Yes either that or cormorants. They are very similar. @Rooster will know for sure. I think a cormorant inhabits a larger territory maybe even up to Alaska. Anhinga's are in much warmer coastal areas.Are those anhinga's?
If I saw one like this I would call it a water turkey or snake bird. You can better identify it if the bird is swimming because an anhinga has the entire body underwater and the only thing visible is the neck and head. It looks like a snake swimming from a distance.
Gators snack off of them.