• Title, Summary, Keyword: deep-sea corals

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Evaluation of Jeju/Tsushima Hermatypic Corals as Sea Surface Temperature (SST) Recorders (제주/쓰시마 조초성 산호의 수온 기록자로서의 가능성 평가)

  • Hyeong, Ki-Seong;Shimamura, Michiyo;Watanabe, Tsuyoshi;Yamano, Hiroya;Sugihara, Kaoru;Kim, Jong-Uk
    • Ocean and Polar Research
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    • v.30 no.3
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    • pp.351-359
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    • 2008
  • In an effort to develop high-resolution sea surface temperature (SST) proxies for mid-latitude regions, two massive reef-building coral species, Alveopora and Favia, were collected from Jeju and Tsushima Islands, respectively. Their skeletons were subsequently analyzed for annual growth banding, Sr/Ca and Mg/Ca ratios. Hermatypic corals are thinly distributed in the waters of Jeju Island, where Alveopora japonica was the only dominant coral species. A higher diversity of hermatypic corals were observed in the waters of Tsushima Island, where Favia sp. was the most common coral species and even forming an about 6-m-high reef structure. Both Alveopora and Favia showed annual growth layers consisting of couplets of high- and low-density bands. Sr/Ca ratio of both species and Mg/Ca ratio of Alveopora also showed seasonal variation, likely reflecting SST variation. These results suggest the possibility that Alveopora and Favia species can be used as potential SST proxies. However, this study also highlights the potential growth disturbance of middle latitude corals due to high rainfall during monsoon and low SST during winter. This possibility should be taken into account in the investigation of Sr/Ca(Mg/Ca)-SST relationships.

New Records of Cold-Water Corals from Korea

  • Song, Jun-Im
    • Animal Systematics, Evolution and Diversity
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    • v.32 no.3
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    • pp.197-206
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    • 2016
  • Two cold-water coral taxa, Octocorallia in the class Anthozoa and Stylasteridae in the class Hydrozoa, were identified. Deep-water samples were collected in fishing nets at depths ranging between 20 and 200 m along the coasts of the East Sea in Korea from 1976 to 1993. The two species found in this study represent new records for Korea: Paragorgia arborea (Linnaeus, 1758) in the class Anthozoa, and Stylaster profundiporus Broch, 1936 in the class Hydrozoa. Two families, Paragorgiidae and Stylasteridae, are also newly recorded in Korea. Furthermore, the species name of another cold-water gorgonian species, Primnoa pacifica (Kinoshita, 1907) in the family Primnoidae, is amended in this report. The two newly recorded cold-water coral species from Korea are described in detail based on their morphological characteristics. Paragorgia arborea is characterized by its growth form, medulla and cortex, zooid dimorphism, canal system, and spicule composition. Stylaster profundiporus is distinguished by its external skeletal characteristics, such as the coordination of dactylopores and gastropores, presence or absence of gastrostyles and dactylostyles, cyclosystem orientation, ampullar position, gastropore tube shape, and coenosteal texture.

An Evaluation on the Implementation of UNGA Resolutions in Management of Korean Deep-sea Fisheries in the High Seas (공해 저층어업 규제동향과 대응방안 분석)

  • Shin, Yong-Min
    • The Journal of Fisheries Business Administration
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    • v.42 no.1
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    • pp.1-18
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    • 2011
  • This paper analyze a description of Korean fleet using bottom gears on the high seas. The need for this study arises from international moves to address the effects of fishing with bottom gears on vulnerable marine ecosystems (VMEs) and in view of a communication on the Korean policy in respect of this. There is growing concern over the impact of fishing using gears that come into contact with the seabed (bottom gears), in particular in deep-sea areas where vulnerable marine ecosystems including seamounts, hydrothermal vents and cold water corals are located. Korea is an important stakeholder in high seas bottom gear fisheries. For the past eight years, the issue of protecting biodiversity in the deep-sea in areas beyond national jurisdiction has been extensively debated by the United Nations General Assembly (UNGA) and in other international fora. As a result of the report and a review by the UNGA of the effectiveness of the measures called for in resolution 59/25, the UN General Assembly called for a series of specific actions to be taken by States and RFMOs in UNGA resolutions 61/105 in 2006 and 64/72 in 2009 adopted by consensus. Korea attaches great importance to the protection of marine ecosystems and has made active efforts to implement the UNGA Resolution 61/105 in areas where there is a regional fisheries management organization, a process of establishing such organization or no such multilateral regime. For the effective implementation of the UNGA Resolution 61/105 and 64/72, Korea views that the development of support tools and, most importantly, the development of a global database on VMEs are urgently needed because many countries lack the ability to identify VMEs and to assess whether individual bottom fishing activities would have significant adverse impacts on their own.

Diagenesis of the Carbonate Rocks of the Seamounts In the Federated States of Micronesia, Central Pacific (중앙태평양 마이크로네시아 군도 해저산 일원에서 발견되는 탄산염암의 속성작용)

  • Woo, Kyung-Sik;Choi, Yoon-Ji;Lee, Kyeong-Yong;Kang, Jung-Keuk;Park, Byong-Kwong
    • The Sea
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    • v.3 no.4
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    • pp.214-227
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    • 1998
  • This study was carried out to investigate the composition and diagenesis of the carbonate rocks from the seamounts in the Federated States of Micronesia, Central Pacific. Most of the samples were dredged from the water depth of about 1000-3000 m mainly in Chuuk Island, Hunter Bank, Caroline Ridge and Yap Trench. The carbonate rocks are either pelagic sediment mainly of planktonic foraminifera or shallow-marine sediment of corals, calcareous algae, mollusks and echinoderms. The rocks are altered texturally and chemically, except for those from the Hunter Bank and Yap A. The presence of shallow-marine cements suggests that the carbonate sediment has been subsided or reworked to the present water depth after deposition in shallow-marine environments. The texture of the carbonate sediment is reminiscent of meteoric diagenesis; however, the stable carbon isotopic composition of the altered rock samples shows affinity with that of sea water and the oxygen isotopic values are slightly enriched or same as compared to those of unaltered samples. These stable isotopic data suggest that the carbonate sediment of the study area has been diagenetically altered in the present deep-marine environment.

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Two anthozoans, Entacmaea quadricolor (order Actiniaria) and Alveopora japonica (order Scleractinia), host consistent genotypes of Symbiodinium spp. across geographic ranges in the northwestern Pacific Ocean

  • Chang, Soo-Jung;Rodriguez-Lanetty, Mauricio;Yanagi, Kensuke;Nojima, Satoshi;Song, Jun-Im
    • Animal cells and systems
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    • v.15 no.4
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    • pp.315-324
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    • 2011
  • The actiniarian sea anemone, Entacmaea quadricolor, and the scleractinian coral, Alveopora japonica, host symbiotic dinoflagellates belonging to the genus Symbiodinium (Freudenthal). We studied the host-symbiont specificity of these two anthozoan hosts in the northwestern Pacific Ocean. Symbionts within the two hosts were identified using partial large subunit (LSU) ribosomal DNA (rDNA) and complete internal transcribed spacers (ITS) 1 rDNA regions. The host, E. quadricolor, was identified using the partial LSU rDNA molecular marker. Genetic analysis showed that E. quadricolor only harbors dinoflagellates belonging to subclade C1/3 of the genus Symbiodinium. Moreover, no genetic variation was detected among the symbionts of E. quadricolor within the study region (Korea and Japan), even though the two distant sites were separated by more than 1000 km, at collection depths of 1 m in shallow and 13-16 m in deep water. Whilst scleractinian corals host multiple Symbiodinium clades in tropical waters, A. japonica, sampled over a wide geographical range (800 km) within the study region, only hosts Symbiodinium sp. clade F3. The high specificity of endosymbionts in E. quadricolor and A. japonica within the northwestern Pacific Ocean could be accounted for because symbiotic dinoflagellates within the host anemones appear to be acquired maternally, and the Kuroshio Current might affect the marine biota of the northwestern Pacific. However, the consistency of the symbiotic relationships between these two anthozoan hosts and their endosymbionts could change after climate change, so this symbiotic specificity should be monitored.