Depth profiles of the total cell numbers of the first 500 m of the water column. Days −1, IN station days 9, 18, and 36, and OUT station day 16 were investigated additionally to the WML at depths of 100, 300, and 500 m. Missing values (*) for SAR11 at days 14 and 16 (OUT) are due to limited sample quantities. In addition, no sampling was done at 500 m on day 18 (#). Error bars are omitted for simplicity. t, time.