As an update, I visited the wetland last month. You are able to park on the edge of the Sani Resort, close to the water treatment plant. From there a track leads up the western side of the wetland, so access is very easy. Plenty of Pygmy Cormorant and the expected Squacco Heron, Black-crowned Night Heron, Purple Heron, Bee-eater, Red backed & Woodchat Shrike, Great Reed Warbler, Marsh Harrier etc.
Another gem of a wetland is the Agios Mamas Marsh, just north of the canal on Kassandra. Probably around 20 mins away from Sani by car. Short-toed Snake Eagle, Marsh Harrier, Great Spotted Cuckoo, Gt Short-toed Lark, Tawny Pipit, loads of waders, Gr Flamingo and White-winged Tern.
We stayed in Afitos on Kassandra and there was some decent farmland birding just west of the town with Turtle Dove and numerous Black-headed Bunting amongst others. A great area overall. I was on a family non birding type holiday but trying to do as much birding as possible, usually early morning. I finished with a trip list of 89 which I was well pleased with.
I also did a boat trip to the Halkidiki Monasteries. I used this as a means to over 5 hours at sea hoping for Scopoli’s Shearwater. I saw three plus over 200 Yelkouan Shearwater.