Extended Data Fig. 1: β⁽²⁾ and NCD2 score density plot for the native, saline Baie de L’Isle Verte population (St. Lawrence drainage, Atlantic clade).

Higher β⁽²⁾ scores and lower NCD2 scores signify stronger signatures of long-term balancing selection. β⁽²⁾ scores are higher and NCD2 scores are lower on average for ‘parallel’ candidate SNPs (blue) relative to the rest of the genome (grey).