The record-setting flood on the Patuxent River that shut down parts of Route 4 and Route 301 on September 8 also created chaos and danger for the animals living in Jug Bay marshes. Mattress-sized clumps of uprooted marsh plants and large logs floated fast downstream. The current in the river’s main channel was pumping three times faster than normal.     On the river’s edges, where wild rice and cattail stalks poked above the brown waters, the heads of red-bellied and...