The annual cycle of nanoflagellates in the Central Cantabrian Sea (Bay of Biscay)

摘要: Abstract The annual cycle of nanoflagellates (NF) including autotrophic (ANF), heterotrophic (HNF) and mixotropic (MNF) flagellates carried out in a temperate sea (Central Cantabrian Sea, southern Bay Biscay) is presented. Three stations with characteristics ranging from coastal to oceanic conditions were analysed order compare NF response this gradient. Samples monthly collected at each station three different depths between February 2002 December 2002. CTD profiles also taken station. grouped according their trophic status into ANF, HNF MNF. Abundance biomass determined for group. showed general pattern consisting maximum July secondary maxima March October minimum values May. ANF the most important fraction, making major contribution (nearly 75%) total all stations. represented over 20% along cycle, except peak spring found every MNF reached less than 5%, showing low seasonability. Small (2–5 µm) dominated throughout cycle. Microplankton community was terms abundance biomass. A significant positive correlation ( r 2  = 0.49) obtained 2–5 µm 10–20 µm HNF–MNF biomasses, suggesting possible relationship these groups which should be cautiously taken. No relationships microplankton or nutrients indicating that regulation numbers complex probably implicates other groups. In addition this, unexpected Chl concentration misplacing upwelling events render necessary perform additional studies fully understand precise behaviour Sea. To best our knowledge, first study considers functional