Wildfire and the effects of shifting stream temperature on salmonids

Beakes, MP; Moore, JW; Hayes, SA; Sogard, SM

HERO ID

2509145

Reference Type

Journal Article

Year

2014

Language

English

HERO ID 2509145
In Press No
Year 2014
Title Wildfire and the effects of shifting stream temperature on salmonids
Authors Beakes, MP; Moore, JW; Hayes, SA; Sogard, SM
Journal Ecosphere
Volume 5
Issue 5
Page Numbers 63
Abstract The frequency and magnitude of wildfires in North America have increased by four-fold over the last two decades. However, the impacts of wildfires on the thermal environments of freshwaters, and potential effects on coldwater fishes are incompletely understood. We examined the short-term effects of a wildfire on temperatures and Steelhead/Rainbow Trout (Oncorhynchus mykiss) bioenergetics and distribution in a California coastal stream. One year after the wildfire, mean daily stream temperatures were elevated by up to 0.6 degrees C in burned compared to unburned pools. Among burned pools, light flux explained over 85% of the variation in altered stream temperatures, and 76% of the variation in light flux was explained by an index of burn severity based on proximity of the pool to burned streamside. We estimated that salmonids of variable sizes inhabiting burned pools had to consume between 0.3-264.3 mg of additional prey over 48 days to offset the 0.01-6.04 kJ increase in metabolic demand during the first post-fire summer. However, stomach content analysis showed that fish in the burned region were consuming relatively little prey and significantly less than fish in the reference region. Presumably due to starvation, mortality, or emigration, we found a significant negative relationship between the change in total salmonid biomass over the post-fire summer and the average energy costs (kJ.g(-1).day(-1)) within a burned pool. This study demonstrates that wildfire can generate thermal heterogeneity in aquatic ecosystems and drive short-term increases in stream temperature, exacerbating bioenergetically stressful seasons for coldwater fishes.
Doi 10.1890/ES13-00325.1
Wosid WOS:000337164100014
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword bioenergetics; climate change; disturbance; endangered species; fire; landscape ecology; riverscape; riparian