I'll bow to everyone else's greater knowledge but I'm not 100% convinced.
They certainly weren't 'sport fish', I could have walked down the jetty, reached over and picked one up!!!
I decided to not mention that to the 'all the gear' fisherman about 100 yards further down the river.
I only ever went fishing as a kid . . . Mostly aged 9-12 when we lived on a WWII MTB, I used to go for mackerel and bass off Shoreham harbour arm . . .or mullet off the end of our home/boat up,river , in Shoreham, Caught the odd bass, mackerels literally jumped on the feathers, but Mullet . . . .slipperier than Tory mp's. Apparently they taste crap and are loaded with needle like bones . . . . When I foul hooked one I gave it to the cat. He nibbled round the edges!