He’s prolly just trying to be funny and make a wise crack. I don’t know your lake but my lake is sitting at 59 and at that temp the Shad are all over at every depth and move around a ton. You can find them up in 5 ft or out in 50. I fish Lewisville and Sunday there were huge clouds of gizzard Shad out in 30 ft. I look in depressions, ledges and edges, points, channels, flats. Pretty much any shred of structure you can find Shad on or next to. Very easy to catch if you have a deep net and sonar. Usually only takes 1 throw this time of year. I’m not saying this is the best way to get Gizzard Shad, only what works for me. I almost forgot to mention most bridge columns will hold bait as well but you will shred more nets around them.