What did you say about my mother? The complexities of maternally derived chemical signatures in otoliths

Connecting maternal migratory behavior with the behavior and ecology of their progeny can reveal important details in the ecology of a population. One method for linking maternal migration to early juvenile life-history is through maternal chemistry recorded in otoliths. Despite the wide use of maternal signatures to infer anadromy, the duration and dynamics of maternal otolith signatures are not well understood. Shifts in the elemental ratios and strontium isotope ( 87 Sr/ 86 Sr) chemistry in otoliths from juvenile Chinook salmon ( Oncorhynchus tshawytscha ) correlate with the timing of hatch and emergence respectively, indicating a chemical marker of these ontological stages. Additionally, analysis of maternal signatures show that maternally derived 87 Sr/ 86 Sr may be influenced by equilibration of the mother to freshwater, and in some cases the 87 Sr/ 86 Sr signatures of the eggs can shift significantly after being laid. These results provid...