• 한국물환경학회지
• /
• 제36권1호
• /
• pp.36-47
• /
• 2020

Three large scale weirs were constructed 2010 - 2011 in the Namhan river, Korea. The purpose of this study was to investigate the spatial distribution of benthic macroinvertebrates and the influence of environmental factors at the weirs 2014 - 2015. The number of species was higher in the riparian zone than in the transition or the limnetic zone. This seems to be because of the diversification of microhabitats and food sources according to the development of littoral zones. From the riparian zone to the limnetic zone, the individual abundance proportion of gathering collectors among functional feeding groups decreased, and that of filtering collectors increased. In the limnetic zone, sprawlers and climbers among habitat orientation groups decreased, and burrowers increased. This means that coarse particulate organic matter originated from land or riparian zone was transformed to fine particulate organic matter in the limnetic zone. Asian clam (Corbicula fluminea) and chironomids were dominant species based on individual abundance. Asian clam, a major taxon considering biomass, was abundant toward the limnetic zone. This is becasue of the shallow depth, suitable water current, slightly coarse substrate, and good water quality. There was no significant relationship between the water quality and the characteristics of the benthic macroinvertebrate community because the water quality was spatially not heterogenous. The more influential factors for benthic community were physical factors, especially water depth. Water depth showed a markedly significant correlation with Shannon-Weaver's species diversity (r=-0.90), Margalef's species richness (r=-0.82), and McNaughton's dominance (r=0.86). Water depth showed a positive correlation (r=0.68) with the Kong and Kim BMSI (Bentic Macroinverebrates Streambed Index), and this may be related to the coarse substrate of the limnetic zone.

• Animal Systematics, Evolution and Diversity
• /
• 제22권1호
• /
• pp.29-35
• /
• 2006

Two ciliates of suborder Euplotina collected from the two habitats (estuarine littoral and sewage treatment plant) in Ulsan, Korea were Euplotes charon ($M\ddot{u}ller$, 1773) and Diophrys oligothrix Borror, 1965. These two species are reported for the first time from Korea. The description was based on the observation of living and silver impregnated specimens. Diagnostic characteristics of these species are as follows. E. charon: size in vivo about $90-130\times65-80{\mu}m$, adoral zone of membranelles over 79.5% of cell length with 54-80 adoral membranelles; right margin of the peristome shaped sinusoidal form and passed through adoral zone of membranelles; buccal cavity wide anteriorly; 10 frontoventral, 5 transverse, 4 caudal cirri, 12 dorsal kineties, mid-dorsal kinety with 21 -25 dorsal bristles; silver-line system double-eurystomus type. D. oligothrix: size in vivo about $80-90\times30-70{\mu}m$; body shape ovoid with prominent right concave posterio-lateral end, two irregular elongated macronuclei with one micronucleus, respectively; 7 fronto-ventral, 5 transverse, 2 left marginal and 2 caudal cirri, 4 dorsal kineties with prominent bristles about $9-14{\mu}m$ long in vivo.

• 생태와환경
• /
• 제38권spc호
• /
• pp.31-38
• /
• 2005

Diel change in urea decomposition activity of epiphytic algae on Phragmites stems and phytoplankton in a shallow littoral reed zone in the south basin of Lake Biwa was investigated with an in situ technique using $^{14}C$-labelled urea. The daily rates of urea decomposition (sum of urea carbon incorporation rate and $CO_2$ liberation rate) by epiphytic and planktonic algae were calculated as 180 ${\mu}$ mole urea surface shoot area $m^{-2}\;day^{-1}$ and 210 ${\mu}$ mole urea $m^{-3}\;day^{-1}$. The chlorophyll a specific urea decomposition rates of epiphytic and planktonic algae were 4.7 to 6.4 and 4.4 to 6.2 ${\mu}$ mole urea mg chl. $a^{-1}$ incubation $time^{-1}$ in daytime and 4.2 to 5.7 and 2.4 to 3.5 ${\mu}$ mole urea mg chl. $a^{-1}\;time^{-1}$ in nighttime, respectively. High values were obtained during 12:00 ${\sim}$ 18:00 and low values during 00:00 ${\sim}$ 06:00 for both epiphytic and planktonic algal communities. A clear diel periodicity in the urea decomposing activity of the planktonic algae was observed. The activity of the epiphytic algae, on the other hand, showed no destinctive variation during a day. The present results indicate that epiphytic algae are one of the significant urea decomposers in a reed zone, and that the diel patterns are quite difference between both algal communities.

• 한국해양공학회지
• /
• 제30권6호
• /
• pp.498-504
• /
• 2016

In this study, to predict the effect of beach nourishment at Haeundae Beach, the waves and wave-induced currents were compared before and after beach nourishment using the XBEACH model. Representative wave conditions were determined for the data observed during 2014 (KHOA). Then, the Hs,max and Hs,1/10 values, and their prevalent directions, were used in the numerical modeling input data. A variable grid system was used for the $5km{\times}2.5km$ model areas, and irregular waves based on the JONSWAP spectrum were given as incident wave conditions. In the summer season, eastward wave-induced currents were developed along the beach by the incident wave direction. Before the beach nourishment, the maximum speed around the surf zone was 1.2-1.5 m/s in the central zone of the beach, whereas the maximum speed increased to 1.4-1.6 m/s at the same areas when the currents toward Mipo Harbor were blocked as an effect of the groins after the beach nourishment. In the winter season, westward wave-induced currents were developed along the beach by the incident wave direction. After the beach nourishment, the maximum current speed increased slightly around the surf zone in the central area of the beach, and the littoral current speed decreased at the submerged breakwaters located at Dongbaek Island. As a result, after the beach nourishment, the maximum wave-induced currents increased about 10% in the surf zone of the central area of the beach.

• 한국물환경학회지
• /
• 제23권5호
• /
• pp.676-682
• /
• 2007

The bacterial number, extracellular enzyme activities and structure of bacterial community which are major constituent of aquatic ecosystem within the artificial vegetation island (AVI) were compared to those of the nearby pelagic lake waters in order to evaluate the possibility of the AVI as a eco-technological measure for water quality improvement and restoration of littoral zone in man-made reservoirs. There was not a significant difference in the total number of bacteria, but the number of active (viable) bacteria within the AVI was about 0.7 to 4.1 times higher than nearby pelagic lake water. The ratio of the number of active bacteria versus the total number of bacteria was also higher in the AVI than nearby pelagic lake water. The activities of ${\beta}$-glucosidase and phosphatase were 1.0 to 13.1 and 0.8 to 7.3 times higher respectively in the AVI than nearby pelagic lake water, showing that microorganisms were more active within the AVI. The bacterial communities of the two waters, examined by FISH method, did not indicate a clear difference in the springtime when the growth of macrophytes was immature, but during summer and fall it showed a clear difference indicating the formation of distinct bacterial community within the AVI compared to nearby lake water. From the results of this study, we conclude that AVI can contribute to make up the littoral ecosystem which show rapid cycling of matters through active detritus food chain in the dam reservoirs which have unstable aquatic ecosystem due to short hydraulic residence time and to strengthen the self-purification capacity of the lake.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2005년도 춘계학술대회
• /
• pp.502-506
• /
• 2005

2003년 11월과 2004년 4월의 2회에 걸쳐 상용조류발전소 건설 예정지인 울돌목에서 발전소 건설로 인해 야기될 주변생태환경의 변화를 파악하기 위해 4개 지점의 주변 암반조간대에 형성된 기존의 부착생물상 조사가 수행됐다. 울돌목 주변의 암반조간대에 형성된 부착생물상은 서식 형태에 따라 크게 대형해조류(Macroalgae)를 포함한 고착생물, 소 이동성 부착동물, 이동성 소형 무척추동물 등으로 구분된다 부착생물상은 서식양상에 있어 각각의 정점별 특이성이 관찰되었으며, 이는 각기 다른 비생물학적 요인에 따라 지역 특유의 서식환경이 조성되어 있음을 시사하는 간접적인 결과로 간주된다. 이같은 지역 간 생물상 차이는 조위에 따른 수직분포 분석결과 주로 중부조간대를 중심으로 형성된 생물상에 따라 대별되고 있음이 발견되었다.

• Journal of Plant Biology
• /
• 제28권3호
• /
• pp.199-206
• /
• 1985

Antithamnion miharae (Tokida) Itono was investigated in field and laboratory culture. The plant grows in lower littoral zone through out the year in Korea. The gland cells occur scarcely or commonly according to the populations, but the terminal hairs in the female plants are not observed. The structure of vegetative thallus and the reproductive organs in culture are similar to those of field materials, except for the number of gonimoblasts, which become five to six in contrast to one to three of the field. A typical Polysiphonia-type life history is repeated in culture. This species which produces tetrahedral tetrasporangia is markedly distinguished from Antithamnion glandulifera sensu Kylin (=Antithamnionella glandulifera (Kylin) Wollaston) which produces cruciate tetrasporangia, while the plants reported by Dawson (1962) and Wollaston (1971) as A. glandulifera seem to be conspecific with A. miharae by the fact that they have the tetrahedral tetrasporangia in stead of cruciate ones.

• 생태와환경
• /
• 제34권1호통권93호
• /
• pp.54-61
• /
• 2001

저온에서 메탄발생 경로의 변화에 대하여 팔당호 연안대에서 채취한 저질토 슬러리를 배양하여 실험하였다. 저질토 슬러리의 메탄발생속도는 5${\sim}$45$^{\circ}C$ 범위에서 온도가 상승함에 따라서 지수함수적으로 증가하여 45$^{\circ}C$에서 7.4 nmol${\cdot}$g$^{-1}{\cdot}$h$^{-1}$로서 최대에 달한 후 급격히 감소하였다. 배양온도를 고온인 30$^{\circ}C$에서 저온인 15$^{\circ}C$로 감소시키면 메탄발생속도와 수소축적속도가 감소하였고 아세트산은 일시적으로 축적되었다. 배양온도 15$^{\circ}C$와 30$^{\circ}C$에서 클로로포름은 메탄발생을 완전히 억제하였고 메탄발생의 직접적 기질인 수소와 아세트산이 축적되었다. 이 수소와 아세트산의 축적량을 메탄발생량으로 환산하면, 아세트산으로부터의 메탄발생량은 30$^{\circ}C$와 15$^{\circ}C$에서 각각 총메탄발생량의 14%와 75%로 추정되었다. 또한 저온에서 저질토 슬러리에 아세트산을 19 mM 이상으로 첨가하면 메탄발생이 저해되었다. 결국 저온 조건에서는 메탄발생에 대한 아세트산의 상대적 기여도가 증가하고, 고농도의 아세트산에 의하여 메탄과정이 저해되었다. 그러므로 팔당호 연안대 저질토의 유기물 혐기분해에서 아세트산-이용 메탄발생과정은 저온에서 핵심과정이 되고, 고농도의 아세트산에 의한 병목현상이 일어난다고 판단된다.

• 생태와환경
• /
• 제42권2호
• /
• pp.212-220
• /
• 2009

본 연구는 2008년 11월에 마산저수지를 대상으로 어류 종조성 및 섭식길드 및 오염내성길드에 따른 생태지표 특성을 분석하고, 이와 연관된 화학적 수질 특성 변화를 분석하였다. 채집된 어류는 총 12종(6과)으로 나타났고, 주요 우점종은 피라미, 치리, 참붕어 등으로 나타났다. 한국 고유종은 3종만이 출현하였으며, 외래도입종은 떡붕어 1종이 출현하였다. 생태지표 특성 분석에 따르면, 내성종 및 잡식종의 상대풍부도는 각각 98%로 단연 우점하는 것으로 나타나, 이화학적 질적저하 및 물리적 서식지 교란요인에 의한 영향을 반영하고 있었다. 호안에 따른 종분포 특성 분석 결과, 정수식물이 발달한 호안에서 대부분의 어류가 95% 이상이 채집된 것으로 나타났다. 또한 하상 기질 특성에 따른 분석 결과, 뻘(Silt)로 된 구간에서 가장 많은 종 (11종, 91.7%)이 채집되어, 하상기질에 따라 유의한 차이를 보이고 있었다. 화학적 수질자료 분석에 따르면, 호수 영양상태 지표인 총인(TP) 및 Chl-a의 농도는 모두 과영양상태인 것으로 나타났으며, 호수의 유기물오염의 지표로 사용되는 COD도 평균 10.9 mg $L^{-1}$로 나타났다. 마산저수지의 이러한 수질저하는 어류의 섭식구조(잡식종의 증가) 및 내성종의 증가 등을 통해 반영되었다. 향후 마산저수지의 어류상 및 어류 종조성이 향상을 위해서 수질 개선 및 서식지 복원이 펼요할 것으로 사료된다.

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2002년도 춘계학술대회 논문집
• /
• pp.257-262
• /
• 2002

Numerical model introduced in this study combines wave refraction-diffraction, breaking, bottom friction, lateral mixing, and critical shear stress and three sub-models for simulating waves, currents, and bottom change were briefly discussed. Simulations of beach processes and harbor sedimentation were also described at the coast neighboring Bangpo Harbor, Anmyundo, Chungnam, where the area has suffered from accumulation of drifting sand in a small fishing harbor with a wide tidal range. We also made model test for the case of a narrow tidal range at Nakdong river's estuary area to understand the effect of water level variation on the littoral drift. Simulations are conducted in terms of incident wave direction and tidal level. Characteristics of wave transformation, nearshore current, sediment transport, and bottom change are shown and analyzed. We found from the simulation that the tidal level impact to the sediment transport is very important and we should apply the numerical model with different water level to analyze sediment transport mechanism correctly. Although the model study gave reasonable description of beach processes and harbor sedimentation mechanism, it is necessary to collect lots of field observation data, including waves, tides and bottom materials, etc. for better prediction.