An Energy Budget for the Zoobenthos of Mirror Lake, New Hampshire

We combined our data on abundance, biomass, and diet of benthic animals in Mirror Lake with estimates of annual P/B (production/biomass) ratios to construct a model of energy flow through the zoobenthos of this small, oligotrophic lake. Because we included the rarely study meiofauna (all metazoans < 0.5 mm), our model provides the first accounting of energy flow through an entire zoobenthic community in freshwater. In Mirror Lake, about half of the zoobenthic assimilation of carbon (14 g°m — 2 °yr — 1 ) is due to the meiofauna. Although detritivory supports about half of community assimilation, benthic algae are an important energy source to the zoobenthos, especially in the littoral zone. We suggest that the importance of benthic algae in lacustrine energy budgets has been underestimated. Major fates of zoobenthic production in Mirror Lake include invertebrate predation, insect emergence, and fish predation. Invertebrate predation is the dominant fate and accounts for 80% of zoobenthic production.