Upwelling
The major upwellings in the ocean are associated with the divergence of currents that bring deeper, colder, nutrient rich waters to the surface. There are at least five types of upwelling: coastal upwelling, large-scale wind-driven upwelling in the ocean interior, upwelling associated with eddies, topographically-associated upwelling, and broad-diffusive upwelling in the ocean interior.
Sendai River
The areas near the mouth of the Sendai are noted for plant species which thrive in sandy areas, notably "Calystegia soldanella", the beach morning glory. Stands of black pines are found in the same area. "Miscanthus sacchariflorus", or Amur silver-grass, is found in the lower reaches of the Sendai where the river has a weaker current. "Celtis jessoensis", the Japanese hackberry, and "Aphananthe aspera", the Muku tree, are found along the lowest of the river.