Can't selective enable bubble sound
 

With Marine Aquarium 2.6 I had it configured to not generate bubble sounds by default, but could press the 'b' key to turn the sound on temporarily (e.g. to demonstrate it to others).

This feature appears to be broken in version 3.0.1. I can now only get sounds if bubbles are enabled in the preferences, in which case the sound is active when Marine Aquarium is displayed (which I don't want) but I can tehn use 'b' to toggle them on and off.

It would be nice if the first option was reinstated in a future update.

Yes, the implementation of the 'b' key is a bit different in MA 3 for the Mac. It essentially changed to a "mute/unmute" button. I see the usefulness of the usage case you presented. Request noted and will be looked at for a future update/revision.