I have my best FWshrimp catching by sweeping the net through or among submerged vegetation. You will usually get some plant materials but they can easily be lifted out of the net leaving small stuff still in the net. Or dump the net in a tub of water the shrimp swim free and you can lift out the weeds.
Bill C, I did just like u stated here. the first day I did it at the vegetation closest to the shore I could get to. the 2nd day I ventured out to some veg beds and tried scooping through the real deep green coon tail veg but was not able to reach the bottom of the lake. so on the passes with the net I would shake out the net ever so careful and I found some un expected creatures. Some insects (looked like a small beatle but colored like a yellow jacket wasp) which was weird because they were under water and a long green looking creature that I did not want to handle. I guess I might be a wuss, when it come to grabbing hold of things I have never seen before. Haha

Tracy