Interior Least Tern Productivity in Relation to Flow in the Central Platte River Valley

Abstract

Implementation of the Platte River Recovery Implementation Program's adaptive management plan has proceeded with the understanding that management uncertainties, expressed as hypotheses, encompass complex physical and ecological responses. Adaptive management in the Platte River ecosystem relies on a combination of monitoring of physical and biological responses to management treatments, predictive modeling, and retrospective analyses. Given the abundance and diversity of fishes inhabiting waterways decreases with groundwater extractions and flow alterations, we used existing interior least tern productivity data and flow data collected from the Central Platte River area for retrospective analyses to assess the influence of forage fish availability on productivity during the brood-rearing season. Our analyses suggest that low flows during the least tern brood-rearing season do not have a negative relationship with interior least tern productivity. As such, we used this indirect line of evidence to build empirical support to assess the forage fish–related hypotheses in the Platte River Recovery Implementation Program's adaptive management plan, and we concluded forage fish abundance does not limit interior least tern productivity on the Central Platte River.