Brassica napus L. is a crucial oilseed crop and holds significant economic value for Canada. There are several seed quality types of B. napus, including canola with low erucic acid (used for edible purposes), as well as genotypes with high erucic acid, mainly used for industrial applications. This research was directed at increasing erucic acid levels in high erucic acid rapeseed (HEAR). The goal was to identify and characterize minor-effect quantitative trait loci (QTL) related to erucic acid content in two distinct doubled haploid (DH) populations, CBLD2 and CBER2. Both populations utilized two HEAR parents to fix the known FAE1 genes and focus on identifying minor QTL impacting erucic acid content. The populations were phenotype in two locations over two years. Erucic acid content was evaluated using gas chromatography and the DH populations were genotyped using genotyping-by-sequencing (GBS). QTL were detected on various chromosomes, illustrating the polygenic regulation of erucic acid. Specifically, significant QTL were discovered on chromosomes A04, A07, and C08 in CBLD2, explaining up to 27 %, 21 %, and 22 % of phenotypic variation, respectively. In the CBER2 population, stable QTL on chromosomes A01, A02, and A05 accounted for 7-9 %, 7-9 %, and 11-18 % of variation, respectively. Analysis also revealed a positive correlation between erucic acid and oil content, and no significant correlation between erucic acid and other agronomic traits. This suggests erucic acid content is regulated independently from other agronomic characteristics. These insights into the genetic foundation of erucic acid content in B. napus are crucial for marker-assisted breeding, aiming to enhance erucic acid levels for improved agricultural and industrial uses.