Here are some lyrics from the song "Under the Sea" from the film The Little Mermaid:

The newt play the flute
The carp play the harp
The plaice play the bass
And they soundin' sharp
The bass play the brass

Each little slug here
Cutting a rug here

How can Ariel know about flutes, harps, bass, brass instruments, and rugs, but not know what a fucking fork is?  She combs her damn hair with them.  None of those instruments would be very effective under water, and surely mer-people don't use rugs on the ocean floor, do they?  So the only way they could know about them is because they came from the Human world.  And oh, by the way Ariel, that "triton" your dad carries around ... is a giant fork!  Nobody ever looked at that thing and thought, "gee, a smaller version would be perfect for stabbing food and shoveling it into my mouth."

Merfolk are strange.