I'm surprised the snapshots showed up, I've got the snapdirs hidden:
$ zfs list -oname,snapdir NAME SNAPDIR bpool hidden bpool/BOOT hidden bpool/BOOT/ubuntu hidden rpool hidden rpool/ROOT hidden rpool/ROOT/ubuntu hidden rpool/home hidden rpool/home/root hidden rpool/home/sarnold hidden rpool/swap - rpool/tmp hidden rpool/usr hidden rpool/usr/local hidden rpool/var hidden rpool/var/cache hidden rpool/var/lib hidden rpool/var/lib/AccountsService hidden rpool/var/lib/docker hidden rpool/var/lib/nfs hidden rpool/var/lib/schroot hidden rpool/var/log hidden rpool/var/mail hidden rpool/var/snap hidden rpool/var/spool hidden rpool/var/tmp hidden rpool/var/www hidden
I'm surprised the snapshots showed up, I've got the snapdirs hidden:
$ zfs list -oname,snapdir lib/AccountsSer vice hidden lib/docker hidden lib/schroot hidden
NAME SNAPDIR
bpool hidden
bpool/BOOT hidden
bpool/BOOT/ubuntu hidden
rpool hidden
rpool/ROOT hidden
rpool/ROOT/ubuntu hidden
rpool/home hidden
rpool/home/root hidden
rpool/home/sarnold hidden
rpool/swap -
rpool/tmp hidden
rpool/usr hidden
rpool/usr/local hidden
rpool/var hidden
rpool/var/cache hidden
rpool/var/lib hidden
rpool/var/
rpool/var/
rpool/var/lib/nfs hidden
rpool/var/
rpool/var/log hidden
rpool/var/mail hidden
rpool/var/snap hidden
rpool/var/spool hidden
rpool/var/tmp hidden
rpool/var/www hidden