Towards a holistic indicator of flow disturbance impact: fish community size spectra

Alonso Gonzalez, Carlos; Herranz, Javier; Solana Gutierrez, Joaquin; Garcia De Jalon Lastra, Diego; Noble, Richard

Abstract

Fish size-spectra provide a simple synthetic metric to assess the effects of pressures on the overall function of river ecosystems. An exploration of the effects of hydrological pressures on this metric is addressed in order to test its sensitiveness as a potential holistic indicator of ecological integrity. A set of 652 sampling sites with individual fish length data were used to compare the size-spectra among unimpaired sites and sites only affected by hydrological pressures. The variation of size-spectra along a gradient of rheophily was also considered. Our results show that size spectra slopes are naturally steeper in rheophilic than in limnephilic reaches. According to this, hydrological alterations produce different responses in the fish community size spectra. Hydrologically impaired rheophilic reaches show an increase in the ecological efficiency (size spectra slope) but a decrease in community capacity (elevation of the size spectra), whereas limnephilic reaches experience a decrease in the ecological efficiency but an increase in the food-web capacity (increased elevation of the size spectra). Slight differences in the type of the hydrological alteration (e.g. water abstraction vs. hydropeaking) might explain these effects.

Citation

Alonso Gonzalez, C., Herranz, J., Solana Gutierrez, J., Garcia De Jalon Lastra, D., & Noble, R. (2016). Towards a holistic indicator of flow disturbance impact: fish community size spectra. In Proceedings of the 11th International Symposium on Ecohydraulics. Melbourne, Australia, 7-12 February 2016

• Conference Name: 11th International Symposium on Ecohydraulics
• Conference Location: Melbourne, Australia
• Start Date: Feb 7, 2016
• End Date: Feb 12, 2016
• Publication Date: 2016
• Deposit Date: Oct 29, 2018
• Publicly Available Date: Oct 30, 2018
• Book Title: Proceedings of the 11th International Symposium on Ecohydraulics. Melbourne, Australia, 7-12 February 2016
• ISBN: 978 0 7340 5339 8
• Public URL: https://hull-repository.worktribe.com/output/1136066