The copper rockfish is a highly variable species in terms of coloration, and due to this characteristic has been known by several names, depending to some degree upon locality.

Distribution, Stock Structure and Migration.

The copper rockfish is broadly distributed geographically, known from the northern Gulf of Alaska to off central Baja California. It also has a broad bathymetric distribution, known to occur from the shallow subtidal to 620 ft.

Tagging studies indicate that copper rockfish, for the most part, show little movement once they have settled to the bottom. Movement of up to one mile has been noted but the majority of tagged and recaptured copper rockfish are from the locality where they were originally taken. This life-history characteristic of high site fidelity makes this species susceptible to local depletion.

Age and Growth

Copper rockfish have been aged to 41 yr. Off central California, copper rockfish have been aged to 28 yr (a 22.1-in. individual). Size at age for copper rockfish, based on aging whole otoliths, from central California for the first 5 yr is as follows: age 0, to 3.6 in. TL: age 1, 3.7 to 5.9 in. TL; age 2, 4.2 to 9.4 in. TL; age 3, 7.0 to 11.5 in. TL; and age 4, 8.9 to 13.2 in. TL. There appears to be no significant difference in the growth rates between sexes. The maximum-recorded length for coppers is 22.8 inches.

Reproduction, Fecundity and Seasonality

Length at first maturity for males has been found to vary from 11.6 to 14.6 in. TL (3 to 8 yr, respectively), and for females 11.6 to 12.2 in. TL (approximately 5 yr). Length at 50% maturity for males has been documented at 12.6 in. (4 yr), and for females at 13.4 in. (6 yr); and 13.4 in. (6 yr) for a sex-unspecified fish.

As will all rockfishes, coppers are viviparous and highly fecund. Mating occurs in the fall, and in California, larvae are released during winter months (Jan.-Apr.) with a peak in February. Larval duration was found to be one to two months. Young-of-the-year copper rockfish recruit into the nearshore environment at about 0.8 to 1.0 in. during April and May off central California.

Natural Mortality

Calculations of natural mortality (M) have been made from populations in Puget Sound, Washington and was calculated to be 0.1127 using tag/recapture method on fish 5 to 34 yr old.

Diseases

No information is available on diseases in copper rockfish.

Predator/Prey Relationships

Copper rockfish feed on a wide variety of prey items. Juvenile copper rockfish feed primarily on planktonic crustaceans. Larger crustaceans form a major part of their diet as they grow; these include Cancer sp. crabs, kelp crabs, and shrimps. Squid of the genus Loligo and octopi are also important food items. Fishes, which include young-of-the-year rockfishes, cusk-eels, eelpouts, and sculpins, are important forage for larger individuals. As juveniles and adults, copper rockfish are preyed upon by a variety of fishes including other rockfishes, lingcod, cabezon and salmon as well as several species of birds and mammals.

Competition

No information on competition in copper rockfish was found. Due to their co-occurrence with other larger benthic fish species such as cabezon, lingcod, greenlings, and rockfishes such as vermilion, brown, China, and gopher, it is likely that some degree of competition for food and space may occur.

Critical Habitat

Newly recruited copper rockfish initially associate with surface-forming kelps. After several months, and at about 1.6 in., the juveniles settle to the bottom on rocky reefs as well as sandy areas and are referred to as benthic juveniles. Adults are commonly found in kelp bed areas but also frequent deeper rocky reefs. As adults, this species is considered to be epibenthic, normally occurring slightly above the substrate, which is often high-relief rocky shelf and rock-sand interface.

Copper rockfish are an important component of the nearshore rocky reef system and are frequently encountered by scuba divers in this environment. Submersible observations of the biotic community off the Big Sur coast revealed copper rockfish between depths of 72 to 322 ft. The majority of sightings were of individual (solitary) fish occurring over rocky reef or boulder fields and most frequently in areas of high relief. Occasionally an individual was observed over sand.

Status of Stocks

There has been no stock assessment of this species in California. However, there is compelling evidence that copper rockfish populations have severely declined in many areas and large individuals are noticeably less common than in past decades.

Copper rockfish is one of the species taken in the commercial live-fish fishery. Copper rockfish have been an important component of the recreational catch in both skiff and commercial passenger fishing vessel (CPFV) fisheries, especially off central and northern California. Due to its relatively large size, copper rockfish have been considered one of the premium species in the recreational angler's catch and a prime target for the sport diver. Due to their solitary nature, high habitat specificity, and the size they can enter the fishery (as juveniles), the copper rockfish is a prime candidate for local depletion.