Physical determinants of phytoplankton production, algal stoichiometry, and vertical nutrient fluxes

  • Most phytoplankters face opposing vertical gradients in light versus nutrient supplies but have limited capacities for vertical habitat choice. We therefore explored a dynamical model of negatively buoyant algae inhabiting a one-dimensional water column to ask how water column depth and turbulence constrain total (areal) phytoplankton biomass. We show that the population persistence boundaries in water column depth-turbulence space are set by sinking losses and light limitation but that nutrients are most limiting to total biomass in water columns that are neither too shallow or too weakly mixed (where sinking losses prevail) nor too deep and turbulent (where light limitation prevails). In shallow waters, the most strongly limiting process is nutrient influx to the bottom of the water column (e.g., from sediments). In deep waters, the most strongly limiting process is turbulent upward transport of nutrients to the photic zone. Consequently, the highest total biomasses are attained in turbulent waters at intermediate water column depths and in deep waters at intermediate turbulences. These patterns are insensitive to the assumption of fixed versus flexible algal carbon-to-nutrient stoichiometry, and they arise irrespective of whether the water column is a surface layer above a deep water compartment or has direct contact with sediments.

Export metadata

Additional Services

Search Google Scholar
Author:Christoph G. JägerORCiD, S. Diehl, M. Emans
Parent Title (English):The American Naturalist
Document Type:Article (peer reviewed)
Publication Year:2010
Tag:Algae; Biomass production; Nutrient solutions; Nutrient transport; Nutrient uptake; Phytoplankton; Sediments; Turbulence; Water depth
First Page:E91
Last Page:E104
Peer reviewed:Ja
faculties / departments:Forschung und Entwicklung
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie