Catch-Per-Unit-Effort as a Proxy for Cyprinid Abundance in Littoral Areas of Boreal Lakes

Catch-per-unit effort (CPUE) and biomass are often used as parameters to estimate the productive capacity of aquatic systems. Productive capacity is a central component in many environmental impact assessments, particularly those involving the alteration of water bodies for mining and other industries. While CPUE does provide a means to examine relative trends in fish populations over time, it fails to provide a quantitative estimate for fish abundance and biomass, both of which are often time and labour intensive to obtain. Cyprinid species are an important source of forage for many predatory fish species and in addition, represent a key link to the production at the base of aquatic food webs. We quantified the relationship between CPUE and mark-recapture abundance estimates for two cyprinid species with contrasting life-histories in two small boreal lakes over a seven year period. These relationships could potentially be applied to CPUE data from other aquatic systems to provide estimates of abundance and biomass for cyprinid species.