With the fall season upon us, Comprehensive Sturgeon Research Project (CSRP) biologists are already beginning to think of next spring’s field season. During these cooler months, field crews are busy tracking and recapturing pallid sturgeon that they believe will become reproductive during next year’s spawning season. Several pallid sturgeon have been identified by scientists as “fish of interest” based upon past reproductive assessments and their movements throughout the Missouri River.
Pallid sturgeon PLS10-017 was originally implanted with telemetry devices in the spring of 2010 as a non-reproductive female. In June of 2012, this female was recaptured and reimplanted with telemetry devices with fresh batteries at river mile (RM) 543.7 near Peru, Nebraska (for more information on data storage tags see the previous post “Where Are You When I’m Not Looking?”). At that time, she had small, white-gray eggs that were visible in the ultrasound and through the small incision made during surgery. Field crews hope to recapture PLS10-017 this fall to determine if her eggs have developed to the point where they can confidently predict that she will likely spawn in the spring of 2013. PLS10-017 was last located at RM 554.9 during August’s river sweep.
Female pallid sturgeon PLS11-018 was originally captured, implanted with telemetry devices, and released near river mile 185 during the spring of 2011. Since then, tracking crews have located her on 25 different occasions throughout the Missouri River. PLS11-018 was found at RM 341.9 in late March of 2012 and was last located at RM 602.6 near the end of September. This steady upstream movement could indicate that PLS11-018 may be getting an early start on a spring spawning migration. Similar to PLS11-018, female pallid sturgeon PLS08-035 has been moving up the Missouri River. From her initial capture date in 2008 through January 2012, this female has moved only 2.5 miles. Starting in May of 2012, PLS08-035 has moved upstream approximately 85 miles. Could she also be getting a head start on a spring spawning migration? Biologists will be targeting these females this fall to find out.