Dreissenid Veligers As a Food Source for Silver and Bighead Carp in Lakes Erie and Michigan: A Bioenergetics Model

The Laurentian Great Lakes have experienced dramatic ecosystem changes within the past 200 years. Two Asian carps (bighead carp Hypophthalmichthys nobilis and silver carp H. molitrix) have colonized the Mississippi and Ohio River basins of central North America and are poised to infiltrate the Great Lakes. Many risk assessment models for Asian carps have focused on zoo- and phytoplankton food sources, but have not included invasive zebra and quagga mussels (Dreissena) veligers in the models. The objective of this study is to assess the potential of Dreissena veligers as a potential food source. Fish Bioenergetics 3.0 was used to model silver and bighead carp growth.  The bioenergetics model parameters for both species followed published values with modifications found in other literature. Proportion of maximum consumption was used at the level where fish maintain their weight. Based on the newly developed models Asian carps were able to sustain condition and grow when veliger densities approached and surpassed 1,600 veligers per liter. Previous bioenergetics models that indicate Asian carps may not have an adequate food supply in large portions of lakes Erie and Michigan should be reconsidered with this alternative food source in mind.