DUNGENESS CRAB

The issues: Toxic algal blooms delayed the 2015 season until March 2016. Though it’s too early to say for sure whether the season will open on time this year, ocean conditions have certainly improved. But because algal blooms are becoming more persistent and frequent, there is concern that future seasons will often have to deal with threats of closure or abbreviation. Crab is also affected by ocean acidification. Commercial season: November through June The commercial Dungeness crab fishery can be traced to the mid-1800s in San Francisco. While it’s had plenty of ups and downs, last year was devastating for many crabbers, in an unprecedented way. A bloom of pseudo-nitzschia, a type of algae that is common in early fall but usually goes away in time for crab season, stretched from Southern California to Alaska. Caused by unusually warm ocean temperatures, the bloom resulted in levels of domoic acid toxic to humans in Dungeness crab all along the California coast.

The season was delayed until March, which meant no local crab at Thanksgiving, Christmas and dozens of annual crab feeds, a Northern California tradition.

There have been pockets of pseudo-nitzschia in the ocean this fall, but this time at a normal level.

However, public health officials say it is still too early to make any definitive predictions regarding the season.

Dungeness crab, though, face another long-term threat: ocean acidification. NOAA Fisheries’ Northwest Fisheries Science Center research shows crab eggs and larvae exposed to more acidic water have slower growth and greater loss. There’s also research indicating that ocean acidification could increase the toxicity of algal blooms like pseudonitzschia.