Journal of Oceanography

, Volume 72, Issue 1, pp 129–139

Deep-sea meiofauna off the Pacific coast of Tohoku and other trench slopes around Japan: a comparative study before and after the 2011 off the Pacific coast of Tohoku Earthquake

  • Tomo Kitahashi
  • Himiko Watanabe
  • Ken Ikehara
  • Robert G. Jenkins
  • Shigeaki Kojima
  • Motohiro Shimanaga
Special Section: Original Article Oceanographic observations after the 2011 earthquake off the Pacific coast of Tohoku

DOI: 10.1007/s10872-015-0323-3

Cite this article as:
Kitahashi, T., Watanabe, H., Ikehara, K. et al. J Oceanogr (2016) 72: 129. doi:10.1007/s10872-015-0323-3

Abstract

We compared meiofaunal assemblages obtained from the landward slope of the Japan Trench off the Sanriku region of Honshu Island before the 2011 off the Pacific coast of Tohoku Earthquake, 4.5 months and 1.5 years after the earthquake. Sediment samples were collected after the earthquake along two transects. Meiofaunal density after the earthquake did not differ from that before the earthquake. However, meiofaunal composition after the earthquake was different from that before the earthquake, and the composition dispersion after the earthquake was lower than that before the earthquake. These results suggested that the turbidity current may have affected meiofaunal composition and reduced its variability. These changes were probably caused by the seismic motion and displacement of the substratum after the earthquake, rather than sediment redeposition induced by the earthquake. To assess the effect of the earthquake more thoroughly, we compared meiofaunal assemblage in the Sanriku region before and after the earthquake with that in the Kuril Trench (comparable productivity to the Sanriku region) and Ryukyu Trench (lower productivity). Differences in meiofaunal composition before and after the earthquake within the Sanriku region were lower than those between the Sanriku and Ryukyu regions. These results suggested that deep-sea meiofaunal assemblages are influenced by large-scale disturbances, but changes are within the range of variation generated by surface productivity levels.

Keywords

Meiofauna Meiofaunal composition Earthquake Disturbance Turbidity current Trench slope 

Copyright information

© The Oceanographic Society of Japan and Springer Japan 2015

Authors and Affiliations

  • Tomo Kitahashi
    • 1
    • 6
  • Himiko Watanabe
    • 2
  • Ken Ikehara
    • 3
  • Robert G. Jenkins
    • 4
  • Shigeaki Kojima
    • 1
  • Motohiro Shimanaga
    • 5
  1. 1.Atmosphere and Ocean Research InstituteThe University of TokyoKashiwaJapan
  2. 2.Faculty of ScienceKumamoto UniversityKumamotoJapan
  3. 3.Institute of Geology and Geoinformation, Geological Survey of Japan, AISTTsukubaJapan
  4. 4.School of Natural System, College of Science and EngineeringKanazawa UniversityKanazawaJapan
  5. 5.Center for Marine Environment StudiesKumamoto UniversityKami-AmakusaJapan
  6. 6.Japan Agency for Marine-Earth Science and Technology (JAMSTEC)YokosukaJapan

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