Wintertime rates of net primary production and nitrate and ammonium uptake in the southern Benguela upwelling system

摘要: The elevated levels of primary productivity associated with eastern boundary currents are driven by nutrient- rich waters upwelled from depth, such that these regions typically characterised high rates nitrate-fuelled phytoplankton growth. Production studies the southern Benguela upwelling system (SBUS) tend to be biased towards summer season, yet winter data required compute annual budgets and understand seasonal variability. Net production (NPP) nitrate ammonium uptake were measured concurrently at six stations in SBUS early winter. While euphotic zone NPP was highest nearest coast declined distance shore, a greater proportion potentially exportable open-ocean surface waters, as indicated higher specific f-ratios (ratio total nitrogen consumption) located off continental shelf. Near coast, growth predom...