I use the aquarium a lot as a teaching tool during our ecology unit. It's great to be able to point to the back of the room and give a living example of something we're discussing. A quick example: Those little blackbar chromis each have a distinct territory. In fact, each of the four of them occupies two feet of real estate across the the eight foot tank. When we talk about competition for living space, they illustrate it perfectly. The list goes on, really. I have them make observations of the critters, recording specific adaptations that some of the organisms have.
I've got kids who show up early and/or linger after class each day to check things out. They're always full of questions, so there's countless "teachable moments" with this.
I've got a small group of about 10 middle schoolers who are going to help me with the mini-grant projects: creating virtual field trips for kids in other schools, along with species profiles. I also hope to put some more energy into the breeding project, which has been in a holding pattern for many months at this point.
I'm not sure about working duck hunting into the curriculum, but I am going to start hunting for a grant/opportunity to go to the Galapagos Islands someday. I got bit by the nature/wilderness travel bug in Kenya, and after seeing some video, Galapagos has made it onto the bucket list!