This brochure was written by Scott Meyer, Fishery Biologist, Division of Sport Fish, Alaska Department of Fish and Game, Homer, Alaska. For more information contact the Alaska Department of Fish and Game, Division of Sport Fish: Anchorage (907) 267-2218 Homer (907) 235-8191 http://www.sf.adfg.state.ak.us/statewide/html/sf_home.html This brochure was funded in part through a grant from the National Fish and Wildlife Foundation. Angler’s Guide to the ROCKFISHES of Alaska: BIOLOGY and FISHERY MANAGEMENT Ages, in years, of common rockfishes in the sport harvest. Typical ages in Approximate Species the sport harvest maximum age Pelagic Dusky 7-30 75 Black 9-25 55 Dark 7-30 90 Yellowtail 7-25 65 Non-pelagic Yelloweye 15-50 120 Tiger 20-55 115 Quillback 15-50 90 Silvergray 10-30 80 China 15-40 80 Yelloweye rockfish,Sebastes ruberrimus Copper 10-30 60 Alaska sport fishing regulations divide rockfish into ROCKFISH are among the more two groups based on their preferred habitats: interesting and colorful fishes in the North Pacific Ocean. They also are particularly vulnerable to 1. Pelagic species are found throughout the water overfishing. Maintaining healthy populations requires column, typically in large schools above or around knowledge of their biology as well as innovative rocky shelves or pinnacles. There are six species approaches to fishery management. in this group, but only the black, dusky, dark, and yellowtail rockfish are common in Alaska. Widow There are over 30 species of rockfish (genus rockfish are rarely caught and blue rockfish have not Sebastes) in the Gulf of Alaska, but fewer than 10 yet been confirmed in Alaska. are commonly caught in the recreational fishery. Rockfish have large scales, large fin spines, 2. Non-pelagic species usually stay close to the and smaller spines on the head and gill covers. bottom, often in rocky areas, and generally in Depending on species, adult rockfish may reach 8 deeper water than pelagic species. They are typically to 40 inches in length. Color ranges from bright red, solitary or in small schools, often with a mixture orange, or yellow to blander black and gray. Pelagic of species in an area. Some species are “cryptic”— species resemble bass and are commonly misnamed hiding in cracks or under rocks. All but the six “black bass” or “sea bass.” Yelloweye rockfish are pelagic species mentioned above are non-pelagic. often misnamed “red snapper.” In fact, there are no The most common non-pelagics include yelloweye, true basses (family Serranidae) or snappers (family quillback, copper, silvergray, tiger, and China Lutjanidae) in Alaska, as these fishes prefer warmer rockfish. Rougheye and shortraker rockfish typically waters at lower latitudes. Lingcod, greenlings, and inhabit very deep bays and deep waters along the sculpins (such as Irish lords) are also sometimes edge of the continental shelf, and are often found on mistaken for rockfish. softer bottoms. Rockfish are members of the family Scorpaenidae, or “scorpion fishes,” named for their venomous Life in the Slow Lane fin spines. Although some scorpion fishes have extremely toxic venom, rockfish venom is mildly Rockfish are among the longest-living vertebrates toxic and typically causes only pain or swelling. on earth. Non-pelagic species generally live longer Rockfish venom sacs are located at the base of the than pelagic (see table). Yelloweye rockfish, for dorsal and anal fin spines and, in a few species, example, can reach over 100 years, and rougheye other fins as well. Rockfish do not attack with their and shortraker rockfish occasionally exceed 150 venom, but rather use it only for defense. years. Some of the rockfish you catch today were frolicking in kelp beds in the 1930s, and a few may Black rockfish,Sebastes melanops Dusky rockfish,Sebastes ciliatus have been around when Alaska was purchased from No Free Lunch Russia in 1867. Rockfish are an integral part of the food chain Most rockfishes do not start reproducing until in the North Pacific. They eat a variety of foods, they are at least 5-7 years old, and some may not including plankton, adult and larval crabs, shrimp, reproduce until they’re 15-20 years old or more. and small fishes such as sand lance, herring, and Rockfish don’t lay eggs like most fishes. Instead, they juvenile rockfish. In turn, rockfish are eaten by larger mate and fertilize the eggs internally. The developing rockfish, lingcod, Pacific cod, sablefish, halibut, embryos receive nourishment from the female. After Chinook (king) salmon, sculpins, sharks, seabirds, several months, the females give birth to thousands marine mammals, and humans. or millions of tiny larvae. Most of the larvae die when swept offshore by currents or eaten by other animals. The survivors grow while riding the currents Vulnerable to Overfishing for several months, then settle onto the ocean floor Rockfish are more vulnerable to overfishing than and hide in kelp, eelgrass, or around rocks. As the most other fishes. Anglers can easily locate their juvenile fish grow and mature they move to adult preferred rocky habitat using navigational charts habitats in deeper water. or sonar. Once found, rockfish are relatively easy The survival of larval rockfish is believed to be closely to catch. Most species grow quickly in the first few linked to oceanographic factors such as temperature, years of life, becoming fairly large before they are currents, and food availability. Rockfish are long-lived mature. Harvesting fish before they can reproduce and can produce millions of offspring each year, impairs the population’s ability to replace itself. allowing their populations to persist through long A major factor contributing to rockfish vulnerability periods where conditions are unfavorable for survival is that their swim bladder (a balloon-like organ used of offspring. to adjust buoyancy) is not vented. When rockfish are Tagging studies have shown that although pelagic brought to the surface from deep water, the gases species can move hundreds of miles, most were in the swim bladder expand, compressing internal recaptured within 20 miles of the tagging site. Non- organs and often pushing the stomach inside out pelagic species, on the other hand, generally have into the mouth cavity. Other injuries may include small home ranges, and may rarely venture more than ruptured swim bladders, ruptured blood vessels a few hundred yards from their favorite reef. For this in internal organs, gas bubbles inside the eye, and reason, heavy fishing pressure can reduce rockfish bulging eyes. The photographs of yelloweye, China, populations in local areas. and silvergray rockfish in this brochure all show bulging eyes as a result of pressure changes. Fish The abundance of most rockfish species in Alaska is unknown. Assessment of nearshore rockfish stocks is difficult and expensive. Many sampling gears cannot be used in the rocky habitats favored by nearshore rockfishes. Submersibles and remotely operated vehicles have been used to assess populations in selected preferred habitats, but these methods are costly to apply over large areas. Assessment methods are complex and still under development. Given the lack of information on stock status, fishery management has proceeded cautiously. Recreational and subsistence fisheries in Alaska are managed under some of the most restrictive bag limits on the Pacific Coast, usually with special provisions for less productive non-pelagic species such as yelloweye Quillback rockfish,Sebastes maliger rockfish. Recreational harvest has varied from year to year but generally increased in southeast and southcentral Alaska since the late 1970s. Anglers have released about as many rockfish as they with inflated swim bladders cannot submerge on harvested, not all of which survived. Commercial their own, and when released at the surface are rockfish fisheries are managed under harvest caps unlikely to survive. that include directed harvest, and in some cases, When you consider their ease of capture, limited incidental catch (or “bycatch”) in fisheries for other movements, late maturity, low annual productivity, species. Commercial fishery regulations often include and low survival rate when released, it is easy to trip limits to manage within the caps. Mandatory see why rockfish populations are vulnerable to retention has been implemented in some fisheries overfishing. in recent years to improve accounting of removals by species. Despite these measures, it is widely believed that the true level of fishery removals is Management Hurdles not well understood and that additional controls and Rockfish are excellent table fare and have long measures may be warranted. been harvested in commercial, recreational, and subsistence fisheries from California to Alaska. But some rockfish populations have been severely Marine Reserves— reduced through overfishing, even when managers were aware of the potential for overfishing and took An Effective Tool? steps to limit harvest. From British Columbia to Marine reserves, or areas that are closed to some or southern California, populations of several species all fishing, are increasingly being used in the eastern are now at a small fraction of their unfished level, Pacific for sustainable management of rockfish and the status of other species has not yet been fisheries. The potential short-term benefits of determined. Several fisheries have been severely reserves include rebuilding overfished populations, restricted in order to rebuild rockfish populations. protecting essential spawning or nursery habitat, Because the annual production of new fish is so enhancing genetic and species diversity, and low, sustaining a harvest year after year requires reducing bycatch. Protection of spawners guarantees maintaining a high abundance of spawners. Envision some level of reproduction, and larvae and juvenile a rockfish population as a low-interest savings fish may disperse from closed areas to areas where account. To live off the interest (sustain a moderate fishing is open. In the long term, reserves have harvest), you have to maintain a large balance.