Recently, Potomac River blue catfish have been in the spotlight. On February 23, 2012, a Pennsylvania angler caught an 80-pound, 12-ounce blue catfish in the Potomac River near Fort Washington. The enormous blue catfish broke the Maryland State record, surpassing the previous record holder by 13 pounds. The previous record fish was caught in 2008 not far from where Wetzel caught his fish.
Blue catfish are native to the Mississippi River Valley and were introduced to the James and Rappahannock Rivers in the 1970s. Since then, the fish have reproduced and spread throughout the tidal Potomac River system. Flathead catfish, another non-native invasive species, and blue catfish have subsequently turned up in the Nanticoke, Susquehanna and Northeast Rivers, Upper Chesapeake Bay and other waters.
source: MD DNR