Habitat used by Macrhybopsis chubs associated with channel modifying structures in a large regulated river: implications for river modification

Abstract

We examined use of channel modifying structures (CMS; e.g., engineered rock dikes, channel sandbars) and their associated smaller spatial-scale habitats (SSH) on lower Missouri River, USA, by speckled chub (Macrhybopsis aestivalis), sicklefin chub (M. meeki) and sturgeon chub (M. gelida) from June through October, 2006 to identify important habitat characteristics that could aid conservation. We sampled chubs primarily in six CMS types: L-dikes, wing-dikes, kicker dikes, rootless dikes, channel sandbars and bank-lines. Ninety-three per cent of chubs were collected from L-dikes, wing-dikes and channel sandbars. Unidentifiable Macrhybopsis chubs (UHY) were less than 35-mm TL, were collected early in the sampling season and were most associated with L-dikes where mean bottom current velocity was slow (0.07 m/s). Chubs large enough to be identified to species were associated with large channel sandbars where mean bottom current velocity was faster (0.34 m/s). Chubs from wing-dikes were more abundant in shallow water (<1.2 m deep) adjacent to bars than in deeper (>1.2 m deep), open-water areas ( p ¼ 0.007). Month accounted for 54% and CMS with SSH 18% of explained variation in chub species distribution and abundance. Our results demonstrate that CMS in the contemporary lower Missouri River channel provide multiple habitats for multiple life-stages of Macrhybopsis chubs (e.g., nursery and post-nursery habitats). L-and wing-dikes may provide surrogate nursery habitats for chubs where in-channel slow-velocity areas were lost after river channelization. Managing CMS to address life history stages and an ecologically appropriate proportion and distribution of dike to channel sandbar habitats may be critical for conservation of native Macrhybopsis chubs in lower

The emblematic minnows of the North American Great Plains: A synthesis of threats and conservation opportunities

“…(); 10 Ridenour et al. (); 11 Miranda and Killgore (); 12 Luttrell et al. (); 13 Hesse (); 14 Hampton and Berry Jr (1997); 15 Herzog, Ostendorf, Hrabik and Barko (); 16 Hatch et al.…”

“…Western silvery minnow, plains minnow and Red River shiner were reported from backwaters, side channels, mainstream borders and depressional environments (Hesse, ; Houston, ; Kilgore & Rising, ; Welker & Scarnecchia, ). Conversely, sturgeon chub and Pecos bluntnose shiner were reported in swift velocity mainstem habitats (Kehmeier, Valdez, Medley & Myers, ; Ridenour, Starostka, Doyle & Hill, ; Welker & Scarnecchia, ). Despite the commonalities in mesohabitat, habitat partitioning between western silvery minnow and plains minnow has been observed at finer spatial scales.…”

“…However, appropriate or suitable habitat is poorly understood for most PBS species (see Habitat section). Examples of physical aspects of the habitat template associated with PBS species include particular channel‐modifying structures in the Missouri River (Ridenour et al., ), as well as continuums of depth, velocity and substrate composition in the Arkansas River (Luttrell et al., ), Rio Grande (Heard et al., ), Brazos River (Wilde & Durham, ) and Pecos River (Hoagstrom, Brooks & Davenport, ; Hoagstrom, Archdeacon, Davenport, Propst & Brooks, ). In each of these examples, stream flow‐governed habitat templates are the “master variable” (sensu Power, Sun, Parker, Dietrich & Wootton, ) regulating habitat availability for PBS species (Hoagstrom, Brooks & Davenport, ; Hoagstrom, Brooks & Davenport, ; Worthington, Brewer, Farless, et al., ; Worthington, Brewer, Grabowski, et al., ).…”

Reproductive strategy, spawning induction, spawning temperatures and early life history of captive sicklefin chub Macrhybopsis meeki

“…This study has confirmed M . meeki are litho‐pelagophils, where the eggs and larvae have a drifting phase and previous studies have found that juveniles are found in inshore shallow habitats (Reeves, ; Ridenour et al ., ; Starks et al ., ). As with other riverine broadcast spawners, retention of M .…”

Scaling fish metacommunities in stream networks: synthesis and future research avenues

“…For example, different mesohabitat types (e.g., large islands) are formed above and below the confluence zone in the mainstem, which maintain different fish communities from the naturally flowing reaches to some extent (Ridenour et al 2009(Ridenour et al , 2011. Since the number, distribution and significance of different mesohabitat patches differ among the different basin types (e.g., heart vs elongated), differences in their effect on the assembly of fish communities among the different basin types are expected.…”