Abstract
Biotic calcification has yet to be considered in most freshwater carbon budgets, despite previous calculations that suggest the importance of calcifying animals in altering inorganic carbon cycling. The freshwater snail, Melanoides tuberculata, has achieved a high abundance and a biomass of 34.2 g AFDM m-2 after invading Kelly Warm Springs in Grand Teton National Park approximately five years ago. This high biomass suggests that introduced populations of Melanoides may alter ecosystem processes. We measured Melanoides growth rates and biomass to calculate the production of biomass, shell mass, and C02 for comparison with ecosystem carbon pools and fluxes. Melanoides calcification in Kelly Warm Springs produced up to 10.4 mmol C02 m-2 day-1 during summer months. Despite extremely high primary production and respiration in Kelly Warm Springs (-379 mmol C02 m-2 day-1 and 445 mmol C02 m-2 day-1 , respectively), C02 produced from biotic calcification increased total C02 production in Kelly Warm Springs from 65.9 to 76.3 mmol C02 m-2 day-1 . This rate of C02 production via biotic calcification is within the range of those previously calculated for freshwater systems and suggests the importance of considering the role of calcification in inorganic carbon budgets for areas dominated by calcifying organisms.