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

<p class="western"><span lang="en-US">Phytoplankton populations have been in a steep decline in the elbe estuary since several decades. </span>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.</p> <p class="western">We approach this problem with a novel langrangian model. <span lang="en-US">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&#8217;s harbor.&#160; </span><span lang="en-US">In detail, o</span>r 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.</p> <p class="western">We will present results from experiments looking at Phytoplankton retention mechanics to avoid outwashing and depth related mortality in the navigational channel.</p>