"Why doesn't Sardis have those Asian carp?"
On the upper lake?
People catch shad at the outlet tunnel and bait lines on the upper lake. They don't know the difference between Asian carp and shad.
They are in every outlet channel of the Big 4.

Enid does it's habitat day the first Saturday of February. Lot of volunteers, guess to be 80 to 100 if not more plus MDWFP and COE employees. Lot of extras that provide lunch.
The last habitat day at Sardis that I know of was about 8 years ago. There were 2 of us C.C members, a couple of MDWFP and about 10 COE employees. I carried a load of Christmas trees to Holiday lodge last after talking with the manager. Leave the there, we will put them out somewhere. Will you have a habitat day in February? Not that we plan on.
Nader has moved their habitat day to the first or second Saturday of December. If they post it on their website/facebook it's usually during that week.
Habitat is mostly staked out on the flats. People don't like getting to close to the water because of mud.