Greg Stunz, Thomas Minello, and Jay Rooker (TAMU-CC)

The purpose of this study is to evaluate the feasibility of using otolith trace element signatures of an estuarine-dependent finfish to determine the contribution of different nursery areas to adult stocks.  Specifically, we are attempting to use red drum ( Sciaenops ocellatus ) as a “model” species and characterize trace element signatures of this economically important teleost from several nursery habitats in Texas.

Otolith of a juvenile Red Drum showing growth rings.

Broad-scale spatial variation of elemental signatures will be examined to see if salient differences are present among and within presumed nursery grounds in Texas.  In addition, we plan to rigorously test the reproducibility of results over temporal scales to determine if differences in elemental fingerprints are stable over time.    Further, we will use this technique to identify the otolith of a juvenile Red Drum showing source (natal origin) of adult red drum stocks in growth rings the northern Gulf of Mexico and then assess the relative contribution of different nursery grounds.  As a result, fundamental questions regarding the value and health of natural ecosystems will be addressed and elucidated with this novel technique.