Abstract
Atlantic Salmon ( Salmo salar ) populations have experienced significant declines in recent decades. In Canada, conservation efforts are divided into 16 designatable units (DUs) to address unique regional challenges among genetically distinct populations. The Cape Breton Highlands, previously subdivided into two of these DUs, are a particularly understudied region in Atlantic Canada, as a result of limited assessments due to their remoteness and difficulty of access. This study aimed to update the knowledge gap in the distribution and abundance of Atlantic Salmon parr in the region and identify environmental variables influencing their presence. Electrofishing surveys were conducted across 24 rivers, specifically targeting data‐deficient systems. Atlantic Salmon parr were detected in four rivers not previously recorded as supporting populations, while they were not recorded in four rivers where they had historically been documented. We found that the difference in Salmon parr abundances between DUs was not significant, suggesting that DU boundaries may not have reflected ecological realities, and could be adjusted to enhance the precision of conservation designations across the region.