Amendment 31 to the Pacific Coast Groundfish Fishery Management Plan (FMP) was completed in June 2023. Under Amendment 31, 20 stocks for 14 managed groundfish species were adopted.
Amendment 31 defines stock units, including geographic delineations within the jurisdiction of the FMP, for black rockfish, canary rockfish, copper rockfish, Dover sole, lingcod, Pacific spiny dogfish, petrale sole, quillback rockfish, rex sole, sablefish, shortspine thornyhead, squarespot rockfish, vermilion rockfish, and vermilion/sunset rockfish. This analysis focuses on population structure of these priority species. Population structure is a foundation to understand if a stock of a species is a single population, with a single areal delineation or if the species comprises multiple populations along its Pacific Coast range and should therefore be considered as multiple stocks in multiple, distinctly delineated, areas.
The Council considered a total of six action alternatives under this action: Alternative 1 would define each priority species as a single stock, coastwide. Alternative 2 would define certain priority species as two stocks, specifying stocks north and south of 40° 10′ N. lat. (Alternative 2) or north and south of 42° N. lat. (Sub-Alternative 2a). Alternative 3 would define certain priority species as three stocks, delineating the stocks to match state boundaries (Alternative 3) or as a Washington and Oregon stock, a northern California stock, and a southern California stock (Sub-Alternative 3a). Alternative 4 would define certain priority species as four stocks, delineating it as a Washington stock, an Oregon stock, a northern California stock and a southern California stock. The Council adopted Alternative 1 for canary rockfish, Dover sole, Pacific spiny dogfish, petrale sole, rex sole, sablefish, shortspine thornyhead, and squarespot rockfish. The Council adopted Alternative 2 for lingcod and Alternative 2a for copper rockfish, and vermilion (N. of 42° N. lat.) and vermilion/sunset rockfishes (S. of 42° N. lat.). The Council adopted Alternative 3 for black and quillback rockfishes.