Otolith microchemistry of adult bigheaded carp for determining early-life environments in the Upper Mississippi River 2016-2018

Data set includes water Sr:Ca, Ba:Ca, and δ18O for the Mississippi River and tributaries, and otolith Sr:Ca, Ba:Ca, and δ18O data from bigheaded carp (Silver Carp and BIghead Carp) collected in navigation pools 16-19 of the Upper Mississippi River in 2016 to 2018. Bigheaded carp (Bighead Carp and Silver Carp) are invasive species in the US and have spread throughout most of the lower Mississippi River Basin. Population abundance upstream of Lock and Dam 19 (LD19) on the Upper Mississippi River (UMR) has likely been limited by the high-head dam at this location, which restricts all upstream fish passage to the lock chamber. To determine early-life environments of adult bigheaded carp captured upstream LD19 at the invasion front, in an area of intense management (Pools 16-19), we measured otolith (lapillus) stable isotope composition and elemental microchemistry of 146 Silver Carp (n = 77 females and n = 69 males) and 141 Bighead Carp (n = 76 females and n = 65 males). Otolith oxygen isotope ratios (δ18O) and elemental ratios (Sr:Ca and Ba:Ca) were compared to values of isotope and elemental ratios in water from putative early-life environments to assign early-life environment for each fish.