Abstract
There eixt huge tidal flats in Roberts Bank, Vancouver, which is one of the world's largest tidal flats for migratory birds. Since Roberts Bank tidal flat is located at the mouth of the large river, Fraser River, it is expected that ecological and hydrological enviromnents are affected by snow melt flood. Although biofilm is revealed to be one of the most significant factor for migratory birds, it has not been found how biofilm is formed and is sustained. This study thus aims to investigate salinity, which is expected to be significant factor for the formation of biofilm. As results, hydraulic pressure is found to be always negative from inland to the ocean, which forms stable advection and diffusion conditions inside of the tidal flat, and it is found that positive salinity gradient is also formed inside of the tidal flat stably from inland to the ocean.
