For those of us, like myself, who miss the bubble sounds, there is a temporary solution I have implemented. Get Forest, available for free at
http://www.macunicorn.com/forest/index.htm Download the program and the Other Worlds pack. In the Elements section there is an Ocean module that is very relaxing and compatible with the Marine Aquarium. Launch that module before your Marine Aquarium Screensaver and you'll have waves washing your computer during and after when the bubble sounds stop. Enjoy!
{EDIT: URL Fixed}