Effects of spawning salmon on the size spectra of stream insect communities

Resource type
Thesis type
(Thesis) M.Sc.
Date created
2021-08-16
Authors/Contributors
Abstract
Spawning Pacific salmon disturb stream ecosystems through their spawning behaviour and subsidize them via nutrients from carcasses. To further understand the net effects of spawning salmon in streams, I examined size distributions (size-spectra) of stream insect communities across a salmon density gradient. This size-based method offers a novel, ecologically meaningful way to understand the net effects of salmon in stream ecosystems. I used a Before-(during)-After, Control-Impact observational approach in 15 streams along the central coast of British Columbia to determine how slopes and intercepts of stream insect biomass size-spectra change before, during, and after a fall salmon run. I found no effect of salmon density on size spectra intercepts in any season and steeper size-spectra slopes (attributed to greater numbers of smaller insects and fewer larger insects) with increasing salmon density in the fall. These data may indicate differential effects of disturbance and subsidization on stream insect size classes.
Document
Extent
31 pages.
Identifier
etd21624
Copyright statement
Copyright is held by the author(s).
Permissions
This thesis may be printed or downloaded for non-commercial research and scholarly purposes.
Supervisor or Senior Supervisor
Thesis advisor: Reynolds, John
Language
English
Member of collection
Attachment Size
etd21624.pdf 1.45 MB