Tohoku National Fisheries Research Institute, Japan Fisheries Research and Education Agency, 3-27-5, Shinhama, Shiogama, Miyagi 985-0001, Japan.
Department of Marine Biotechnology, Faculty of Life Science and Biotechnology, Fukuyama University, Ohama, Onomichi, Hiroshima 722-2101, Japan.
Mar Pollut Bull. 2020 Aug;157:111235. doi: 10.1016/j.marpolbul.2020.111235. Epub 2020 May 29.
We investigated two sediment cores to understand whether a tsunami in Onagawa Bay, Japan caused environmental changes. The value of δC ranged from -21.9‰ to -24.3‰ and of δN ranged from 5.1 to 5.9‰. We conclude that the source of the sediment in the present study area was mainly oceanic and not terrestrial. The chlorophyll concentration ranged from 1.8 to 4.0 μg/g ww, and did not vary greatly between surface and bottom layers. We inferred that all layers were deposited after the tsunami. The major phytoplankton taxa in sediments were diatoms from DNA sequencing. The presence of harmful dinoflagellates was minor. The concentrations of several heavy metals decreased slightly after the tsunami. We inferred that heavy metals in sediments were diluted by the tsunami disturbance. The land in Onagawa suffered serious damage, but disturbance of the seabed was much less evident.
我们研究了两个沉积物岩芯，以了解日本女川湾的海啸是否导致了环境变化。δC 值的范围为-21.9‰至-24.3‰，δN 值的范围为 5.1 至 5.9‰。我们的结论是，本次研究区域沉积物的来源主要是海洋的，而不是陆地的。叶绿素浓度范围为 1.8 至 4.0μg/g ww，表层和底层之间没有太大差异。我们推断所有层都是在海啸之后沉积的。沉积物中的主要浮游植物类群是通过 DNA 测序获得的硅藻。有害甲藻的存在较少。几种重金属的浓度在海啸后略有下降。我们推断，海啸干扰导致沉积物中的重金属被稀释。女川的陆地遭受了严重的破坏，但海底的干扰则不那么明显。
