Elemental concentrations in the fin rays of white sturgeon (Acipenser transmontanus) by laser ablation sampling-inductively coupled plasma-mass spectrometry (LAS-ICP-MS)

Laser Ablation Sampling-Inductively Coupled Plasma-Mass Spectrometry (LAS-ICP-MS) was found to be a precise but inaccurate technique for determining elemental concentrations in fin rays from white sturgeon. The primary source of variation in the elemental composition of the fin rays was among the annual growth zones. Concentrations of Sr, Mg, Zn, Ba, Sn, Mn, K, and Na, were significantly different among annual growth zones, concentrations of Mg, Sn, K, and Na varied significantly between the right and left lobes within the fin ray, and concentrations of Sr, Zn, Ba, Sn, and K varied significantly as sampling within a fin ray progressed distally from the point of articulation. As well, it was determined that the elemental composition in the fin ray may change over time. However, there were also significant similar concentrations of Sr, Mg, Pb, Br, Zn, Ba, Sn, Mn, and Na in the fin rays between two capture periods. Despite variability within fin rays and. the changes in their elemental composition with time, several elements in the fin rays were linked to changes in the sturgeon's external environment. Concentrations of Sr within the fin rays suggested that white sturgeon in the lower Fraser River are not diadromous, but many spend extended periods of time in the Fraser River estuary as juveniles. It was recommended that when collecting white sturgeon fin rays for biomonitoring studies, the side of the fish and the distance distal from the point of articulation from which the fin ray was removed, be standardized to improve the reproduceability of the data.