• ALGAE
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• 제29권1호
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• pp.15-25
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• 2014

The number of species of non-native and invasive marine algae is growing, with concomitant public concern about native ecosystems and coastlines. Gelidium vagum, recently introduced from northeast Asia to Europe and North America, commonly occurs from the intertidal to subtidal zones in Korea, China, and Japan. To investigate the level of genetic diversity of native populations, we analyzed mitochondrial cox1 and cob from 108 specimens of G. vagum from Korea, China, eastern Russia, including from the Netherlands and USA. The haplotype network of individual and cox1 + cob datasets revealed no genetic structure in local populations, suggesting genetic flow between Korean populations. Our results corroborate a typical pattern of genetic diversity for introduced species, with low levels in introduced populations and high levels in native populations. All haplotypes were shared between the Netherlands and USA, but not between Korea and the Netherlands / USA except cox1. Additional sampling will identify donor populations in native northeast Asian waters. This is the first report of the utility of the mitochondrial coding cob sequences in red algae.

• ALGAE
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• 제31권2호
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• pp.129-136
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• 2016

The Mediterranean Sea is currently facing dramatic changes and threats, including change in native species and accidental introductions. The introduced green alga Codium fragile subsp. fragile (Suringar) Hariot influences diversity and community structure in some parts of the world. This paper documents the distribution of this species in Tunisia and provides a morphological description of C. fragile subsp. fragile in Northern Tunisia. Results confirm the identity of Tunisian specimens as the invasive subspecies C. fragile subsp. fragile. This is the first morphological characterization of this subspecies in Tunisia.

• ALGAE
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• 제22권1호
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• pp.17-21
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• 2007

Sargassum filicinum Harvey, a brown alga (Phaeophyceae) native to Northeastern Asia, has been recently reported from the coast of Southern California (USA). Here we report the occurrence and range extension of this introduced species, as we found the alga at La Jolla and Rancho Packard in Todos Santos Bay, Baja California, Mexico. The first collections of S. filicinum correspond to several immature plants, found on September 8, 2005, drifting in the intertidal zone at La Jolla. Later on November 9, 2006, we found a well-established population in Rancho Packard in the middle intertidal zone to 2 m depth. Since S. filicinum is an annual monoecious species with air bladders, the risk there is a high risk of spreading rapidly along the Pacific, as in the case for S. muticum. The population in Rancho Packard extends 500 m along the coast, consisting mainly of young plants with an average length of 30 cm and a density of 5 thallus/m2. This is the first record of this invasive species for the Mexican Pacific coast, and it represents the southern limit along the Pacific coast of North America. This finding suggests that this invasive species has successfully colonized the Pacific coast of North America and its distributional range is still expanding.

• 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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• 제24권4호
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• pp.231-238
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• 2009

The genus Grateloupia is the largest with more than 96 currently recognized species in the family Halymeniaceae, but morphological features of the genus are highly homoplasious making species identification difficult. In this study, we analyzed rbcL gene from 34 samples collected in Korea and compared the haplotypes of Korean species with those already published. The rbcL tree confirmed the occurrence of eight species in Korea: G. asiatica, G. catenata, G. divaricata, G. elliptica, G. imbricata, G. lanceolata, G. subpectina, and G. turuturu. All, except G. asiatica and G.catenata, been introduced from their native northeastern Asian waters to Australasian, European, and North American waters. The introduced haplotypes of G. lanceolata in Europe and North America were absent in Korea, while haplotype sharing of G. turuturu in Korea and Europe was common. Further sampling will show a source population of each introduced species and also provide a correct list of Grateloupia from Korea, including the other remaining 11 species of the genus.

• ALGAE
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• 제25권4호
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• pp.205-216
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• 2010

The marine red alga Kappaphycus alvarezii is a major source of $\kappa$-carrageenan. It has been introduced in 20 countries including India. Recently, several reports have expressed concerns about Kappaphycus invasion on Acropora corals at Kurusadai Island in the Gulf of Mannar, India, which is part of a marine bioreserve. To understand the extent of the Kappaphycus invasion, 27 randomly selected locations around Kurusadai Island and the mainland coast were surveyed during May-August 2008 and July 2009. Our rigorous sampling revealed that K. alvarezii was confined to two different patches of 105 m $\times$ 55 m and 8 m $\times$ 9 m located at the southeastern part of Kurusadai Island. The actual extent of the K. alvarezii canopy coverage was 76.7 $m^2$, accounting for less than 0.0035% of the total coral reef area. The daily growth rate of the K. alvarezii at Kurusadai was 0.7%. K. alvarezii was not observed in the coral reef area of the adjoining Pullivasal and Poomarichan Islands or the Palk Bay area cultivation sites. The lack of functional reproductive cycle, low spore viability, and the absence of microscopic phases in the life cycle of this alga coupled with the abundance presence of herbivores may restrict the further spread of this alga, so its invasive potential at Kurusadai Island is considered remote.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2004년도 SMICS 2004 International Symposium on Maritime and Communication Sciences
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• pp.43-48
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• 2004

A pilot-scale system of 20t/h for the treatment of ship's ballast water and the setup of dissolved hydroxyl radical was introduced in this paper. With this experimental system, the kill efficiencies of bacteria, mono-algae, protozoan reach 100% within 2.67s when dissolved OHㆍconcentration is 0.6mg/L. At the same time, the effect of hydroxyl radicals on the photosynthesis pigments of phytoplankton was done. The results indicate that the contents of chi-a, chl-b, chl-c and carotenoid are decreased to 35~64% within 8.0s further to the lowest limit of test after 5 minutes. When dissolved OHㆍratio concentration is 0.68mg/L, the attenuation efficiencies of photosynthesis pigment are 100%. Therefore the invasive marine species can be killed in the process of the inputting and discharge ship's ballast water.

• 한국해양학회지:바다
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• 제15권1호
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• pp.36-40
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• 2010

선박평형 수는 유독 와편모조류 및 다양한 미세조류의 국제적인 이동경로로 알려져 있다. 본 연구에서는 선박평형 수에 있는 와편모조류의 다양성을 조사하기 위하여 와편모조류 특이적인 PCR primer와 종 특이적인 real-time PCR 유전자 탐침자를 이용하였다. 선박평형 수 시료에 대한 광학현미경 조사에서는 와편모조류가 매우 낮은 농도로 관찰되었지만, SSU rDNA의 cloning 및 염기서열 분석 결과에서는 기생 와편모조류, 초미세플랑크톤, 어패류 폐사 원인종 등 다양한 종류가 확인되었다. 본 연구 결과는 종 톡이적 PCR primer와 같은 분자생물학적 방법이 선박 평형 수에 외래 유입종의 신속 정확한 진단에 유용함을 보여주고 있다.

• ALGAE
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• 제32권1호
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• pp.57-66
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• 2017

The red alga Gracilaria vermiculophylla, a species native to the waters of Korea and Japan, has invaded marine coastal areas of Europe and the Americas, thriving in conditions that differ from those of its native habitat. In recent years, G. vermiculophylla has been discovered in the Long Island Sound (LIS) estuary growing alongside the native congener Gracilaria tikvahiae. The goal of this study was to determine whether the two strains of G. vermiculophylla from different regions of the world have evolved genetic differences (i.e., ecotypic differentiation) or if the physiological performance of the strains simply reflects phenotypic plasticity. Two strains of G. vermiculophylla (isolated in Korea and LIS) and a strain of the LIS native G. tikvahiae were grown for four weeks under temperatures ranging from 20 to $34^{\circ}C$ using a temperature gradient table (all other environmental conditions were kept constant). At the end of each week, wet weight of each sample was recorded, and thalli were reduced to the original stocking density of $1gL^{-1}$ (excess biomass was preserved for tissue carbon and nitrogen analysis). Generally, the growth rates of Korean G. vermiculophylla > LIS G. vermiculophylla > G. tikvahiae. After one week of growth G. tikvahiae grew 9.1, 12.0, 9.4, and 0.2% $d^{-1}$, at temperatures of 20, 24, 29, and $34^{\circ}C$, respectively, while G. vermiculophylla (LIS) grew 6.6, 6.2, 5.7, and 3.6% $d^{-1}$. G. vermiculophylla (Korea) grew 15.4, 22.9, 23.2, and 10.1% $d^{-1}$, much higher than the two strains currently inhabiting the LIS. On average, the LIS G. vermiculophylla strain contained 4-5% DW N, while the Korean strain and G. tikvahiae had more modest levels of 2-3% N DW. However, tissue N content declined as temperature increased in LIS and Korean G. vermiculophylla. The non-native haplotype may have evolved genetic differences resulting in lower growth capacity while concentrating significantly more nitrogen, giving the non-native a competitive advantage.