• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.155-156
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• 2000

연안 해역에서 해조류와 부착패류는 양식장 시설 뿐만아니라 수취구 어선바닥 등에서 그 피해는 심각한 실정이다. 해조류에 의한 부착은 잎파래 가시파래 등이 주가 되고 패류로는 홍합과 따개비가 주를 이룬다 이들의 부착방지를 위해서 염소살균, TBTO (Tributyltin oxide), CuSO$_4$등의 처리를 하고 있지만 이러한 처리에 의해서는 또다른 환경 문제가 야기되고 있다. 이같은 부착방지 물질 탐색의 일환으로 흥합을 탐색 대상종으로 선택하여 각종 해조류 추출물들로부터 부착 방지 효과를 조사하였다. 그 결과 고리매(Sytosimphon lomentaria)로부터 가장 높은 활성을 확인 하였고, TLC, silica-gel chromatography, Ion-exchange, HPLC를 통해 정제 하였다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.147-148
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• 2000

Marine algae는 주된 fouling organism으로 전세계에 널리 분포되어 있고, 경제적 손실을 가져온다. 특히나 container ships와 large tanker에서 자라는 algae는 마찰력의 증가로 인한 speed 감소와 연료비의 증가와 같은 문제점을 가진다. 그래서 현재 antifouling paint로 TBT화합물을 사용하고 있지만, 이것은 해양생물에 나쁜 영향을 미치는 것으로 나타나 TBT 화합물 사용에 대해 제한하고 있다. 따라서 본 연구에서는 해조류 추출물을 이용하여 무독성 천연 방오물질의 탐색을 목적으로 우선 선박이나 양식장 그물등에 많이 부착 성장하는 가시파래를 대상으로하여 이의 antifouling 효과를 나타내는 물질을 찾고자 한다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.199-200
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• 2001

해조류중 특히 방사무늬 김 (Porphyra yezoensis)의 양식기술은 인공채묘기술이 개발된 이래 양식 및 가공분야의 많은 기술적 진보를 거듭해 오고있으며 양식장은 천해 해역으로 하천수의 유입으로 인한 풍부한 영양염류의 공급을 받고있는 지역에 있다. 이러한 영양염류는 김의 생장촉진에 도움을 주는 반면에 여러 가지 미생물, 미세조류, 부착조류 등의 증식도 함께 촉진하여 결과적으로 김 성장에 대한 영양분의 경쟁관계, 질병유발 김 양식의 생산력 저하등의 문제점들을 동시에 유발하고 있다. (중략)

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.4
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• pp.243-251
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• 2012

Real-time monitoring for environmental factors(temperature, salinity, chlorophyll, etc.) and carbonate components( pH and $fCO_2$) was conducted during 5-6th of July, 2012 at a seaweeds farm in Gijang, Busan. Surface temperature and salinity were ranged from $12.5{\sim}17.6^{\circ}C$ and 33.7~34.0, respectively, with highly daily and inter-daily variations due to tide, light frequency(day and night) and currents. Surface $fCO_2$ and pH showed a range of $381{\sim}402{\mu}atm$ and 8.03~8.15, and chlorophyll-a concentration in surface seawater ranged 0.8~5.8 ${\mu}g\;L^{-1}$. Environmental and carbonate factors showed the highest/lowest values around 5 pm of 5th July when the lowest tidal height and strongest thermocline in the water column, suggesting that biological production resulted in decrease of $CO_2$ and increase of pH in the seaweed farm. Processes affecting the surface $fCO_2$ distribution were evaluated using a simple budget model. In day time, biological productions by phytoplankton and macro algae are the main factors for $CO_2$ drawdown and counteracted the amount of $CO_2$ increase by temperature and air-sea exchange. The model values were a little higher than observed values in night time due to the over-estimation of physical mixing. The model suggested that algal production accounted about 14-40% of total $CO_2$ variation in seaweed farm.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.3
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• pp.203-210
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• 2016

In this study, nine heavy metals were analyzed in seaweeds collected from market and laver culture farm of Korea and a food safety assessment were also carried out for these heavy metals. The level of heavy metal concentrations in seaweeds was in the following order: Fe>As>Zn>Cu>Cd>Pb>Cr>Ni>Hg. Except for zinc and cadmium, seven heavy metals were significantly higher in cultured laver than in processed laver. Significant correlation was observed Cr-Fe in cultured laver and Cu-Zn, Cd-Cu, Cd-Zn and Pb-Ni in processed laver and Cu-Cr, Cu-Zn, Cd-Cr and Ni-Fe in sea tangle and Zn-Fe, Cr-Fe, Cr-Zn, Cd-Ni, Cu-Cd and Cu-Pb in processed sea mustard. Considering differences in heavy metal concentration between processed laver and cultured laver and in correlation among heavy metals, removal efficiency of heavy metals may be attributed to seaweed treatment process. The average weekly intakes of Cu, Cd, Zn, Fe and Hg via seaweeds consumption were about 0.1~7.6% of PTWI (Provisional Tolerable Weekly Intakes). Therefore, it was found that heavy metals in the seaweeds were very safe for consumption.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.1
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• pp.11-17
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• 2014

In this study, a hydraulic model experiment under wave conditions was carried out to investigate the gap/distance between two near-unit farm lines that affects the rope kink and shape variation of a seaweed farm during mooring block movement. As a result, rope kink occurred during the low wave height condition as the gap/distance between the two near-unit farm lines decreased. The seaweed farm maintained a stable shape in the higher wave height conditions as the gap/distance between the two near-unit farm lines increased. This result indicates that rope kink is sensitively affected by the gap/distance between the two near-unit farm lines. A tendency to increase the critical wave height was observed when mooring block movement occurred, and as the mooring block weight and wave period increased. From the experimental results in which incident wave conditions and the mooring block weight changed, as the front side mooring block weight increased from 3.0 to 8.0 tons, the seaweed farm was stable, and rear side mooring block movement hardly occurred. The observed tension of the seaside mooring line was a maximum at about 3.0 ton/m.

• Ecology and Resilient Infrastructure
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• v.2 no.1
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• pp.64-79
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• 2015

We investigated the tidal current, hydrographic data, and benthic environment of major sea cucumber (Holothuroidea, de Blainville, 1834) habitats in Baengnyeongdo, Jindo and Uljin to understand the optimal environmental or ecological habitat for sea cucumbers. The three study areas were characterized by a cold-water mass of temperatures ranging $12{\sim}18^{\circ}C$, with an active circulation between the surface and deep waters. According to an analysis of the tidal current map, a strong flow velocity of $100{\sim}120cm\;s^{-1}$ appeared in Baengnyeongdo and Jindo. The three sea cucumber habitats showed the common characters of a bottom sediment composed of sand-silt, a diverse seaweed colony and benthic organisms, and boulders and rocks which provide a hideout for the organisms. We aimed to draw the optimal habitat condition for sea cucumbers in Korea, and the result showed that the low water temperature, rapid water flow, active vertical mixing between surface and deep waters, bottom composed by sand-silt, large rocks, and diverse seaweed colony and benthic organism were important factors. The optimal habitat for Juvenile sea cucumbers was the intertidal areas characterized by a muddy bottom, reef, and seaweed. The optimal habitat for adult sea cucumbers was characterized by a place where sand and mud are mixed, and the body size of the sea cucumber was proportional to water depth, and the relatively large boulders and rocks compared to the intertidal area.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.3
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• pp.177-185
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• 2012

Wave field measurements were made over a period of 18 days to study the spatial distribution of incident wave on seaweed tarm field around Gumil-up Sea, Wando, Korea. These measured data were compared with data from the Geomun-do ocean weather/wave observation buoy. A numerical simulation model that combined the offshore design wave with the seasonal normal incoming wave was used to study the incident wave distribution surrounding a seaweed farm. The results are summarized as follows. (1) On-site wave measurements showed that the major relationship between maximum and significant wave height was $H_{max}=1.6H_{1/3}$. (2) Offshore incident wave energy reaching the coast was greatly influenced by the wind direction. A north wind reduced the incident wave energy and a south wind increased it. (3) The calculated maximum wave height under the design wave boundany conditions was in the range of 4~5 m and the reduction in the incident wave height ratio ranged from approximately 38.1% to 47.6% at Gumil-up Sea. Under normal wave conditions, the maximum wave heights were 3.6~4.0 m in summer and 2.3~2.7 m in winter while the reduction in the incident wave height ratio was about 41.8% to 49.1%. (4) The sea state in the southern area of Gumil-up was the most affected by ocean waves, whereas the sea state in the northern area was very stable. The significant wave ratio in the south was about six times that in the north.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.620-625
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• 2018

Pyropia yezoensis is one of the most extensively cultivated seaweeds used as food in Korea. However, the quality and yield of Pyropia farms are frequently affected by outbreaks of thallus discoloration. The objective of this study was to develop a simple and rapid method to evaluate P. yezoensis discoloration caused by nutrient deficiencies. A colorimeter was used to quantify the color of P. yezoensis in nutrient deficient media over 10 days. Quantitative values of lightness (L), redness (a), and yellowness (b) measured with a colorimeter were used as indicators of P. yezoensis discoloration. The vacuoles of P. yezoensis were observed at 4 days and swelled gradually from 6 days onward. The three colorimeter parameters L, a, and b values showed significantly different values with culture period. The lightness (L) value was darker initially, and continued to lighten over culture period. The yellowness (b) value increased, but the redness (a) value decreased throughout this study. The a/b ratio and redness (a) values from the colorimeter were important P. yezoensis color change indicators. The discoloration group of P. yezoensis had quantitative values for parameters of L above 70, a below 2.6, and b above 15.0. The results of this study showed that quantitative colorimetric measurements can be used as tools for simple and rapid detection of P. yezoensis discoloration.

• 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.