Phytoplankton trajectories in the Elbe estuaries - examinig retention and die-off in the Hamburg harbor

Phytoplankton populations have been in a steep decline in the elbe estuary since several decades. Previous studies using concentration based biochemical models helped to further the understanding of the ecosystem in general but fail to pinpoint specific reasons due to their high complexity.

We approach this problem with a novel langrangian model. By explicitly simulating phytoplankton trajectories, we are able to examine bathymetry-related effects. These effects can play a big role in the Elbe estuary due the high average depth in the navigational channel of Hamburg’s harbor.  In detail, or model represent processes like turbulent dispersion, vertical migration and stranding mechanics to study this problem. To our knowledge this is the first time that this problem is tackled with such a method that includes biological processes in an estuarine context.

We will present results from experiments looking at Phytoplankton retention mechanics to avoid outwashing and depth related mortality in the navigational channel.