I'm a Norwegian and I'm curious to know more about the strategic ideas the Germans had in taking Norway and in particular the north of Norway. Where they interested in the fishing? How did the occupation impact the fishermen?
The reason is simple: they needed iron. Kiruna in Sweden has one of the largest reserves of iron ore in Europe, but the only way how to conveniently transport it to Germany was through the ice-free Norwegian port of Narvik in the far north.
According to M Tamelander and N Zetterling "Den nionde april - Nazitysklands invasion av Norge 1940" ("The ninth of April - Nazi Germany's invasion of Norway 1940") securing the supply of iron from Sweden and the access to the Northern Sea which would allow an naval blockade/action against Great Britain was the major reasons. This does not happen in a vacum; Hitler was - not without reason - afraid for an allied action against Norway and Sweden in some form, and lots of the initial planning was done in relation to the war between Finland and the Soviet Union, and a possible allied intervention in that war. "Den nionde april" also gives a good overview (as far as I can tell, I have not read any other detailed work on the matter) on the various planing stages and conflicts in the German high command leading up the invasion. Tamelander and Zetterling does not mention either Troms and Finnmark nor fishing and given the rushed nature of both the planning and execution of the invasion it seem unlikely that fishing was of any importance, if considered at all. Which does not mean the Germans was not interested once they were in possession of Norway.
I don't know if the book I site have been translated to English, but I am quite certain I have seen a Norwegian translation, and regardless OP - being Norwegian - should be able to read it. I recommend it, it certainly gave me a much better picture of what happened than my (Norwegian) education and some more popular works on the war. In particular it cleared up a number of myths that I had heard about what the allies planned or did not plan to do in the weeks and months before Germany invaded. If any actual historians have read this book I would be interested in a comment regarding how generally accepted the view they present in the book is.
hi! you may find some additional info in these previous threads
What was Norway's role in WWII and how significant was it?
Thanks for all these great inputs. A follow up question: What would life have been like for the average fisherman in fishing villages around Narvik and Lofoten? How did the occupation impact their work and lives? If their livelyhood was compromised, would they be tempted to go to work for the germans?