Do fish go with the flow? The effects of periodic and episodic flow pulses on 0+ fish biomass in a constrained lowland river

Walton, S. E.; Nunn, Andy D.; Probst, Wolfgang Nikolaus; Bolland, Jon D.; Acreman, M. C.; Cowx, I. G.

Abstract

The hydrological regime is a significant driver of fish population dynamics in rivers, but there is a dearth of information regarding the mechanisms behind its effects on temperate species, especially non-salmonids. This study investigated the effects of periodic and episodic flow pulses on 0+ fish biomass in a constrained lowland river. De-seasonalized cross-correlation analysis was used to examine time-lagged correlations in episodic signals, in isolation of seasonal periodicity, to identify the responses and response timings of 0+ fish production to abiotic variables, and whether apparent “pulse-depletions” in biomass occur instantaneously (e.g., due to fish displacement during high pulses) or after a time lag. As anticipated, 0+ fish biomass was highest during periods of low discharge and high temperatures in summer, but cross-correlation analysis revealed a negative impact of high pulses on 0+ fish biomass with a lag of 7 months. There was no evidence for an instantaneous pulse-depletion effect of discharge on 0+ fish biomass, suggesting that the indirect effects of high pulses, such as habitat or food-web modifications, are more influential.

Citation

Walton, S. E., Nunn, A. D., Probst, W. N., Bolland, J. D., Acreman, M. C., & Cowx, I. G. (2017). Do fish go with the flow? The effects of periodic and episodic flow pulses on 0+ fish biomass in a constrained lowland river. Ecohydrology, 10(1), Article e1777. https://doi.org/10.1002/eco.1777

• Journal Article Type: Article
• Acceptance Date: Aug 12, 2016
• Online Publication Date: Aug 15, 2016
• Publication Date: 2017-01
• Deposit Date: Aug 19, 2016
• Publicly Available Date: Aug 19, 2016
• Journal: Ecohydrology
• Print ISSN: 1936-0584
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 10
• Issue: 1
• Article Number: e1777
• DOI: https://doi.org/10.1002/eco.1777
• Keywords: 0+ fish biomass; Fish production; Hydroecology; River discharge; Cross-correlation; Time lag
• Public URL: https://hull-repository.worktribe.com/output/442351
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1002/eco.1777/full
• Additional Information: This is the peer reviewed version of the following article: Walton, SE., Nunn, AD., Probst, WN., Bolland, JD., Acreman, M., Cowx, IG. Do fish go with the flow? The effects of periodic and episodic flow pulses on 0+ fish biomass in a constrained lowland river. Ecohydrol. 2017;10:e1777. doi:10.1002/eco.1777, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/eco.1777/full . This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
• Contract Date: Aug 19, 2016