Mbo, "I lobster and never flounder...". Grrrroannnnn! (Where are those rotten tomatoes when you need 'em?) That's almost as bad as Spaw's song titles.
Some other fishing-related songs that come to mind are:
Skinny Minnie Fishtail - novelty song about a fisherman who catches a mermaid (sung by Teresa Brewer in the 1950s)
Shrimp Boats (sung by Jo Stafford in the 1950s)
Curimaõ (sp?) - Portugese fishing song recorded by the Limeliters
Los Pescadores (sp?) - sung (written by?) Buffy St. Marie
Black Water (Doobie Brothers -- mentions catfish jumping)
Blue Bayou (...Where there's fishing boats with their sails afloat ...)
Catfish John -- wonderful song
The Lobster (Or The Crayfish) - several versions in the DT and forum
Three Little Fishies (Fee Widdo Fiddies) was a big hit for Kay Kyser and his band in the mid 1930s. The first chorus is the "boop, boop, diddum, dattum, wottum, shoo." The ensuing choruses get sillier and sillier, until the last one is pure sound effects. It's worth looking up a tape of the Kyser version.
Then, of course, many sea chanties specifically refer to fishing, either for whales or for other prey.