Record Details
Effects of water withdrawals on macroinvertebrate emergence: Unexpected results for three holometabolous species
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Effects of water withdrawals on macroinvertebrate emergence: Unexpected results for three holometabolous species |
| Names |
Brown, P. D.
(creator) Wooster, D. (creator) Johnson, S. L. (creator) DeBano, S. J. (creator) |
| Date Issued | 2012-03 (iso8601) |
| Note | This is a scanned version of a published article. The original can be found at: http://onlinelibrary.wiley.com/journal/10.1002/%28ISSN%291535-1467. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. |
| Abstract | Small, low-head diversion dams are capable of withdrawing much of the flow of a river, often resulting in elevated water temperatures. Accelerated growth and development of aquatic invertebrates has been demonstrated in warmer temperatures, suggesting that the timing of insect emergence and adult body size may be significantly altered by water withdrawals. To examine the influence of summer water withdrawals on aquatic invertebrate life histories, emergence timing and adult body mass of three holometabolous species were monitored continuously for 9–10 weeks on the Umatilla and Walla Walla Rivers in arid northeastern Oregon. On each river, multiple sample sites were located along gradients of decreasing discharge and increasing water temperatures caused by successive diversions. Despite reductions in discharge of up to 93% and increases in average water temperature of up to 4.6°C from upstream to downstream, timing of median emergence was unaltered for Helicopsyche borealis, Petrophila confusalis and Glossosoma traviatum. However, in a laboratory experiment, higher temperatures led to earlier emergence for H. borealis. Water temperature in the field study was not significantly correlated with reduced adult body size of these species, though female P. confusalis were 31% smaller at the warmest sample site. Holometabolous life histories and high temperature tolerances are possible explanations for the observed resistance of these species to life history alteration. |
| Genre | Article |
| Topic | life history |
| Identifier | Brown, P. D., Wooster, D., Johnson, S. L. and DeBano, S. J. (2012), Effects of water withdrawals on macroinvertebrate emergence: Unexpected results for three holometabolous species. River Research and Applications, 28: 347–358. doi: 10.1002/rra.1460 |
