source of data :
Couce, Engelhard, Schratzberger (2019).
Reconstruction of North Sea trawling effort 1985-2015. Cefas, UK. V2.
doi: https://doi.org/10.14466/CefasDataHub.61
link to download data :
https://www.cefas.co.uk/data-and-publications/dois/reconstruction-of-north-sea-trawling-effort-1985-2015/
Beam Trawl and Otter trawl in the North Sea through years from 1985 to 2015 :
