• Korean Journal of Environment and Ecology
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• v.25 no.2
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• pp.156-165
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• 2011

It is selected seven sites for marine algal flora and community structure and investigated seasonally from December 2008 to November 2009 in Gogunsan Islands, the west coast of Korea. A total of 58 species including 10 green, 16 brown and 32 red algae were collected and identified. Among these species, 11 species were found throughout the year. Annual mean biomass in dry weight were 213.8 g $m^{-2}$ at Sinsido 1, 143.1 g $m^{-2}$ at Sinsido 2, 133.3 g $m^{-2}$ at Sinsido 3, 164.0 g $m^{-2}$ at Munyeodo, 116.9 g $m^{-2}$ at Seonyudo, and 145.1 g $m^{-2}$ at Jangjado. Maximum biomass was recorded in Sinsido 1, and minimum mean biomass was Sinsido 4. The dominant species based on biomass were Sargassum thunbergii, Ulva pertusa, Sargassum fusiforme and Corallina pilulifera. S. thunbergii was the representative alga occurred at all seasons. The flora investigated could be classified into six functional groups such as coarsely branched form (46.6%), filamentous form (27.6%), sheet form (17.2%), thick leathery form (3.4%), jointed calcareous form (3.4%) and crustose form (1.7%). The R/P, C/P and (R+C)/P value reflecting flora characteristics were 0.33~0.75, 1.11~2.50, 1.47~3.25, respectively. Diversity index (H') and dominance index (DI) indicated that stability of seaweed community of Gogunsan Islands was unstable and environmental conditions were bad. According to multidimensional scaling (MDS) and cluster analysis, Gogunsan Islands were divided into three distinct groups. The first group was Sinsido 2, Sinsido 3, Seonyudo and Muyeodo and the second group comprised Sinsido 1 and Jangjado and the other was Sinsido 4 due to meaningful difference in similarity.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.2
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• pp.175-185
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• 2020

Quantitative and qualitative surveys were conducted during scuba diving activity between May 2017 and June 2017 in order to analyze spring marine algal community structure at Gijang-gun, Busan. A total of 121 species including 13 (10.7 %) Chlorophyta, 18 (14.9 %) Phaeophyta, and 90 (74.4 %) Rhodophyta were identified. The species count in the subtidal zone (110 species) was twice as high as in the intertidal zone (56 species). In terms of regions, 88,76, and 75 species were found in Mundong, Gongsu, and Daebyeon, respectively. Mean biomass for the whole study area was 1,501.5 g·m^-2, higher for the subtidal zone (1,869.4 g·m^-2) than for the intertidal zone (1,133.5 g·m^-2). Mean biomass by region values were 2,234.0 g·m^-2, 1,228.1 g·m^-2, and 1,044.4 g·m^-2 for Mundong, Gongsu, and Daebyeon, respectively. Ulva australis, Sargassum thunbergii, and Corallina pilulifera had high biomass in the intertidal zone, while Sargassum macrocarpum, Undaria pinnatifida, and Phycodrys fimbriata had high biomass in the subtidal zone. The composition ratio of marine algal functional forms suggests that the entire study area had 'Low' status, and all sites fell within 'Low' to 'Moderate' status. Results indicate that opportunistic species are widely distributed throughout the Gijang-gun coast, hence potential effects of disturbance and environmental pollution should be considered. Seaweed farming in particular - a major activity along the Gijang-gun coast -, together with effects of other anthropogenic activities such as national fishing port development and the coastal improvement project, could have long-term effects on marine algal communities. Therefore, long-term monitoring and management plans for marine algal communities will be required.