Marine Harvest's plans to bring all its net pen sites under Aquaculture Stewardship Council (ASC) certification remains far from complete, even as the window for meeting its 2020 goal is slowly closing.

The group first made the commitment to the switch in 2013, as part of its membership in the Global Salmon Initiative (GSI).

Since that time, however, progress has been slow, and as of the end of 2016, only 25 percent of the company's sites -- 59 in total -- had been certified, according to the group's annual report.

By the end of this year, the company is targeting an additional 15 sites, but that rate puts the group at just 50 percent certified by 2020.

Marine