I was on an Ecology Staff for 4 years before moving on to bigger and better things on the Camp Staff. I have taught a wide range of merit badges from Mammal, Bird, Rep & Amphi Studies, Weather, Nature, Space Ex, and more i can't name off the top of my head.
Croakers and Peepers hike @ night
Astronomy Hike or Observation
Service Projects (Our camp had a camp award and a service project was manditory, these improve the ecology of camp)
Big Fish Award (biggest fish caught during the week)
Naturalist Award & Conserverator Award (both scouting awards i believe)
Fishing Out