Fatty Acid Profiling of Fish Fin Tissues: Implications for Non‐Lethal Sampling Methods

Fatty acid (FA) profiling is crucial for understanding fish health and diet. However, the critical status of many fish species makes lethal sampling problematic and/or prohibited. This study evaluates the potential of fish fin tissues as non‐lethal alternatives to muscle tissue for FA profiling using Atlantic Salmon ( Salmo salar ). Lipid extractions from the muscle, adipose fin, inner‐caudal fin, and outer‐caudal fin tissues of 11 individuals were analyzed using a modified version of the Mojonnier method. Linear regressions for FA composition and concentration revealed a strong relationship between adipose fin and muscle tissues ( R 2 = 0.98, p < 0.001 and R 2 = 0.98, p < 0.001; respectively). The relationships between outer‐caudal fin and muscle tissue for either FA composition and concentration were also significant ( R 2 = 0.64, p < 0.001 and R 2 = 0.62, p < 0.001, respectively). Both outer‐caudal and adipose fin tissues had lower intra‐tissue variability than muscle tissue. This study suggests that adipose fin tissue may provide a suitable non‐lethal alternative for FA profiling in fish, given its strong correlation with muscle tissue, minimal intra‐tissue variation, and consistency in FA composition and concentration. Despite exhibiting distinct FA profiles relative to muscle tissue, outer‐caudal fin tissue showed consistent proportional relationships that may support its application in non‐lethal FA studies where adipose fins are unavailable. Non‐lethal FA sampling methods support research and conservation efforts and offer an ecologically responsible tool for the study and protection of fish populations worldwide.