Locations of sampling stations and schematic of circulation in summer in the research area. Different colors of the stations indicate different tintinnid assemblages.

<p>Green filled circles: East China Sea neritic assemblage; red filled circles: Japan Sea warm water assemblage; blue filled circles: boreal assemblage without neritic genera influence (B1 assemblage); black filled circles: boreal assemblage with neritic genera influence (B2 assemblage); open circles: no tintinnid was found. A: Soya Current. a: Sōya Strait, b: Tsugaru Strait. Current positions are according to Springer et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153379#pone.0153379.ref019" target="_blank">19</a>], Longhurst [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153379#pone.0153379.ref020" target="_blank">20</a>], Senjyu [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153379#pone.0153379.ref021" target="_blank">21</a>] and Steele et al. [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153379#pone.0153379.ref022" target="_blank">22</a>].