ZFS offsite backup

Hi,

does anyone know if with the command,

zfs send pool/fs@snap | gzip > backupfile.gz

for an offline backup to safe multiple stages of pool, the file inside this backup file are zfs checksum protected? Can i see in later one receive stream if files are corruped?

It would be nice if there were an option in the zfs plugin for send and later receive (import pool) to and from backup files eg. from/to an usb disk.

Thank you for your help.