• Asian Journal of Turfgrass Science
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• v.11 no.2
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• pp.125-137
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• 1997

Five dictyostelid cellular slime molds were isolated from the littoral grassland ecoystems of the lake Paldangho, safeguard of waterworks, Kyounggi-do, South Korea. They were Poiysphoadylium violceum, Dictyosielium aureo-stipes var. aureo-stipes D crassicaule, D macrocephalum and D gigauteum. P. violaceum was dominant species. It live on the low nutrient and barren soils as the littoral zone destabilized in surface soils, litters and chemicals by inundation an rain precipitation. Key words: Cellular slime mold, Littoral grassland ecosystem.

• Korean Journal of Environmental Biology
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• v.28 no.4
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• pp.188-195
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• 2010

The Abundance of zooplankton was studied in the pelagic and the littoral zone in four shallow reservoirs along with the Nakdong river basin of S. Korea. In the pelagic zone, there was a higher zooplankton density ($477.5{\pm}312.4$ ind. $L^{-1}$) than in the littoral zone during our study period (t=2.337, p<0.05). Overall, Rotifers were the most abundant group in the studied reservoirs. However, there are no significant correlations between the pelagic and the littoral zone in physical and chemical parameters. In the pelagic and the littoral zone, zooplankton density usually increased with increasing density of aquatic plants in the littoral zone. However, this study showed different trends. Although macrophyte abundance was higher in the littoral zone than in the pelagic zone, zooplankton abundance was higher in pelagic zone. Moreover, when macrophytes (Trapa japonica and Spirodela plyrhiza) covered the complete water surface of the reservoir, zooplankton abundance was higher. It appears that comparisons between the pelagic and the littoral zone give important cues on the selection of habitats by zooplankton. It is assumed that a higher density of aquatic plants does not always imply a higher density of zooplankton in the littoral zone. Furthermore, when the water surface was covered with aquatic plants, the zooplankton communities showed the highest density in the pelagic zone. These results imply that habitat selection of the zooplankton community (Rotifers) is influenced by aquatic plant density with an associated decrease in predation pressure during summer.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.13 no.1
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• pp.18-34
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• 2001

Statistical analysis oflong-tenn wave data resulted from HYPA(HYbrid PArametric wave model) for the eastern coast of Korea was performed. Subsequently a simple approach for predicting the global annual and seasonal littoral drifts has been derived to estimate littoral sediment budget.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2002.11a
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• pp.137-140
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• 2002

To determine if fish density, biomass, species richness, and species diversity were greater in ecotone than the stream and littoral zones, I sampled fish monthly in the Ledbetter Creek through Ledbetter Creek Embayment in Kentucky Lake, Kentucky, from April to October 1996 by using throw traps. During the first four months (daytime only) fish density did not vary significantly among zones or among months. However, there were significant differences among zones during the last three months and the stream zone had significantly higher mean fish density than both the littoral zone and the ecotone. Fish biomass also differed significantly among zones during the last three months. The stream zone had the highest mean fish biomass among zones, significantly higher than the ecotone, but not different than the littoral zone. There were no statistically significant differences among zones during the first four months, but mean fish biomass in the stream zone was about eight times higher than the ecotone, The stream zone had the highest fish species richness among zones. Differences were significant among zones during the last three months, and the stream zone (0.98 $\pm$ 0.04) had significantly greater mean fish species richness than the ecotone (0.45 $\pm$ 0.01), but not significantly than the littoral zone (0.56 $\pm$ 0.17). Fish species richness differed significantly among months during the first four months, Monthly species diversities ranged from 0.62 to 1.96 in the stream zone, 0 to a.57 in the ecotone, and 0 to 2.60 in the littoral zone. Combined species diversities in the stream, the ecotone , and the littoral zones were 2.72, 3.58, and 3.10, respectively, There were five families of fishes captured frequently enough for their individual numbers to comprise at least 8 % of the total. Family rankings in the stream zone were opposite of the littoral zone. Percidae was the most abundant family and Clupeidae was absent in the stream zone, whereas Percidae was uncommon and Clupeidae was the most abundant family in the littoral zone. Atherinidae was dominant in the ecotone. Five of the most abundant species comprised 65 % of the total number. The guardian darter occurred only in the stream zone, and it was consistently found in riffles. Longear sunfish and central stoneroller also had significant differences of mean fish densities among zones, and they were found mostly in the stream zone. Threadfin shad and bullhead minnow were almost exclusively caught in the littoral zone. I finally concluded that the ecotone between the stream and the littoral zone in this small-scale freshwater aquatic ecosystem was not as productive as the ones in other ecosystems.

• Korean Journal of Ecology and Environment
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• v.43 no.4
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• pp.513-517
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• 2010

The diel swarming of Moina macrocopa and the relationship between environmental factors were evaluated in a shallow reservoir. The littoral density of Moina macrocopa maintained low from night to noon, reached maximum density at the afternoon with compact swarms at the waters' edge, and dispersed after sunset. The recruitment of Moina macrocopa and changes of water temperature (r=0.709, p<0.001) and juvenile fish density (r=0.511, p=0.002) in the littoral zone showed a significant positive relationships. After the induction of diel horizontal migration toward littoral zone, therefore, direct juvenile fish predation pressure should be induced Moina macrocopa swarming.

• Animal cells and systems
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• v.2 no.3
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• pp.333-339
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• 1998

Litter decomposition is a key process in energy flow and nutrient cycling in the freshwater littoral zone, and is regulated by physicochemical properties of litters. Using a litterbag method, we compared the decomposition rates of 16 different litter types from 10 plant species of the emergent macrophytes for one year in the littoral zone of the Paltangho Reservoir, Korea. The regression analysis fitted to the various decomposition models showed that mass loss of the litters with time best fitted an asymptotic function. The litters of the emergent macrophytes were composed of two compartments, labile and refractory. The macrophytic litters showed a great variety in decomposition dynamics depending on sources of litters. The labile compartment of the initial litter mass was in a wide range between 18% and 99%, and their decomposition rates varied from 0.0037 to 0.0131 day-1. The decomposition processes of the emergent macrophytes were determined by the relative amounts of the labile and refractory compartments and by the decomposition rate of the habile one in the littoral zone.

• Economic and Environmental Geology
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• v.16 no.2
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• pp.65-78
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• 1983

This report deals with the sedimentological study of the littoral sand of beaches in the Busan area. The purpose of this report is to know the grain size, mineralogical composition, heavy mineral and clay mineral of the beach sands, and gravity measurements of the Nagdong River Deltas. 1) As a whole, the littoral sand of the beaches are composed of uniformly medium grained, moderately sorted and nearly symmetrical. The barrier sand of the Nagdong Estuary is composed of fine grained, well sorted and nearly symmetrical. 2) The littoral sand of the beaches is transported by saltation and rolling. The barrier sand of the Nagdong Estuary is transported by suspension and saltation. 3) In the littoral sand of the beaches, the ratio of feldspar to quartz is 1 :2.31 and in the barrier sand of the Nagdong Estuary 1:1.40. 4) The content of heavy mineral of samples ranges from 0.54 to 3.87 %. The principal heavy minerals are hornblende, pyroxene, epidote, garnet, leucoxene, zircon, apatite, magnetite, hematite and ilmenite with minor accessories of rutile and olivine. 5) The x-ray diffraction analysis of the clay mineral informs the existence of quartz, feldspar, kaolinite and montmorillonite. The montmorillonite is considered to have been derived from the alteration of acidic volcanic rocks. 6) To determine the depositional structure of the Nagdong Estuary, Gravity measurements were made. Free air anomaly ranges from 14.5 mgal to 33.5 mgal and Bouguer anomaly ranges from 14.3 to 23.5 mgal and both are closely related to the topography. According to the interpreted layer structure, the upper layer composing sand, silt and clay, the intermediate layer composing sand with gravel, the lower layer composing weathered and soft rock, and bed rock composing hornfels or andesite. 7) The depositional environments of the study, the littoral area is dominated by the marine environment and the Nagdong Estuary by the mixed environment.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1782-1790
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• 2018

Assessment of microorganism viability is useful in many industrial fields. A large number of methods associated with the use of fluorescent probes have been developed, including fluorimetry, fluorescence microscopy, and cytometry. In this study, a microvolume spectrofluorometer was used to measure the membrane potential variations of Escherichia coli. In order to estimate the sensitivity of the device, the membrane potential of E. coli was artificially disrupted using an ionophore agent: carbonyl cyanide 3-chlorophenylhydrazone. The membrane potential was evaluated using two ratiometric methods: a Rhodamine 123/4',6-diamidino-2-phenylindole combination and a JC-10 ratiometric probe. These methods were used to study the impact of freezing on E. coli, and were compared with the conventional enumeration method. The results showed that it was beneficial to use this compact, easy-to-use, and inexpensive spectrofluorometer to assess the viability of bacterial cells via their membrane potential.

• Journal of Ecology and Environment
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• v.38 no.3
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• pp.383-388
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• 2015

Reservoirs consist of two different environments, the littoral and the pelagic zone, and different fishing gear is commonly used in each zone-gill nets in the pelagic zone and electrofishing in the littoral zone. However, an active fishing gear, the cast net, is normally used instead of electrofishing for scientific studies in South Korea. In order to estimate cast net effectiveness for determining fish status in reservoirs, the study was conducted at 15 reservoirs with two different fishing gears: a cast net in the littoral zone and gill nets in the pelagic zone. When combining catches of both gears, species richness increased substantially compared to using one gear only. There was a size difference in fish caught by each net, and small fish were predominantly caught with the cast net due to its small mesh size (7 mm). The combined length of six species, used for length-weight relationship analysis, collected with the cast net was smaller than that collected with gill nets (independent t-test, P < 0.05). In this study, cast net sampling provided sufficient data for the littoral zone, but not enough to identify the overall fish assemblage in studied reservoirs. Utilization of only one gear can therefore lead to substantial underestimation of fish status, and a combination of both gears is recommended for determining more reliable estimates of fish status in reservoirs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.2
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• pp.247-258
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• 2014

To evaluate the influence of the external force components on the littoral currents in the Gusipo beach, Jeonbuk, West Coast of Korea where a wide tidal sand flat developed, a coupled hydrodynamic model considered real time tidal currents and wave-induced currents was constructed in which the EFDC for tides and tidal currents, the SWAN for waves and the SHORECIRC for wave-induced currents were used as the hindcasting models. A series of field observations for tides, tidal currents and incident waves were carried out and especially to observe the littoral currents in the tidal sand flat, the GPS mounted and light weight drogues were used. Also wind data were collected from the adjacent weather station. To analyze the littoral current components, the numerical drogue tracking results considered real time winds, tides and waves were compared with the field drogue data. The drift speed of numerical drogues was reproduced as the range of 68.0~105.2% compared with the field data and the velocity error of main direction component showed a good result as -16.7~10.0%. As a result, in the mild slope tidal flat including wide surf zone, the tides and winds were the major affection component of the littoral currents, on the other hand, the wave-induced currents seemed the minor component when the incident wave heights were relatively small.