A clarification:
Mr. Quesnel,
To answer your question, if a person is angling for Aurora Trout via an Ontario sport fishing licence/tag, they may catch and release an unlimited number of Aurora Trout, even after they've retained their single allowable Aurora Trout. Similarly, if an angler is fishing for Aurora Trout via an Ontario conservation fishing licence/tag, they may catch and release an unlimited number of Aurora Trout.
Of note though, anglers may not fish up or cull any retained Aurora trout in any day, or at at any point thereafter, until such time as they've voided themselves of any previously retained trout. For example, a person angling under an Ontario sport fishing licence/tag may catch and retain a single Aurora Trout one day and continue to catch and release Aurora Trout for the remainder of the day. The following day, unless the retained Aurora Trout has been consumed or given away to another person for their possession for example, the angler may only catch and release Aurora Trout. To rephrase, an angler cannot retain any more Aurora Trout allowable (i.e.: one (1) on an Ontario sport fishing licence/tag), until such time as they void themselves of the previously retained Aurora Trout.
Again, I trust that this answers your question.