Historic Data

The historic data presented on this page features the South Bay region of Lake Nipigon only. To learn more about the data for other Nipigon areas such as West Bay, the Nipigon River, and Nipigon Bay, check out the full PDF document called...

"Update on brook trout rehabilitation in the Ontario waters of Lake Superior, Lake Nipigon, and the Nipigon River"


You always remember your first... fish that is. Underwater release of my first 25" Nipigon BrookTrout.


Brook trout ( Salvelinus Fontinalis ) were once common throughout much of Lake Superior, Lake Nipigon, and the Nipigon River. This area was renowned for its large brook trout and supported a legendary sport fishery dating back to the 1850's. Brook trout populations throughout this region have declined from historic highs due to a number of anthropogenic factors including construction of roads and railways, log driving, land clearing, introduction of exotic species, and overfishing.

Since their original decline a number of different approaches have been used in an effort to restore brook trout populations. From the 1920's to the 1980's more than four million brook trout were stocked in many locations along the Ontario shoreline of Lake Superior, throughout the Nipigon River, and in southern Lake Nipigon. However, stocking programs were largely unsuccessful and have been discontinued. Angling regulations became increasingly protective over time. Prior to 1885, harvest was unrestricted and anglers in the Nipigon area could reportedly harvest barrels of trout each day.

Despite efforts at rehabilitation, the status of brook trout stocks and their associated fisheries continued to cause concern among anglers and fisheries managers in the early 2000's, prompting numerous actions. Habitat protection and creation were important in efforts to rehabilitate the Nipigon River during the 1990's. Artificial spawning sites were created and plans were developed to regulate fluctuating water levels caused by hydroelectric generation.


Goals for brook trout management in Lake Superior and Lake Nipigon

  • Restore to 1930's levels of abundance and structure
  • Restore to allow angler catch rates of 1 brook trout every 2 hours of fishing
  • Restore to provide angler catch rates of 1 brook trout longer than 56 cm (22in) for every eight hours of fishing

1923-2003 South Bay Brook Trout Population


The historical records indicate a healthy spawning population from 1923 to '33. Studies in the 80's to 2003 indicate the population has leveled off around 200 to 300 fish at South Bay. 




This graph indicates the size of all brook trout sampled in the South Bay study area.

Tagging studies and spawn collection programs have provided information on the number and size of brook trout using spawning shoals in South Bay of Lake Nipigon since the 1920's. The historical number of brook trout which spawn on shoals in South Bay was estimated using records of spawn collection. Technicians lived in buildings near spawning sites and it is thought that spawn was collected from most brook trout spawning in these areas. Personal diaries of hatchery managers and technicians describe the volume of eggs collected each year. The number of eggs collected each year was estimated by multiplying the typical number of eggs per litre by the annual volume of eggs collected. The number of females was estimated by dividing the number of collected eggs by the fecundity of Lake Nipigon brook trout, which range from 300 to 2,8 00 eggs per female. To estimate the total number of brook trout used for spawn collecti on the number of males was assumed to be equal to the number of females.


The graph with the fish background is my represention of the blue MNR graph above. It shows the percentage of the spawning population based on length of each fish measured. SBmycolouredgraph


Drop in mean age

Over an 8 year period, the mean age of the brook trout dropped from 4.1 to 2.5 years. This is a classic sign of over havesting and fishing pressure. As a result of this data, along with other factors, the MNR recommended a change in the fishing regulation to the current 22" limit which took place in 2005. Learn more about the Rehabilitation assessment conducted after the 2005 regulation change.


4.1 yrs


4.7 yrs


3.0 yrs


2.5 yrs




History of Brook Trout Angling Regulations


  • 1885 and prior: Harvest was unrestricted and anglers in the Nipigon area could reportedly harvest barrels of trout each day
  • 1887: Ontario first regulated a province-wide fishing season for brook trout, (May 1 – September 15)
  • 1926: first Province-wide possession limits
  • 1979: regulations allowed each angler to possess fifteen fish or ten pounds plus one fish from the Ontario waters of Lake Superior.
  • 1990: possession limits were reduced to 2 brook trout longer than 46 cm (18.1in) were imposed for Lake nipigon and the Nipigon River
  • 1997: Limits reduced on the river to one brook trout longer than 50 cm (20 in) and this regulation was extended to Nipigon Bay in 2000.
  • 2005:daily possession limit to 1 brook trout with a minimum length of 56 cm (22 in).