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 Outpost for Fishing Merit Badge and enthusiasts (off camp if better fishing)
Possibly Surveys of special animals on camp
Bring in experts if you have indangered species on camp
Show off Critters use as an educational tool.
Fish cooking and cleaning demonstration
Daily Weather Reports/ weather wheel or fire meter
Ecology isn't always the most popular area in camp, to get scouts down to the area Euchre Tournements are a hit @ my Camp, do it on a night where there isn't a lot going on such as outpost night if you have one. While the scouts are having fun it gets them down to the area and looking around as well.