Steven R. Chipps
Brian G. Blackwell
Robert P. Hanten
Trevor M. Selch
2019
<p><span>We collected Walleye </span><i>Sander vitreus</i><span> (May–October) from Bitter and Twin lakes, South Dakota to assess seasonal- and diet-related variation in tissue mercury (Hg) concentration. The average Hg concentration in Walleye was 43–68% higher in the spring for Bitter (</span><i>p </i><span>< 0.008) and Twin Lakes (</span><i>p </i><span>< 0.017) compared with summer or autumn months. Bioenergetics analysis of Bitter Lake Walleye showed that consumption of fish prey (primarily Fathead Minnow </span><i>Pimephales promelas</i><span>) increased from late summer through winter and was linked to increased Hg accumulation in Walleye the following spring. Mercury concentration varied significantly with Walleye age but was similar for comparably-aged male (0.62 μg/g) and female fish (0.62 μg/g). However, after adjusting for Walleye size (total length, mm), mean Hg concentration was greater in male (0.66 μg/g) compared with female (0.50 μg/g) fish, likely due to slower growth rate of male Walleye. At 425 mm, male Walleye in Bitter Lake were approximately 1 year older than female fish. These findings show that diet, age, and gender-related growth affect Hg concentration in Walleye and are important factors to consider in fish contaminant monitoring programs.</span></p>
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10.1007/s00244-019-00658-1
en
Springer
Influence of season, sex, age and diet composition on mercury concentration in Walleye Sander vitreus
article