Elbe data

• summary of the discussion with peer and Erik erick.fladung@… peer.doering-arjes@… Within the Elbe system, mostly restocking takes places with a mean value of 0.196 kg/ha for restocking and only 0.029 kg/ha for natural migration. For this reason, building the EDA model on distance to the sea and expected migration, and the effect of barriers on eel repartition does not really make sense. Data are available for restocking. They separate eel into three categories. Glass eel, young yellow eels, and older yellow eels. These data are available per bundeslanders per year. We need to connect them to the riversegments and years.

A restocked eel will be estimated to possibly influence the eel density or biomass from let's say year 2 to 12 if it is a glass eel, year 0 to 10 if it is a young yellow eel... For each year the sum of recruitment possibly influencing will be calculated. This will then be divided by the water surface within the county to have a possible influence in eel per ha. A link between riversegments and counties will be established. When two counties border a riversegment, or when the riversegment is within some distance from a county, the sum of corresponding stocking will be done (this is sum to be made in sql). The density for a given year will thus respond to three different variables corresponding to the different stocking size.

• Task(peer & Erick)
  • Send table prepared for Daniele which contains information on growth... necessary for the computation.
  • translate the headings for the stocking table.
  • try to see wether there are data available for fyke net fisheries (either in number or kg per night)
  • try to see if there are data avalaible for electrofishing, either for survey of the waterframework directive, or from contac within the institute
  • send gis map of local riversegments along with projection system used
  • send gis map of bundeslanders within the elbe.

• If data are available to fit the model