North Korea's reported vessel traffic dropped sharply in June last year and is yet to recover back to previous levels, analysis of 20 months of detailed tracking information shows.

The numbers highlight an overall trend which correlates with reduced vessel activity on the part of North Korea's merchant fleet, as the DPRK has adjusted to a new, stricter sanctions environment.

But other ships likely owned by North Korean proxies and registered in different jurisdictions may have picked up some of the slack, with increased reporting in the early part of this year.

Trying times