Distribution of the Marine Debris on Seafloor from the Primary Report of Five Cruises After the Great East Japan Earthquake 2011

Abstract

The Tohoku Ecosystem-Associated Marine Science (TEAMS) project started from 2011 with the aim of revealing the impacts of the 2011 tsunami and to assess the present state of the marine ecosystem in affected areas over time during the next decade. TEAMS collected various data such as bathymetry, geography, oceanography, benthos and tsunami-debris not only from our project but also from the archived data at our respective institutes and in public databases. Integration of data and creation of habitat maps are expected to contribute to our understanding of the effects of large tsunamis, present the status of marine biodiversity in the area, and lead to the identification of key areas for ensuring ecosystem resilience. Here we focus on information of marine debris identified from deep-sea images and sonar data. We conducted data integration and collated information in a GIS database. Our preliminary results suggest that the impact of the tsunami debris in deep-sea areas (ca. 200-500m) was not as severe as in coastal environments. Accumulations of tsunami debris were found mainly in submarine canyons. Although different types of debris occur so far in mixed aggregations, differences in the movement and decomposition patterns of these different materials are expected to lead to both positive and negative effects on the environment in different ways.