Research

14 pages, 4522 KiB

Open AccessArticle

Comparative Analysis of Sequence Polymorphism in Complete Organelle Genomes of the ‘Golden Tide’ Seaweed Sargassum horneri between Korean and Chinese Forms

by Seo Yeon Byeon, Kyeong-Sik Cheon, Sangil Kim, Suk-Hyun Yun, Hyun-Ju Oh, Sang Rul Park, Tae-Hoon Kim, Jang Kyun Kim and Hyuk Je Lee

Sustainability 2020, 12(18), 7280; https://doi.org/10.3390/su12187280 - 04 Sep 2020

Cited by 6 | Viewed by 2829

Abstract

Drifting and inundating brown seaweed Sargassum horneri biomass is called “golden tide”, as it resembles golden massive algal blooms like green tides. This phenomenon occurs globally and its serious ecological impacts on coastal ecosystems have recently begun to be paid attention to. In [...] Read more.

Drifting and inundating brown seaweed Sargassum horneri biomass is called “golden tide”, as it resembles golden massive algal blooms like green tides. This phenomenon occurs globally and its serious ecological impacts on coastal ecosystems have recently begun to be paid attention to. In the present study, by sequencing whole organelle genomes of Korean indigenous S. horneri, we aimed to develop novel molecular markers that can be used for differentiating indigenous from nonindigenous individuals. To this end, we analyzed sequence polymorphisms in mitochondrial (mt) and chloroplast (cp) genomes of two Korean benthic samples in comparison to Chinese ones as a reference. We mapped mt genomes of 34,620~34,628 bp and cp genomes of 123,982~124,053 bp for the Korean samples. In comparative analyses, mtDNA cytochrome c oxidase subunit II (cox2) gene showed the highest number of single nucleotide polymorphisms (SNPs) between Korean and Chinese individuals. NADH dehydrogenase subunit 7 (Nad7)-proline tRNA (trnP) intergenic spacer (IGS) in the mt genome showed a 14 bp insertion or deletion (indel) mutation. For the cp genome, we found a total of 54 SNPs, but its overall evolution rate was approximately four-fold lower than the mt genome. Interestingly, analysis of Ka/Ks ratio in the cp genome revealed a signature of positive selection on several genes, although only negative selection prevalent in mt genome. The ‘candidate’ genetic markers that we found can be applied to discriminate between Korean indigenous and nonindigenous individuals. This study will assist in developing a molecular-based early detection method for effectively managing nonindigenous S. horneri in Korean waters. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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13 pages, 7761 KiB

Open AccessArticle

Variations in the Temporal and Spatial Distribution of Microalgae in Aquatic Environments Associated with an Artificial Weir

by Suk Min Yun, Sang Deuk Lee, Pyo Yun Cho, Seung Won Nam, Dae Ryul Kwon, Chung Hyun Choi, Jin-Young Kim and Jong-Suk Lee

Sustainability 2020, 12(16), 6442; https://doi.org/10.3390/su12166442 - 10 Aug 2020

Cited by 1 | Viewed by 1938

Abstract

The construction of weirs causes changes in the aquatic environment and affects several aquatic organisms. To understand the ecosystem in the Sangju Weir, Gyeongsangbuk-do Province, variations in the spatiotemporal distribution and composition of microalgae communities were analyzed. Microalgae were collected fortnightly from April [...] Read more.

The construction of weirs causes changes in the aquatic environment and affects several aquatic organisms. To understand the ecosystem in the Sangju Weir, Gyeongsangbuk-do Province, variations in the spatiotemporal distribution and composition of microalgae communities were analyzed. Microalgae were collected fortnightly from April to November 2018 from six sites in the Nakdonggang River. There was significant variation in environmental factors, microalgal community structure, and flora. Microalgae communities were dominated by diatoms (e.g., Fragilariacrotonensis, Ulnariaacus, and Aulacoseiraambigua), green algae (e.g., genera Eudorina and Desmodesmus), cyanobacteria (e.g., genera Anabaena and Microcystis). Multidimensional scaling indicated that species composition and diversity were generally similar among sites but varied between the bottom and the surface and middle water layers. Vertical migration of microalgae was difficult to investigate because of the thermocline in the study area and high turbidity in the lower layer. The distribution of microalgae was little affected by the construction of the weir, but the formation of thermocline changed microalgae communities in the water layer. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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21 pages, 5181 KiB

Open AccessArticle

Key Factors Controlling Primary Production and Cyanobacterial Harmful Algal Blooms (cHABs) in a Continuous Weir System in the Nakdong River, Korea

by Jisoo Choi, Jun Oh Min, Bohyung Choi, Dokyun Kim, Jae Joong Kang, Sang Heon Lee, Kwangsoon Choi, Heesuk Lee, Jinyoung Jung and Kyung-Hoon Shin

Sustainability 2020, 12(15), 6224; https://doi.org/10.3390/su12156224 - 03 Aug 2020

Cited by 3 | Viewed by 3017

Abstract

To identify key factors that control primary production (P.P.) and trigger cyanobacterial harmful algal blooms (cHABs), we investigated spatio-temporal variations in P.P. in a continuous weir system in the Nakdong River once or twice a month from April to October 2018. P.P. was [...] Read more.

To identify key factors that control primary production (P.P.) and trigger cyanobacterial harmful algal blooms (cHABs), we investigated spatio-temporal variations in P.P. in a continuous weir system in the Nakdong River once or twice a month from April to October 2018. P.P. was measured through an in-situ incubation experiment using a ¹³C tracer. Relative proportion of pigment-based phytoplankton composition was calculated by the CHEMTAX program based on pigment analysis using a high-performance liquid chromatography (HPLC). P.P. was higher in spring (1130 ± 1140 mg C m⁻² d⁻¹) and summer (1060 ± 814 mg C m⁻² d⁻¹) than autumn (180 ± 220 mg C m⁻² d⁻¹), and tended to increase downstream. P.P. was negatively related to PO₄³⁻ (r = −0.41, p < 0.01) due to utilization by phytoplankton during the spring and summer when it was high. The relative proportion of pigment-based cyanobacteria (mainly Microcystis sp.) was positively correlated with water temperature (r = 0.79, p < 0.01) and hydraulic retention time (HRT, r = 0.67, p < 0.01), suggesting that these two factors should affect cHABs in summer. Therefore, to control HRT could be one of the solutions for reducing cHABs in a continuous weir system. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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Graphical abstract

9 pages, 2070 KiB

Open AccessCommunication

Effective Harmful Organism Management I: Fabrication of Facile and Robust Superhydrophobic Coating on Fabric

by Chang-Ho Choi, Yeongwon Kwak, Min Kyung Kim and Dong Gun Kim

Sustainability 2020, 12(15), 5876; https://doi.org/10.3390/su12155876 - 22 Jul 2020

Cited by 5 | Viewed by 2042

Abstract

Advances in harmful organism management are highly demanding due to the toxicity of conventional coating approaches. Exploiting biomimetic superhydrophobicity could be a promising alternative on account of its cost-effectiveness and eco-friendliness. Here, we introduce a facile method to fabricate a robust superhydrophobic coating [...] Read more.

Advances in harmful organism management are highly demanding due to the toxicity of conventional coating approaches. Exploiting biomimetic superhydrophobicity could be a promising alternative on account of its cost-effectiveness and eco-friendliness. Here, we introduce a facile method to fabricate a robust superhydrophobic coating on a fabric substrate. This is achieved by sequentially spraying TiO₂-epoxy resin nanocomposite material and fluorocarbon-silane modified SiO₂ nanoparticles (FC-silane SiO₂ NPs). The superhydrophobicity is attributed to the nanoparticles constituting a micro/nano hierarchical structure and the fluorocarbon of the modified SiO₂ NPs lowering the surface energy. The epoxy resin embedded in the coating layer plays an important role in improving the robustness. The robustness of the superhydrophobic surface is demonstrated by measuring the water slide angle of surfaces that are subject to salty water at 500 rpm stirring condition for up to 13 days. This study focuses on ensuring the superhydrophobicity and robustness of the coating surface, which is preliminary work for the practical management of macrofoulers. Based on this work, we will perform practical harmful organism management in seawater as a second research subject. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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14 pages, 2174 KiB

Open AccessArticle

Temporal and Spatial Distribution of the Toxic Epiphytic Dinoflagellate Ostreopsis cf. ovata in the Coastal Waters off Jeju Island, Korea

by Jaeyeon Park, Jinik Hwang, Jun-Ho Hyung and Eun Young Yoon

Sustainability 2020, 12(14), 5864; https://doi.org/10.3390/su12145864 - 21 Jul 2020

Cited by 7 | Viewed by 2534

Abstract

The temporal and spatial distribution of the toxic epiphytic dinoflagellate Ostreopsis cf. ovata was investigated off the Jeju coastal waters, Korea, from July 2016 to January 2019. The results showed that the presence of Ostreopsis cf. ovata in 184 macroalgae was 79.3%, and [...] Read more.

The temporal and spatial distribution of the toxic epiphytic dinoflagellate Ostreopsis cf. ovata was investigated off the Jeju coastal waters, Korea, from July 2016 to January 2019. The results showed that the presence of Ostreopsis cf. ovata in 184 macroalgae was 79.3%, and it was more frequently attached to red algae and brown algae than to green algae. The abundance of Ostreopsis cf. ovata as determined by quantitative real-time polymerase chain reactions (qPCR) and microscopic analysis was 4–3204 cells g⁻¹, and the maximum abundance observed in September 2018, when the water temperature was 24.4 °C. The abundance was higher in summer and autumn than in spring and winter. Spatially, high abundance was observed in autumn on the northern coast of Jeju Island and, in summer, in the southern and eastern coastal waters. The water temperature of Jeju coastal waters in winter remained higher than 15 °C, and this species could be overwintering in the Jeju waters. Therefore, further monitoring and research are needed to evaluate the proliferation of Ostreopsis cf. ovata, which contains a novel toxin with unidentified effects on humans. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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13 pages, 3538 KiB

Open AccessArticle

Comparison of Distribution and Density of Nemopilema nomurai by Water Columns Using Echo Counting and Echo Integration Methods

by Kyoung Yeon Kim, Weol Ae Lim, Jinho Chae, Gunhee Sung, Wooseok Oh and Kyounghoon Lee

Sustainability 2020, 12(14), 5823; https://doi.org/10.3390/su12145823 - 20 Jul 2020

Cited by 1 | Viewed by 1787

Abstract

In this study, the distribution of Nemopilema nomurai in the waters of Mijo-myeon, Namhae and Gijang-gun, Busan was analyzed; furthermore, echo counting and echo integration methods were used to compare the distribution density. The acoustic system used in the study was a split [...] Read more.

In this study, the distribution of Nemopilema nomurai in the waters of Mijo-myeon, Namhae and Gijang-gun, Busan was analyzed; furthermore, echo counting and echo integration methods were used to compare the distribution density. The acoustic system used in the study was a split beam scientific echosounder operating at 38 and 120 kHz (EK-60, Simrad, Norway). Echo counting and echo integration methods were used to determine the density of N. nomurai distributed in the survey areas. The distribution of N. nomurai by water columns, estimated using an echo counting method, was concentrated at approximately 10 m deep in the waters of Mijo, Namhae and 10–50 m deep in the waters of Gijang, Busan; moreover, the distributed depth varied by the surveyed date and time. It was shown that analyzing the acoustic scattering strength of jellyfish obtained from the echo counting method would be more effective for distributional survey of N. nomurai with two frequency system. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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14 pages, 3279 KiB

Open AccessArticle

Density Estimation of Antarctic Krill in the South Shetland Island (Subarea 48.1) Using dB-Difference Method

by Seok-Gwan Choi, Jinho Chae, Sangdeuk Chung, Wooseok Oh, Euna Yoon, Gunhee Sung and Kyounghoon Lee

Sustainability 2020, 12(14), 5701; https://doi.org/10.3390/su12145701 - 15 Jul 2020

Cited by 2 | Viewed by 2039

Abstract

This study is aimed to estimate the density of Antarctic krill that inhabit in the area around South Shetland Island by using a dB-difference method. An acoustic survey was conducted from 13 to 24 April in 2016 in the sea of South Shetland. [...] Read more.

This study is aimed to estimate the density of Antarctic krill that inhabit in the area around South Shetland Island by using a dB-difference method. An acoustic survey was conducted from 13 to 24 April in 2016 in the sea of South Shetland. Acoustic data on frequency 38 and 120 kHz were collected. The Antarctic krill echo was extracted for the S_{V120-38 kHz} range of 0.4–14.3 dB, which was obtained by applying the size of the collected Antarctic krill in this study (25–60 mm). The mean Antarctic krill density across the survey area was 33.65 g m⁻² (CV = 45.97%). Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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13 pages, 1882 KiB

Open AccessArticle

Environmental Risk Assessment of Living Modified Microorganisms (LMM) on the Indigenous Microbial Community

by Hyosun Lee, Dong-Uk Kim, Jigwan Son, Seong-Bo Kim and Jong-Ok Ka

Sustainability 2020, 12(14), 5566; https://doi.org/10.3390/su12145566 - 10 Jul 2020

Cited by 1 | Viewed by 2346

Abstract

Recent advance of biotechnology enabled development of various living modified microorganisms (LMMs) uses in the field of environmental remediation, food industry, biopesticide, and so on. Consequently, such LMMs have the potential to be released into the natural environment, either intentionally or unintentionally, or [...] Read more.

Recent advance of biotechnology enabled development of various living modified microorganisms (LMMs) uses in the field of environmental remediation, food industry, biopesticide, and so on. Consequently, such LMMs have the potential to be released into the natural environment, either intentionally or unintentionally, or exposed to the natural ecosystem during the applications. To investigate the unintended effects of LMMs on soil microorganism populations and communities, microcosm study was conducted using the recombinant microorganism, Corynebacterium glutamicum SEM002 carrying the D-psicose-3-epimerase from Agrobacterium tumefaciens as a model LMM. In addition, potential gene transfer from the LMMs into the soil environment in the microcosm was examined. As a result, small differences in LMMs were observed in populations of soil microorganism such as total bacteria, kanamycin-resistant bacteria, total fungi and total actinomycete. Also, more than 93% of the kanamycin resistance gene from the LMMs was degraded in the microcosm during the 90 days. On the basis of the experimental results, the LMMs showed no distinct impact on soil microorganism populations and communities. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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12 pages, 1321 KiB

Open AccessArticle

Genetic and Morphologic Variation in a Potential Mosquito Biocontrol Agent, Hydrochara Affinis (Coleoptera: Hydrophilidae)

by Ji Hyoun Kang, Changseob Lim, Sung Hwan Park, Wang Gyu Kim, Nattawut Sareein and Yeon Jae Bae

Sustainability 2020, 12(13), 5481; https://doi.org/10.3390/su12135481 - 07 Jul 2020

Cited by 4 | Viewed by 2499

Abstract

Hydrochara affinis (Coleoptera: Hydrophilidae), a water scavenger beetle, was recently identified as a natural and effective agent for biological mosquito control; it was reported to exhibit high rates of mosquito larvae predation. However, maintaining the quality (i.e., natural ecological attributes, such as genetic [...] Read more.

Hydrochara affinis (Coleoptera: Hydrophilidae), a water scavenger beetle, was recently identified as a natural and effective agent for biological mosquito control; it was reported to exhibit high rates of mosquito larvae predation. However, maintaining the quality (i.e., natural ecological attributes, such as genetic variation) of laboratory-reared populations is essential for ensuring the long-term success of biological control programs. Accordingly, here, we aimed to use mitochondrial Cytochrome c oxidase subunit I (COI) sequences to document the genetic diversity, population structure, and phylogenetic position of natural and lab-reared H. affinis populations in South Korea and use geometric morphometric analysis to investigate the populations’ morphological divergence. The natural H. affinis populations possessed high genetic diversity and numerous COI haplotypes, suggesting that these populations were healthy and could be directly applied to mosquito habitats without alterations to their natural genetic attributes. The lab-reared populations also possessed high genetic diversity and, thus, the potential for high adaptive capacity to new environments. Although no distinct population genetic structures were observed, quantitative variation was observed in the body shape of both the natural and lab-reared populations. The high levels of genetic and morphologic variation observed in the H. affinis populations examined here indicate the species’ favorable conservation status, genetic diversity, adaptive capacity, and, thus, “suitability” for field application as an effective mosquito control agent. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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25 pages, 2567 KiB

Open AccessArticle

Nitrogen Deficiency-Dependent Abiotic Stress Enhances Carotenoid Production in Indigenous Green Microalga Scenedesmus rubescens KNUA042, for Use as a Potential Resource of High Value Products

by Seung-Woo Jo, Ji Won Hong, Jeong-Mi Do, Ho Na, Jin-Ju Kim, Seong-Im Park, Young-Saeng Kim, Il-Sup Kim and Ho-Sung Yoon

Sustainability 2020, 12(13), 5445; https://doi.org/10.3390/su12135445 - 06 Jul 2020

Cited by 18 | Viewed by 3258

Abstract

The microalgal strain Scenedesmus rubescens KNUA042 was identified in freshwater in Korea and characterized by evaluating its stress responses in an effort to increase lipid and carotenoid production. Under a two-stage cultivation process, the algal strain that generally exhibits optimal growth at a [...] Read more.

The microalgal strain Scenedesmus rubescens KNUA042 was identified in freshwater in Korea and characterized by evaluating its stress responses in an effort to increase lipid and carotenoid production. Under a two-stage cultivation process, the algal strain that generally exhibits optimal growth at a nitrate (source of nitrogen) concentration of 0.25 g L⁻¹ was challenged to different exogenous stimuli—salinity (S), light intensity (L), combined L and S (LS), and nitrogen deficiency (C)—for 14 days. Lipid production and carotenoid concentration increased in a time-dependent manner under these physicochemical conditions during the culture periods. Lipid accumulation was confirmed by thin layer chromatography, BODIPY staining, and fatty acid composition analysis, which showed no differences in the algal cells tested under all four (C, S, L, and LS) conditions. The quality of biodiesel produced from the biomass of the algal cells met the American Society for Testing and Materials and the European standards. Total carotenoid content was increased in the LS-treated algal cells (6.94 mg L⁻¹) compared with that in the C-, S-, and L-treated algal cells 1.75, 4.15, and 1.32 mg L⁻¹, respectively). Accordingly, the concentration of canthaxanthin and astaxanthin was also maximized in the LS-treated algal cells at 1.73 and 1.11 mg g⁻¹, respectively, whereas lutein showed no differences in the cells analyzed. Conversely, chlorophyll a level was similar among the C-, S-, and LS-treated algal cells, except for the L-treated algal cells. Thus, our results suggested that S. rubescens KNUA042 was capable of producing carotenoid molecules, which led to the maximum values of canthaxanthin and astaxanthin concentrations when exposed to the combined LS condition compared with that observed when exposed to the salinity condition alone. This indicates that the algal strain could be used for the production of high-value products as well as biofuel. Furthermore, this article provides the first evidence of carotenoid production in S. rubescens KNUA042. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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12 pages, 1707 KiB

Open AccessArticle

Effects of Different Nutrient and Trace Metal Concentrations on Growth of the Toxic Dinoflagellate Gymnodinium catenatum Isolated from Korean Coastal Waters

by Kyong Ha Han, Hyun Jung Kim, Zhun Li, Joo Yeon Youn, Kyeong Yoon Kwak, Min Ho Seo, Jinik Hwang, Sang Deuk Lee, Suk Min Yun, Seok Jin Oh, Jong Woo Park, Weol-Ae Lim and Hyeon Ho Shin

Sustainability 2020, 12(12), 4992; https://doi.org/10.3390/su12124992 - 18 Jun 2020

Cited by 6 | Viewed by 3720

Abstract

The effects of the addition of nutrients (nitrate: N; phosphate: P; and vitamin B₁) and trace metals (iron: Fe; Copper: Cu; and selenium: Se) on the growth of Gymnodinium catenatum, which was isolated from Korean coastal waters, were investigated. The [...] Read more.

The effects of the addition of nutrients (nitrate: N; phosphate: P; and vitamin B₁) and trace metals (iron: Fe; Copper: Cu; and selenium: Se) on the growth of Gymnodinium catenatum, which was isolated from Korean coastal waters, were investigated. The Korean isolate of G. catenatum grew under a wide range of concentrations of N and P. Whilst high concentrations of N (> N: P ratio of 23.5) did not stimulate the growth rate, an enhanced growth rate and cell density were observed with the addition of P. The experimental addition of vitamin B₁ revealed that G. catenatum is not dependent on vitamin B₁ for growth. Moreover, the addition of Fe and Cu resulted in no significant differences in the growth patterns and rates of G. catenatum between the controls and treatments. It is thus possible that growth of the Korean isolate of G. catenatum does not require high concentrations of Fe and Cu. However, the cell densities were enhanced in the stationary phases of treatments upon addition of Se, and the maximum cell densities were higher than those in the culture experiments upon additions of other nutrient and trace metals. Our findings indicate that G. catenatum prefers P and Se for proliferation, rather than other nutritional sources. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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12 pages, 2045 KiB

Open AccessArticle

Adsorption Strategy for Removal of Harmful Cyanobacterial Species Microcystis aeruginosa Using Chitosan Fiber

by Yun Hwan Park, Sok Kim, Ho Seon Kim, Chulhwan Park and Yoon-E Choi

Sustainability 2020, 12(11), 4587; https://doi.org/10.3390/su12114587 - 04 Jun 2020

Cited by 22 | Viewed by 2890

Abstract

Microcystis aeruginosa is one of the predominant species responsible for cyanobacterial-harmful algal blooms (Cyano-HABs) in water bodies. Cyano-HABs pose a growing number of serious threats to the environment and public health. Therefore, the demand for developing safe and eco-friendly solutions to control Cyano-HABs [...] Read more.

Microcystis aeruginosa is one of the predominant species responsible for cyanobacterial-harmful algal blooms (Cyano-HABs) in water bodies. Cyano-HABs pose a growing number of serious threats to the environment and public health. Therefore, the demand for developing safe and eco-friendly solutions to control Cyano-HABs is increasing. In the present study, the adsorptive strategy using chitosan was applied to remove M. aeruginosa cells from aqueous phases. Using a simple immobilization process, chitosan could be fabricated as a fiber sorbent (chitosan fiber, CF). By application of CF, almost 89% of cyanobacterial cells were eliminated, as compared to those in the control group. Field emission scanning electron microscopy proved that the M. aeruginosa cells were mainly attached to the surface of the sorbent, which was correlated well with the measurement of the surface area of the fiber. We tested the hypothesis that massive applications of the fabricated CF to control Cyano-HABs might cause environmental damage. However, the manufactured CF displayed negligible toxicity. Moreover, we observed that the release of cyanotoxins and microcystins (MCs), during the removal process using CF, could be efficiently prevented by a firm attachment of the M. aeruginosa cells without cell lysis. Our results suggest the possibility of controlling Cyano-HABs using a fabricated CF as a non-toxic and eco-friendly agent for scaled-up applications. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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12 pages, 1103 KiB

Open AccessArticle

The Influence of Manila Clam (Ruditapes philippinarum) on Macrobenthos Communities in a Korean Tidal Ecosystem

by Sang Lyeol Kim, Hyung Gon Lee, Su Min Kang and Ok Hwan Yu

Sustainability 2020, 12(10), 4205; https://doi.org/10.3390/su12104205 - 20 May 2020

Cited by 4 | Viewed by 2971

Abstract

We investigated the biological impact of extensive Manila clam (Ruditapes philippinarum) aquaculture on macrobenthic communities in a tidal ecosystem in Korea. We collected macrobenthos (>1 mm in length) samples seasonally in the intertidal zone in Geunsoman, Taean, Korea from April 2011 [...] Read more.

We investigated the biological impact of extensive Manila clam (Ruditapes philippinarum) aquaculture on macrobenthic communities in a tidal ecosystem in Korea. We collected macrobenthos (>1 mm in length) samples seasonally in the intertidal zone in Geunsoman, Taean, Korea from April 2011 to December 2014. We identified 146 macrobenthos species, including 60 polychaetes, 53 crustaceans, and 16 mollusks. A biota–environment matching (BIO–ENV) analysis indicated that the benthic community was affected by mean sediment grain size (Mz), total organic carbon (TOC), and R. philippinarum biomass. We found no correlation between R. philippinarum and the main dominant species (Heteromastus filiformis, Ceratonereis erythraeensis, and Ampharete arctica), which have a different feeding strategy; thus, this may result in a lack of competition for food resources. In addition, we found that flourishing R. philippinarum positively affects the macrobenthos density but negatively affects the biodiversity index. Moreover, competition between species does not occur clearly, and environmental variables (sediment, organic carbon) are important. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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10 pages, 1532 KiB

Open AccessArticle

Current Distribution and Status of Non-Native Freshwater Turtles in the Wild, Republic of Korea

by Kyo Soung Koo, Soorim Song, Jae Hyeok Choi and Ha-Cheol Sung

Sustainability 2020, 12(10), 4042; https://doi.org/10.3390/su12104042 - 14 May 2020

Cited by 15 | Viewed by 3119

Abstract

Globally, an increase in the transportation and expansion of the pet market is the most important cause of the invasion of non-native species. Invasion of non-native species disturbs native ecosystems and leads to socio-economic problems. The pet trade involving turtles has been globally [...] Read more.

Globally, an increase in the transportation and expansion of the pet market is the most important cause of the invasion of non-native species. Invasion of non-native species disturbs native ecosystems and leads to socio-economic problems. The pet trade involving turtles has been globally recognized as the route through which non-native species enter ecosystems. As a result, the invasion of non-native turtles worldwide is causing problems such as competition, predation, transmission of parasites, and hybridization with native turtles. Every year, both the number of non-native turtles imported as pets in the Republic of Korea and the number of introduced species found in the wild is increasing. However, the current status of non-native turtles in the wild is not well known, posing major challenges to their management. In this study, we aimed to determine the current status of non-native turtles introduced into the wild in Korea. We analyzed the factors associated with the detection and distribution of non-native turtles. In total, 1587 of non-native turtles (three families, six genera, and 13 species including subspecies) were found in 648 sites in Korea: Chelydra serpentina, Mauremys sinensis, Chrysemys picta bellii, Graptemys ouachitensis, G. pseudogeographica pseudogeographica, G. p. kohni, Pseudemys concinna, P. nelsoni, P. peninsularis, P. rubriventris, Trachemys scripta elegans, T. s. scripta, and T. s. troostii. There was relationship between the distribution of non-native turtles and environmental factors such as precipitation and temperature. Moreover, human factors such as number of human populations and size of region were significantly related with the distribution and number of non-native turtles. In conclusion, it is likely that human factors are associated with the influx of invasive turtles to the natural habitat, while the possibility of survival and adaption for the turtles is associated mainly with environmental factors. Our result will be an essential guideline not only for understanding the current status of non-native turtles in Korea, but also for establishing strategies for management and control. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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16 pages, 4432 KiB

Open AccessArticle

First Report of the Dinoflagellate Genus Effrenium in the East Sea of Korea: Morphological, Genetic, and Fatty Acid Characteristics

by Nam Seon Kang, Eun Song Kim, Jung A Lee, Kyeong Mi Kim, Min Seok Kwak, Moongeun Yoon and Ji Won Hong

Sustainability 2020, 12(9), 3928; https://doi.org/10.3390/su12093928 - 11 May 2020

Cited by 5 | Viewed by 2858

Abstract

Most species in the family Symbiodiniaceae are symbiotic partners to invertebrate and protist hosts, but a few live freely in water columns. Here, a free-living dinoflagellate was isolated from the waters off the Dokdo Islands in the East Sea of Korea. Morphological and [...] Read more.

Most species in the family Symbiodiniaceae are symbiotic partners to invertebrate and protist hosts, but a few live freely in water columns. Here, a free-living dinoflagellate was isolated from the waters off the Dokdo Islands in the East Sea of Korea. Morphological and molecular analyses show this isolate belongs to Effrenium voratum. Prior to the present study, E. voratum had been reported to live in the waters in the temperate latitudes in the western North Pacific, the southwest Western Pacific, the eastern North Pacific, the eastern Atlantic, and the Mediterranean Sea. To our knowledge, this is the highest latitude in the western North Pacific, where E. voratum has been reported. This report extends the known range of this dinoflagellate to the temperate waters of the western North Pacific Ocean. The sequence of the D1/D2 region of the large subunit ribosomal DNA (LSU rDNA) was identical to E. voratum found in Jeju Island, Korea, Tsushima Island, Japan, and Cook Strait, New Zealand, suggesting this species is cosmopolitan. However, it was different by 1 bp from those found in Blanes, Spain and Santa Barbara, USA. In the phylogenetic tree built on the basis of the LSU (D1-D2) rDNA region sequences, this dinoflagellate was clustered within a clade, including all the other E. voratum strains. Morphological characteristics were like those of strains found in the waters of Jeju Island. This is the first report conducted on the fatty acid profile of fully characterized E. voratum. Importantly, the isolate possessed a high ratio of long-chain omega-3 polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) relative to total lipid. This dinoflagellate could be a candidate for commercial applications, such as aquaculture feed and essential omega-3 PUFA productions. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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15 pages, 1398 KiB

Open AccessArticle

Population Dynamics of the ‘Golden Tides’ Seaweed, Sargassum horneri, on the Southwestern Coast of Korea: The Extent and Formation of Golden Tides

by Sun Kyeong Choi, Hyun-Ju Oh, Suk-Hyun Yun, Hyuk Je Lee, Kyounghoon Lee, Young Seok Han, Sangil Kim and Sang Rul Park

Sustainability 2020, 12(7), 2903; https://doi.org/10.3390/su12072903 - 06 Apr 2020

Cited by 19 | Viewed by 3446

Abstract

Since 2015, troublesome masses of floating Sargassum horneri have been introduced via ocean currents and winds to the southwestern coastline of Korea, including Jeju Island. These massive mats have caused considerable damage to the aquaculture industry, tourism, and the marine ecosystem. Most previous [...] Read more.

Since 2015, troublesome masses of floating Sargassum horneri have been introduced via ocean currents and winds to the southwestern coastline of Korea, including Jeju Island. These massive mats have caused considerable damage to the aquaculture industry, tourism, and the marine ecosystem. Most previous studies of S. horneri have focused on cultivation, the development of gene markers, and photosynthetic activity, but few data on population dynamics are available. We investigated the population dynamics of native S. horneri off the southwestern coast of Korea with the aim of predicting the formation of golden tides. Populations at two sites had obligate annual life cycles. Thalli were recruited during the period September–November, grew during the period December–April, and senesced by July. This pattern reflected seasonal trends in water temperature. Specific growth rates and heights of the thalli at Munseom were significantly higher than those at Jindo. The greatest environmental difference between the two sites is probably the degree of exposure to wave action. Mortality density (thalli lost per unit area) in the Munseom population was highest during the period December–January (i.e., 2–3 months after recruitment) and in March. Most thalli in the Jindo population died off in July when water temperatures increased. The maximum average biomass of S. horneri thalli detaching from the substrata reached 1.6 kg fresh weight m^–2 during January and March. Thus, large-scale drifting mats were formed by S. horneri detachment from the substrata. Despite the differences in space and environment between China and Korea, our findings will enable quantitative assessments of the overall floating Sargassum biomass in the East China and Yellow Seas. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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21 pages, 6912 KiB

Open AccessArticle

Variation in Phytoplankton Community Due to an Autumn Typhoon and Winter Water Turbulence in Southern Korean Coastal Waters

by Seung Ho Baek, Minji Lee, Bum Soo Park and Young Kyun Lim

Sustainability 2020, 12(7), 2781; https://doi.org/10.3390/su12072781 - 01 Apr 2020

Cited by 24 | Viewed by 2685

Abstract

We evaluated changes in the phytoplankton community in Korean coastal waters during October 2016 and February 2017. Typhoon Chaba introduced a large amount of freshwater into the coastal areas during autumn 2016, and there was a significant negative relationship between salinity and nutrients [...] Read more.

We evaluated changes in the phytoplankton community in Korean coastal waters during October 2016 and February 2017. Typhoon Chaba introduced a large amount of freshwater into the coastal areas during autumn 2016, and there was a significant negative relationship between salinity and nutrients in the Nakdong estuarine area, particularly in the northeastern area (Zone III; p < 0.001). The abundance of diatom species, mainly Chaetoceros spp., increased after this nutrient loading, whereas Cryptomonas spp. appeared as opportunists when there was relatively low diatom biomass. During winter, biotic and abiotic factors did not differ among the surface, middle, and lower layers (p > 0.01; ANOVA), implying that water mixing by winter windstorms and low surface temperature (due to the sinking of high-density water) physically accelerated mixing of the whole water column. Diatoms predominated under these conditions. Among diatoms, the centric diatom Eucampia zodiacus remained at high density at the inshore area and its abundance had a negative correlation with water temperature, implying that this species can grow at cold temperatures. On the other hand, the harmful freshwater diatom Stephanodiscus hantzschii mainly appeared in conditions with low salinity and high nutrients, implying that it can persist even in the saltwater conditions of the Nakdong Estuary. Our results indicate that hydro-oceanographic characteristics, such as river discharge after an autumn typhoon and winter water turbulence, have major effects on the composition of phytoplankton communities and can potentially affect the occurrence and characteristics of harmful algal blooms in southern Korean coastal waters. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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17 pages, 3053 KiB

Open AccessArticle

Environmental DNA and Specific Primers for Detecting the Invasive Species Ectopleura crocea (Hydrozoa: Anthoathecata) in Seawater Samples

by Philjae Kim, Tae Joong Yoon and Sook Shin

Sustainability 2020, 12(6), 2360; https://doi.org/10.3390/su12062360 - 18 Mar 2020

Cited by 5 | Viewed by 3237

Abstract

In marine environments, environmental DNA (eDNA) can be effectively detected and possibly quantified when combined with molecular techniques, as demonstrated by several recent studies. In this study, we developed a species-specific primer set and a probe to detect the distribution and biomass of [...] Read more.

In marine environments, environmental DNA (eDNA) can be effectively detected and possibly quantified when combined with molecular techniques, as demonstrated by several recent studies. In this study, we developed a species-specific primer set and a probe to detect the distribution and biomass of an invasive hydrozoan in South Korea, Ectopleura crocea. These molecular markers were designed to amplify a 187 bp region based on mitochondrial cytochrome c oxidase subunit I (COI) of E. crocea and were tested on seawater samples from 35 Korean harbors in 2017. Of the 35 sites we investigated, only nine harbors returned positive detections when using traditional survey methods, while surveys based on the use of eDNA techniques detected E. crocea DNA in all seawater samples. These results suggest that eDNA surveys based on molecular techniques are more effective at identifying species distribution and estimating biomass than traditional surveys based on visual assessment of morphology. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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19 pages, 3155 KiB

Open AccessFeature PaperArticle

Comparison of HPLC Pigment Analysis and Microscopy in Phytoplankton Assessment in the Seomjin River Estuary, Korea

by Minji Lee, Nam-Il Won and Seung Ho Baek

Sustainability 2020, 12(4), 1675; https://doi.org/10.3390/su12041675 - 24 Feb 2020

Cited by 10 | Viewed by 3650

Abstract

The distribution of microalgal species in estuaries shows marked gradients because of the mixing of marine and fresh water during tidal exchanges. To assess the spatio-temporal distribution of phytoplankton in the Seomjin River estuary (SRE), Korea, we investigated the seasonal phytoplankton communities along [...] Read more.

The distribution of microalgal species in estuaries shows marked gradients because of the mixing of marine and fresh water during tidal exchanges. To assess the spatio-temporal distribution of phytoplankton in the Seomjin River estuary (SRE), Korea, we investigated the seasonal phytoplankton communities along a salinity gradient in the estuary using both high performance liquid chromatography (HPLC) pigment analysis and light microscopy. Both types of analysis indicated that marine planktonic diatoms generally dominated at downstream sites having salinities >10, whereas freshwater species dominated at upstream sites having salinities <5. High levels of the pigments fucoxanthin and alloxanthin were found at upstream sites in the SRE in late spring. During summer, relatively high levels of the pigment peridinin were present in downstream areas of the SRE, and relatively high levels of diatoms occurred in upstream areas. In autumn, small Cryptomonas species were found in high abundance based on microscopic analysis, while CHEMTAX analysis of photosynthetic pigments showed relatively high concentrations of the diatom pigment fucoxanthin, implying the co-occurrence of a small unidentified phytoplankton. During winter, when the estuarine waters were well mixed, both the microscopic and CHEMTAX analyses showed that diatoms dominated at most stations. Seasonal and horizontal gradients in environmental conditions were clearly influenced by the salinity and nutrient loadings, especially the nitrate+nitrite and silicate concentrations. In particular, the ratio of photoprotective carotenoid pigments (PPCs) to photosynthetic carotenoid pigments (PSCs) was relatively low during all four seasons. This was predominately because of the high productivity of diatoms, which have a very low ratio of PPCs to PPSs. The SRE is a favorable habitat for diatoms because it is a high turbulence area having rapid water movement as a result of tidal changes. Overall, there was consistency in the data derived from the microscopy and chemotaxonomy analyses, suggesting that both methods are useful for analysis of the phytoplankton community structure in this complex estuarine and coastal water ecosystem. Full article

(This article belongs to the Special Issue Harmful Organisms and their Management for Sustainable Environment)

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