Effects Of Fin Ray Removal On The Swimming Performance Of Subadult White Sturgeon (Acipenser transmontanus)

Several populations of white sturgeon (Acipenser transmontanus) on the Pacific Coast of North America currently support recreational fisheries; however, quantifiable age and growth data are needed to ensure effective management.  Methods for non-lethal sampling of pectoral fin spines have been used to obtain similar data from other sturgeon species; however, effects on the swimming performance of white sturgeon have not been assessed. The objective of this study was to assess the affects of two different fin-spine sampling methods (T1-notch removal; T2-full removal) on the swimming performance and behavior of captive white sturgeon (n=15 per treatment).  Using a modified Brett-type swim chamber, we determined critical station-holding speed (CSHS) and swimming behaviors to quantify significant differences in the swimming performance of sturgeon subjected to each fin spine sampling method. Our results showed that mean CSHS (± SE) of controls, T1, T2 were 115 cm/s (± 3.8), 108 cm/s (± 2.3), and 110 cm/s (± 2.6) respectively, indicating that fin-spine sampling had no significant effect on CSHS.  Results from this study suggest that non-lethal sampling of pectoral fin spines in white sturgeon is minimally invasive.  Additional experiments are being conducted to evaluate long-term effects of fin spine sampling on the survival and growth of white sturgeon.