Assessment of the effectiveness of muck-digesting bacterial pellets

Abstract

Kindervater E, Oudsema M, Hassett MC, Partridge CG, Steinman AD. 2022. Assessment of the effectiveness of muck-digesting bacterial pellets. Lake Reserv Manage. XX:XX–XX. We assessed the ability of Mukk Busster bacterial pellets to decrease organic matter (OM) in lake sediments, as well as their impact on overlying water quality and the native bacterial community composition. Sediment and water from 3 lakes in Newaygo County, Michigan, were incubated for 8 weeks in enclosed tubes with 3 treatments: (1) temperature (ambient or ambient plus 3 C); (2) oxygen level (oxic or anoxic); and (3) pellets (present or absent). We found no statistically significant differences in change in OM between pelleted and control treatments. Sediments were also tested with or without pellets in open bins to include more sediment volume and surface area; again, there was no treatment effect of pellets. OM responses differed among lakes: Irrespective of pellet treatment, there was a slight increase in Hess Lake OM, a significant increase in Brooks Lake OM, and a significant decline in Pickerel Lake OM. We have no definitive explanation for the increases in OM, but because they occurred in both types of experimental containers, we believe the increases were not an artifact. The dominant genera in the bacterial community differed only among lakes, not among the pellet vs. control treatments. Our doses exceeded recommendations (due to the small sediment area used), which the manufacturer claims can change the bacterial composition, but our genetic analysis showed no differences in the flora. We conclude that these pellets are not an effective treatment to reduce sediment OM in these lakes. Supplemental data for this article is available online at https://doi.org/10.1080/10402381.2022.2029635.