| Contaminant accumulation models are increasingly used to estimate bioenergetics of fish populations. Often, required inputs for these models—namely growth and contaminant accumulation in fish and their diet—are estimated rather than measured directly. Using a methylmercury (MeHg) accumulation model, I demonstrated that certain methods for estimating these inputs can result in significant error in model estimates of consumption and activity. I identified two key components in minimizing this error: First, input estimates based on data collected late vs. mid-summer were less variable. Second, seasonal patterns in fish dietary McHg were identified; thus, seasonal estimates of dietary MeHg were biased compared to annual estimates, which translated into biases around estimates of consumption and activity. Also, I developed predictive models of annual MeHg in zoobenthos from lake pH and DOC. Similar published models for zooplankton suggest that environmental factors affecting McHg in littoral foodwebs are similar to those in pelagic foodwebs. |
