Marine Ecosystem Networks in the Seto Inland Sea Analyzed with Coastal Connectivity

Abstract

Connectivity evaluates stochastic processes of larval dispersal due to chaotic coastal circulations (e.g., Mitarai et al., 2009). In the present study, we quantify Lagrangian PDFs and connectivity using many Lagrangian particles released from 140 source sites in the modeled SIS circulation field in a double-nested, high-resolution ROMS configuration (Uchiyama et al., 2012). In winter, the fraction of particles transported to another region is about less than 40% except for both the channels, suggesting that particles largely remain in the release region. The regional connectivity is correlated with the seasonal variation of the mass fluxes at the straights between two neighboring regions. Particles released from Harima-Nada, representing larvae of marbled sole, are mainly transported towards the northern shore of Shodo Island, while particles arriving there originate mostly from the western shore of Harima-Nada.

Transportation of Sediment and Heavy Metals Resuspended by a Giant Tsunami Based on Coupled Three-Dimensional Tsunami, Ocean, and Particle-Tracking Simulations

“…This indicates that sediment resuspended in the seawater barely settles; for example, grains migrate only 15 m downward over approximately 2 months. Therefore, the settling speed of the silt is negligible and is not considered in the particle-tracking simulation; previous studies frequently used a similar assumption (e.g., [26]). The particle-tracking simulation was conducted over 2 months, beginning at the resuspension occurrence induced by the giant tsunami.…”