Using Otolith Chemistry to Identify Source, Introduction Timing, and Important Natal Habitats for Invasive Fishes

Knowledge of source environment for invasive fishes and the timing of their initial invasion or introduction are potentially valuable for developing strategies to prevent further introductions or invasions.  However, such information has often been difficult to obtain.  Following establishment of a non-native fish species, identification of natal habitats supporting population persistence is potentially beneficial for directing and enhancing efficiency of control efforts. Microchemical and stable isotopic analyses of otoliths have emerged as tools with the potential to identify origin and determine introduction timing of exotic fishes, provided that source and receiving environments possess consistently distinct elemental or isotopic signatures.  These techniques can also be used to identify recruitment sources for established populations of invasive species in locations where persistent differences in chemical signatures among habitats exist.  Recent applications of otolith microchemistry and stable isotope analysis to Asian carps and other invasive fishes will be discussed.