• ALGAE
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• 제17권2호
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• pp.127-133
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• 2002

The red seaweed Eucheuma serra is a high yielding source of lectins. The plants were collected from a depth of 5-6 meters and cultured in the laboratory, field and deep seawater. A Daily Growht Rate (DGR) of 3.5% was observed at 18℃ with a low light of 30μmol photon $ m^{-2} · s^{_1}$ in the laboratory. When the plants were cultured in the field at different depths during winter onths of December and January, best growth was observed at 1 m depth and a DGR of 2.14±0.04% was recorded. The plants grown in the tank with a continuous supply of deep seawater showed a DGR of 8.2% The results indicate that E. serra can be cultivated in large scale both in deep seawater in the tank and in the field for the extraction of lectins at a commercial scale.

• ALGAE
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• 제22권1호
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• pp.31-36
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• 2007

The gametophytic filaments of two genetically distinct taxa of Bangia from New Zealand showed unusual rhizoidal development in comparative culture experiments. In the past Bangia has been reported to possess simple, colourless rhizoids that extend from the basal cells of the unbranched filaments, whereas in this study the rhizoids observed became pigmented and multicellular. A reversal of growth direction occurred and filamentous extensions developed from the rhizoids under some culture conditions. These extensions were either prostrate or resembled new gametophytic filaments. This is the first report for filamentous members of the Bangiales of the development of such stolon-like rhizoids, apparently serving as a form of vegetative reproduction.

• ALGAE
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• 제20권1호
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• pp.31-36
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• 2005

Scinaia latifrons Howe occurs in rhodolith beds between 9 to 27 m depths at San Lorenzo channel, Gulf of California, Mexico. As very little was known about the morphometrics of this normally temperate species in a subtropical area, we investigated the phenological changes from December 1998 to December 1999. The gametophytic phase of the species was present from late February to late May, which represented a shorter time period to other known species in the genus. Our results suggested that two gametophytic cohorts develop over winter and early spring based on the size class structure of the frond height. Thalli became reproductively mature at a small size (1-2 cm in height) and all the plants were monoecious. Scinaia latifrons at the study location underwent allometric growth, indicated by the lack of correlation between size, width of the plants, or branching patterns.

• ALGAE
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• 제27권1호
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• pp.43-54
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• 2012

A mathematical model of the commercial harvest of Palmaria palmata (Dulse) is presented based on a logistic model and field data collected on Digby Neck, Nova Scotia from 14 harvested shores during May to August, 2010. Field observations used to estimate model parameters included cover of Dulse before and after harvest from Dulse dominated boulders for which surface area was estimated, and from which fresh biomass of harvested Dulse was weighed. Over all the surveys the average harvest fraction was about 50%, and the total resource was about $1,600g\;m^{-2}$. With growth rates in excess of 4% per day and a 50% harvest of the standing crop each month, the model suggests that the Dulse resource is sustainable at current harvest levels.

• ALGAE
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• 제18권4호
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• pp.333-339
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• 2003

To establish a cultivation method of Petalonia fascia, seeds and seedlings cultures and growth tests were performed at the Daeri aquafarm in Haeui, Shinan, Jeollanamdo, Korea. Gametes were easily released from the mature plurilocular sporangia. They developed to crustose discoidal stolons and grew to filamentous and discoidal stolons. The indoor seeding was performed by using the 100-150 ${\mu}m$long fragments of stolons on Porphyra nets and the erect thalli developed from the cuttings when the seawater temperatures were 10-15$^{\circ}C$. In the experimental cultivation in the sea, 1-2mm long plantlets were found after 15 days of cultivation; after two months thalli grew to their maximal size of 215-355 mm long blades; after three months the length of thalli began to decrease due to distal disintegration and the plant color changed to yellow and epiphytic diatoms were attached on the thalli, which deteriorated the quality of products. The cultivation of P. fascia by the regeneration of filamentous-discoidal complexes was carried out successfully for the first time in Korea.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 추계 수산관련학회 공동학술대회발표요지집
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• pp.204-205
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• 2001

Manful algae, Cochlodinium polykrikoides has damaged to fisheries organisms by making massive blooms mainly in the South Sea during the higher water temperature season since 1995 in Korea. Ecological and hydrodynamic studies of the species offer useful information in understanding its bloom mechanism giving promising data for the modeling and prediction of the blooms. (omitted)

• ALGAE
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• 제32권1호
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• pp.1-13
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• 2017

Seaweed aquaculture technologies have developed dramatically over the past 70 years mostly in Asia and more recently in Americas and Europe. However, there are still many challenges to overcome with respect to the science and to social acceptability. The challenges include the development of strains with thermo-tolerance, disease resistance, fast growth, high concentration of desired molecules, the reduction of fouling organisms and the development of more robust and cost efficient farm systems that can withstand storm events in offshore environments. It is also important to note that seaweed aquaculture provides ecosystem services, which improve conditions of the coastal waters for the benefit of other living organisms and the environment. The ecosystem services role of seaweed aquaculture and its economic value will also be quantitatively estimated in this review.

• 환경위생공학
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• 제13권2호
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• pp.1-13
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• 1998

Seasonal variation of algae distribution were studied in the Chuam reservoir from August 1996 to July 1997. As a result, 127 taxa were observed, representing 6 classes, 14 orders, 5 suborders, 29 families, 2 subfamilies, 54 genus, 118 species, 7 variaties and 2 formula. The majors of them are Chlorophyceae (59 taxa), Bacillariophyceae(39 taxa) and Cyanophyceae(20 taxa). The number of species was that 35 and 31 taxa were occurred in August 1996 and April 1997, 11 and 17 taxa in July 1997 and October 1996 respectively at Dam station, 53 taxa were occurred in September, 18 taxa in November at Munduck station. The biomass composition of occurrence species were as fallowes; Cyanophyceae are 80%, Bacillariophyceae 14% and Chlorophyceae 5% at Dam station and Cyanophyceae are 90%, Bacillariophyceae 1.3% and Chlorophyceae 0.4% at Munduck at Munduk station. At Munduk station, water bloom occurred by Cyanophyceae(99.9%, 3.7 $\times$ 10$^{7}$ cells/L) in November 1996 and the major causing algae was Microcrystis aeruginosa. Microcystis aeruginosa was dominant species (dominant index : 0.72 - 0.99) during summer and autumn, Fragilaria crotonensis and Asterionella formasa (DI : 0.33 - 0.74) during winter and spring. The water quality factors of the Chuam reservoir were that the values of water temperature ranged of 3.6 - 31.4$\circ$C, pH 6.7 - 9.0, conductivity 69.6-118.2 $\mu $s/cm, and turbidity 1.0-22.5 NTU, and the proper temperature of water for algae growth was 15 and 16.7$\circ $C in April and November. Also the concentration of dissolved oxygen(DO) ranged of 6.8-15.5mg/L, total nitrogen(T-N) 0.54-1.78 mg/L, total phosphrous (T-P) 0.003-0.034 mg/L, and chlorophyll-a 0.9-23.2mg/m$^{3}$. The concentration of Chlorophyll-a was in inverse proportion T-N/T-P ratio.

• ALGAE
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• 제21권3호
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• pp.323-332
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• 2006

Mitochondrial distribution and abundance were assessed during the growth of apical and subapical cells in the red algae Colaconema caespitosum (J. Agardh) Jackelman, Stegenga and Bolton and Antithamnion cruciatum (C. Agardh) Nägeli after staining with 3,3’-dihexyloxacarbocyanine iodide [DiOC6(3)] and 2,4’-dimethylaminostyryl-Nethylpyridinium iodide (DASPEI). In fully elongate apical cells of C. caespitosum there were 100-120 mitochondria. During apical cell enlargement and division there is a doubling and then halving of the mitochondrial numbers. Apical cells prior to cytokinesis in young filaments are smaller than in mature filaments (ca. 50 and 100 μm long, respectively) and have fewer mitochondria (ca. 100 and 120 mitochondria per cell, respectively). In older vegetative cells mitochondria tend to aggregate at opposite ends of the cells with some mitochondria associated with the central nucleus or at points of apparent branch initiation. There is a greater density of mitochondria in apical cells of smaller versus larger plants (one mitochondrion per 6.3 μm3 and 9.8 μm3, respectively), suggesting that apical cells of younger plants may be more metabolically active. Male and female gametophytic thalli of Antithamnion cruciatum had similar numbers of mitochondria in apical cells of indeterminate axes, as did gametophytic and sporophytic thalli. There were about 40-50 mitochondria in fully elongated apical cells with about half this number in newly divided apical and subapical cells. Apical cells of determinate branches had more mitochondria (60-77) than indeterminate branches (60-70 vs. 40-50). In both species and in all cell types mitochondrial numbers were highly correlated with cell size.

• ALGAE
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• 제35권2호
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• pp.145-155
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• 2020

Specimens of red algae corresponding to the peyssonnelioid genus Sonderophycus were collected at Kure Atoll, Hawai'i, at a depth range of 88-94 m depth during mesophotic surveys of the Papahānaumokuākea Marine National Monument, Hawaiian Islands, and were analyzed using morphological and molecular approaches. Analyses of mitochondrial cytochrome oxidase subunit 1 and chloroplast rbcL DNA sequences demonstrated that the Hawaiian specimens were identical to one another yet distinct from the three other species currently recognized within the genus (S. capensis [Montagne] M. J. Wynne, S. coriaceus [Womersley & Sinkora] M. J. Wynne, and S. fervens Dixon), as well as the likely congener, Peyssonnelia caulifera Okamura, and are proposed here as a new species: Sonderophycus copusii A. R. Sherwood. Sonderophycus copusii is morphologically distinct from other members of the genus by the following combination of characters: the presence of occasional secondary perithallial growth, emergence of rhizoids from the hypobasal cuticle at a strongly acute angle, a lack of horizontally directed filaments in the lower perithallus, and the lack of a stipe. This is the first record of the genus Sonderophycus in the Hawaiian Islands. Sonderophycus copusii was documented as a dominant member of the algal community at Kure Atoll, and thus may play a significant ecological role in the deep-water benthic community of Kure Atoll, along the lines of reports of deep water peyssonnelioid beds in the Mediterranean, Red Sea, and Caribbean. This study further highlights the unexplored diversity of the Peyssonneliales in Hawai'i, and emphasizes more generally the degree of as yet undiscovered biodiversity of algae at mesophotic depths.