caa a22 4500 606226605 CHVBK 20210128101153.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s10641-014-0264-5 doi (NATIONALLICENCE)springer-10.1007/s10641-014-0264-5 The influence of fluctuating ramping rates on the diets of small-bodied fish species of boreal rivers [Elektronische Daten] [Kimberly Tuor, Karen Smokorowski, Steven Cooke] The response of aquatic organisms to flow regulation at hydro facilities has become a key issue for the development of sustainable management practices intending to reduce the impact in regulated rivers. In previous studies, unrestricted ramping rates have been found to have a negative effect on invertebrate communities and shortened the length of the food web. The decrease in the length of the food web was inferred from a significant decrease in the difference between macroinvertebrates and fish δ13N signatures, equivalent to the loss of the one trophic level. A before-after-control-impact (BACI) design was applied to determine the possible effects of ramping rate restrictions on the diet of small-bodied fishes in a boreal river in northern Ontario. Stomach contents were identified to the taxonomic level of order. Using these data, abundance, diversity and taxa composition were calculated to yield an understanding of the alterations that occurred in the food web, and how fish species diets may have changed to compensate for the shift in the invertebrate trophic level. It was found that unrestricted ramping rates were associated with an increase in invertebrate abundance within the stomach contents. There was no effect from the change to unlimited ramping for both stomach content EPT abundance and species diversity, as both rivers followed a similar trend over time. After unrestricted ramping rates, a greater frequency of baseline taxa and a lower frequency of predatory macroinvertebrates were found within the altered river stomach contents compared to what was expected. This demonstrates that the diets of small-bodied fishes have changed to compensate for the alterations to the food web due to unrestricted ramping rates, and implies that ramping rates should be taken into consideration in the regulation of operating regimes on altered rivers. Springer Science+Business Media Dordrecht, 2014 Stomach content analysis nationallicence Ramping rate fluctuation nationallicence Regulated rivers nationallicence Food web nationallicence Tuor Kimberly Institute of Environmental Science, Carleton University, K1S 5B6, Ottawa, ON, Canada aut Smokorowski Karen Great Lakes Laboratory for Fisheries and Aquatic Sciences, Fisheries and Oceans, P6A 6W4, Sault Ste. Marie, ON, Canada aut Cooke Steven Institute of Environmental Science, Carleton University, K1S 5B6, Ottawa, ON, Canada aut Environmental Biology of Fishes Springer Netherlands 98/1(2015-01-01), 345-355 0378-1909 98:1<345 2015 98 10641 https://doi.org/10.1007/s10641-014-0264-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10641-014-0264-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tuor Kimberly Institute of Environmental Science, Carleton University, K1S 5B6, Ottawa, ON, Canada aut NATIONALLICENCE 700 1- Smokorowski Karen Great Lakes Laboratory for Fisheries and Aquatic Sciences, Fisheries and Oceans, P6A 6W4, Sault Ste. Marie, ON, Canada aut NATIONALLICENCE 700 1- Cooke Steven Institute of Environmental Science, Carleton University, K1S 5B6, Ottawa, ON, Canada aut NATIONALLICENCE 773 0- Environmental Biology of Fishes Springer Netherlands 98/1(2015-01-01), 345-355 0378-1909 98:1<345 2015 98 10641