• Korean Journal of Ecology and Environment
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• v.54 no.1
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• pp.39-48
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• 2021

In order to control algal bloom, which causes environmental problems such as eutrophication in freshwater ecological environments, many attempts have recently been made using biological approaches. Among them is filtration using bivalve. Algae control with filter-feeding bivalves is emerging as an eco-friendly method. In this study, bivalves collected at Baekje weir in Geum River in Korea from Jun to Sep 2020 were tested to find out the possibility of algae control using filter-feeding bivalves through laboratory experiments. The Unio douglasiae, Anodonta woodiana, and Anodonta arcaeformis collected from Baekje weir were put into a water tank (2 L) containing Clorella vulgaris, and as a result, the average filtration rate was 95.9% per animal after 24 hrs. Calculating this with the Chl-a concentration converted to a calibration curve, it was found that the average of 154.84 ㎍ L^-1 of Chl-a was reduced. Based on this calculation, the possibility that one bivalve can eliminate Chl-a in one month is 0.0005%. It is expected that the effect is 20.14% when there are 40,000 animals. These results indirectly showed how effective bivalve's ability to control Chl-a in their habitat is. Although this study was limited to calculating the algae control ability of aquatic ecosystem based on the filtration rate of bivalve and the corresponding Chl-a reduction rate, it is thought that it will be used as basic data for integrated research from various factors and viewpoints (phytoplankton, aquatic plants, benthic organisms, and sediments) through additional research.

• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.285-290
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• 2018

Six taxa of unrecorded Korean species of charophytes are described. Freshwater and aerial charophytes were collected from the bark of trees, reservoirs, small ponds and swamps from April 2017 to September 2017. The newly recorded species of Korea were Cosmarium quadrifarium f. octastichum, Euastrum turneri, Spondylosium nitens var. triangulare, Staurastrum kouwetsii, Staurodesmus dickiei var. latus, and Klebsormidium subtile. K. subtile was transferred from Stichococcus subtilis.

• Korean Journal of Environmental Agriculture
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• v.5 no.2
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• pp.130-134
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• 1986

This study was performed to determine the aquatic toxicity of 3 chemicals(butachlor, trichlorfon, and BPMC) to 3 teat organisms (fish, crustacean, and algae) which represent each trophic level in freshwater ecosystem, and to compare the sensitivity of these organisms to 3 chemicals with short-term test. Scenedesmus subspicatus, unicellular algae, was the most sensitive species of 3 organisms to butachlor and the ratio between least and most sensitive organisms was 5.7. Moina rectirostris, freshwater invertebrate, was also more sensitive organism than S. subspicatus and Oryzias latipes to trichlorfon and BPMC, and their ratios were 260,000 and 5,090. As a result, remarkable differences were observed in the sensitivities among the test organisms with different chemical structure and mode of action of the chemicals. Therefore, it is recommended that a set of tests on different species, including the representative species of fish, invertebrate, and algae, should be required in short-term aquatic toxicity test for chemicals introduced into the Korean environment.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.289-295
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• 2017

The freshwater algae were collected at reservoirs and small ponds in Gyeonggi-do and Jeju-do on June 2016. Four species of Korean previously unrecorded algae were collected in domestic fresh waters: Coelastrum rugosum, Cosmarium baccatum, Cosmarium norimbergense and Staurastrum connatum var. pseudoamericanum. The morphological characteristics of the four taxa identified in this study were showed mostly similar to the characteristics of the previously reported characteristics. However, Cosmarium baccatum was larger than the previously recorded species and Staurastrum connatum var. pseudoamericanum was wider than the previously recorded species.

• Journal of Ecology and Environment
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• v.36 no.4
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• pp.293-302
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• 2013

The present study summarizes the occurrence, distribution and autecology of 12 taxa of the class Cyanophyceae collected from several swamps, reservoir and highland wetlands in South Korea from 2009 to 2012. A new species, Anabaena koreana sp. nov. and 11 taxa of blue-green algae newly recorded are described and illustrated. Anabaena koreana is similar to A. oumiana, A. spiroides and A. crassa in that the trichomes form regular coils. However, A. koreana is distinguished from these three species by the morphological characteristics of the vegetative cell, heterocyst, and akinet shape and size. This study considers 12 blue-green algal species, including a new species, Anabaena koreana sp. nov. and 11 species that are recorded for the first time in the Korean freshwater algal flora. Among them, the genus Nostochopsis Wood ex Bornet et Flahault 1886 had not previously been recorded in Korea.

• ALGAE
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• v.27 no.2
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• pp.95-108
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• 2012

Using genetic sequencing (COI-5P, LSU, $rbc$L) to elucidate their phylogenetic positions and then morphological characters to distinguish each from existing species, three procumbent species, including two novel species, from warm temperate Northern Hemisphere waters are added to the recently resurrected genus $Halopeltis$ J. Agardh: $H.$ $adnata$ (Okamura) comb. nov. from Korea, $H.$ $pellucida$ sp. nov. from Bermuda and $H.$ $willisii$ sp. nov. from North Carolina, USA. Prior to these reports, the genus was confined to the Southern Hemisphere and tropical equatorial waters of the Northern Hemisphere although the latter records lack molecular confirmation. These three additional species join the six known species presently residing in $Halopeltis$.

• ALGAE
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• v.20 no.4
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• pp.295-298
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• 2005

The growth of subaerial microalgae on historic buildings or various cultural properties causes discoloration and physico-chemical deterioration of the surfaces. We collected a subaerial chlorophyte, Chlorella sp., from the stone Standing Buddha statue at Jungwon Miruksazi, which is a national treasure of Korea, and found dormant, thickwalled spores with regular pentagonal ornamentation along with the vegetative Chlorella cells. The morphology of Chlorella resting spores was compared to that of the other green algal resting cells. The ornamented spores and smooth-walled vegetative cells revived in 2 weeks in a liquid freshwater medium and started reproduction by autospores. To our knowledge, the ability of Chlorella to form ornamented dormant spores in drought condition was not previously recorded. The ornamentation of spores would supplement taxonomic characteristics of this genus.

• ALGAE
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• v.24 no.2
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• pp.57-60
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• 2009

We described a freshwater filamentous zygnematacean species, Zygnema cruciatum (Vaucher) Agardh in Korea,based on light microscopy and scanning electron microscopy. Zygnema cruciatum is characterized by unbranched fil-amcnts of short cylindrical cells, two stellate chloroplasts per cell, a pyrenoid in each chloroplast. Cells are 32-39 $\mu$m in width and 35-50 $\mu$m in length, Conjugation is scalariform and female gametangia are cylindrical or slightlyenlarged. Zygospores are yellow-brown, spherical or broadly ovoid, 35-44 $\mu$m wide and 40-47 $\mu$m long. Under SEM, wall of zygospore has pitted mesospore and pits are 1.4-1.8 $\mu$m in diameter and 3-4 $\mu$m apart from each other.

• ALGAE
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• v.19 no.3
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• pp.271-276
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• 2004

One hundred and fifty four micro algal strains, newly isolated from nationwide freshwaters in Korea, were screened for their anticancer, ant diabetic, and antibiotic activities. The micro algal strains were cultured with different nutritional conditions that were divided into 4 groups as follows; a normal Allen medium, nitrogen (N)-limited medium, phosphorus (P)-limited medium, and N and P-limited medium. Algal biomass was extracted with a mixture of acetone:H₂O (1:1, v:v) and the extracts were used for the screening of bioactive materials. Anticancer, ant diabetic, and antibiotic materials were screened by the methods of vaccinia Hl-related protein tyrosine phosphates (VHR DS-PTPase) inhibition, protein tyrosine phosphates 1B (PTP1B) inhibition, and paper disk. The inhibition activity of VHR DS-PTPase was observed in 18 strains, having a maximum 79% inhibition from Anabaena affinis and the inhibition activity of PTP1B was observed in 9 strains, having a maximum 97% from Sphaerocystis schroeteri. Microcystis aeruginosa incubated in an N and P-limited medium showed antibiotic activity in 8 species out of 13 pathogenic bacteria. As a whole, it seemed that the stressed condition such as N and/or P limitation increased the production of bioactive materials in micro algae.

• ALGAE
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• v.32 no.2
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• pp.131-137
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• 2017

Although green algae of the genus Closterium are considered ideal models for testing toxicity in aquatic ecosystems, little data about the effects of toxicity on these algal species is currently available. Here, Closterium ehrenbergii was used to assess the acute toxicity of copper (Cu). The median effective concentration ($EC_{50}$) of copper sulfate based on a dose response curve was $0.202mg\;L^{-1}$, and reductions in photosynthetic efficiency ($F_v/F_m$ ratio) of cells were observed in cultures exposed to Cu for 6 h, with efficiency significantly reduced after 48 h (p < 0.01). In addition, production of reactive oxygen species significantly increased over time (p < 0.01), leading to damage to intracellular organelles. Our results indicate that Cu induces oxidative stress in cellular metabolic processes and causes severe physiological damage within C. ehrenbergii cells, and even cell death; moreover, they clearly suggest that C. ehrenbergii represents a potentially powerful test model for use in aquatic toxicity assessments.