Coccolithophore assemblages and morphotypes of Emiliania huxleyi in the boundary zone between the cold Oyashio and warm Kuroshio currents off the coast of Japan

Large Emiliania huxleyi specimens (≥4.2 μm in length) only occurred north of the Oyashio Front, while to the south, E. huxleyi were consistently ≤4.1 μm long, regardless of the morphotype. Large E. huxleyi can be a useful paleoenvironmental indicator for reconstructing past migrations of the Kuroshio and Oyashio Currents in the North Pacific Ocean.