Not part of the April Fool's joke, honest. We had a database server that was acting up, and in the course of trying to fix the problem we had to turn off Aquariums, which turned out to be one of the more active portions of the site.
Everything should be fixed and tiptop now -- database server has been brought into line.
The announcement of the new aquarium quest caused everyone on the site to hit their aquariums at the same time, or so it seemed to us. Anyway, the announcement's been taken down while we make sure everything's okay, and we'll be slowly metering people back in. So: if you can't get in right now, just try in a little bit.
They did all sorts of magical development things that I have no understanding of to make Aquariums run a lot more quickly. You should especially notice speed improvements when playing Booty Grab, and when viewing a forum that has a lot of tanks with mermaids in signatures. So get grabbin'!