The news is bleak for Canada's Atlantic mackerel fishery.

An assessment by the Department of Fisheries and Oceans (DFO) says serious harm is occurring and recovery is threatened by overfishing, according to a CBC news report.

Scientists say the spawning population is down 86 percent from levels seen two decades ago, and the number of fish surviving to breed is at all-time lows, according to the CBC story.

The assessment blames overfishing in Canada and the United States for the current condition of the stock. Mackerel is used primarily as bait in the lobster fishery.

The total allowable catch in Canada was 10,000 tons in 2018 — down from nearly 55,000 tons in 2005. The US quota this year is 9,100 tons. The situation is further complicated because water temperatures in the Gulf of St Lawrence and other fishing areas are rising.

DFO is expected announce the 2019 Canadian mackerel quota in the coming weeks.

In addition, the Marine Stewardship Council (MSC) has made protection of Atlantic mackerel a condition of its certification of the region's lobster fishery, so the health of the mackerel fishery could have a trickle-down effect.