Lots of rain brings organics into the bays and gulf and take up O2 with weak tides and calm winds this can cause a fish kill or sometimes a "jubilee" where many species of crab and shrimp, as well as flounder, eels, redfish, mullet, ETC will leave deeper waters and swarm—in large numbers and very high density—in a specific, shallower coastal area of the bays. I grew up on Mobile by and got to experience this a couple times filled a few octets with flounder and crabs , shrimp redfish and specs its a free for all