LITTLE ROCK, Ark. – The polar vortex that covered The Natural State in snow and wreaked havoc on people’s plumbing also may have caused some temporary setbacks with threadfin shad populations in some Arkansas lakes, but biologists at the Arkansas Game and Fish Commission say there’s little cause for concern. Threadfin shad are abundant in most Arkansas lakes and are one of the primary food sources for game fish like bass, walleye, white bass and large crappie. They are more delicate than many other forage species and often struggle when water temperatures drop to 40 degrees. Each winter, some lakes will see shad die-offs from cold temperatures, and anglers may notice an exaggerated impact once their favorite lakes thaw in the next few days.