• ALGAE
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• 제22권3호
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• pp.221-228
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• 2007

Frequent occurrences of green tides caused by Ulva species (Ulvales, Ulvophyceae) associated with eutrophication along enclosed coasts are currently causing environmental problems in coastal ecosystems. In addition, increasing intercontinental introductions of coastal marine organisms, including Ulva, are also a serious issue. However, due to the considerable morphological plasticity of this genus, the taxonomy of Ulva species based on morphological studies is problematic. Therefore, in order to elucidate the species diversity and seasonal changes of the dominant Ulva species in Mikawa Bay, central Honshu, Japan, we made seasonal collections of Ulva species at seven localities, and identified the dominant species using the ITS2 rDNA region sequences. We identified the following nine taxa as common Ulva species in the area: 1) Ulva pertusa Kjellman; 2) U. ohnoi Hiraoka et Shimada; 3) U. linza L.; 4) U. californica Wille; 5) U. flexuosa Wulfen; 6) U. fasciata Delile; 7) U. compressa L.; 8) U. armoricana Dion et al.; 9) U. scandinavica Bliding. Among the species, U. pertusa was most common and dominant from spring to summer, and U. ohnoi from autumn to winter. Ulva californica and U. scandinavica have not been reported before from Japan.

• 한국해양바이오학회지
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• 제14권1호
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• pp.51-60
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• 2022

A green alga specimen was collected from the eastern coast of Korea. This species shared the typical features of genus Ulva and was characterized by irregularly shaped thalli, relatively small and thick thallus, entire undulate margins without serrations, and one or two pyrenoids per cell. In a phylogenetic tree, based on sequences of the nuclear-encoded internal transcribed spacer region, it nests as a sister clade to a few species including Ulva ohnoi, which has a relatively large thallus. This Korean algal specimen differs from the species forming the same subclades, including U. ohnoi, Ulva fasciata, Ulva reticulata, and Ulva gigantean, and has a relatively small (3-8 cm) and thick (60-100 ㎛) thallus. Of these species, U. ohnoi, originally described from Japan, is similar to the Korean alga as it had a thick thallus of 30-90 ㎛, but it has microscopic serrations on the thallus margin, unlike the Korean alga. The genetic distance between the Korean alga species and the aforementioned species was determined to be 1.8%-4.8%, indicating an inter-specific divergence level at the genus Ulva. Herein, Ulva grossa sp. nov. (Ulvales, Chlorophyta) from Korea is described based on the morphological and molecular analyses.

• 환경생물
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• 제19권1호
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• pp.37-42
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• 2001

The biomass of Ulva mats was surveyed in a lower rocky shore of the southern coast of Korea during the 1998-1999 winter. The population selected for the present study was located on the tidal zone ranging from 118 cm to 130 cm below mean sea level (MSL), where abundance of Ulvu species was highest. The biomass of Ulva species increased gradually from December 1998 until February 1999, reaching the maximum of 374 g dry wtㆍm$^{-2}$ in February. The biomass varied little among the sampling quadrats for each sampling time. Over the course of the study a total of 16 taxa were sampled from Ulva mats, of which 5 were macrophytes and 11 were macroinvertebrates. Rodophyta comprised 3 taxa, followed by Phaeophyta of 2 taxa, but there was no Chlorophyta except for Ulva species. The macrofaunal assemblage was consisted of 8 taxa of Mollusca, 2 Arthropoda and 1 Annelida. There was a dramatic increase in Mytilus sp. in February. Moreover, the trend of biomass were similar between some macroinvertebrates and Ulva species. The results suggested that macroinvertebrates may play an important role in nutrient dynamics as well as food web. Further experimental evidence may be necessary to explain the correlation between Ulva mats and abundance of coexisting macroinvertebrates.

• ALGAE
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• 제34권4호
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• pp.253-266
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• 2019

Several species classified to the genus Ulva are primarily responsible for causing green tides all over the world. For almost two decades, green tides have been resulted in numerous ecological problems along the eastern coast of Jeju Island, Korea. In order to characterize the species of Ulva responsible for causing the massive blooms on Jeju Island, we conducted DNA barcoding of tufA and rbcL sequences on 183 specimens of Ulva from eight sites on Jeju Island. The concatenated analysis identified five bloom-forming species: U. australis, U. lactuca, U. laetevirens, U. ohnoi and a novel species, U. pseudo-ohnoi sp. nov. Among them, U. australis, U. lactuca, and U. laetevirens caused to the blooms coming mainly from the substratum. U. ohnoi and U. pseudo-ohnoi sp. nov. were causative the free-floating blooms. Four species, except U. australis, are characterized by marginal teeth. A novel species, U. pseudo-ohnoi sp. nov., is clearly diverged from the U. lactuca, U. laetevirens, and U. ohnoi clade in the concatenated maximum likelihood analysis. Accurate species delimitation will contribute to a management of massive Ulva blooms based on this more comprehensive knowledge.

• Journal of Plant Biology
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• 제29권3호
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• pp.175-183
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• 1986

Marine algal flora and intertidal vegetation around Samchonpo power plant, south coast of Korea, were investigated at three sites, specially referred to the seasonal variation of the species from April to October, 1982. A total of 84 species were identified; 8 green, 19 brown and 57 red algae. Among three sampling sites investigated, 65 species were collected at the first site located in front of the power plant, 66 at the second site, Namildae beach, and 61 at the third, Sinsudo, respectively. The algal vegetation at the first site was dominated in cover by Sargassum thunbergii and Ulva pertusa in April, Corallina spp. Ulva pertusa in July, and Chondria crassicaulis and Ulva pertusa in October. At the second site, it was dominated in cover by Sargassum thunbergii, Gigartina tenella and Ulva pertusa in April, Sargassum thunbergii and Ulva pertusa in July, and Chondria crassicaulis and Ulva pertusa in October, whereas at the third site Sargassum thunbergii and Ulva pertusa in April, and Chondria crassicaulis in October, respectively. The biomass among three investigated sites showed 2,360 g-fresh wt/$m^2$ on an average; 283 g-dry wt/$m^2$ at the first, 277 g-dry wt/$m^2$ at the second, and 256 g-dry wt/$m^2$ at the third site, respectively.

• 한국수산과학회지
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• 제4권3_4호
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• pp.105-112
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• 1971

1970넌 6월부터 1971넌 5월까지 여수 오동도의 2개 조사지점에서 월 2회 조사한 해조 군락은 아래와 같다. 1. 총출현종은 69종으로 녹조류 12종, 갈조류 17종 및 홍조류 40종이며, 조사 장소에 따른 출현종의 뚜렷한 차이는 없었다. 2. 계절별 해조 군락은 대부분 주년 출현종으로 층위가 형성되어 출현종의 변화가 적으나 Ulva pertusa, Enteromorpha sp., Sphacelaria sp., Scytosiphon iomentaria, Colpomenia sinuosa, Sargassum thunber gii, Pterocladia tenuis, Amphiroa ephedrea, Carpopeltis affinis, Gigartina tenera, Polysiphonia yendoi, Chondria crassicaulis, Symphyocladia atiuscula등은 피도의 증감이 많았다. 3. 층위의 출현종은 대체로 변화가 적어, $200\~150cm$층은 Gloiopeltis complanata, G. furcata, Enteromorpha sp.등이고 $150\~100cm$층은 Ulva pertusa, Chondria crassicaulis, Sargassum thunbergii등이며, $100\~50cm$층은 Gigartina tenera, Pterocladia tenuis, Scytosiphcn lomentaria, Polysiphonia yendoi 등이고, 제일 아래층인 50cm 이하에는 Sargassum sagamianum, Cystophyllum sisymbrioides, Gelidium amansii, Acresorium yendoi, Microcladia elegance등으로 층위가 형성되었다. 4. A, B 두 조사지점은 100cm층을 중심으로 아래층에는 차이가 적으나 위층에는 차이가 있어, A지점에는 Gloiopeltis complanata, Corallina pilulifera, Chondria crassicaulis, Sargassum thunbergii, Polysiphonia yendoi 및 Ulva pertusa등으로 층위가 형성되나, B지점에는 Gloiopeltis complanata, G. furcata, Enteromurpha sp. 및 Ulva pertusa등으로 층위가 간단하였다. 5. Taniguti의 해조 군락 분류에 의하면 Myelophycus caespitosus 군단의 Gigartina intermedia-Sargassum sagaminnum군집 (Sargasseto-Gigartinetum Taniguti)에 속한다.

• Journal of Species Research
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• 제11권4호
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• pp.266-277
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• 2022

The current surveys of Ulva in the subtidal area around Jeju Island give a chance to discover unrecorded green algal species of the Korean macroalgal flora. As a result of this investigation, we found Ulva adhaerens Matusmoto & Shimada, inhabiting the subtidal regions, up to 15 m deep, and conducted the DNA barcoding on plastid rbcL-3P and tufA regions with describing the morphological characteristics. Our specimens of U. adhaerens forms a monophyletic clade with the Japanese type specimen and U. piritoka Ngāti Kuri, Heesch & W.A. Nelson from New Zealand exhibiting each 0.3% sequence divergences, respectively, in the plastid rbcL-3P. The genetic variation of U. adhaerens clade is 1.0-3.9% in rbcL-3P and 4.8-9.8% in tufA to each Ulva species, including the generic type, U. lactuca Linneaus. The morphology of Korean U. adhaerens specimens is identical to the type specimens of U. adhaerens from Japan having the development of rhizoidal filaments from both of the cell layers of the distromatic blade and the extension of rhizoidal clumps with adhesive trait between blades by extended rhizoidal clumps at the basal blades. The thallus attachment to substrate is by numerous minute discoidal plates made up of rhizoids originating from the inner part of distromatic blades in basal. Although there are still some problems to resolve the relationship between U. adhaerens and U. piritoka in the rbcL dataset and the phylogenetic pattern of the Group II intron of rbcL, we propose the new record of U. adhaerens in Korean macroalgal flora based on the morphological characteristics of Korean specimens. Continued study of the genus Ulva by morphological and molecular assessment will delimit the species of Ulva, elucidate the relationships between them, and uncover the species diversity.

• ALGAE
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• 제30권1호
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• pp.59-66
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• 2015

The growth and hole formation of Ulva australis were examined at seven coastal areas of Korea between July and August, 2013. Animal species and weight growing on the Ulva fronds were estimated at Haseom, Pohang, and Woedo. The effects of wave exposure on the morphological features and residential animals of Ulva fronds were investigated at wave-exposed and sheltered sites of Seongsan on October 19, 2013. U. australis had different frond areas ($82-665cm^2$), hole areas ($2.5-6.3cm^2$), and hole numbers (9.8-41.3 holes) at the seven sites. Within $0.1m^2$ of Ulva frond, hole areas ranged from 0.37 to $5.94cm^2$, and between 4.9 and 36.2 holes were observed. Fourteen residential animal species were observed at the three evaluated sites, 75.0 (Haseom) to 408.7 individuals $100g^{-1}$ Ulva (Pohang) per site. The dominant residential species at each site differed with Amphithoe sp. at Haseom, Monodonta spp. at Pohang, and Pagurus sp. at Woedo. The growth (frond area, wet weight) and hole number of Ulva fronds, and the number of residential animals were significantly greater in samples collected from the sheltered shore than the wave-exposed shore of Seongsan. The present results showed U. australis grew well at sheltered shores and had more holes on the fronds due to abundance of residential animals. The dominant residential animals (crabs, gammaridea, and snails) were similar in the Ulva populations of sheltered and wave-exposed shores, but greater species diversity was observed at the exposed shore (18 species ver. 11 species). In conclusion, U. australis is a keystone species providing habitat to various invertebrates and frond holes are positively correlated to the number of residential animals.

• ALGAE
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• 제33권4호
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• pp.329-340
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• 2018

The present study was to determine the effects of salinity on the growth and nutrient bioextraction abilities of Gracilaria and Ulva species, and to determine if these seaweeds can be used for nutrient bioextraction under hypo- and / or hyperosmotic conditions. Two Gracilaria species, G. chorda and G. vermiculophylla, and two Ulva species, U. prolifera and U. compressa, were cultured at various salinity conditions (5, 10, 15, 20, 30, 40, and 50 psu) for 3 weeks. Results showed that the growth rates, nutrient uptake, tissue nutrient contents and nutrient removal were significantly affected by salinity and species. All four species were euryhaline with the highest growth rates at 20 psu. Among the four species, U. prolifera, U. compressa, and G. vermiculophylla showed potential to be used for nutrient bioextraction in estuaries and / or land-based fish farms due to their rapid growth, high nutrient uptake, high tissue carbon and nitrogen accumulation and removal capacities.

• Journal of Ecology and Environment
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• 제37권4호
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• pp.379-385
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• 2014

Two marine ulvalean species (Chlorophyta) were collected from the southern and eastern coasts of Korea. One is morphologically characterized by usually unbranched or little branched ribbon-shaped thalli, fronds with spirally twisted basal portions and usually undulate margins and 1 (-2) pyrenoids per cell. The other has irregularly shaped thalli, undulate and dentate margins in the fronds, small macroscopic denticulations along the margin and (1-) 2-3 pyrenoids per cell. In phylogenetic tree based on molecular data, the two species nest in the same clade with Ulva flexuosa and U. rigida, respectively. These two Korean entities are identified as U. flexuosa and U. rigida, respectively, based on morphological and molecular analyses. This is the first record of Ulva flexuosa and U. rigida in Korea.