• Title/Summary/Keyword: Coastal ocean

Search Result 4,469, Processing Time 0.038 seconds

Mitochondrial OXPHOS genes provides insights into genetics basis of hypoxia adaptation in anchialine cave shrimps

  • Guo, Huayun;Yang, Hao;Tao, Yitao;Tang, Dan;Wu, Qiong;Wang, Zhengfei;Tang, Boping
    • Genes and Genomics
    • /
    • v.40 no.11
    • /
    • pp.1169-1180
    • /
    • 2018
  • Cave shrimps from the genera Typhlatya, Stygiocaris and Typhlopatsa (TST complex) comprises twenty cave-adapted taxa, which mainly occur in the anchialine environment. Anchialine habitats may undergo drastic environmental fluctuations, including spatial and temporal changes in salinity, temperature, and dissolved oxygen content. Previous studies of crustaceans from anchialine caves suggest that they have possessed morphological, behavioral, and physiological adaptations to cope with the extreme conditions, similar to other cave-dwelling crustaceans. However, the genetic basis has not been thoroughly explored in crustaceans from anchialine habitats, which can experience hypoxic regimes. To test whether the TST shrimp-complex hypoxia adaptations matched adaptive evolution of mitochondrial OXPHOS genes. The 13 OXPHOS genes from mitochondrial genomes of 98 shrimps and 1 outgroup were examined. For each of these genes was investigated and compared to orthologous sequences using both gene (i.e. branch-site and Datamonkey) and protein (i.e. TreeSAAP) level approaches. Positive selection was detected in 11 of the 13 candidate genes, and the radical amino acid changes sites scattered throughout the entire TST complex phylogeny. Additionally, a series of parallel/convergent amino acid substitutions were identified in mitochondrial OXPHOS genes of TST complex shrimps, which reflect functional convergence or similar genetic mechanisms of cave adaptation. The extensive occurrence of positive selection is suggestive of their essential role in adaptation to hypoxic anchialine environment, and further implying that TST complex shrimps might have acquired a finely capacity for energy metabolism. These results provided some new insights into the genetic basis of anchialine hypoxia adaptation.

Mitigation in Saemangeum Bay

  • Shin, Moon-Seup;Tetsuo Yanagi;Hong, Sung-Kun
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
    • /
    • 1995.10a
    • /
    • pp.139-140
    • /
    • 1995
  • The reclamation area of Saemangeum(Kunsan) located between 126。10´E - 126。50´ E and 35。35´N - 36。05´N at the western coast of Korea. The construction of the 33km sea dike is building in the Saemangeum area. When the construction of the sea dike in the coastal region takes plase, there exists, a certain amount of soil which is diffused by the tidal current. (omitted)

  • PDF

Dynamic Behavior of a Moored Floating Fish Farm in Ocean Waves

  • Matsubara, Yuhei
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
    • /
    • 1992.08a
    • /
    • pp.126-129
    • /
    • 1992
  • The most of nearshore areas along the coastline of the Sea of Japan are not blessed with the gulfs or natural reefs. So in those areas so many kinds of man-made Fish Aggregation Devices (FADs) and artificial aquatic habitats have been submerged to cultivate and proliferate the aquatic resources. However, to utilize the ocean space furthermore effectively, the technology of offshore aqua-culture must be developed by coastal engineers and oceanographers.(omitted)

  • PDF

A Nested OGCM Simulations with Restart Dataset --Strategy for Simulating Fine Structures of Circulation for NW Pacific

  • Park, Byung-Ho;Wei Zexun;Guohong Fang;Park, Young-Jin
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
    • /
    • 2000.09a
    • /
    • pp.182-187
    • /
    • 2000
  • Laboratory for Coastal and Ocean Dynamics Studies at Sungkyunkwan University and Department of Physical Oceanography, Institute of Oceanology, Chinese Academy of Sciences has been working on cooperative studies on ocean circulation. (omitted)

  • PDF

Attenuation of High-Frequency Wave Energy Due to Opposing Currents

  • Suh, Kyung-Duck;Lee, Dong-Young-
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
    • /
    • 1993.07a
    • /
    • pp.20-25
    • /
    • 1993
  • In coastal waters, more often than not, waves propagate on currents driven by tidal forces, earth’s gravity, or wind. There have been a number of studies for dealing with the change of wave spectrum due to tile presence of current. Based on the conservation of wave action, Hedges et al. (1985) have proposed an equation which describes the influence of current on the change of wave spectrum in water of finite depth. (omitted)

  • PDF

Physical processes related to coastal water quality problems

  • Takeoka, Hidetaka
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
    • /
    • 1996.10a
    • /
    • pp.60-63
    • /
    • 1996
  • Industrialization and urbanization of coastal areas in recent years have brought about a lot of coastal marine environmental problems. Water quality problems such as eutrophication or pollution by toxic chemicals are especially serious, threatening coastal ecosystems. These problems are mainly induced by anthropogenic loads of materials from the land. In order to design suitable counter measures, we should well understand the processes causing the problems. (omitted)

  • PDF

A Bed Schematized Two-dimensional Sediment Transport Model

  • Jin, Jae-Youll;Kim, Hyo-Seob;Lee, Kwang-Soo;Yum, Ki-Dai
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
    • /
    • 1992.08a
    • /
    • pp.158-165
    • /
    • 1992
  • Bottom sediments, in various types of sediment transport models, have been usually assumed to be horizontally and/or vertically homogeneous. The assumption may be appropriate in well-sorted sedimentary environments including sand beaches and high turbid regions of fine grained cohesive sediments. (omitted)

  • PDF

Evaluation of the Possibility of Developing Organic Matter Indicators in Coastal Environments: Utilization of Dissolved Organic Carbon and Fluorescent Dissolved Organic Matter (연안환경에서 유기물 지표 개발을 위한 가능성 평가: 용존유기탄소와 형광용존유기물질 활용)

  • Lee, Min-Young;Yang, Kyungsun;Kim, Sunchan;Kim, Tae-Hoon
    • Ocean and Polar Research
    • /
    • v.43 no.2
    • /
    • pp.65-72
    • /
    • 2021
  • In order to evaluate the dissolved organic carbon (DOC) and fluorescent dissolved organic matter (FDOM), as indicators of organic matter in the coastal environments, we measured the concentrations of DOC, FDOM, and chemical oxygen demand (COD) in saline groundwater (Woljeong, Pyoseon, and Hwasun beaches) and coastal seawater (Haengwon, Gwideok, Pyoseon, and Yeongnak) in Jeju, Korea. The highest concentrations of DOC and COD in groundwater were found in Woljeong and Pyoseon, and those in coastal water were observed in Haengwon and Pyoseon, indicating that the higher concentrations of DOC and COD seem to be associated with saline groundwater-driven dissolved organic matter (DOM) and/or biogeochemical processes. According to origin and optical properties of DOM using FDOM as a tracer, proportion of humic-like FDOM, more refractory DOM, was relatively greater in the groundwater than in the coastal water. With regard to this result, there was no relationship between DOC and COD in groundwater, while DOC showed a good positive correlation (r2 = 0.66) with COD in coastal water. This result indicates that COD as an indicator of assessment of DOM has a limitation in which it is difficult to quantify refractory DOM. Although DOC is a potential alternative to COD in the coastal environments, particulate organic carbon cannot be negligible due to relatively higher concentration compared to the open ocean. Therefore, the use of total organic carbon (TOC) as a replacement of COD in the coastal ocean is important, and the evaluation criterion of the TOC is necessary in order to evaluate of organic matter indicator in the various coastal environments.

An Application of CADMAS-SURF to the Wave run-up in Permeable Coastal Structures (투과성 해안구조물의 Wave Run-up에 대한 CADMAS-SURF의 적용)

  • YOON HAN-SAM;CHA JONG-HO;KANG YOON-KOO
    • Journal of Ocean Engineering and Technology
    • /
    • v.19 no.4 s.65
    • /
    • pp.49-55
    • /
    • 2005
  • We constructed and demonstrated a numerical CADMAS-SURF(V4.0) model that reproduces the wave run-up characteristics on the slope of coastal structures and applied it to a permeable coastal structure. We also compared the numerical model with published experimental results on the hydrodynamic phenomena of structures and some numerical results for a modified Pbreak model. In conclusion, the CADMAS-SURF model efficiently simulated wave run-up on the slope of a permeable coastal structure. The inflow/outflow effects from the porous structure boundary were approximately $15\%$ more than with the modified Pbreak model. Nevertheless, the descriptions of the internal hydraulic characteristics still could not be full!! exacted from the result(Fig. 1 참조)s obtained in our model experiment.

Calculations of Storm Surges, Typhoon Maemi (해일고 산정 수치모의 실험, 태풍 매미)

  • Lee, Jong-Chan;Kwon, Jae-Il;Park, Kwang-Soon;Jun, Ki-Cheon
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.20 no.1
    • /
    • pp.93-100
    • /
    • 2008
  • A multi-nesting grid storm surge model, Korea Ocean Research and Development Institute-Storm surge model, was calibrated to simulate storm surges. To check the performance of this storm surge model, a series of numerical experiments were explored including tidal calibration, the influence of the open boundary condition, the grid resolutions, and typhoon paths on the surge heights using the typhoon Maemi, which caused a severe coastal disasters in Sep. 2003. In this study the meteorological input data such as atmospheric pressure and wind fields were calculated using CE wind model. Total 11 tidal gauge station records with 1-minute interval data were compared with the model results and the storm surge heights were successfully simulated. The numerical experiments emphasized the importance of meteorological input and fine-mesh grid systems on the precise storm surge prediction. This storm surge model could be used as an operational storm surge prediction system after more intensive verification.