|History of the KBS Pond Lab|
In 1971, a grant from the National Science Foundation (NSF) to Michigan State University provided funds for the construction of 18 experimental ponds, two holding ponds and a reservoir.
Each experimental pond was approximately 30 m in dia. with a maximum depth of 2 m and was lined with vinyl plastic to prevent seepage losses. The liners in the original 18 ponds were covered with 25 cm of compacted topsoil.
After construction, the ponds were allowed to colonize naturally with flora and fauna from surrounding lakes, and within a few years the experimental ponds closely resembled natural systems. These conditions provided the opportunity to conduct a number of significant experiments in the late 1970’s and early 1980’s on species interactions and habitat selection in fishes.
However, by the mid-1980’s, the ponds had become choked with dense, persistent stands of macrophytes (predominantly Ceratophyllum). These conditions made many types of experiments impossible. In 1987, a grant from the NSF program for Field Stations and Marine Laboratories funded the renovation of 9 of the original 18 ponds.
In these nine ponds, the organic rich sediments and plastic liners were removed. New 20 mil PVC liners were then installed and were covered with a mixture of sand and clay (25 cm depth). This sand/clay substrate was relatively nutrient poor compared to the original topsoil. The remaining original 9 ponds were renovated in a similar manner in late summer 2000, again with support from the NSF and MSU.
These renovations successfully returned the ponds to a more pristine state, although successional processes continue to push them towards denser macrophyte cover and more eutrophic conditions through time. Total phosphorous concentration in the open water of the ponds is generally in the mesotrophic range (15-20 µg/L).