Extrapolating site or depth specific measurements to the entire lake can be problematic as there can be significant metabolic variability both vertically and horizontally within a lake (see variability section). For example, many lake metabolism studies only have a single epilimnetic estimate of metabolism, however, this may overestimate metabolic characteristics about the lake such as NEP depending on the mixed layer depth to light extinction depth ratio. Averaging daily metabolism estimates over longer time periods may help overcome some of these single site extrapolation issues, but one must carefully consider the implications of the metabolic estimates and not over extrapolate measurements.