Seafood of the Week - Rainbow Trout

Rainbow trout

The rainbow trout (Oncorhynchus mykiss) is a species of salmonid native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes "steelhead trout") is an anadromous (sea-run) form of the coastal rainbow trout (O. m. irideus) or Columbia River redband trout (O. m. gairdneri) that usually returns to fresh water to spawn after living two to three years in the ocean. Freshwater forms that have been introduced into the Great Lakes and migrate into tributaries to spawn are also called steelhead.

Adult freshwater stream rainbow trout average between 1 and 5 lb (0.5 and 2.3 kg), while lake-dwelling and anadromous forms may reach 20 lb (9.1 kg). Coloration varies widely based on subspecies, forms and habitat. Adult fish are distinguished by a broad reddish stripe along the lateral line, from gills to the tail, which is most vivid in breeding males.

Wild-caught and hatchery-reared forms of this species have been transplanted and introduced for food or sport in at least 45 countries and every continent except Antarctica. Introductions to locations outside their native range in the United States (U.S.), Southern Europe, Australia and South America have damaged native fish species. Introduced populations may impact native species by preying on them, out-competing them, transmitting contagious diseases (such as whirling disease), or hybridizing with closely related species and subspecies, thus reducing genetic purity. Other introductions into waters previously devoid of any fish species or with severely depleted stocks of native fish have created world-class sport fisheries such as the Great Lakes and Wyoming's Firehole River.

Some local populations of specific subspecies, or in the case of steelhead, distinct population segments, are listed as either threatened or endangered under the Endangered Species Act. The steelhead is the official state fish of Washington.








Resident freshwater rainbow trout adults average between 1 and 5 lb (0.45 and 2.27 kg) in riverine environments, while lake-dwelling and anadromous forms may reach 20 lb (9.1 kg). Coloration varies widely between regions and subspecies. Adult freshwater forms are generally blue-green or olive green with heavy black spotting over the length of the body. Adult fish have a broad reddish stripe along the lateral line, from gills to the tail, which is most pronounced in breeding males. The caudal fin is squarish and only mildly forked. Lake-dwelling and anadromous forms are usually more silvery in color with the reddish stripe almost completely gone. Juvenile rainbow trout display parr marks (dark vertical bars) typical of most salmonid juveniles. In some redband and golden trout forms parr marks are typically retained into adulthood. Some coastal rainbow trout (O. m. irideus) and Columbia River redband trout (O. m. gairdneri) populations and cutbow hybrids may also display reddish or pink throat markings similar to cutthroat trout. In many jurisdictions, hatchery-bred trout can be distinguished from native trout via fin clips, typically placed on the adipose fin.

Rainbow trout are a popular game fish for fly fishers.

Rainbow trout and steelhead are highly regarded game fish. Rainbow trout are a popular target for fly fishers, and several angling methods are used. The use of lures presented via spinning, casting or trolling techniques is common. Rainbow trout can also be caught on various live and dead natural baits. The International Game Fish Association recognizes the world record for rainbow trout as a fish caught on Saskatchewan's Lake Diefenbaker by Sean Konrad on September 5, 2009. The fish weighed 48 lb (22 kg) and was a genetically modified hatchery escapee. Many anglers consider the rainbow trout the hardest-fighting trout species, as this fish is known for leaping when hooked and putting up a powerful struggle. It is considered one of the top five sport fish in North America and the most important game fish west of the Rocky Mountains.

There are tribal commercial fisheries for steelhead in Puget Sound, the Washington coast and in the Columbia River, but there has been controversy regarding over-harvesting of native stocks.

The highly desirable sporting qualities and adaptability of the rainbow trout to hatchery rearing and new habitats resulted in it being introduced to many countries around the world by or at the behest of sport fishermen. Many of these introductions have resulted in environmental and ecological problems, as the introduced rainbow trout disrupt local ecosystems and outcompete or eat indigenous fishes. Other introductions to support sport angling in waters either devoid of fish or with seriously depleted native stocks have created world-class fisheries such as in the Firehole River in Yellowstone National Park, and in the Great Lakes.

Rainbow trout and potatoes

Rainbow trout is popular in Western cuisine and both wild-caught and farmed fish is eaten. It has tender flesh and a mild, somewhat nutty flavor. Wild fish has a stronger, gamier taste than farmed fish. While the taste of wild-caught trout is often promoted as superior, it is illegal to sell or market wild-caught rainbow trout, which are legally classified as game fish, in the United States. Thus, rainbow trout and "steelhead" sold in American restaurants is farmed. Farmed rainbow are considered one of the safest fish to eat and are noted for high levels of vitamin B and a generally appealing flavor. Seafood Watch ranks farmed rainbow as a "Best Choice" fish for human consumption.

The color and flavor of the flesh depends on the diet and freshness of the trout. Farmed trout and some populations of wild trout, especially anadromous steelhead, have reddish or orange flesh as a result of high astaxanthin levels in their diets. Astaxanthin is a powerful antioxidant that may be from a natural source or a synthetic trout feed. Rainbow trout raised to have pinker flesh from a diet high in astaxanthin are sometimes sold in the U.S. with labeling calling them "steelhead". As wild steelhead are in decline in some parts of their range, farmed rainbow are viewed as a preferred alternative. In Chile and Norway, rainbow trout farmed in saltwater sea cages are sold labeled as steelhead.

Trout can be cooked as soon as they are cleaned, without scaling, skinning or filleting. If cooked with the skin on, the meat tends to hold together better. While trout sold commercially in Europe is often prepared and served this way, most trout sold commercially in the U.S. have had heads removed and have been fully or partially deboned and filleted. Medium to heavy bodied white wines, such as chardonnay, sauvignon blanc or pinot gris are typical wine pairings for trout.