LaunchDaemon not recognised
Try the following (one-line command) :

sudo chown -R couchdb:couchdb /opt/local/var/lib/couchdb/ /opt/local/var/log/couchdb/ /opt/local/etc/couchdb/ /opt/local/var/run/couchdb


Then reboot.

If it doesn't work, what version of MacPorts and CouchDB do you have ?