Water Stewardship Information Sources
| Citation | Johnston, N.T., E.A. MacIsaac, P.J. Tschaplinski, and K.J. Hall. 2004. Effects of the abundance of spawning sockeye salmon (Oncorhunchus nerka) on nutrients and algal biomass in forested streams. Can. J. Fish. Aquat. Sci. 61(3):384-403. |
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| Organization | FLNRO |
| URL | https://www.for.gov.bc.ca/hfd/library/ffip/Johnston_NT2004CanJFishAquatSci.pdf |
| Abstract/Description or Keywords | We used natural variation in sockeye salmon (Oncorhynchus nerka) spawner biomass among sites and years in three undisturbed, forested watersheds in interior British Columbia to test the hypotheses that salmon were a major source of particulate organic matter inputs to the streams and that carcass biomass determined stream-water nutrient concentrations and epilithic algal production. Sockeye carcasses were retained at the spawning sites, primarily (75– 80%) by large woody debris (LWD) or pools formed by LWD. The abundance and distribution of sockeye salmon determined stream-water nutrient concentrations and epilithic chlorophyll a concentrations during late summer and early fall when most primary production occurred in the oligotrophic streams. Periphyton accrual rates were elevated at sites with high salmon biomass. Peak chlorophyll a concentration increased with increasing carcass biomass per unit discharge above a threshold value to reach maxima 10-fold greater than ambient levels. Epilithic algae were dominated by a few common, large diatom taxa. Salmon carcasses were the dominant source of particulate organic carbon in low gradient stream reaches. Nutrient budget modeling indicated that most of the salmon-origin nutrients were exported from the spawning streams or removed to the terrestrial ecosystem; diffuse impacts may extend over a much larger area than simply the sites used for spawning. |
| Information Type | article |
| Regional Watershed | Vancouver Island South |
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| Comments | |
| Project status | ongoing |
| Contact Name | Peter Tschaplinski |
| Contact Email | [email protected] |