Yeah, I used to get loads from the Wansbeck/Sandy Bay/Cambois area but haven't been fishing a lot in the last couple of years. When I did go the other week all my fish were clean and healthy so I mentioned it - seems they've not seen any in the Tyne for a while either, they're a bit bemused as to why they appear for a while then vanish again. I told the lady I'd log any catches I get and would enquire on here also - I'll relay catch reports to her rather than have her bombarded with mails.
If people can log clean (normal) fish aswell it might help them investigate the cause, we all catch a lot of flounders most years so keeping a little notebook of numbers, area and size (plus whether clean or mutated) might help a lot to finding out why the issue happens and what is causing it.
I used to see anything from none, to 1/3rd and even upto 1/2half of my flounders at the Wansbeck mouth/Sandy Bay were affected. Either double-dark (maybe at worst upto 1-2 in 10 fish), dark markings appearing on the white (most often ie around 5-6 in 10 fish)), multiple eyes/eyes on the pale side (maybe 1 in 10) or more rarely double pale/pale marks on the dark side (less than 1 in 10). But I'm going back to the late 1990's/early 2000's when I fished this area a lot so I'm not really upto speed on what people are catching there...
I first fished the area in about 1995, all normal fish, it was probably around the end of the 90's when I caught my first messed up flounder, then for a few years they were more common than healthy/normal fish..... Question remains as to why it keeps happening?!