• ALGAE
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• 제27권4호
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• pp.225-234
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• 2012

Zygnema is a conjugating filamentous green algal genus that is distributed in a broad range of freshwater habitats, from sea level to alpine summits. Although more than 150 species have been described worldwide, their taxonomy remains unclear, probably owing to their relatively simple morphology. We investigated the detailed morphology of Korean Zygnema species, combined with analysis of the plastid psbA gene from 22 specimens of the genus and putative relatives, in order to develope a key to their identification and isolation, and to determine their relationships. We recognized two species of Zygnema; Z. insigne and Z. leiospermum, based on morphological characters such as width of the vegetative cell, position of zygospores, dimensions and form of spores, shape of female gametangia, and color of mesospores. The analysis of psbA data was consistent with morphological comparison. The pairwise divergence between two species was 3.7-4.1% (34-38 bp) in psbA sequences. The phylogeny of psbA revealed the monophyly of Z. insigne and Z. leiospermum together with two isolates of Z. circumcarinatum from Germany and Scotland. This is the first report on the psbA gene phylogeny of Zygnema.

• ALGAE
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• 제22권3호
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• pp.193-199
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• 2007

This study was carried out to investigate the charateristics of environmental factors and the species compositions of phytoplanktons and periphytons in order to analyze the marine ecosystem (DOK1-3) with freshwater (Mul) in the coast of Dokdo. Mean values of conductivity (TSD) (44.3 mS cm–1), total dissolved solids (30.9 mg L–1), salinity (31.8 psu), total suspended solids (39.2 mg L–1), and ash-free dry matter (AFDM) (8.8 mg L–1) were higher in DOK1- 3 than those in Mul (3.2 mS cm–1, 2.3 mg L–1, 1.9 psu, 2.8 mg L–1 and 2.8 mg L–1, espectively), while mean amounts of soluble reactive phosphorus (SRP) (7.5 μg P L–1) and soluble reactive silicon (SRS) (0.1 μg Si L–1) were significantly lower in DOK1-3 than those in Mul (117.3 μg P L–1 and 4,105 μg Si L–1, respectively). The phytoplanktons was a total of 59 species in Dokdo, which were composed of 1 species (1.7%) for Chrysophyceae, 43 species (72.9%) for Bacillariophyceae and 15 species (25.4%) for Dinophyceae. The biomass (Chl-a, phaeopigment and AFDM) of epilithic algae (ELA), epizooic algae (EZA) and epiphytic algae (EPA) were varied with the kinds of substrates (EPA > ELA > EZA) in the whole stations. Water environments was comparatively clean in the coast of Dokdo as comparing with those of the land. However, the monitoring of marine ecosystem in the Dokdo should be continued for species conservation according to the global warming by the climatic change.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2830-2832
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• 2011

• 환경생물
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• 제36권3호
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• pp.277-284
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• 2018

In 2017, the freshwater algae were collected from reservoirs, small ponds, soil, and rocks in Korea. Eight taxa of Chlorophyta (Chlorophyceae and Trebouxiophyceae) have been newly reported in Korea. The unrecorded indigenous species were Chlorolobion braunii, Coelastrum pseudomicroporum, Coelastrum reticulatum var. cubanum, Monoraphidium nanum, Tetrachlorella incerta, Ecdysichlamys obliqua, Gloeotila scopulina, and Stichococcus jenerensis.

• 해양환경안전학회지
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• 제22권6호
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• pp.738-749
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• 2016

낙동강 상류지역 건설사업 이후, 식물플랑크톤의 시 공간 분포특성을 파악하기 위해 2013년 2월부터 2015년 12월까지 낙동강 하구둑에서 가덕도 동편에 이르는 수역에서 격월로 환경요인과 식물플랑크톤을 조사하였다. 환경요인은 연간 유의한 차이를 보이지 않았으나, 상 하부수역 및 계절적 차이가 나타났다. 상부수역은 돌말류, 녹조류, 남조류가 하부수역보다 높았고, 특히 담수돌말류와 남조류가 우점하였다. 반면 하부수역은 와편모류가 주로 출현하였다. 상관분석 결과, 상부수역은 Stephanodiscus spp., Asterionellopsis formosa, Microcystis spp.가 주로 담수방류에 의한 인위적인 유입과 관련성이 나타났다. 우점종과 상관관계가 나타난 환경요인은 수온, 풍속, DIP, DIN 등으로 나타났다. 하부수역에서 상위종으로 출현한 와편모류는 대부분 영양염류 및 바람과 상관성이 나타났다. 특히 하부수역에서 Prorocentrum donghaiense은 DIN, 풍속, 강풍발생 일수와 음의 상관성이 나타났고, 하계시기에 집중적으로 출현한다. 유사도와 PCA분석에서도 상부수역은 시기적인 구분이 뚜렷하지 않은 반면 하부수역에서는 계절적인 차이가 발생하였다. 하부수역은 2014년 일부시기를 제외하고, 크게 와편모류가 증가하는 6-8월과 돌말류가 우점하는 10-4월로 구분되었다. 이는 지리적 특성에 의한 담수 방류의 영향범위 차이가 담수종과 영양염류의 유입을 변화시켜 식물플랑크톤 군집특성에 영향을 미치고 있음을 의미한다.

• 환경영향평가
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• 제10권2호
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• pp.109-121
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• 2001

탐진강댐 상류 하천의 본류와 지류에서 부유조류 및 부착조류를 중심으로 조사하였다. DO는 9.0~9.2 mg $O_2/l$ 범위였고, pH와 전기전도도는 각각 7.0~7.1, $98{\sim}100{\mu}S/cm$ 범위였다. 수중 무기영양염 중 $NH_4$와 $NO_3$는 평균값이 각각 $40{\sim}56{\mu}g\;N/l$, $489{\sim}611{\mu}g\;N/l$ 범위로서 $NO_3$가 $NH_4$보다 9~15배 더 풍부하였다. SRP와 SRSi의 평균농도는 각각 $2{\mu}g\;P/l$, 1.6 mg Si/l로서 특히 Si는 강우가 집중된 하계에 다소 많았다. N/P 및 Si/P의 비는 각각 248~261, 640~740 범위로서 담수조류의 생장에 P가 제한영양염으로 추정되었다. 부유조류의 chl-a는 평균값이 $5{\sim}13{\mu}g/l$ 범위였다. 부착조류의 chl-a, 불활성색소 및 유기물 함량의 평균값은 본류에서 각각 $50.3mg/m^2$, $11.9mg/m^2$ 및 $11.5g/m^2$이었고, 지류에서 각각 $30.1mg/m^2$, $5.6mg/m^2$ 및 $7.8g/m^2$로서 본류가 지류보다 1.5~2.1배 높았다. 담수조류의 개체밀도로 본 주요 종조성은 규조류 Achnanthes linearis, A. minutissima, Fragilaria crotonensis, Gomphonema gracile 및 Tabellaria flocculosa였고 남조류는 Microcystis aeruginosa가 해당하였다. 분류군별 비율에서 식물 플랑크톤과 부착조류는 규조류>녹조류>남조류의 순이었고 다른 분류군에 비해 규조류가 월등히 많았다.

• ALGAE
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• 제20권2호
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• pp.113-120
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• 2005

The freshwater blooms mainly blue-green algal blooms occur frequently in the lower Naktong River in summer, which provoke many socio-economical problems; therefore, the early detection of bloom events are demanding through the quantitative and qualitative analyses of blue green algal species. The in vivo fluorescence properties of cultured strains of Microcystis aeruginosa, M. viridis, M. wesenbergii, M. ichthyoblabe, Anabaena cylindrica, A. flos-aquae, and Synedra sp. were investigated. Wild phytoplankton communities of the lower Naktong River were also monitored at four stations in terms of their standing stocks, biomass and fluorescence properties compared with its absorption spectram. The 77K fluorescence emission spectra of each cultured strains normalized at 620 nm was very specific and enabled to detect of blue green algal biomass qualitatively and quantitatively. The relative chlorophyll a concentration determined by chlorophyll fluorescence analysis method showed significant relationship with chlorophyll a concentration determined by solvent extraction method ($R^2$ = 0.906), and the blue-green algal cell number determined by microscopic observation ($R^2$ = 0.588), which gives insight into applications to early detection of blue green algal bloom.

• Fisheries and Aquatic Sciences
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• 제23권6호
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• pp.15.1-15.14
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• 2020

Background: Large rivers are ecological treasures with high human value, but most have experienced decades of degradation from industrial and municipal sewage, row-crop agricultural practices, and hydrologic alteration. We reviewed published analyses of long-term fish diversity publications from three intensively managed large river ecosystems to demonstrate the conservation potential of large river ecosystems. Results: We show how the incorporation of recent advances in river concepts will allow a better understanding of river ecosystem functioning and conservation. Lastly, we focus on the Wabash River ecosystem based on high conservation value and provide a list of actions to maintain and support the ecosystem. In the Wabash River, there were originally 66 species of freshwater mussels, but now only 30 species with reproducing populations remain. Although there were multiple stressors over the last century, the largest change in Wabash River fish biodiversity was associated with rapid increases in municipal nutrient loading and invasive bigheaded carps. Conclusions: Like similarly neglected large river systems worldwide, the Wabash River has a surprising amount of ecological resilience and recovery. For instance, of the 151 native fish species found in the 1800s, only three species have experienced local extinctions, making the modern assemblage more intact than many comparable rivers in the Mississippi River basin. However, not all the changes are positive or support the idea of recovery. Primary production underpins the productivity of these ecosystems, and the Wabash River phytoplankton assemblages shifted from high-quality green algae in the 1970s to lower less nutritional blue-green algae as nutrient and invasive species have recently increased. Our recommendations for the Wabash River and other altered rivers include the restoration of natural hydrology for the mainstem and tributaries, nutrient reductions, mechanisms to restore historical hydrologic patterns, additional sediment controls, and improved local hydraulics.

• ALGAE
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• 제31권1호
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• pp.61-72
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• 2016

Arctic microalgae thrive and support primary production in extremely cold environment. Three Arctic green microalgal strains collected from freshwater near Dasan Station in Ny-Alesund, Svalbard, Arctic, were analyzed to evaluate the optimal growth conditions and contents of fatty acids. The optimal growth temperature for KNF0022, KNF0024, and KNF0032 was between 4 and 8℃. Among the three microalgal strains, KNF0032 showed the maximal cell number of 1.6 × 107 cells mL^-1 at 4℃. The contents of fatty acids in microalgae biomass of KNF0022, KNF0024, and KNF0032 cultured for 75 days were 37.34, 73.25, and 144.35 mg g^-1 dry cell weight, respectively. The common fatty acid methyl esters (FAMEs) analyzed from Arctic green microalgae consisted of palmitic acid methyl ester (C16:0), 5,8,11-heptadecatrienoic acid methyl ester (C17:3), oleic acid methyl ester (C18:1), linoleic acid methyl ester (C18:2), and α-linolenic acid methyl ester (C18:3). KNF0022 had high levels of heptadecanoic acid methyl ester (26.58%) and heptadecatrienoic acid methyl ester (22.17% of the total FAMEs). In KNF0024 and KNF0032, more than 72.09% of the total FAMEs consisted of mono- and polyunsaturated fatty acids. Oleic acid methyl ester from KNF0032 was detected at a high level of 20.13% of the FAMEs. Arctic freshwater microalgae are able to increase the levels of polyunsaturated fatty acids under a wide range of growth temperatures and can also be used to produce valuable industrial materials.

• ALGAE
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• 제30권1호
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• pp.1-13
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• 2015

A new macroscopic riverine red algal species, Lemanea manipurensis sp. nov. (Batrachospermales) is described from Manipur in northeast India. It has a sparsely branched, pseudoparenchymatous thallus with a single, central axial filament that lacks cortical filaments. Spermatangia occur generally in isolated, low and indistinct patches or form an almost continuous ring around the axis. Carposporophytes project into the hollow thallus cavity without an ostiole. The most striking morphological feature is the carposporophyte with very short gonimoblast filaments having cylindrical, narrow and sparsely branched sterile filaments, the terminal cell of each branch with a single, large, elongate carpospore. The widely distributed L. fluviatilis has spherical carpospores in long branched chains. Phylogenetic analysis of rbcL sequence data and comparison with other Batrachospermales clearly show that our specimens do not align with other species of Lemanea and Paralemanea investigated thus far. Five specific names attributed in previous literature (1973-2014) to Lemanea from Manipur, L. australis, L. catenata, L. fluviatilis, L. mamillosa, and L. torulosa are rejected until critical anatomical and molecular evidence is available for specimens from the Manipur river systems. Taxa referable to Paralemanea were not confirmed for India in this study. In view of the high demand for food and medical uses of L. manipurensis in northeast India, conservation measures are needed for its long term survival. The present paper constitutes the first combined morphological / molecular study on a freshwater red alga from India.