A Model of Phytoplankton Production in the Marginal Sea Ice Zone of the Barents Sea

Abstract

The primary production in the Barents Sea must be high since it can sustain large stocks of fish. The factors controlling the primary production is not well understood. This paper takes the physical conditions (as far as we know them) in some of the ice-covered areas of the Barents Sea as an input to a plankton model. Simulations with different combinations of vertical turbulence and ice cover indicate that the ice concentration is important in shallow areas with strong tidal mixing, whereas the date of the start of melting of the ice and the resulting stabilization of the water column are more important in deeper parts of the Arctic waters. Where the Atlantic waters flow towards the ice border, the primary production starts early in the spring. High phytoplankton concentration is always found in this area. Study of the model results shows that the following mechanism could he responsible for the elevated biomass: turbulent Atlantic water, relatively rich in nutrients, stabilizes when meeting the ice or brackish water from the melting process and allows a high growth rate as soon as there is enough light early in the spring. High production may last for 2-3 months in this area.

Keywords

• Modeling
• phytoplankton
• ecosystem