Sulphurous Lake, Lake Trout Quota

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-November 30

Proposed Regulations: 

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


Although only 380 hectares in size, Sulpherous Lake supports one on the highest quality fisheries in the province for the combination of kokanee, rainbow trout, and lake trout which draws a large amount of fishing pressure for its smaller size. Lake trout regulations on Sulphurous Lake were changed from catch and release only to a daily possession limit of 1 in 2013. Prior to the regulation change the lake trout population was assessed 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. The population was assessed again recently which showed a 90% decline to unsustainable levels. The reduction in harvest opportunity is proposed to improve the status of lake trout in Sulphurous Lake and follow up assessment is scheduled to occur in 2025.

Additional Information: 

SPIN was conducted in 2018 and found catch averaged 0.06 lake trout per net, which is a 90% decline from densities observed during the 2009 survey when catch averaged 0.89 lake trout per net. This decline is most likely attributed to increased daily possession limits implemented in 2013. Lake trout in Sulphurous Lake are likely to become extirpated if harvest is not reduced. The target density for lake trout in Sulphurous Lake is 0.4 lake trout per net. A follow up survey is scheduled planned for 2024 to monitor if the population is recovering to the desired target and weather harvest can be increased or further decreased. Using catch from SPIN nets as a measure of lake trout abundance was calibrated on Horse Lake in 2021 and confirmed that SPIN catch is proportional to the actual abundance of fish in the lake. The lake trout population in Sulphurous Lake can be classified as low density and at risk of extirpation.