Did the Swedish cod fishery expand in the past years?
If by 'fishery' you mean "amount of fish caught", the answer is a qualified no. Sweden's catch has been stable or perhaps slightly increasing since a low in 2005, but the catch is still much lower than a decade ago (Statistics Sweden). This is presumably due in large part to the quotas set on Total Allowable Catch for various sea regions.

If by 'fishery' you mean "amount of fish in the sea", the answer is a qualified yes. Most Swedish cod catch (>90%) comes from the Baltic, where stocks have been recovering since 2006 after steep declines in the eighties (ICES full report and executive summary for Eastern Baltic). Presumably, this recovery is also due in large part to the quotas set on Total Allowable Catch, i.e. to the reduction in cod mortality due to fishing. 




Sweden's cod catch for all regions, and the ICES estimated Spawning Stock Biomass of cod in the Eastern Baltic. Both are in thousands of metric tons, but note that the scales differ by a factor of ten)





No idea how this is affecting import/export, although Statistics Sweden might have that data. One biology related possibility is that Eastern Baltic stocks (presumably accessed more by Sweden) are doing better than North Sea stocks (presumably accessed more by Norway), but that's just a guess, you'd have to check the data.