Potential of Otolith Microchemistry to Distinguish Nursery Areas of Salmon within River Simojoki

Draining into the northern Baltic Sea, River Simojoki is an important spawning river for Atlantic salmon. The present study aimed to preliminary explore potential of analysing elemental composition otoliths distinguish within-river nursery area origin Parr were sampled at three areas in and smolts unknown near mouth during migration sea. concentrations multiple elements strontium 87Sr/86Sr isotopic ratio analysed using single- multi-collector laser ablation inductively coupled plasma mass spectrometry, respectively. Based on otolith variables, parr could be reclassified discriminant function analysis random forest with a success rate 53.3% 63.3%, However, uppermost river, rates 90% 100%, Applying classification models trained samples determine which smolt originated from was constrained by limited sampling parr, both sample sizes coverage found river.