Smallmouth Bass

Identification & Biology
Alias' : Smallie, black bass, bronzeback, brown bass, redeye
Latin Name : Micropterus dolomieu
Category : Fish
Description :
  • Flat, oval shaped body that grows 25-40 cm long on average
  • Large, long head with dark bars that radiate from the eyes
  • Two joined dorsal (back) fins that appear as one
  • Back and top of the head range from brown to green, the sides are lighter and more bronze with thin vertical bars. Underside is cream coloured to white.

 

The Smallmouth Bass is a warm-water fish species known for sport fishing. It is one of two species of “black bass” in BC, with the other being the Largemouth Bass. Spawning typically begins in the spring, when temperatures exceed 10 degrees Celsius. A female Smallmouth Bass may produce up to 10,000 eggs and spawn several times per season. They are carnivorous fish and feed on crayfish, insects, and smaller fish. Smallmouth Bass larvae will feed on various zooplankton.

Smallmouth Bass can be confused with the non-native Largemouth Bass. The main distinguishing features are side-body pattern and mouth size.  In comparison to Smallmouth Bass, Largemouth Bass have a dark horizontal line running from gills to tail, and have a larger mouth that extends past the center of the eye. Smallmouth Bass has a smaller mouth that only extends to the beginning of the eye.

Look Alikes
Habitat

Smallmouth Bass are a native fish species to eastern and central North America, however, they are not native to B.C. Within the province, Smallmouth Bass have been introduced to Southern Vancouver Island, Okanagan, Thompson, and Kootenay Regions, along with the Beaver Creek Watershed in the Cariboo. They prefer lakes, rivers, and streams that reach summer temperatures of 15-21 degrees Celsius and have clean, clear water. They thrive in moderately shallow water in rocky and sandy areas. They are less associated with dense growths of aquatic vegetation than the Largemouth Bass. A common place to find Smallmouth Bass is under the cover of submerged logs and docks.

Impact & Risks
  • Smallmouth Bass are top predators and can reduce native fish populations.
  • They can affect the food web by reducing small invertebrates and fish.
  • These fish are often a danger to native fish fry such as Salmon and Trout, posing a risk to recreational and commercial fisheries.
  • They are capable of carrying parasites that can harm native fish species.
Prevention & Mitigation
  • Do not possess, breed, ship or release Smallmouth Bass in B.C.
  • Use of live bait is prohibited in B.C.
  • Do not release aquarium fish into the wild.
  • Properly clean, drain, dry  your boat and equipment before entering a new water body.
    • CLEAN  off all plant parts, animals, and mud from boat and equipment (e.g. boots, waders, fishing gear). Use a power wash station if available
    • DRAIN  onto land all items that can hold water (e.g. buckets, wells, bilge, and ballast)
    • DRY  all items completely before launching into another body of water
  • Raise awareness to avoid the spread of this species in B.C.
  • Report Smallmouth Bass, or any other invasive species via the Report Invasives phone app, that is available from the provincial website: www.gov.bc.ca/invasive-species

 

Okanagan Distribution

Priority Level Definitions

Watch For - Poses a significant threat (very high risk) and does NOT presently occur in the region OR is relatively new to the region and is very limited in extent.
High - High risk/impact; limited population with significant potential to spread in the region.
Medium - Medium risk/impact; limited distribution – broader population distribution with potential to spread further in a region.
Low - Low risk/impact; may be widespread or not, may be of concern in specific situations with certain high values – e.g. specific agriculture crops. Some species may be treated primarily with biological control agents.