I was very interested in your comment so I did a quick search and found this.
Although not from DPI but a report none the same.
http://www.sunraysiadaily.com.au/sto...-protect-fish/
This from DPI Victoria.
http://www.depi.vic.gov.au/__data/as...od-fishery.pdf
Upon reading these articles, I would have to agree with the proposal on size limit only, as they do taste best in this size range, however the taking of one fish at these sizes I do not agree with.