The Effect of Capture, Handling, and Tagging on Hematological Variables in Wild Adult Lake Sturgeon

Abstract

We measured hematocrit and plasma osmolality, cortisol, lactate, glucose, and chloride in wild lake sturgeon Acipenser fulvescens after gill-net capture (24-h sets) and multiple bouts of brief (2–3-min) air exposure during removal from nets and again during measurement and tagging procedures. Our objective was to evaluate the physiological consequences associated with capture, handling, and tagging activities commonly employed during mark–recapture studies and to determine whether blood chemistry values moved toward a resting state after a 3-d recovery period. Lake sturgeon that were caught during spring tagging activities showed plasma cortisol, glucose, lactate, osmolality, and chloride levels similar to those exhibited by maximally stressed lake sturgeon in published laboratory studies. After the 3-d recovery period, all physiological stress indicators had approached a nonstressed state and the values were similar to those previously reported for resting lake sturgeon. It appears that capture–mark–recapture programs that subject lake sturgeon to stressors similar to those applied here do not pose a significant threat to this often legislatively protected species.