Kelp Rockfish, Sebastes atrovirens

Kelp Rockfish, Sebastes atrovirens.Fish caught from within Monterey Bay, Monterey, California, August 2020. Length: 22 cm (8.7 inches). Catch, photograph and identification courtesy of Luke Ovgard, Klamath Falls, Oregon.

Kelp Rockfish, Sebastes atrovirens. Fish caught from shore in San Francisco, California, February 2014. Length: 23 cm (9.1 inches). Catch, photograph, and identification courtesy of Eli (obsessiveangling.wordpress.com). Identification reconfirmed by Milton Love, University of California, Santa Barbara, Goleta, California.

Kelp Rockfish, Sebastes atrovirens. Fish caught from coastal waters off San Diego, California, September 2017. Length: 26 cm (10 inches). Catch, photograph and identification courtesy of Ben Cantrell, San Diego, California.

Kelp Rockfish, Sebastes atrovirens. Fish caught from coastal waters off Catalina Island, California, December 2020. Length: 31 cm (12 inches). Catch, photograph, and identification courtesy of Josh Leisen (joshadventures.com), Gaylord, Michigan.

Kelp Rockfish, Sebastes atrovirens. Fish caught  from coastal waters off Jerónimo island, Baja California, November 2022. Length: 33 cm (13 inches). Catch, photograph and identifications courtesy of Chris Wheaton, Fullerton, California.

The Kelp Rockfish, Sebastes atrovirens, is a member of the Rockfish and Scorpionfish or Scorpaenidae Family, that is known in Mexico as rocote sargacero. Globally, there are one hundred and eight species in the genus Sebastes, of which fifty-three are found in Mexican waters, all in the Pacific Ocean.

The Kelp Rockfish has a thin oval body with a depth that is 39% to 43% of standard length. Adults vary in color from white to various shades of brown, yellow, and red. Their gill covers are dark and their body is covered with darker flecks. Juveniles have 5 brown vertical bars over a clear, white or light brown background. As fish mature, they lose their vertical bars and display specks in faint vertical columns. Their head has a sharp snout, large eyes, multiple large spines, and a mid-sized terminal mouth. Their anal fin has 3 spines and 6 to 8 rays; their caudal fin is square; the dorsal fin has 13 spines and 12 to 15 rays; and, their very large pectoral fins have 16 to 18 rays. They have 28 to 36 gill rakers.

The Kelp Rockfish is found both demersal and mid-water in complex habitats including kelp forests and rock structures at depths up to 82 m (270 feet). They reach a maximum length of 43 cm (17 inches). As of January 1, 2024, the International Game Fish Association world record stood at 0.91 kg (2 lbs 0 oz) with the fish caught in coastal waters off Pacific Grove, California in August 2013. They are normally found as solitary individuals or in small aggregations. They are generally non-migratory with small home ranges. They feed on zooplankton, small fish, crabs, shrimp, and snails. Juveniles are a favorite prey of Bocaccios. Reproduction is oviparous with each female releasing between 10,000 and 340,000 pelagic eggs annually. They have a lifespan of up to 25 years. The Kelp Rockfish is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

In Mexican waters the Kelp Rockfish is a resident of the Pacific Ocean but has a limited distribution being found from Guerrero Negro, Baja California, northward along the central and northwest coasts of Baja.

The Kelp Rockfish is most likely confused with the Brown Rockfish, Sebastes auriculatus (thicker and deeper body; brown to red-brown coloration; orange lines radiating backwards from eyes) and the Grass Rockfish, Sebastes rastrelliger (heavier body; green coloration; small black spots on body; short stubby gill rakers). Juveniles are very difficult to distinguish from juvenile Black-and-yellow Rockfish, Copper Rockfish, and Gopher Rockfish.

From a conservation perspective the Kelp Rockfish has not been formally evaluated. They are not considered an important food fish. They are sold as a live fishery component and can be found in ethnic fish markets of Northern Baja. They are caught with good frequency by recreational anglers from boats, jetties, and piers and by sports divers. A significant decline in their population levels has been documented over the last 30 years.