• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.5
• /
• pp.532-539
• /
• 2010

Seaweed biomass was estimated in the rocky subtidal zone of Daejin on the mid-east coast of Korea using a destructive sampling method from February to November 2007. Monthly sampling was conducted at depths of 5, 10 and 15 m using 50 $\times$ 50 cm quadrats. A total of 73 species, including 5 chlorophytes, 25 phaeophytes, 43 rhodophytes and one seagrass were identified. Average seaweed biomass was 2,852.3 g wet wt. $m^{-2}$ and biomass values varied monthly from 1,189.8 g to 7,523.7 g. The species dominant in biomass were Laminaria japonica (481.7 g), Sargassum confusum (470.85 g), Undaria pinnatifida (422.57 g), Costaria costata (282.16 g), Odonthalia corymbifera (174.46 g), S. sagamianum (163.22 g) and S. horneri (122.18 g). The vertical distribution of algae was characterized by S. confusum and U. pinnatifida at 5 m, L. japonica and U. pinnatifida at 10 m, and O. corymbifera and L. japonica at 15 m depth. The C/P, R/P and (R+C)/P values were 0.20, 1.72 and 1.92, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.6
• /
• pp.927-934
• /
• 2014

Marine algal flora and community structure were seasonally examined at Jungjado, on the southern coast of Korea, from July 2007 to May 2008. A total of 112 seaweeds, including 15 green, 24 brown, and 73 red algae, were identified and 33 species were found throughout the year. The average seaweed biomass was 145.78 g dry weight $m^{-2}$, and the biomass was maximal in winter (184.74 g) and minimal in autumn (106.17 g). The dominant and subdominant species in terms of biomass were Sargassum thunbergii and Grateloupia elliptica in summer, S. thunbergii and Corallina pilulifera in autumn, S. thunbergii and Chondracanthus intermedius in winter, and Sargassum fusiforme and G. elliptica in spring. The vertical distribution patterns of seaweeds from the upper to lower intertidal zones at Jungjado were S. thunbergii - Ulva conglobata - Gelidium elegans in summer; Caulacantus ustulatus - Chondria crassicaulis - C. pilulifera in autumn; Ulva australis - S. thunbergii - G. elliptica in winter; and Gloiopeltis tenax - S. fusiforme - G. elliptica in spring. Seasonally the evenness, richness, and diversity indices tended to have their highest values during the winter and their lowest values in the summer. However, the dominant index was recorded as lowest in winter and highest in the summer. The C/P, R/P, and (R+C)/P values reflecting the flora characteristics were 0.58, 3.04, and 3.62, respectively.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.24 no.5
• /
• pp.545-552
• /
• 2018

In this study, we performed a mesocosm experiment to estimate the mass balance of Nutrients (DIN, DIP) in a phragmites australis community. We developed 4 mesocosm tanks which is available to circulate seawater with adjustable tide levels and flooding times. Each of the mesocosm tanks were filled with phragmites australis and sediment from Jinudo in Nakdong Estuary. We investigated DIN, DIP concentrations in three layers (seawater-phragmites australis-sediment) to estimate the mass balance of Nutrients and biomass. Growth rates were also investigated. The results can be summarized as follows. 1) In spring, rhizome biomass was higher than that of aerial stem by about 6.3~9.7%. In summer, aerial stem biomass was higher than that of rhizome about 19.2~21.2 %. 2) Th Growth rate of phragmites in Mesocosm Tank A was faster than in Mesocosm Tank D by about 2 to 3 times for aerial stem and rhizome. 3) The Concentration of nutrients (DIN, DIP) in each mesocosm Tank showed 2~3 % variance in spring and summer. 4) The biomass in each mesocosm varied by about 23 % which was higher than the concentration variance for each mesocosm tanks.

• Ocean and Polar Research
• /
• v.42 no.1
• /
• pp.63-76
• /
• 2020

This study sought to assess the stock status and analyze the management effects with regard to the Black scraper, which is one of the more commercially important species in Korea. The catch amounts of Black scraper have significantly decreased since 1991. In this analysis, a Bayesian state-space model was utilized to assess the biomass of the Black scraper given the limited data. Model results showed that MSY and B_MSY of Black scraper were estimated to be 26,587 tons and 365,200 tons, respectively. In addition, the current biomass level of the Black scraper was assessed to be only 2.1% (7,549 tons) of B_MSY. For this reason, the effects of a moratorium policy on the Black scraper were evaluated. The results showed that if such a moratorium policy was implemented, it would take at least 18-40 years to restore the biomass level of the Black scraper to B_MSY depending upon its growth rates.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.6
• /
• pp.732-739
• /
• 2011

Marine algal flora and community structure were examined at four sites at Tongyeong, Korea, from February to December 2009. Eighty-two algal species were identified, including 10 green, 25 brown, and 47 red algae. During the study period, the number of species was highest at the Dukpo (61 species) site followed by the Gajodo (60 species), Yepo (58 species), and Chilchundo (53 species) sites. Seaweed biomass ranged from 578.11 to 678.26 g, with the maximum and minimum at Chilchundo and Yepo, respectively. Dominant species in term of biomass were Sargassum thunbergii at Yepo, Dukpo, and Gajodo and Gelidium amansii at Chilchundo. The vertical distribution from the high to low intertidal zone was Sargassum thunbergii and Chondria crassicaulis; Sargassum thunbergii and Ulva linza; Ulva pertusa, Sargassum fulvellum, and Gelidium amansii. Two groups clearly segregated in a cluster analysis, a Yepo/Dukpo group (group A) and a Gajodo/Chilchundo (B), indicating relatively strong differences in similarity. The seaweed community structure of group A was characterized by higher biomass and higher species richness of brown algae than were observed in group B. Additionally, the biomass ratio and the species richness of green algae was lower in group A. These differences in seaweed community structure may have been resulted from the effects of cold effluents.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.6
• /
• pp.947-959
• /
• 2015

Variations in the species composition, biomass and size distribution of fisheries resources in the Uljin marine ranching area were investigated using trammel nets at two stations (artificial reef and natural rocky area) from 2009 to 2010. During the survey, a total of 74 species were sampled with a mean density of 132 ind./net and mean biomass of 21.56 kg/net. In the natural rocky area, a total of 45 species were sampled at a mean density of 202 ind./net and mean biomass of 28.81 kg/net, while in the artificial reef area, samples included a total of 56 species, with means of 62 ind./net and 14.30 kg/net. The dominant species, comprising over 3% of the total number of individuals, were Suberites ficus (30.8%), Ovalipes punctatus (19.2%), Paralichthys olivaceus (11.7%), Pleuronectes herzensteini (4.7%), Kareius bicoloratus (3.5%), Pseudopleuronectes yokohamae (3.5%) and Eopsetta grigorjewi (3.0%). The dominant species, in terms of biomass, comprising over 5% of the total biomass, were P. olivaceus (22.1%), S. ficus (18.7%), O. punctatus (7.2%), Hexagrammos otakii (6.6%), P. yokohamae (5.7%), K. bicoloratus and P. herzensteini (5.3%). A cluster analysis and non-metric multidimensional scaling (nMDS) analysis based on the Bray-Curtis similarity of fourth root transformed data for number of species and individuals, was divided into two groups: the artificial reef area (group A) and the natural rocky area (group B).

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.6
• /
• pp.935-944
• /
• 2014

To elucidate the variation of species composition, biomass and size distribution of fishery resource in the Uljin marine ranching area was investigated at the 4 stations from 2009 to 2010 based on the dredge sampling. During the survey period, a total of 41 fishery resource species were sampled with a mean density of $2,554,633\;ind./km^2$ and mean biomass was $32,946kg/km^2$. A total 36 fishery resource species were sampled with a mean density of $3,198,793\;ind./km^2$ and mean biomass $41,177kg/km^2$ in 2009 and it were sampled a total 31 species, mean $1,910,473kg/km^2$ and $24,716kg/km^2$ in 2010. The major individual-dominant species, occupying over 1% of total individuals, were Gomphina veneriformis (2,491,818 ind., 82.2%), Umbonium costatum (221,973 ind., 8.7%), Mactra chinensis (49,879 ind., 2.0%), Glossaulax didyma hayashii (49,879 ind., 1.9%), Blepharipoda liberate (37,714 ind., 1.5%) and Paguridae spp. (27,266 ind., 1.1%). The major biomass-dominant species, occupying over 1% of total biomass, were G. veneriformis (25,124 kg, 76.3%), G. didyma hayashii (2,596 kg, 7.9%), M. chinensis (2,024 kg, 6.1%), Ovalipes punctatus (921 kg, 2.8%) and Glossaulax didyma didyma (567 kg, 1.7%). From the cluster analysis based on Bray-Curtis similarity matrix of fourth root transformed data of species number and individuals was divided into 2 different groups of the fishery resource community (Group A-St.1, Group B-Sts. 2, 3, 4). The 2009 and 2010 mean Shell length (mm) of G. veneriformis was 37.73 mm, 29.76 mm and M. chinensis was 62.03 mm, 44.94 mm, respectively.

• Korean Journal of Environment and Ecology
• /
• v.28 no.1
• /
• pp.10-23
• /
• 2014

This study was carried out to examine seaweed community structure and distribution of crustose coralline algae at the intertidal and subtidal zones of Gallam, Samchuk, eastern coast of Korea. Total 112 species including 14 of green algae, 33 of brown algae, and 65 of red algae were collected and identified. Among these species, 29 species were found throughout the year. The dominant species which contributed significantly to the total biomass were Ulva pertusa, Colpomenia spp., Sargassum fulvellum, Sargassum fusiforme, Sargassum muticum, Sargassum thunbergii, Corallina pilulifera, and Gelidium elegans. Annual seaweed biomass in dry weight was 66.7 $gm^{-2}$ and maximum biomass was recorded seasonally in summer (107.5 $gm^{-2}$), while minimum was recorded in autumn (36.2 $gm^{-2}$). In seaweed functional group analyses, coarsely branched form was the most dominant functional group constituting from 40.0 to 48.6% of the total flora. Ecological state group ESG II, as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, consisted of 46~61 species, constituting 76.7~82.4%. Crustose coralline algae was observed throughout all seasons. Species of the crustose coralline algae were largely classified into Lithothamnion lemoineae, Lithophyllum okamurai, Lithophyllum yessoense, and Hydrolithon gardineri. The coverage of crustose coralline algae seems to be lower than that of other studies from 36.8% to 11% on average.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.4 no.1
• /
• pp.80-92
• /
• 1999

This study was conducted to describe the community structure of macrobenthos in Aenggang Bay, the southern coast of Korea. Sampling was performed seasonally using van Veen grab from October 1994 to August 1995. A total of 233 species occurred; polychaetes accounted for 90 species, crustaceans 66 species, and mollusks 46 species. The mean density of macrobenthos was 1,358 ind./$m^2$, and polychaetes accounted for 64% of total abundance with its density of 874 ind./$m^2$. Mean macrobenthic biomass was 261.96 gWWt/$m^2$, and echinoderms accounted for 52.6% of total biomass with its biomass of 137.76 gWWt/$m^2$. Dominant species were a serpulid worm, Ditrupa arientina (245 ind./$m^2$), a cirratulid worm, Tharyx sp. (166 ind./$m^2$), and a scaphopod Fustaria nipponica (132 ind./$m^2$). Ditrupa arientina and Fustaria nipponica were distributed mainly in the mouth of Aenggang Bay, whereas Tharyx sp. showed its high density in the central region of the bay. The study area showed a regional difference in species richness, abundance, and biomass; the eastern region of the bay sustained relatively more abundant and richer macrobenthos than the western part. The study area could be divided into 5 regions by the cluster analysis based on the species composition of macrobenthos; the inner bay, two central regions, and two mouth areas of the bay.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.10 no.2
• /
• pp.103-108
• /
• 2005

For more accurately describing the durations of the light and the dark phases of micro-algal cells over the whole light-dark cycle, and probing into the relationship between the liquid circulation time or velocity, the aeration rate and cell density, a series of experiments was carried out in 10 cm light-path flat plate photobioreactors. The results indicated that the liquid flow in the flat plate photobioreactor could be described by liquid dynamic equations, and a high biomass output, higher content and productivity of arachidonic acid, $70.10\;gm^{-2}d^{-1},\;9.62\%$ and 510.3 mg/L, respectively, were obtained under the optimal culture conditions.