• Title/Summary/Keyword: the Indian Ocean

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Relative Microalgal Concentration in Prydz Bay, East Antarctica during Late Austral Summer, 2006

  • Mohan, Rahul;Shukla, Sunil Kumar;Anilkumar, N.;Sudhakar, M.;Prakash, Satya;Ramesh, R.
    • ALGAE
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    • v.24 no.3
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    • pp.139-147
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    • 2009
  • Microalgae using a submersible fluorescence probe in water column (up to 100 m) were measured during the austral summer of 2006 (February) in Prydz Bay, East Antarctica (triangular-shaped embayment in the Indian sector of Southern Ocean). Concurrently, environmental parameters such as temperature, salinity and nitrogen (nitrate, ammonium, urea) uptake rates were measured. The concentration of phytoplankton is relatively high due to availability of high nutrients and low sea surface temperature. Phytoplankton community is dominated by diatoms whereas cryptophytes are in low concentration. The maximum concentration of total chlorophyll is 14.87 ${\mu}g\;L^{-1}$ and is attributed to upwelled subsurface winter water due to local wind forcing, availability of micro-nutrients and increased attenuation of photosynthetically available radiation (PAR). Concentration of blue-green algae is low compared to that of green algae because of low temperature. Comparatively high concentration of yellow substances is due to the influence of Antarctic melt-water whereas cryptophytes are low due to high salinity and mixed water column. Varied concentrations of phytoplankton at different times of Fluoroprobe measurements suggest that the coastal waters of Prydz Bay are influenced by changing sub-surface water temperature and salinity due to subsurface upwelling induced by local winds as also melting/freezing processes in late summer. The productivity is high in coastal water due to the input of macro as well as micro-nutrients.

Studies on the Korean Deep Sea Fishing Industry Administration -Analysis of present situation and prospects- (한국의 해외 원양어업 경영에 관한 연구 - 현황 분석과 전망 중심으로-)

  • 김우성
    • The Journal of Fisheries Business Administration
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    • v.1 no.2
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    • pp.1-22
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    • 1970
  • Our fisheries protucts industry has developed rapidly during past 10 years ; production was about twice: fihing fleets increased twice in number and 3 times in tonnage ; export was 5 times. Govermment is trying to develop deep sea fisheries in order to surmount the depression of coast fisheries. At present more than 270 deep sea fishing boats are working with superior skill to other country at the South Pacific, the Atlantic, the Indian, and the North Pacific Ocean. Our deep sea fisheries is consisted of the tuna long line and the trawler. The tuna long line of them has 230 crafts in 1969 ana the deep sea trawler has 40 crafts, too. Comparing to 1962, the number of the deep sea fishing boats has been increased highly to 54 times, 7.71 times average per year increasing rate. The rate of the tuna long line to the trawler at the end of 1969 shows 85:15, More than half of them are 100~200 (equation omitted), if we classify them according to (equation omitted) or boat craft. 70% of them has less than 5 years ships age. The Korean Marine Industry Development Corporation has more than 1/3 fishing fleets, with 91 crafts, if We consider it according to corporation. Considering it according to the financial resources, dependence upon foreign loan is as high as 88%. Catches was 74, 450 M/T ($24, 663, 000)at the end of November in 1969 and it was increased to 113.5 times in catch amount and 118 times in value, comparing to those of 1962. Considering it according to the ocean, the order is arranged to the Pacific, the Atlantic, and the Indian Ocean. The average production amount of each craft is 250~400 S/T a year. The result of export took up 1/3 of total fisheries product export with $ 22, 398, 000 at the end of november in 1969. Employee cost of fishing coast is 8% higher than other fishing. The profit is highest in our fisheries. Most of the products except the trawler fishing are sofa at the fishing grounds to the processing company, and they lose much money. They buy most of bait from Japan, giving $8~10 for 1C/S(10kg). Fish price is $390~520 according to the kind of fish for S/T at the fishing grounds, and the rapid frozen fishes brought to Japan are about $ 800 for S/T. There is much difference. in price. Problems 1. Want of self capital. 2. To get the refrigeration boats enough. 3. International Fishing Regulation. 4. To get high price and to secure consuming grounds. 5. To get home-production of bait. 6. To exploit new fishing grounds. 7. To get larger boats. 8. To get mariner enough. When the problems mentioned above are solved, the Deep Sea Fisheries of oun courtry will be developed more largely.

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Morphology, molecular phylogeny, and pigment characterization of an isolate of the dinoflagellate Pelagodinium bei from Korean waters

  • Potvin, Eric;Jeong, Hae Jin;Kang, Nam Seon;Noh, Jae Hoon;Yang, Eun Jin
    • ALGAE
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    • v.30 no.3
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    • pp.183-195
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    • 2015
  • The dinoflagellate genus Pelagodinium is genetically classified in distinct sub-clades and subgroups. However, it is difficult to determine whether this genetic diversity represents intra- or interspecific divergence within the genus since only the morphology of the type strain of the genus Pelagodinium, Pelagodinium bei, is available. An isolate associated with the genus Pelagodinium from Shiwha Bay, Korea, was recently cultured. This isolate was clustered with 3 to 4 strains from the Atlantic Ocean, Mediterranean Sea, and Indian Ocean. This cluster was distinct from the subgroup more closely associated with P. bei. The morphology of the isolate was analyzed using optical and scanning electron microscopy and was almost identical to that of P. bei except that this isolate had two series of amphiesmal vesicles (AVs) in the cingulum, unlike P. bei that has one series. When the pigment compositions of the isolate and P. bei were analyzed using high-performance liquid chromatography, these two strains had peridinin as a major accessory pigment and their pigment compositions were almost identical. In addition, the swimming behaviors of these two strains were very similar. The reexamination of the type culture of P. bei revealed two series in the cingulum as for the isolate. The new findings on the number of series of AVs in the cingulum, the pigment composition, and the swimming behaviors suggest that P. bei and the isolate are conspecific despite their genetic divergence. This study provides a basis to further understand the molecular classification within Pelagodinium combining genetic, morphological, pigment, and behavioral data.

The Development of Ensemble Statistical Prediction Model for Changma Precipitation (장마 강수를 위한 앙상블 통계 예측 모델 개발)

  • Kim, Jin-Yong;Seo, Kyong-Hwan
    • Atmosphere
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    • v.24 no.4
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    • pp.533-540
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    • 2014
  • Statistical forecast models for the prediction of the summertime Changma precipitation have been developed in this study. As effective predictors for the Changma precipitation, the springtime sea surface temperature (SST) anomalies over the North Atlantic (NA1), the North Pacific (NPC) and the tropical Pacific Ocean (CNINO) has been suggested in Lee and Seo (2013). To further improve the performance of the statistical prediction scheme, we select other potential predictors and construct 2 additional statistical models. The selected predictors are the Northern Indian Ocean (NIO) and the Bering Sea (BS) SST anomalies, and the spring Eurasian snow cover anomaly (EUSC). Then, using the total three statistical prediction models, a simple ensemble-mean prediction is performed. The resulting correlation skill score reaches as high as ~0.90 for the last 21 years, which is ~16% increase in the skill compared to the prediction model by Lee and Seo (2013). The EUSC and BS predictors are related to a strengthening of the Okhotsk high, leading to an enhancement of the Changma front. The NIO predictor induces the cyclonic anomalies to the southwest of the Korean peninsula and southeasterly flows toward the peninsula, giving rise to an increase in the Changma precipitation.

Ferrying to the Other Shore: Silla Seafarers and Avalokiteśvara Faith in the East Asian Maritime World

  • Erika Erzsebet VOROS
    • Acta Via Serica
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    • v.8 no.2
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    • pp.125-154
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    • 2023
  • Historically, commerce was a significant factor in the proliferation and development of Buddhism, which is especially manifest in the cult of the bodhisattva Avalokiteśvara. Iconographic and textual evidence testifies that maritime trade on the Indian Ocean played a fundamental role in the formation of Avalokiteśvara worship. The sea was also a major conduit through which elements of the Avalokiteśvara faith were transmitted from India through China to Korea and Japan, the easternmost ends of the Silk Road. These elements include Avalokiteśvara's role as a maritime savior, oceanic symbolism, and the concept of the bodhisattva's worldly abode, Potalaka. Cultic sites dedicated to maritime safety were established at important transport hubs in East Asia. Due to China's strategic location on the Silk Road, as well as its cultural influence, the most important cultic sites were founded in China, first on the Shandong Peninsula, then in the southern Jiangnan region, in present-day Zhejiang Province. Especially notable is the role that Korean seafarers played in this process by assisting monks in search of the Dharma, establishing temples, and transmitting religious beliefs across the ocean. The present study focuses on the role that maritime figures played in the cultural exchanges between Korea, China, and Japan examined through Avalokiteśvara faith. By this, it aims to demonstrate how Korean seafarers inherited and continued the traditional relationship between commerce and Buddhism, while extending the Maritime Silk Road to the "East Asian Mediterranean."

Molecular analyses and reproductive structure to verify the generic relationships of Hypnea and Calliblepharis (Cystocloniaceae, Gigartinales), with proposal of C. saidana comb. nov.

  • Yang, Mi Yeon;Kim, Myung Sook
    • ALGAE
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    • v.32 no.2
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    • pp.87-100
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    • 2017
  • The genera Hypnea and Calliblepharis of the family Cystocloniaceae are discriminated by their female reproductive structure, especially in the formation of carposporangia and gonimoblasts. Hypnea saidana, once classified based on obsolete evidence, has not been studied phylogenetically using molecular analysis and detailed reproductive structure though it shares many morphologic features with the genus Calliblepharis. To provide better understanding of generic relationship of H. saidana with Hypnea and Calliblepharis, we carried out molecular analyses using the nuclear-encoded small subunit ribosomal DNA (SSU) and chloroplast-encoded large subunit of the RuBisCO (rbcL), and exact morphological observations focusing on the reproductive structures of wild specimens. Our molecular phylogeny showed that H. saidana is closely related to Calliblepharis, but distinct from the clade of Hypnea. Female reproductive structure of H. saidana characterized by upwardly developing chains of carposporangia, central reticulum of cell, and gonimoblast filaments not connected to the pericarp provides definite evidence to assign the taxonomic position of this species to Calliblepharis. Based on our combined molecular and morphological analyses, we have proposed Calliblepharis saidana comb. nov., expanding the distribution of Calliblepharis habitat from the eastern Atlantic South Africa, the northern Indian Ocean, Australasia, and Brazil to the western Pacific Ocean.

Carotenoid Pigments from Suspended and Sinking Particulate Matter in Prydz Bay, Antarctica

  • Noh, Il
    • Journal of Environmental Science International
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    • v.20 no.11
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    • pp.1357-1371
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    • 2011
  • Suspended and sinking particles were collected during ODP Leg 119 to the Indian Ocean sector of the Antarctic Ocean. Field work was carried out at four sampling sites in Prydz Bay. Two of these sites were located in the Outer Bay, and two in the Inner Bay. At the four locations, a total of ten deployments of a sediment trap array were made. The concentrations of carotenoids both in suspended and sinking particulate matter in Prydz Bay were analyzed using HPLC. Fucoxanthin was the dominant carotenoid pigments both in suspended and sinking particles. The present study also indicates that 19'-hexanoyoxyfucoxanthin-containing prymesiophytes (Phaeocystis spp.) was abundant in the study area. The flux rates of carotenoids were generally highest at 50 m, and approximately double the flux rates at deeper horizons, however, at Inner Bay sites, the mean flux rates of carotenoids were greatest at 200 m, and 3 times greater than that of 50 m. Such anomalous high fluxes at 200 m imply that grazers were locally abundant between 100 m and 200 m at these sites close to land, and this hypothesis is supported by visual evidence of lots of fecal pellets in the 200 m trap. Integrates standing stocks versus sinking pigments data support that particulate material in Prydz Bay was not recycled rapidly.

Chlrorophylls and their Degradation Products using High Performance Liquid Chromatography (HPLC), with Data from Suspended and Sinking Particulate Matter in Prydz Bay, Antarctica

  • Noh, Il
    • Journal of Navigation and Port Research
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    • v.35 no.4
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    • pp.323-334
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    • 2011
  • Suspended and sinking particles were collected in austral summer during ODP Leg 119 to the Indian Ocean sector of the Antarctic Ocean. Field work was carried out at four sampling sites in Prydz Bay. Two of these sites were located in the Outer Bay, and two in the Inner Bay. At the four locations, a total of ten deployments of a sediment trap array were made. The concentrations of chlorophylls and their degradation products both in suspended and sinking particulate matter in Prydz Bay were analyzed using HPLC. Chlorophylls a and c were the dominant algal pigments both in suspended and sinking particles. Because of the abundance of fecal pellets at Site 740, the mean fluxes at 200 m averaged 6 fold greater than that at 50 m. This implies that a dense swarm of zooplankters, presumably large copepods and/or salps, may "feed and excrete" mainly in between 100-200 m depths at this site, closest to land in Prydz Bay. Interestingly, The flux of phaeophorbide a was generally similar in magnitude to that of chlorophyll a throughout the study areas. This is an evidence that materials escaping from near-surface regions in austral summer derive mainly from the gazing of zooplankters. "New production" from sediment-trapped CHL pigment fluxes in Prydz Bay was estimated using f-ratio of 0.15, ranging from 520 to $1,605\;{\mu}gC\;m^{-2}\;day^{-1}$.

Inner harbour wave agitation using boussinesq wave model

  • Panigrahi, Jitendra K.;Padhy, C.P.;Murty, A.S.N.
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.1
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    • pp.70-86
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    • 2015
  • Short crested waves play an important role for planning and design of harbours. In this context a numerical simulation is carried out to evaluate wave tranquility inside a real harbour located in east coast of India. The annual offshore wave climate proximity to harbour site is established using Wave Model (WAM) hindcast wave data. The deep water waves are transformed to harbour front using a Near Shore spectral Wave model (NSW). A directional analysis is carried out to determine the probable incident wave directions towards the harbour. Most critical threshold wave height and wave period is chosen for normal operating conditions using exceedence probability analysis. Irregular random waves from various directions are generated confirming to Pierson Moskowitz spectrum at 20m water depth. Wave incident into inner harbor through harbor entrance is performed using Boussinesq Wave model (BW). Wave disturbance experienced inside the harbour and at various berths are analysed. The paper discusses the progresses took place in short wave modeling and it demonstrates application of wave climate for the evaluation of harbor tranquility using various types of wave models.

Robust Diagnostic World Ocean Circulation with Half-Degree Resolution (1/2$^{\circ}$해상도의 진단적 전구 해수순환모형 연구)

  • 최병호;웨이체첸;팡구오홍;최영진
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.13 no.1
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    • pp.80-87
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    • 2001
  • Global robust diagnostic models are established based on MOM of GFDL to study the circulation in the world ocean. The horizontal grid sizes 1/2 degree, and the vertical water column is divided into 21 levels. The hydrographic data are taken from Levitus et al.(1994) and the wind stress from Hellerman and Rosenstein (1983). Based on the model results the horizontal volume, heat and salt transports across some representative sections are calculated. The preliminary results show that Though the cross-equator volume transports in the Atlantic, Indian and Pacific Oceans are all small, the heat transports across equator in the Atlantic are northward. This is clearly a result of the southward flow of the North Atlantic Deep Water and the northward compensating warm flow in the upper layer. The annual mean of the cross-equator heat transport in the Pacific Ocean from the present model is significantly lower than that calculated by Philander et at. (1987). This might indicate the importance of the Indonesian Throughflow in the heat transport in the Pacific Ocean. Our calculation shows that the heat transport through the Indonesian Archipelago is 0.5 PW, which is comparable with the poleward heat transport in the North Atlantic and Pacific Oceans. The difference in heat transports across the sections 5 and 6 demonstrates the important role of the Agulhas Current in the heat balance of the world ocean.

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