The Presence/Absence maps of phytoplankton in the Greater North Sea
https://www.emodnet-biology.eu/data-catalog?module=dataset&dasid=6587 was created by Willem Stolte and Luuk van der Heijden (Deltares). It estimates absences from presence-only occurrence data available at EMODnet-Biology. This was done by looking carefully at the sampling methods. The product is provided as a refined dataset with a presence/absence flag and as raster maps with gridded probability of occurrences.
The product was the basis for further analysis: Using DIVAnd software and a Neural Network as interpolation methods, a second product was created by Alexander Barth and Charles Troupin (University of Liege): Probability maps for different phytoplankton species in the North Sea
https://www.emodnet-biology.eu/data-catalog?module=dataset&dasid=6588
You can download the products clicking on the hyperlinks above. For further information please have a look at the Product Stories:
* Presence/Absence maps of phytoplankton in the Greater North Sea:
https://www.emodnet-biology.eu/blog/presenceabsence-maps-phytoplankton-greater-north-sea
* Probability maps for different phytoplankton species in the North Sea:
https://www.emodnet-biology.eu/blog/probability-maps-different-phytoplankton-species-north-sea