As a result, 114 species, including 2 blue-green, 69 red, 25 brown and 18 green algae, were identified. The R/P value(2.8) is higher than that of other regions of the southern coast of Korea. Sheet and filamentous groups of the functional groups of algae showed higher composition rate in spring and summer than in autumn and winter, but coarsely branched and thick leathery groups showed an opposite tendency. Cluster analysis based on species presence suggested the existence of 5 distinct groups in spring, but 3 groups in the other seasons. The species exhibiting important value above 20 were as follows: Porphyra suborbiculata, Corallina pilulifera, Hizikia fusiforme, Sargassum thunbergii, Undaria pinnatifida, Ishige okamurai, Chondria crassicaulis, and crustose coralline algae. The coverage of algal communities composed only of crustose coralline algal complex was higher than that of other algal complex, but occurrence frequency of these two communities was indifferent. It is suggested that the occurrence in high quantity of crustose coralline algae from this area is related to grazing by herbivorous animals.

• Journal of Korean Society of Environmental Engineers
• /
• v.35 no.4
• /
• pp.247-256
• /
• 2013

In this study, alginate beads containing birnessite (Bir-AB), a highly reactive oxidative catalyst for the transformation of phenolic compounds, was prepared and its 1-naphthol (1-NP) removal efficiency was investigated in a batch test. Based on scanning electron microscopy image, it can be inferred that the alginate gel cluster acts as a bridge which bind the birnessite particles together. Kinetic experiment with Bir-AB of different mixing ratios of birnessite to alginate (Bir : AG=0.25 : 1~1 : 1 w/w) indicate that pseudo-first order kinetic constants, $k(hr^{-1})$ for the 1-NP removals increased about 1.5 times when the birnessite mixing ratio was doubled. The removals of 1-NP was found to be dependent on solution pH and the pesudo-first order rate constants were increased from 0.331 $hr^{-1}$ at pH 10 to 0.661 $hr^{-1}$ at pH 4. The analysis of total organic carbon for the reaction solutions showed that a higher removal of dissolved organic carbon was achieved with Bir-AB as compared to birnessite. HPLC chromatographic analysis of the methanol extract after reaction of 1-NP with Bir-AB suggest that the reaction products could be removed through incorporation into the aliginate beads as a bound residue. Mn ions produced from the oxidative transformation of 1-NP by birnessite were also removed by sorption to Bir-AB. The Bir-AB was recovered quantitatively by simple filtration and was reused twice without significant loss of the initial reactivity.

• Korean Journal of Environmental Biology
• /
• v.28 no.3
• /
• pp.133-142
• /
• 2010

This study was performed to investigate the community structure of the macrobenthic invertebrates around Ui Island, Sinan-gun, Jeollanam-do, Korea. Benthic invertebrates were collected during May and September 2008 at seven stations. A total of 63 macrobenthic species was collected. The overall average macrobenthos density and biomass were 268 inds. $m^{-2}$ and 11.54 gWWt $m^{-2}$, respectively. Based on abundance data, there were 5 dominant species accounting for approximately 72.00% of total individuals. The polychaetes Notomastus latericeus, Scolelepis sagittaria, Amaeana occidentalis, Glycera chirori and the amphipoda Mandibulophoxus mai were found in high densities. The conventional multi-variate statistics (cluster analysis and non-metric multidimensional scaling) applied to assess spatial variation in macrobenthic assemblages. As a result, three communities could be distinguished: a sand dominated, a mixed sediment and a third community in the mud dominated station. The community in the sand dominated station was characterized by high abundance of the polychaetes S. sagittaria and the amphipods M. mai, Monoculodes sp. and Grandifoxus malipoensis. However, the most common species within the mixed sediment station were the polychaetes N. latericeus, A. occidentalis and amphipoda Urothoe sp.. Finally the mud dominated station was numerically dominated by the polychaetes Scolelepis sp., Heteromastus filiformis and Sigambra tentaculata. In conclusion, the sediment composition may be important factors controlling of the macrobenthic community structure in the study area.

• Horticultural Science & Technology
• /
• v.32 no.6
• /
• pp.812-818
• /
• 2014

Raising seedlings is important for fruit crops and is especially significant for strawberries as it accounts for 80% of their cultivation. However, there are few studies on raising seedlings of strawberries by hydroponics. Since strawberries show clear differences in growth characteristics based on cultivar, it is necessary to develop suitable fertilizer formula, concentration and pH for each cultivar, and also to examine the amount of nutrient feeding appropriate for each medium type. A key to raising seedlings of strawberries by hydroponics is the development of strategies to manage the concentration of nutrient solution. The mother plants of 'Daewang' strawberries were planted on hydroponics benches filled with cocopeat on March 28, 2012. Three nutrient solution treatments were employed during the term of raising seedlings: a type that supplied EC $0.6dS{\cdot}m^{-1}$ nutrient solution for 30 days and only water for 20 days [0.6 (30) + 20]; a type that supplied EC $1.2dS{\cdot}m^{-1}$ nutrient solution for 30 days and only water for 20 days [1.2 (30) + 20]; and a type that supplied EC $1.2dS{\cdot}m^{-1}$ nutrient solution for 50 days [1.2 (50)]. The plants were then planted on hydroponics benches filled with cocopeat on September 20, and managed with EC $0.6-0.8dS{\cdot}m^{-1}$ strawberry nutrient solution developed by Yamazaki. After planting, shoot growth, flowering rate and fruit quality of the first cluster were investigated. The petiole length, leaf length, leaf width and crown diameter showed the highest grown in the [1.2 (50)] treatment, followed by [1.2 (30) + 20], and then [0.6 (30) + 20], indicating that the higher concentration of nutrient solution was preferable for raising seedlings. However, the growth differences among treatments gradually disappeared as growth continued, and the crown diameter especially grew to exhibit almost no difference at all among treatments. The point of flowering came first in [0.6 (30) + 20], followed by [1.2 (30) + 20] and then [1.2 (50)]. The [0.6 (30) + 20] treatment showed much earlier flowering than other treatments, which implies that low-concentration nutrient solution may be beneficial to the flowering of 'Daewang' strawberries while raising seedlings. There was no statistically significant difference among treatments in fruit length, fruit diameter and fruit firmness. Fruit weight in [1.2 (50)] treatment was significantly higher than other treatments. However, soluble solids of fruit was the lowest in [1.2 (50)] treatment. Together, the results of this experiment imply that it is better to supply EC $0.6dS{\cdot}m^{-1}$ solution for 30 days and then supply only water for 20 days to adequately manage concentration of nutrient solutions during the period of raising seedlings of strawberries by hydroponics.

• Korean Journal of Ecology and Environment
• /
• v.51 no.1
• /
• pp.60-70
• /
• 2018

The distribution of benthic macroinvertebrates was investigated at 1,157 sites of 7 main water systems in Korea, including 442 sites of Han River system (Namhan River, Bukhan River, Han River main stream, Anseongcheon, etc.), 305 sites of Nakdong River system (Nakdong River, Hyeongsan River, Taehwa River, etc.), 199 sites of Geum River system (Geum River, Sapgyocheon, Mangyeong River, Dongjin River, etc.) 102 sites of Seomjin River system (Seomjin River), 102 sites of Yeongsan River system (Yeongsan River, Tamjin River, etc.), and 7 sites of Jeju stream system. A total of 151 families were found in the whole survey sites, including 141 families in Han River, 122 in Nakdong River, 115 in Geum River, 106 in Seomjin River, 113 in Yeongsan River, and 50 in Jeju. Chironomidae (20.8%) was the most dominant species in Korea, followed by Hydropsychidae (17.1%), Baetidae (12.6%), Tubificidae (10.3%), Heptageniidae (8.6%), Ephemerellidae (6.3%), Asellidae (2.7%), Leptophlebiidae (2.4%), Planariidae (1.7%), and Tipulidae (1.6%). Substrates compositions consisted of large sand (22.6%), large gravel (18.4%), silt (10.5%), and boulder (8.2%). The mean stream width was 133.5 m and the mean watercourse width was 61.7 m. The mean water depth and velocity were 30.2 cm and $33.1cm\;s^{-1}$, respectively. Results of cluster analysis based on distributional characteristics of benthic macroinvertebrates were divided into six groups according to the frequency of benthic macroinvertebrate taxa which appeared in the study area. Finally, altitude, current velocity and substrate composition were the most influencial factors determining the distribution patterns of macroinvertebrate communities.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.7 no.1
• /
• pp.8-19
• /
• 2002

Spatial distribution pattern of macrozoobenthos was studied along the salinity gradient and sedimentary environment in the Watancheon estuary, Beobseongpo, southwest coast of Korea. Ten stations were set from the mouth towards the head of estuary. Three replicate sediment samples were taken using a van Veen grab (surface area $0.1m^{2}$) at each station between June 1998 and January 1999. A total of 114 species were collected during the study period and they are composed of 44 species of polychaetes (39%), 34 of crustaceans (30%), 24 of molluscs (21%) and 12 of miscellaneous. The former two taxa together accounted for 69% in the total number of species. The mean density was 3,053 ind./m$^{2}$, comprising 2,536 ind./m$^{2}$ from polychaetes (83%) and 439 ind./m$^{2}$, crustaceans (14%). Moreover, the mean biomass was 58.23 gwwt./m$^{2}$, consisting of 29.56 gwwt./m$^{2}$ from polychaetes (51%), 23.38 gwwt./m$^{2}$, molluscs (40%). A spionid polychaete Minuspio japonica, two corophiid amphipods Grandidierella japonica and Corophium sinense, a bivalve Potamocorbula amurensis were major dominants at the head of estuary where the salinity was relatively lower compared with contiguous sites. The distributions of M. japonica and G. japonica were significantly related to the salinity and sediment environment, respectively, whereas C. sinense and P, amurensis showed no significance. The nereid polychaete, Hediste japonica, also predominated at the head of the estuary where bottom salinity was relatively low. Species diversity was high at the mouth area whereas low diversity and few species number were seen at the stations in the head of the estuary, influenced by freshwater and sandy sediment. Based on the cluster analysis, the macrobenthic community was classified into four station groups from head (station group A) toward mouth (group D) in the study area. The number of species and abundance between station group B and C were significantly different. And the abundance of between two neighboring station groups (station group A and B, B and C, C and D) was also different. These results suggested that the spatial distribution pattern of macrobenthos in this estuary seemed mainly related to gradients in bottom salinity and sediment grain size among environmental factors.