Dreissenid mussels (Dreissena polymorpha and Dreissena bugensis) reduce microzooplankton and macrozooplankton biomass in thermally stratified lakes

Abstract

We conducted a survey of 50 thermally stratified lakes with similar nutrient concentrations and morphometries in Michigan to examine the direct and indirect effects of dreissenid mussels on the biomass and community composition of microzooplankton and macrozooplankton. Twenty-five lakes were infested with dreissenid mussels (invaded), while 25 lakes were dreissenid free (uninvaded). In invaded lakes, phytoplankton biomass was 24% lower, and water clarity was 21% greater. Total microzooplankton biomass was 44% lower, with ciliate and rotifer biomass 39% and 45% lower, respectively, in invaded lakes. Total macrozooplankton biomass was 33% lower, largely driven by a 40% lower biomass of Daphnia spp. in invaded lakes. In contrast, dreissenid status had no significant influence on total copepod biomass, calanoid biomass, or cyclopoid biomass. Our microzooplankton results are similar to those of previous studies conducted in shallow, well-mixed systems, although the magnitude of the dreissenid influence in our study was smaller, as might be expected in thermally stratified systems. On the other hand, ours is the first study to document lower biomass of Daphnia spp. and reduced rotifer diversity in invaded lakes. In contrast, we found no difference in macrozooplankton community structure. Dreissenids likely affected zooplankton directly through predation (microzooplankton) and indirectly through resource competition (micro-and macrozooplankton). Understanding how dreissenid mussels affect both microand macrozooplankton will help us to identify the potential mechanisms by which higher trophic levels (e.g., fish) are influenced by these invaders.

The effects of hypolimnetic anoxia on the diel vertical migration of freshwater crustacean zooplankton

“…, Kissman et al. ). We identified cyclopoids to the genus resolution for one vertical tow sample in each of the 24‐h sampling campaigns to identify the major genera present.…”

Effects of invasive zebra mussels on phytoplankton, turbidity, and dissolved nutrients in reservoirs

“…Therefore, additional studies that compare conditions in reservoirs with and without zebra mussels are needed to test the hypotheses outlined above. Specifically, surveys of reservoirs such as those that have previously been conducted in Michigan lakes with and without zebra mussels (Raikow et al, 2004;Knoll et al, 2008;Kissman et al, 2010), will allow for a determination of zebra mussel impacts on the biological and chemical conditions of reservoir ecosystems. enumerated and identified by Dr. Russ Rhodes, Missouri State…”

“…Anabaena typically dominate cyanobacterial communities in Kansas reservoirs ; therefore, cyanobacterial blooms may be less frequent and/or of reduced magnitude in invaded reservoirs. In order to test this hypothesis under more natural conditions, however, we suggest that biovolumes of Anabaena be compared in reservoirs with and without zebra mussels similar to those surveys that were conducted for natural lakes in other parts of the country (e.g., Knoll et al, 2008;Kissman et al, 2010). Furthermore, monitoring changes in phytoplankton community composition over time following zebra mussel invasion in newly invaded reservoirs could also be used to test this hypothesis.…”

Comparing seasonal dynamics of the Lake Huron zooplankton community between 1983–1984 and 2007 and revisiting the impact of Bythotrephes planktivory

“…Over the past decade, however, the zooplankton communities in Lakes Michigan and Huron have changed with cladocerans and cyclopoids declining in abundance (Barbiero et al, 2009a;Fernandez et al, 2009;Kerfoot et al, 2010), while calanoid copepods are either remaining stable or even increasing (Barbiero et al, 2009b;Fernandez et al, 2009). Possible explanations for these changes include: 1) ongoing declines in offshore nutrient concentrations (Barbiero et al, 2009a;Evans et al, 2011;Mida et al, 2010) and the resultant competitive advantages to calanoids (McNaught, 1975;Richman and Dodson, 1983;Santer, 1994); 2) the expansion of quagga mussels and their filtering of phytoplankton (Fahnenstiel et al, 1995;Vanderploeg et al, 2010) and microzooplankton (Kissman et al, 2010;MacIsaac et al, 1991;Pace et al, 1998) that herbivorous and omnivorous cladocerans and cyclopoids feed upon; 3) excessive planktivory from invertebrate predators such as Bythotrephes longimanus (Bunnell et al, 2011;Lehman, 1991;Lehman and Cáceres, 1993) that prefer herbivorous cladocerans (Schulz and Yurista, 1999;Vanderploeg et al, 1993).…”