Assessment of Floodplain Benthic Invertivores on the Missouri River

Floodplain connectivity is important to the life history of many lotic fishes by providing access to spawning, nursery, and foraging habitat.  We assessed catch rates of benthic invertivorous fishes and potential relations with benthic invertebrates at three Missouri River floodplain study sites (Baltimore, Dalbey, and Overton Bottoms) as part of a larger floodplain monitoring study during the high water event of 2011.  Benthic invertebrate catch rates were initially high at Baltimore and Dalbey but declined dramatically as high water persisted (see adjacent poster by Miller and Gosch).  Similar trends were evident for benthic invertivores.  Species-specific differences were rare among invertivores within each sampling trip; thus, catch rates were pooled.  Invertivore catch rates were similar among sites, but differed among sampling trips with the highest catch rates observed shortly after inundation.  Multidimensional scaling also showed relatively high dissimilarity of catch rates between early and late sampling trips.  Linear regression analysis suggested invertebrate catch rates can explain a large amount of variation in invertivore catch rates.  Our results suggest that short-term inundation may be more beneficial to benthic invertivores than prolonged inundation.