Seasonal zooplankton dynamics in main channel and backwater habitats of the Upper Mississippi River

Abstract

This study used stratified random sampling to examine the spatial and temporal distribution of zooplankton communities in a large floodplain river (Mississippi River, USA). Potential mechanisms controlling zooplankton abundance and community structure were considered. Main channel and backwater habitats included in this study differed between a turbid upper pool reach where aquatic macrophytes were sparse and a lower pool reach which was considerably less turbid and had extensive aquatic macrophyte coverage. Samples were collected monthly during the summer over a 2-year period and multivariate analysis was used to examine the spatial and temporal distribution of zooplankton. Significant differences were found in zooplankton density and community composition among habitats and reaches within the pool. Rotifers were the dominant taxa and seasonality was pronounced, with peak densities often occurring in late-spring.Community structure varied by habitat and reach, which suggests that water quality, physical habitat characteristics, presence of aquatic macrophytes, and zooplankton sources can all influence the zooplankton communities of the Upper Mississippi River. Characterization of the zooplankton communities provides a basis for understanding changes in the river ecosystem and examination of zooplankton communities among habitats provides insight into the mechanisms affecting zooplankton dynamics.

Comparisons of zooplankton and phytoplankton in created shallow water habitats of the lower Missouri River: implications for native fish

“…She showed that zooplankton abundances were significantly higher in a backwater than they were in the mainstem for most sampling periods. With respect to other large rivers, Burdis and Hoxmeier (2011) reported that zooplankton were more abundant in Mississippi River backwaters than they were in main channel habitats. They attributed these differences in zooplankton to longer residence times, higher levels of primary production, and/or increased water clarity in backwaters.…”

“…Increased levels of suspended sediment and higher discharge can in turn negatively impact zooplankton. In particular, larger-bodied taxa such as cladocerans and copepods tend to be more abundant in riverine habitats with slower velocities, lower turbulence, lower turbidity, and longer residence times (Sluss et al 2008;Burdis and Hoxmeier 2011). High concentrations of suspended solids can clog zooplankton filtering appendages, decrease feeding rates, and reduce overall growth rates (McCabe and O'Brien 1983;Kirk and Gilbert 1990;Soeken-Gittinger et al 2009).…”

Developing a shared understanding of the Upper Mississippi River: the foundation of an ecological resilience assessment

“…Community structure of phytoplankton and zooplankton is strongly influenced by TSS and connectivity with lentic areas (Wahl et al 2008, Burdis and Hoxmeier 2011, Manier 2014. Current velocity and substrate type within the channel influence the distribution of benthic invertebrates (Fremling 1960, Seagle et al 1982, Anderson and Day 1986, Dettmers et al 2001b, and connectivity with adjacent lentic areas provides important sources of invertebrate drift (Eckblad et al 1984, Sheaffer andNickum 1986b).…”

“…In late spring and summer, backwater habitats often have increased water residence time, low velocities, shallow depths, food resources, and warm temperatures that are important for growth and development of larval fish Nickum 1986a, Nannini et al 2012). Backwaters generally support diverse phytoplankton, zooplankton, and macroinvertebrate communities that serve as important food sources for larval and adult fishes (Eckblad et al 1984, Sheaffer and Nickum 1986b, Wahl et al 2008, Burdis and Hoxmeier 2011, Ochs et al 2013, though these food sources can be influenced by water level variability and substrate composition (Flinn et al 2008). Submersed vegetation and other forms of structural complexity, such as coarse woody debris, provide protection from predation (Dewey et al 1997) and promote growth (Richardson et al 1998) and abundance of certain young-of-year species (DeLain and Popp 2014).…”

Echoes of a flood pulse: short-term effects of record flooding of the Illinois River on floodplain lakes under ecological restoration

“…fitted with a stop-valve near the bottom. Tube samplers collect integrated samples throughout the water column that provide zooplankton densities comparable to other sampling devices (Lewis & Saunders, 1979;DeVries & Stein, 1991), and have commonly been used to sample shallow lake and wetland habitats (e.g., Parkos et al, 2003;Lemke & Benke, 2009;Schuyler et al, 2009;Burdis & Hoxmeier, 2011). This sampling approach was used consistently during this study to quantify zooplankton in these shallow, vegetated floodplain lakes in order that samples could be compared between sites and within each site over time.…”