Grass shrimp have preferences in aquatic vegetation, but just about any species will work. They will also utilize sunken brush and even rocky areas to take cover and forage. They are very common in the backwaters formed by wing dams along the rocky rip rap. I catch them extensively in rocky jetty areas as well. The grass shrimp species TJ is speaking off is native all the way to southern Canada, so cold weather is not an issue with them...
