All I have is J.A. Bjerkan, silversmith, born 1850 in Bodø in Nordland Norway. My source says he marked JB. Your mark might be newer...? He was married to Hedvig Fredrikke Bjerkland 1857-1913. That's all, sorry...
Thanks, it seems there's virtually nothing in terms of info anywhere on Johannes Andreas Bjerkan other than as you say he's listed as a silversmith in Bodø. I noticed the 'N' in Bjerkan is backwards on the stamped mark. Not sure on the date of the spoon but it appears he is still on the census in 1910 as a silversmith in Bodø.
Since the fineness is punched 830 it means promille (830/1000). Indicating the fineness in promille was implemented in January 1st 1893 in Norway. Your spoon cannot be older that that.