• ALGAE
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• 제35권3호
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• pp.237-252
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• 2020

Temperate rocky reefs dominated by the giant kelp, Macrocystis pyrifera, support diverse assemblages of benthic macroalgae that provide a suite of ecosystem services, including high rates of primary production in aquatic ecosystems. These forests and the benthic macroalgae that inhabit them are facing both short-term losses and long-term declines throughout much of their range in the eastern Pacific Ocean. Here, we quantified patterns of benthic macroalgal biomass and irradiance on rocky reefs that had intact kelp forests and nearby reefs where the benthic macroalgae had been lost due to deforestation at three sites along the California, USA and Baja California, MEX coasts during the springs and summers of 2017 and 2018. We then modeled how the loss of macroalgae from these reefs impacted net benthic productivity using species-specific, mass-dependent rates of photosynthesis and respiration that we measured in the laboratory. Our results show that the macroalgal assemblages at these sites were dominated by a few species of stipitate kelps and fleshy red algae whose relative abundances were spatially and temporally variable, and which exhibited variable rates of photosynthesis and respiration. Together, our model estimates that the dominant macroalgae on these reefs contribute 15 to 4,300 mg C m^-2 d^-1 to net benthic primary production, and that this is driven primarily by a few dominant taxa that have large biomasses and high rates of photosynthesis and / or respiration. Consequently, we propose that the loss of these macroalgae results in the loss of an important contribution to primary production and overall ecosystem function.

• 한국해양바이오학회지
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• 제5권4호
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• pp.8-14
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• 2011

Although marine living organism contains a numerious number of compounds, it is difficult to collect these compounds in a large scale for medicinal application. However, in recent years, several bioactive compounds isolated from marine macroalgae have been proved to be able to provide potential sources for development of medicinal products because they can be obtained in large amount from marine. A number of studies have reported a variety of effects of marine macroalgae but a few anti-inflammatory activity of marine macroalgae have recently been published. Herein, we reviewed novel anti-inflammatory compounds recently isolated from marine brown algae, green algae and red algae. From this survey, in particular, some compounds contained in edible macroalgae exert anti-inflammatory effects with inhibition on cyclooxygenase-2 (COX-2), inducible nitric oxide synthase(iNOS) and matrix metalloproteinases (MMPs) activity regulated by nuclear factor-kappa B transcription factor that play a key role in cancer as well as inflammation, demonstrating to be able to potentially apply to development of anti-inflammatory agent for chemoprevention of cancer. Furthermore, some macroalgae and their compounds with both excellent anti-inflammatory activity and very low toxicity can select a potential candidates capable of preventing or treating several chronic inflammation such as colitis, hepatitis and gastritis, leading to cancer.

• 한국수산과학회지
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• 제45권6호
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• pp.694-703
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• 2012

To understand the characteristics of sedimentary and benthic environments in habitats of naturally-occurring intertidal benthic macroalgae, various geochemical parameters of sediment (grain size, ignition loss [IL], chemical oxygen demand [COD], and acid volatile sulfur [AVS]) and pore water (temperature, salinity, pH, and nutrients) were measured in the southern intertidal zone of Hampyeong Bay at two month intervals from April to October 2009. Ecological characteristics including the distribution and biomass of benthic macroalgae were also investigated. Benthic macroalgae were distributed below 4 to 5 m depth from mean sea level near the lower portion of the intertidal zone where air exposure time is relatively short. The distribution area and biomass of benthic macroalgae gradually decreased during the study period. The surface sediments in the benthic algal region were mainly composed of finer sediments, such as slightly gravelly mud and mud. The temperature, salinity, pH, and nutrient concentrations (except dissolved inorganic nitrogen) in pore water did not differ in regions with and without benthic macroalgae, whereas the mean grain size and the concentrations of IL, COD, and AVS in sediments were much higher in regions harboring benthic macroalgae. The correlation between mean grain size and IL in sediments displayed two distinct gradients and the slope was much steeper in regions harboring benthic macroalgae, indicating that the content of organic matter in benthic algal region is not solely dependent on mean grain size. Our results indicate that the benthic macroalgae in the southern intertidal zone of Hampyeong Bay play an important role in the accumulation of organic matter in sediment.

• 해양환경안전학회지
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• 제27권5호
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• pp.639-646
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• 2021

바다숲 복원과 함께 굴 패각의 새로운 자원화를 위해 굴 패각을 피복시킨 콘크리트 기질을 부산광역시 기장군 일광면 동백리 연안에 설치하여 약 1년간(2020년 1월~11월) 해조류 피도 변화를 모니터링하였다. 1월 모니터링 결과, 대조구인 일반 콘크리트 기질에는 해조류가 출현하지 않았다. 이에 반해 굴 패각을 10 ~ 90 % 피복시킨 실험구에는 해조류가 약 10 ~ 80 %의 피도로 착생한 것을 확인하였다. 또한, 11월 실험구의 피도는 대조구 대비 최대 49 % 높게 나타났다. 이상의 결과로부터 콘크리트 기질의 인공어초에 굴 패각 피복을 통해 인공어초의 해조류 착생을 촉진할 수 있으며, 수산 부산물인 굴 패각의 새로운 자원화 방안을 제시하였다.

• ALGAE
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• 제34권4호
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• pp.315-326
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• 2019

Northeastward drifts of massive Sargassum patches were observed in the East China Sea (ECS) and Yellow Sea (YS) by the Geostationary Ocean Color Imager (GOCI) in May 2017. Coverage of the brown macroalgae patches was the largest ever recorded in the ECS and YS. Three-dimensional circulation modeling and Lagrangian particle tracking simulations were conducted to reproduce drifting trajectories of the macroalgae patches. The trajectories of the macroalgae patches were controlled by winds as well as surface currents. A windage (leeway) factor of 1% was chosen based on sensitivity simulations. Southerly winds in May 2017 contributed to farther northward intrusion of the brown macroalgae into the YS. Although satellite observation and numerical modeling have their own limitations and associated uncertainties, the two methods can be combined to find the best estimate of Sargassum patch trajectories. When satellites were unable to capture all patches because of clouds and sea fog in the ECS and YS, the Lagrangian particle tracking model helped to track and restore the missing patches in satellite images. This study suggests that satellite monitoring and numerical modeling are complementary to ensure accurate tracking of macroalgae patches in the ECS and YS.

• Journal of Plant Biology
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• 제38권2호
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• pp.153-158
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• 1995

Community structure of subtidal macroalgae was investigated at 3 sites of Neobdo Island in August 1994. In total, 66 taxa of red, 21 brown, 14 green, and 2 blue-green algae were identified. The number of species and biomass decreased with increasing depths. Gelidium amansii, Ulva pertusa, Dictyota dichotoma, Sargassum thunbergii, Undaria pinnatifida, Ecklonia cava, and Sargassum horneri had higher frequency and biomass. The vegetation of deeper zone was composed mainly of a few red algae. Substrate characteristic and light intensity were considered as environmental factors determining the underwater vegetation.

• 한국해양바이오학회지
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• 제6권1호
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• pp.8-16
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• 2014

Macroalgae has been strongly touted as an alternative biomass for biofuel production due to its higher photosynthetic efficiency, carbon fixation rate, and growth rate compared to conventional cellulosic plants. However, its unique carbohydrate composition and structure limits the utilization efficiency by conventional microorganisms, resulting in reduced growth rates and lower productivity. Nevertheless, recent studies have shown that it is possible to enable microorganisms to utilize various sugars from seaweeds and to produce some energy chemicals such as methane, ethanol, etc. This paper introduces the basic information on macroalgae and the overall conversion process from harvest to production of biofuels. Especially, we will review the successful efforts on microbial engineering through metabolic engineering and synthetic biology to utilize carbon sources from red and brown seaweed.

• 한국해양생명과학회지
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• 제6권2호
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• pp.117-123
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• 2021

Post-disturbance recovery pattern of subtidal soft corals-macroalgae mixed community and the role of water depth were investigated. The experiment was conducted in a subtidal rock wall of Munseom, Jeju Island, Korea for 2.5 years. Artificial disturbance was done at established treatment plots at depths of 10, 15 and 20 m and were then compared with undisturbed control plots. After disturbance, recovery of soft corals was very slow, whereas macroalgae quickly occupied the plots and reached a similar level as the control in 6 months, and this pattern was consistent at all water depths. This unbalanced speed of recovery caused higher macroalgae establishment than soft corals in treatment compared to control plots, indicating a possible phase shift in the community structure. This study provides an important implication for the necessity of monitoring the influence of disturbance at a larger scale, from a conservation perspective of soft corals in Jeju coast.

• 한국수산과학회지
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• 제48권3호
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• pp.329-336
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• 2015

We examined the effect of substituting squid meal and macroalgae with soybean meal in a commercial diet on the growth and body composition of juvenile abalone Haliotis discus hannai. We randomly distributed 2310 juvenile abalone into 33 rectangular plastic containers and fed them five experimental diets in triplicate as follows. The control diet (Con) consisted of 12% squid meal, 8% corn gluten and 20% soybean meal as protein source, wherein 10% ${\alpha}$-starch, 20% wheat flour, and 5% dextrin were carbohydrate source. The experimental diets, 50% squid meal (SM50), 50% squid meal and 50% macroalgae (SM50+MA50), and 100% squid meal and 50% macroalgae (SM100+MA50) were substituted with the same respective amounts of soybean meal. The fifth experimental diet consisted of the control diet plus 1% diatom powder (DP). We prepared two domestic (Domestic A and B) and two imported (China and Japan) abalone feeds. Finally, we prepared Undaria and sea tangle. We found that the weight gain of abalone fed the Con, DP, and China and Japan diets was significantly greater than that of abalone fed Undaria and sea tangle. We conclude that the substituting squid meal and macroalgae with soybean meal in abalone feed has limited benefits, but supplementing diets with 1% diatom powder is effective in improving weight gain.

• Ocean and Polar Research
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• 제34권1호
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• pp.65-71
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• 2012

Gambierdiscus toxicus, Adachi et. Fukuyo, is a benthic ciguatoxin-producing armored dinoflagellate, often attached to macroalgae. This organism is the primary causative agent of ciguatera fish poisoning which occurs in tropical and subtropical regions. However, regardless of the fact that the population of Gambierdiscus spp. has expanded to such temperate areas from sub-trophic and trophic areas, monitoring of G. toxicus has been lacking in the Korean coastal waters of temperate areas. This study was performed at the uninhabited Baekdo Islands off the southern coast of Korea and at Seopsom Island in the vicinity of Seogwipo, Jeju Province during April and May, 2011. Cell densities of Gambierdiscus spp. on macroalgae at Baekdo and Jeju Island ranged from zero to 56.4 cells $g^{-1}$. Maximum density was recorded on the brown alga Cladophora japonica at St. 3 of Jeju Island. In particular, the cell densities of Gambierdiscus spp. were influenced by the substrate characteristics of macroalgae. In the future, the continuous monitoring of toxic benthic dinoflagellate is necessary to predict and prevent ciguatera poisoning in Korean coastal waters.