Big Lake, Lake Trout

Regulation Number: 
Region 5 - Cariboo
Regulation Type: 
Lake Trout
Closing Date: 
January 6, 2023 at midnight
Decision Statement: 


Current Regulations: 

Lake trout daily quota = 1; lake trout release October 1-30

Proposed Regulations: 

Lake trout daily quota = 1, none of which can be over 50 cm; lake trout release October 1-30


The lake trout population on Big Lake was assessed in 2009 and again in 2021 using Summer Profundal Index Netting (SPIN), which is a calibrated assessment tool that has been used on dozens of lakes across the species North American range. Catch rate in standardized gillnetting declined from 0.28 in 2009 to 0.10 in 2021. Using the SPIN calibration equation this would translate to 500 lake trout larger than 30 cm in the lake before the decline and about 200 currently. This is a small population, which is likely susceptible to extirpation if harvest is not reduced. The reduction in harvest opportunity is proposed to improve the status of lake trout in Big Lake and follow up assessment is scheduled to occur in 2026.

Additional Information: 

Summer Profundal Index Netting (SPIN) catch rate declined from 0.28 in 2009 to 0.10 in 2021. This decline is most likely due to angler effort increasing from 1,000 angler days in the 1990’s and early 2000’s to 4,000 from 2016 to present. To protect the stock from extirpation, more restrictive angling regulations are proposed. The proposed regulation should result in most fish being released as the population is large bodied with most harvested fish being larger than 50 cm. Using catch from SPIN nets as a measure of lake trout abundance was calibrated on Horse Lake in 2021 using mark-recapture and SPIN survey and found the relationship between SPIN catch and population size (measured via mart-recapture) is similar to other lakes across North America. The lake trout population in Big Lake can be classified as low density and at risk of extirpation. SPIN survey is planned for 2026 to evaluate if the population is recovering as planned.