2. Materials andmethods
Four cruises were carried out on the R/V Beidou during 14–28 April
2006, 17 October–3 November 2006, 17–23 March 2007 and 3–9 August
2007 (Fig. 1). At each station, hydrographic measurements and
water samples were conducted using a Seabird SBE 19 CTD profiler
equipped with a 12 Niskin bottle Rosette sampler. Two stations (B2,
B3) were not sampled during the April cruise, one station (H2) during
the October cruise, and Transect Y (Stations Y2–8) during the August
cruise.