Yes, in french the iron part that surrounds the centerboard is called « saumon » which is the same word used for the fish.
In the following link, the chapter « dériveur avec saumon » is what we have on Edel 4 DL ; DL stands for « dériveur lesté », a boat with a centerboard (« dérive ») which has some weight (‘lesté »)
https://www.bateaux.com/article/29892/differents-types-de-lest-voiliers
So yes, when on this site you read « saumon », it’s probably more about the centerboard than the fish.