Applicability of the flood-pulse concept in a temperate floodplain river ecosystem: thermal and temporal components

Abstract

Annual growth increments were calculated for blue catfish (Ictalurus furcatus) and flathead catfish (Pylodictis olivaris) from the lower Mississippi River (LMR) to assess hypothesized relationships between fish growth and floodplain inundation as predicted by the Flood-Pulse Concept. Variation in catfish growth increment was high for all age classes of both species, and growth increments were not consistently related to various measures of floodplain inundation. However, relationships became stronger, and usually direct, when water temperature was integrated with area and duration of floodplain inundation. Relationships were significant for four of six age classes for blue catfish, a species known to utilize floodplain habitats. Though similar in direction, relationships were weaker for flathead catfish, which is considered a more riverine species. Our results indicate the Flood-Pulse Concept applies more strongly to temperate floodplain-river ecosystems when thermal aspects of flood pulses are considered. We recommend that future management of the LMR should consider ways to 'recouple' the annual flood and thermal cycles. An adaptive management approach will allow further determination of important processes affecting fisheries production in the LMR.

Relationships between hydrology, spatial heterogeneity, and fish recruitment dynamics in a temperate floodplain river

“…The flood pulse concept (FPC; Junk et al, 1989) suggests that annual floodplain inundation triggers blooms of primary and secondary production, and fishes in these systems have reproductive ecologies adapted to exploit this pulse of production. In temperate zone rivers, flood pulses that coincide with optimal temperatures have been associated with greater growth and survival of some species (Gutreuter et al, 1999;Sommer et al, 2001;Schramm and Eggleton, 2006) and are predicted to increase fish recruitment whereas the absence of a flood pulse or lack of synchronization between temperature and water rise reduces recruitment success (Bayley, 1991;Halls and Welcomme, 2004). Despite widespread acceptance of the FPC model, recent studies suggest that in rivers where flood dynamics do not follow the optimum described in the FPC, fishes can recruit successfully during low flow periods (Humphries et al, 1999;Humphries et al, 2002;King et al, 2003).…”

Spatial heterogeneity of water temperature across an alpine river basin

“…Recent attention has focused on how river temperature will be influenced by climate change (Webb, 1996;Hari et al, 2006), altered hydrology (Webb et al, 2003;Schramm and Eggleton, 2006), and land use modifications (Johnson and Jones, 2000;Allan, 2004). Such knowledge is important because altered river temperature may drive changes in the future distribution of freshwater species (Caissie, 2006;Brown et al, 2007a).…”

Hydrologic habitat preferences of select southeastern USA fishes resilient to river ecosystem fragmentation

“…Dam removal projects that analyse only community data may be missing opportunities to elucidate more of the positive ecological effects that river restorations generate, and the reality of some important socioeconomic trade-offs that might exist. For example, it is possible, and supported by previous research (Schramm and Eggleton, 2006), that riverine catfish production would be significantly benefited by restoration initiatives in regulated rivers. Whereas channel catfish are a commercially (Mestl, 1999) and now recreationally relevant species (Wilde and Ditton, 1999), this could be a massive production gain that has not been previously addressed or quantified in river restoration studies.…”