Pond Ecosystem Tier 2- Microscopic bacteria and Plants
The life in this first level of the pond ecosystem are those that help to consume waste and convert it into useful things, such as energy and fertilizers.
In the nitrifying cycle, a bacteria called Nitrosomonas converts the ammonia to nitrites. Nitrites are still very lethal to fish, but another bacteria called Nitrobacter can convert the deadly nitrites to nitrates (i.e. fertilizer for the plants). These nitrates are them consumed by the plants in the eco-system, thereby reducing the amount of ammonia. The fish eat the plants, thereby completing the cycle.