The objective of the present study was to investigate the effects of different red seaweeds on in vitro rumen fermentation characteristics and methane gas production. Five species of red seaweed (Chrysymenia wrughtii Yamada, CW; Hypnea sp., Hypnea sp.; Chondria crassicaulis, CC; Gelidium vagum Okamurae, GV; Hypnea saidana Holmes, HS) were obtained from National Institute of Fisheries Science (NIFS) in South Korea. The collected red seaweeds were washed for 3 minutes, and then samples were freeze-dried and ground to a size of a 1 millimeter. The buffered ruminal fluid (50 mL) was incubated with substrates and seaweeds (5% of substrates) at 39℃ for 48 hours. Total gas production was lower than red seaweed treatments excluding the CW treatment (p<0.05; 63.25 mL). Methane production was the lowest in CC treatment (p<0.05; 9.93 mL/g of digestible dry matter). The rumen pH of the red seaweed treatments ranged from 5.98 to 6.08, which was significantly the lowest in the GV treatment (p<0.05; 5.98). There was no significant difference in the total VFA concentration, but propionate (27.53%) was significantly highest in the CW treatment, whereas acetate (53.14%), iso-valerate (3.52%), valerate (1.72%), and A:P ratio (1.93) were significantly lowest (p<0.05). In conclusion, among the five species of red seaweeds, Chondria crassicaulis reduced in vitro methane production without negative effects on dry matter digestibility. Future studies will be needed to determine the optimal inclusion level of Chondria crassicaulis as feed additive to reduce enteric methane production.

감태의 인공채묘시 유주자 및 유리배우체를 채묘하여 양성 생장도를 비교하므로써, 유리배우체의 대량양식 이용 가능성을 시험하였다. 2008년 11월에 유주자 및 유리 배우체를 채묘한 채묘틀을 이용하여 2009년 5월부터 10월까지 전남 완도군 약산면 시험어장에서 양성 생장도를 비교하였다. 유주자 및 유리배우체 채묘 실험구에서 감태 엽체의 엽장과 생체량 등은 유의한 차이를 보이지 않았다.

Grateloupia asiatica and G. divaricata are edibile marine red algae that commonly occur on the east coast of Korea: G. asiatica occurs in sheltered locations such as estuaries or tide pools, and G. divaricata usually grows at the depth of 2~5 meters under the sea where freshwater flows. We compared growth pattern of both species in Aninjin, Gyoam, Hosan, and Sacheon in order to find suitable location for mass culture of the Grateloupia species. In case of G. asiatica, vegetative and tetrasporangial thalli were found in Gyoam and Sacheon, while gametophytic thalli were found in Aninjin. Population from Aninjin was the largest on the average length of thalli (20.6 cm) among populations studied. Population of G. divaricata in Sacheon seems to be maintained mostly with sporophytes. However, Aninjin and Hosan populations consisted of gametophytes and sporophytes in summer. Population from Hosan was the largest on the average length of thalli (19.8 cm). Based on our results, G. asiatica and G. divaricata repeat a typical triphasic life history of red algae on the east coast of Korea.

The species composition and phylogeographical features of marine algal flora of Dok island are investigated. A total of 253 species, 26 green, 67 brown, 160 red, were counted cumulatively since first report by Kang and Park (1969) from Dok island. Among them Ectocarpus corticulatus Saunder, Antithamnion okiense Kajimura are first reported from Korea and Feldmannia irregularis, F. globifera, Spatoglossum crassum newly added by this study. And also, a candidated new species, Dictyota sp. (Dictyotaceae, Phaeophyceae) is collected in this study. A remarkable increasing of warm water brown algal species, eg. Nemacystus decipiens, Sphaerotrichia divaricata, Tinocladia crassa, Petrospongium rugosum, Sargassum yezoense, are observed recently studies. This phenomenon is presumed to be closely related with global warming. For phylogeographical study of marine algae of Dok island we selected two species, one red alga Griffithsia japonica Okamura and one brown alga Dictyota coriacae (Holmes) Hwang, Kim et Lee, which have low dispersal capacity by their Oogamious sexual reproduction. The Dok island's haplotype of G. japonica is clearly distinguished from Oki island haplotype but closely related to the Korean type's haplotypes which distributed in south and east coast of Korea. And also, the Dok island's haplotype of D. coreacea is a unique Korean type which discriminated from Japanese and Taiwanese type. From these results, we proposed the marine algae of Dok island, at least in case of warm water species, were originated from Korean coasts rather than western coast of Japan by the Korean warm current.