Special Issue Paper
The complex interaction of ecology and hydrology in a small catchment: a salmon's perspective
Version of Record online: 4 JAN 2013
Copyright © 2012 John Wiley & Sons, Ltd.
Special Issue: Catchments in the future North: interdisciplinary science for sustainable management in the 21st Century
Volume 27, Issue 5, pages 741–749, 28 February 2013
How to Cite
Cunjak, R. A., Linnansaari, T. and Caissie, D. (2013), The complex interaction of ecology and hydrology in a small catchment: a salmon's perspective. Hydrol. Process., 27: 741–749. doi: 10.1002/hyp.9640
- Issue online: 22 FEB 2013
- Version of Record online: 4 JAN 2013
- Accepted manuscript online: 5 NOV 2012 08:33PM EST
- Manuscript Accepted: 29 OCT 2012
- Manuscript Received: 15 APR 2012
- Atlantic salmon;
- climate change
For the past 22 years, we have monitored hydro-meteorological conditions and fish population dynamics in Catamaran Brook, a 52 km2 catchment in the Miramichi River system of New Brunswick, Canada. Given the long-term nature of the multidisciplinary dataset, we are able to provide an overview of the complex interaction between streamflow and fish population dynamics drawing on previously published material as well as new data analyses. For autumn-spawning fishes like the Atlantic salmon, access to headwater reaches was directly related to streamflow during late October (when they ascend spawning tributaries), as well as the propensity of beaver dams in the stream (also a function of streamflow). Winter streamflow was positively correlated with egg survival, except when rain-on-snow conditions induced severe ice break-up events that likely caused the highest mortalities on record for salmon and other fishes. Juvenile recruitment was significantly influenced by density-dependent processes of growth and competition but further mediated by density-independent factors like winter flow. In spring, fry emergence was largely temperature-driven, although peaks in fry drift were sometimes synchronized with secondary discharge peaks and temperature. Tributaries like Catamaran Brook provide thermal refugia for coolwater fishes like salmon and trout during the summer when wide, shallow main-stem Atlantic rivers experience low discharge and high water temperatures that induce physiological and behavioural stress (i.e. > 23 °C). These phenomena are discussed in detail, especially in terms of how they may be compromised by future changes in hydrologic conditions resulting from predicted climate change scenarios. Copyright © 2012 John Wiley & Sons, Ltd.