• 한국농공학회논문집
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• 제60권3호
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• pp.113-121
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• 2018

The objectives of the research were 1) to develop the low-cost and high efficient desalination system to treat brackish water having high salt contents for irrigation at greenhouses near coast, and 2) to monitor and assess the effects of the brackish water desalination system on soil environment and growth in squash greenhouse cultivation area. The monitoring site was one of the squash greenhouse cultivation farm at Choengam-ri, Jinsang-myun, Gwangyang-si, Jeonnam-Do Monitoring results for groundwater irrigation water quality, and salinity showed a remarkable difference between control and treatment group. The salinity of soil at treatment group was less than at control group. While, the system made possible to increase the squash quantity from 4.7 ea to 6.3 ea at each and the average weight of the harvested squash was increased from 277.2 g to 295.1 g. The applied brackish water desalination system may be appled to reclaim sea or brackish irrigated area as alternative water resources, although long-term monitoring is needed to get more representative results at different level of salinity.

• 한국어류학회지
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• 제18권3호
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• pp.184-192
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• 2006

제주연안에 서식하는 검정망둑 Tridentiger obscurus의 생식주기를 조사하기위해 기수지역에서 2004년 5월부터 2005년 8월까지 총 408마리, 조수웅덩이에서 2004년 7월부터 2005년 8월까지 총 271마리를 채집하였다. 기수지역의 수온은 $11.0{\sim}21.6^{\circ}C$이었다. 조수웅덩이의 수온은 2004년 7~8월에 $30.1{\sim}29.2^{\circ}C$의 범위였으나, 2005년의 수온변화는 기수지역과 유사하여 $11.1{\sim}24.5^{\circ}C$로 조사되었다. 기수지역 암컷의 GSI는 4월에 증가하기 시작하여 5~8월에 높은 값을 유지하였다. 기수지역 검정망둑의 생식주기는 미성숙기 (11~5월), 성숙기 (3~9월), 완숙 및 산란기 (5~9월), 퇴행기 (7~12월)로 조사되었다. 조수웅덩이 암컷의 GSI도 4월에 빠르게 증가하기 시작하여 2005년 7월까지 높은 값을 유지하였다. 그러나 고수온 시기인 2004년 7월에는 낮은 값을 나타내었다. 조수웅덩이에 서식하는 검정망둑의 생식주기는 미성숙기 (8~4월), 성숙기 (3~8월), 완숙 및 산란기 (3~7월), 퇴행기(2004년 7~8월, 2005년 8월)로 조사되었다. 기수지역과 조수웅덩이에 서식하는 검정망둑의 포란수는 각각 1,214~12,109와 2,427~13,892의 범위였고 포란수는 조수웅덩이가 기수지역보다 높았다 (P<0.05). 그리고 두 지역 모두 전장과 체중이 증가할수록 포란수가 증가하는 경향이 있었다. 기수지역에서 전장 111 mm 이상인 개체들은 산란시기에만 관찰된 반면 조수웅덩이에서는 2004년 10월 이후부터 지속적으로 관찰되었다. 그리고 기수지역과 조수웅덩이에서 이러한 개체들의 출현빈도는 각각 0~12%와 11.4~57.9%이었다. 이들 결과로 보아, 검정망둑의 난소 발달은 수온 및 일장의 변화와 밀접한 관련이 있다고 생각된다.

• 생태와환경
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• 제36권2호통권103호
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• pp.215-220
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• 2003

북한 신포지구에 위치하는 3개 호수는(호만포호, 현금호, 대인호)동물플랑크톤 출현 결과와 염분도로 (현금호는 2002년 5월과 10월에 2.8ppt와 0.8ppt, 대인호는 1.5ppt와 0.5ppt) 보아 기수호임이 밝혀졌다. 3개 호수에서 출현한 34종류의 동물플랑크톤 중 요각류와 윤충류가 각각 15종과 7종 동정되었으며 34종류 중 담수종은 24종, 기수종과 해산종은 각각 6종과 4종이었다. 기수성 요각류인 Pseudodiaptomus와 Sinocalanus tenellus는 3개 호수에 모두 분포하고 있었으며 3개 호수 모두에서 기수종과 해산종의 출현양이 동물플랑크톤 출현양의 90%이상을 차지하고 있었다. 5월에 현금호에서 S. tenellus가 입방미터당 59,000개체로 대량 출현하여 이때 기수종과 해산종의 출현양은 전체 동물플랑크톤 출현양의 99%를 넘었다. 연구 지역의 기수호를 보호하기 위한 기초자료를 제공하기 위해서는 장기 조사가 필요한 것으로 나타났다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권6호
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• pp.95-105
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• 2021

Extensive groundwater abstraction has been recognized as one of the major challenges in management of coastal groundwater. The purpose of this study was to assess potential changes of groundwater distribution of northeastern Jeju Island over 10-year duration, where brackish water have been actively developed. To quantitatively estimate the coastal groundwater resources, numerical simulations using three-dimensional finite-difference density-dependent flow models were performed to describe spatial distribution of the groundwater in the aquifer under various pumping and recharge scenarios. The simulation results showed different spatial distribution of freshwater, brackish, and saline groundwater at varying seawater concentration from 10 to 90%. Volumetric analysis was also performed using three-dimensional concentration distribution of groundwater to calculate the volume of fresh, brackish, and saline groundwater below sea level. Based on the volumetric analysis, a quantitative analysis of future seawater intrusion vulnerability was performed using the volume-based vulnerability index adopted from the existing analytical approaches. The result showed that decrease in recharge can exacerbate vulnerability of coastal groundwater resources by inducing broader saline area as well as increasing brackish water volume of unconfined aquifers.

• 한국제4기학회지
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• 제8권1호
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• pp.33-42
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• 1994

The study area is filled up by alluvium which can be classified into lower and upper beds by the facies of deposits and their degree of weathering. The lower bed is not of marine but of fluvial. The upper bed is mainly composed of clay and silt or fine sand beds col-ored dark or dark gray which are of neritic or brackish yielding mollusca fossils. The oyster(Crassostrea ariakensis) obstained from the depth of 3m below the present sea level in the upper bed was dated at 4,100 110Y.B.P. and the veneridae(Meretrix lamarck) 1m height above the present delta plain in the old sand bar was dated at 1,700 85Y,B,P. It is therfore concluded that the study area a small kern col of terrestri-al basin prior to postglacial age had experienced the Holocene transgression. Consequently the study area is considered to have been progressively formed under neritic or brackish circumstance before 1,700Y.B.P.

• Journal of Plant Biology
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• 제12권3호
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• pp.35-41
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• 1969

To clarify the types of brackish region of the Han River Estuary, this research was carried out, and the results obtained on the basis of salinities and phytoplankton are as follows: 1. Geomorphologically, the Han River Estuary is the drowned river valley type. 2. According to the Venice System, the estuarine extent is defined from the lower point of Jollyu-ri to Palmi Island. As a whole the estuarine region is mixo-haline including parts from oligo-haline to poly-haline. 3. In standpont of phytoplankton frequency, the frequency of fresh-water species is high in the upper region of estuary and that of marine species is high in the lower region. The rate of frequency of fresh-water species is inversely proportionate to that of marine species. The area mixedby marine and fresh-water species over estuarine boundary. 4. The frequency of some typical brackish species is very low and almost similar in the whole region.

• Ocean and Polar Research
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• 제28권3호
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• pp.305-315
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• 2006

In order to examine the transition of zooplankton community by the Saemangeum sea dyke, the temporal and spatial distribution of zooplankton community with relation to environmental variables was investigated using data collected in 2004 and 2005. Sixty-one zooplankton taxa were identified. Average abundance (except Noctiluca scintiliam) ranged from 236 to 1810 indiv. $m^{-3}$, and was the highest in May 2005 and the lowest in february 2005. Dominant species were Acartia hongi and Paracalanus indicus, and cirripedia nauplii and zoea were dominant groups. After the closure of the 4th sea dyke, brackish species such as Tortanus derjugini and Pseudodiaptomus inopinus are widely distributed while the abundance of N. scintillans decreased in the northern area inside the dyke. In canonical correspondence analysis (CCA) for examining the relationships among zooplankton, stations and environmental variables, the northern area inside the dyke was distinguished from the other areas and was represented by Acartia spp, and brackish copepods.; Also, this area was characterized by high chlorophyll a concentration and COD, and low diversity.

• Ocean and Polar Research
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• 제43권2호
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• pp.73-88
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• 2021

The community structure and health status of macrobenthos assemblages were investigated in the subtidal area of the Nakdong River estuary, Southern Coast of Korea. Benthic fauna samples were collected seasonally at 8 stations in the subtidal area of the Nakdong River estuary from February 2013 to October 2015. During the survey, a total of 380 species and 4,603 ind./m² of macrobenthos in all sampling areas were collected. The major dominant species were the polychaetes Minuspio japonica, Pseudopolydora kempi, Heteromastus filifomis, Capitella capitata, the amphipod Grandidierella japonica and the bivalvia Arcuatula senhousia. Some species of polychaetes found in the study area consisted of opportunistic species that showed high densities when habitat condition was poor. On the other hand, macrobenthos assemblages in the study area were divided into brackish water and marine groups. Abundance was high in the brackish group, while the number of species and diversity index were high in the oceanic group. The three indices (AMBI, M-AMBI, and BHI) in the assessment of health levels based on the ecological characteristics and number of species in macrobenthic were commonly shown to be in good condition in the group of oceanic stations, while relatively poor conditions were reflected in the group of brackish stations. Compared to other indices, the M-AMBI index of the three indices for health assessment was considered to be a relatively more suitable one to assess benthic ecological conditions.

• 한국환경과학회지
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• 제3권4호
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• pp.333-348
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• 1994

The groundwater levels at 11 sites and the vertical variations o( the water Quality at 1 site were measured to study the characteristic of the groundwater level fluctuation of Cheju Island. The results of the measurements for the groundwater levels were as follows; In the eastern part, inculding Kimnyong, Jongdal and Sungsan, a sinusoidal fluctuation of groundwater levels occurred in response to oceanic tides. The tidal effect on the groundwater level was reduced depending upon the distance from seashore. But time lag showed that the trend is reversed. However, in the Samyang, Kosan and Shinhyo areas show that the groundwater level was directly influenced by the amount of precipitation. Especially, Shinhyo area which southern part in Cheju was affected the most and show upper parabasal groundwater level. In Susan- I which eastern part in Cheju, well rovealed that water Quality changed with the period of a tide. Salinity at the lim, bellow the natural groundwater level, was approched to the brackish groundwater(1000ppm).

• 한국어류학회지
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• 제21권4호
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• pp.311-321
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• 2009

Three categories (freshwater, amphidromous, and marine fishes) of Taiwanese fishes are analyzed on the basis of zoogeographic elements, viz. China element, Indo-China element, Indo-West Pacific element, Indo-Pacific element, North-Pacific element, Japan-Oregon element, and circumtropical element. Freshwater fishes, which include the China and Indo-China elements, are distributed on part of the boundary area between the Palaearctic and Oriental regions of Wallace (1876). Diadromous fishes include the North-Pacific, Indo-China and Indo-West Pacific elements. Taiwanese salmon, a landlocked (initially diadromous) species that became established in Taiwan between 0.5 my B.P. and the early Pleistocene, is recognized as a distinct taxon included within the Oncorhynchus masou complex, which comprises here three species and two subspecies, viz. Oncorhynchus masou masou (Sancheoneo, Songeo, Sakura-masu or Yamame), O. masou ishikawae (Satsuki-masu or Amago), O. sp. (Biwa-masu), and O. formosanus (Taiwanese salmon), based on molecular, morphological and biological studies. Marine fishes are discussed under the following headings, brackish-water fishes (fishes of brackish waters and seas adjacent to continental coastlines, North Pacific and Indo-West Pacific elements; fishes of brackish waters and seas primarily around islands, Indo-West Pacific element), reef fishes (fishes of inshore reefs along continental coastlines from 0 to ca.100 m depth, Indo-West Pacific element; fishes of inshore reefs primarily around islands from 0 to ca.100 m depth, Indo-West Pacific element; fishes of offshore reefs along continental shelf edges from ca.150 to 300 m depth, circumtropical and Indo-Pacific elements; fishes of offshore reefs primarily around islands from ca.150 to 300 m depth, Indo-Pacific element), demersal fishes (fishes on continental shelves shallower than ca.150 m depth, Indo-West Pacific and Japan-Oregon elements; fishes on edges and upper continental slopes from ca.150 m to 500 m depth, Indo-West Pacific, Indo-Pacific, and circumtropical elements; fishes on lower continental slopes to abyssal plains from ca.500 m to 6,000 m depth, circumtropical element and rarely Indo-Pacific element), pelagic fishes (epipelagic fishes from 0 to ca.150 m depth, Indo-West Pacific, Indo-Pacific or circumtropical elements; meso- and bathypelagic fishes from ca.150 to 3,000 m depth, circumtropical element). The distribution of Taiwanese marine fishes are influenced by the Kuroshio Current, low-salinity and low-temperature waters from mainland China, and sea-bottom topography.