California’s Invaders: Northern Pike

(Esox lucius)

General Description

Northern pike
Northern pike. Photo by CDFW.

Northern pike are freshwater fish with elongated bodies and flattened, duckbill-shaped snouts. Their mouths comprise half the length of their head and are full of sharp teeth. Northern pike are dark green to gray in color on their backs and sides with rows of pale, oval spots (wavy lines in juveniles). The coloration on their bellies is white to yellow. Their pectoral (behind the gills) fins are usually tinted orange and the pelvic (belly) fins are commonly mottled with dark blotches. Most northern pike measure 16 to 24 inches in length. 

Current Distribution

Northern pike are not currently found in California. Northern pike were found in Frenchman Reservoir in Plumas County, California in 1988, and were eradicated from the reservoir in 1991 and tributary streams in the Sierra Valley in 1992. Northern pike were discovered in Lake Davis, Plumas County in 1994. An unsuccessful eradication effort occurred in 1997 and northern pike were found again in Lake Davis in 1999. Northern pike were successfully eradicated from California in 2007. Northern pike are native to Eurasia and North America, including most of Canada, Alaska and the interior northern United States from northwestern Vermont and northern West Virginia in the east, across the Great Lakes Region to northeastern Montana and northeastern Kansas in the west. Northern pike are currently found in many areas outside of their native range in the United States and Europe, and have also been introduced to Africa.

Habitat Preference

Northern pike prefer shallow, well-vegetated inshore areas of cold-water lakes, sluggish streams, and river backwaters. Smaller pike tend to be found within patches of aquatic vegetation less than 13 feet from the water surface; larger pike (greater than 15 inches) are usually found at the edge of vegetation in deeper areas. Northern pike are ambush predators that use their coloration and surrounding aquatic vegetation to hide and swiftly snatch prey that passes by. Northern pike can tolerate a wide range of environmental factors, including warm and cold temperatures, brackish waters (low-salinity), and low oxygen levels.

Pathways

Northern pike are one of the most popular game fish in the world due to their aggressive behavior during pursuit of prey. Most northern pike were intentionally introduced to areas outside of their native range when stocked for sport fishing, although some pike have been introduced to new areas via illegal stocking by persons attempting to establish a new sport fishery. Northern pike are on California’s list of restricted animals and cannot be imported, transported, or possessed without a permit.

Impacts

Northern pike are aggressive predators at the top of the food chain. Their diet consists mainly of fish, but they will also eat frogs, snakes, small mammals, and birds if given the opportunity. In areas were northern pike have been introduced, they have altered fish community composition and reduced fish species diversity (including eliminating native species) through predation and competition. If northern pike were to become established in California, they would pose a serious threat to many native fish species populations, including salmon and trout.

Actions Taken if Found

Per California Code of Regulations (Title 14), any northern pike found in California shall be killed immediately by removing the head. CDFW shall be contacted as soon as possible and within 24 hours by calling (888) 334-2258.

Fisheries Branch
1010 Riverside Parkway, West Sacramento, CA 95605 | Fisheries@wildlife.ca.gov