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EDA 2.0 (Eel Density Analysis) is a modelling tool based on a geolocalized river network database to predict yellow eel densities and silver eel escapement.

River networks topology and characteristic of reaches are managed by EDA through the CCM layer.

EDA only needs and uses four tables (as defined in the Guidelines for data exchange):

• Observation place
• Observation o Pressure / impact (obstruction) o Scientific observation
• Batch
• Biological characteristics

We need in fact:

• the presence/absence and the density of yellow eel based on fishing operation in different stations
• the obstacle pressure (characteristics, …)

So for each operation the variables required are:

• Operation id
• Date (YYYY-MM-DD)
• Station id
• Localisation of the station o coordinates x o coordinates y o system of projection

As specified in the guidelines- if this system is retained, the coordinated system used is the GIS system used in the CCM layer: ETRS1989 LAEA (in postgis this is the srid: 3035).

• Density (if estimated)
• Number (total number caught)
• Fishing method (electrofishing, or other scientific method used)
• Description of the mehod
• Total number of eels which length is <15 cm
• Total number of eels which length is in [15-30cm[
• Total number of eels which length is in [30-45cm[
• Total number of eels which length is in [45-60cm[
• Total number of eels which length is >=60cm
• Wetted area of the fishing station in m²
• Fished length
• Fished width
• Effort (if the surface is not provided or not the adequate unit of effort)
• Glass eel transport (a quantity in g or if you don’t exactly know it just add TRUE/FALSE)

If the electrofishing sample is used:

• Number in the first pass
• Number in the second pass…
• Estimation method (Carle & Strubb, De lury…) used

Additional information can also be provided if there are suspected to explain eel density (water alkalinity,…).

For the obstacles’ table:

• Obstacle id
• Localisation of the obstacle o coordinates x o coordinates y o system of projection
• Height of the each obstacle (in m)

optional

• Obstacle impact (a score)
• Turbine number
• Turbine mortality (a rate in % or a number) and a short description of the method to calculate this rate
• Description of the method used for permeability evaluation (to calculate the score in the “Obstacle impact” variable)

Number of fishing minimum: 30 operations per year