Hi Chris- not sure if this is what you're looking for, (maybe more nature than hard science.)

www.bayrestoration.org/education_SummerCamp.html

It's a nature day camp, in Grasonville, MD. Our kids loved it, but they were younger than yours when we attended. (It was several years ago, too- once our kids were in public school, they never finished in time to attend this camp!)

The activities are science/nature based, with some dissecting (minimal, but our kids were about 1st grade then) and lots of exploring the wetlands and beach area. Focus is on environmentalism. Our kids really enjoyed it, but as I said, it was a few years ago.

Don't have experience with this one, but thought it sounded good-

www.cbf.org/Page.aspx?pid=975

both day and residential programs through the Chesapeake Bay foundation. Again, maybe more nature-outdoorsy than you're looking for.