Lake Sturgeon

Lake Sturgeon

Acipenser fulvescens

Status:

  • COSEWIC – Threatened; Great Lakes population.
  • COSSARO – Threatened.

Description:

  • Often referred to as a living fossil, sturgeon date back to the Upper Cretaceous Period – 65 to 100 million years ago when dinosaurs still roamed the earth!  It is Canada’s largest freshwater fish: recorded in excess of 2 m in length and 136 kg in weight, although most sturgeon today are much smaller; average weight  4.5 kg – 36 kg (10 – 80 lb); average length  .9 – 1.5 m (3 – 5 ft).
  • Unlike most fish, they don’t have scales. There are 5 rows of thick armour like platelets along the back and sides; the skin is covered with tiny tooth like projections that give it the feel of fine sandpaper.
  • The fins are dark brown or grey with the single, dorsal fin far back near the caudal fin.
  • Belly is white or light-coloured and contrasts with the darker back and sides; overall, colour is uniform in adults, younger fish may appear blotchy.
  • Vertebrae consist of cartilage not bones.

Habits:

  • Specialized bottom feeder: a large, toothless suctorial mouth is well back of the snout on the underside of the head. There are 4 barbels (whisker like appendages) in front of the mouth, which are used for sensing its surroundings and food.
  • Feeds on insect larvae, crayfish, molluscs, small fish and occasionally plants.

Habitat:

  • Large rivers and lakes.

Reproduction:

  • Females reach maturity between 14 and 33 years, most often from 24-26 years; and 8 to 12 years for males (but may take up to 22 years).
  • Female Lake Sturgeon spawn once every 4 to 9 years while males spawn every 2 to 7 years; spawning occurs on clean, gravel shoals and stream rapids from April to June.
  • Individuals usually return to the same spawning rivers year after year.
  • Females lay 4,000 to 7,000 eggs per pound of fish
  • Typical life-span of a Lake Sturgeon is 55 years for males and 80-150 years for females.

In Our Area:

  • Known spawning areas include the Pickerel and Moon Rivers.  Any of the large river mouths emptying into Georgian Bay could be potential or existing spawning sites. This could include: Severn, Musquash, Go Home, Seguin, Shawanaga, Naiscoot and Magnetawan Rivers.

Threats:

  • Barriers (dams) in tributaries that prevent spawning.
  • Reduced water quality.
  • Predation on eggs and fry.
  • Lake Sturgeon are highly vulnerable to commercial fishing gear (gill nets) and at one time were considered a nuisance and coarse fish.  The exceptionally long period it takes for them to mature makes them vulnerable to harvest well before they have an opportunity to reproduce.  This scenario has contributed significantly to decimation of the species.

Did You Know?
Historically, sturgeon were abundant prior to European settlement and in the mid to late 1800’s, it was among the 5 most abundant fish in commercial catch. The decline was rapid and the sturgeon was extirpated from some of the tributaries and water where they had spawned.

Click here for more information.

Please report any sightings of Lake Sturgeon to the address below.

For more information in this area:

Management Biologist, Parry Sound Ministry of Natural Resources and Forestry

7 Bay St. Parry Sound, P2A 1S4, 705-746-4201

Map image courtesy of the Royal Ontario Museum