Sea Horses in Venice(?)

"Mind you get a fisherman to bring you two or three cavalli di mare, & put them in a basin in your room, and see them swim. But don't keep them more than a day, or they'll die, put them into the canal again."      

         --John Ruskin, in a letter of 1857 to Charles Eliot Norton

I had no idea there were ever sea horses (or cavallucci) in and around Venice until I came upon the above mention of them in a long letter quoted by John Julius Norwich in Paradise of Cities: Venice in the 19th Century.

I supposed they must have vanished from the lagoon long ago, but I asked a Venetian friend, born here in 1941, if he had ever seen any and he answered, yes, of course, when he was a boy. There were a lot of them in the lagoon then, and when the waves became rough on the Lido--agitato is the word he used, which was hard for me to imagine as I've only ever seen the Adriatic lapping calmly as a lake--they would wash up on the strand.

I asked him when they disappeared from the lagoon and he said he didn't know. Though I remembered a previous conversation with him and his wife when they'd referred to a time when the lagoon became littered with floating fish, I think in the late '60s.

Metal or brass sea horses sometimes appear on gondolas, but unlike, say, dolphins, I don't recall sea horses being a prominent decorative motif in Venice. But maybe I've been overlooking them?

A short underwater video on Youtube claims to show a sea horse off the shore of the Lido but, to be honest, it's pretty hard to make out the isolated little fellow--or to be sure he's there at all.

Are there still sea horses around Venice? Has anyone seen them?