Upwelled plankton community modulates surface bloom succession and nutrient availability in a natural plankton assemblage

[摘要] Upwelling of nutrient-rich waters into the sunlit surfacelayer of the ocean supports high primary productivity in eastern boundaryupwelling systems (EBUSs). However, subsurface waters contain not onlymacronutrients (N, P, Si) but also micronutrients, organic matter and seedmicrobial communities that may modify the response to macronutrient inputsvia upwelling. These additional factors are often neglected wheninvestigating upwelling impacts on surface ocean productivity. Here, weinvestigated how different components of upwelled water (macronutrients,organic nutrients and seed communities) drive the response of surface planktoncommunities to upwelling in the Peruvian coastal zone. Results from ourshort-term (10 d) study show that the most influential drivers inupwelled deep water are (1) the ratio of inorganic nutrients(NO x  : PO 4 3 - ) and (2) the microbial community present that canseed heterogeneity in phytoplankton succession and modify the stoichiometry ofresidual inorganic nutrients after phytoplankton blooms. Hence, this studysuggests that phytoplankton succession after upwelling is modified byfactors other than the physical supply of inorganic nutrients. This wouldlikely affect trophic transfer and overall productivity in these highlyfertile marine ecosystems.

[学科分类] 大气科学