Environmental changes in a Mediterranean river: implications for the fish assemblage

Sánchez-Hernández, Javier; Nunn, Andy D.

Abstract

This study examined the impacts of climate change on hydrology and fish population dynamics in a river in central Spain. The objectives were to: (i) contextualise long-term trends in the hydrology (1943–2012) and climate (1985–2011) of the study area, and (ii) identify the environmental factors driving fish population dynamics (1998–2012). Air and water temperatures progressively increased over the study period, whereas there were substantial reductions in mean spring river discharges but increases in peak-flow discharges during the spawning and early larval period of endemic cyprinids in recent decades. In particular, the changes in spring river discharges could have fundamental implications for the future status of the endemic cyprinids because this study revealed a positive influence of stable and low flow conditions during the spawning and early larval period (in late spring) on recruitment success (young-of-the-year densities). The density of young-of-the-year Salmo trutta appeared most influenced by flow conditions during fry emergence and the early larval period (in early spring), with the highest densities associated with low peak-flow hydrological pulses. Overall, fish abundances were significantly influenced by the frequency and duration of high and low hydrological pulses, but there were interspecific and ontogenetic differences in their influence. We conclude that although it is widely accepted that global warming should favour cyprinid over salmonid species, future shifts in hydrology due to climate change could negatively affect some cyprinids, including endemic species.

Citation

Sánchez-Hernández, J., & Nunn, A. D. (2016). Environmental changes in a Mediterranean river: implications for the fish assemblage. Ecohydrology, 9(8), 1439-1451. https://doi.org/10.1002/eco.1737

• Journal Article Type: Article
• Acceptance Date: Mar 12, 2016
• Online Publication Date: Apr 13, 2016
• Publication Date: 2016-12
• Deposit Date: Mar 30, 2016
• Publicly Available Date: Apr 13, 2016
• Journal: Ecohydrology
• Print ISSN: 1936-0584
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 8
• Pages: 1439-1451
• DOI: https://doi.org/10.1002/eco.1737
• Keywords: Abundance; Endemic species; Flow; Threatened species; Water temperature; Climate change
• Public URL: https://hull-repository.worktribe.com/output/434352
• Publisher URL: http://onlinelibrary.wiley.com/doi/10.1002/eco.1737/abstract
• Additional Information: Authors' accepted manuscript of article: Sánchez-Hernández J., and Nunn A. D. (2016) Environmental changes in a Mediterranean river: implications for the fish assemblage, Ecohydrol., 9: 1439–1451. doi: 10.1002/eco.1737.
• Contract Date: Mar 30, 2016