Restoration of a Nova Scotia stream to enhance Atlantic salmon provides few benefits to benthic invertebrates
Stream restoration is often undertaken with the goal of improving habitat for one focal species, most often a salmonid fish such as trout or salmon. Improvements in channel structure, especially the flushing of silt from sediments, should also benefit benthic invertebrate communities, but studies to...
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ftdalhouseuniv:oai:ojs.pkp.sfu.ca:article/6656 2023-05-15T15:31:54+02:00 Restoration of a Nova Scotia stream to enhance Atlantic salmon provides few benefits to benthic invertebrates Têtu, Catherine Mitchell, Sean MacInnis, Charles Taylor, Barry R. 2016-05-07 application/pdf https://ojs.library.dal.ca/nsis/article/view/nsis48-2tetu,mitchell,macinnis,taylor https://doi.org/10.15273/pnsis.v48i2.6656 eng eng Nova Scotian Institute of Science (NSIS) https://ojs.library.dal.ca/nsis/article/view/nsis48-2tetu,mitchell,macinnis,taylor/5848 https://ojs.library.dal.ca/nsis/article/view/nsis48-2tetu,mitchell,macinnis,taylor doi:10.15273/pnsis.v48i2.6656 Proceedings of the Nova Scotian Institute of Science (NSIS); Vol 48, No 2; 211 2292-7743 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2016 ftdalhouseuniv https://doi.org/10.15273/pnsis.v48i2.6656 2022-02-21T08:41:09Z Stream restoration is often undertaken with the goal of improving habitat for one focal species, most often a salmonid fish such as trout or salmon. Improvements in channel structure, especially the flushing of silt from sediments, should also benefit benthic invertebrate communities, but studies to date suggest substantial changes in benthic communities following restoration are not common. In a third-order Nova Scotia stream, we examined the effect of successful restoration to improve habitat for spawning Atlantic salmon on benthic invertebrate communities at sites where clogging of the bottom cobble with fine silt had been alleviated. In a long-term comparison of two restored sites and two degraded sites, only six of 24 insect taxa showed increased population density five or seven years after restoration. In a second comparison of a comparatively undisturbed site against a newly restored site and a site restored eight years earlier, only three invertebrate taxa appeared to respond positively and consistently to restoration. In both studies there were no substantial changes in total invertebrate density, taxa richness, Simpson’s diversity index or other community metrics over five years, except for a decline in the EPT/Chironomids ratio in the second study. Ordination of sites by correspondence analysis showed that, in both studies, benthic communities at unrestored control sites and restored sites were clearly different and did not become more similar through time. A long-term restructuring of the benthic community in the entire brook is suggested by the appearance of silt-intolerant shredders (Lepidostoma, Leuctra) among the most abundant members of the benthos in the second study, replacing silt-tolerant collectors (Tricorythodes, Optioservus) that dominated the earlier study. Habitat factors unaffected by in-stream restoration (frequent high discharge, lack of woody debris) limit benthic communities more than substratum quality. Article in Journal/Newspaper Atlantic salmon Dalhousie University Libraries Journal Hosting Service Proceedings of the Nova Scotian Institute of Science (NSIS) 48 2 211 |
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Stream restoration is often undertaken with the goal of improving habitat for one focal species, most often a salmonid fish such as trout or salmon. Improvements in channel structure, especially the flushing of silt from sediments, should also benefit benthic invertebrate communities, but studies to date suggest substantial changes in benthic communities following restoration are not common. In a third-order Nova Scotia stream, we examined the effect of successful restoration to improve habitat for spawning Atlantic salmon on benthic invertebrate communities at sites where clogging of the bottom cobble with fine silt had been alleviated. In a long-term comparison of two restored sites and two degraded sites, only six of 24 insect taxa showed increased population density five or seven years after restoration. In a second comparison of a comparatively undisturbed site against a newly restored site and a site restored eight years earlier, only three invertebrate taxa appeared to respond positively and consistently to restoration. In both studies there were no substantial changes in total invertebrate density, taxa richness, Simpson’s diversity index or other community metrics over five years, except for a decline in the EPT/Chironomids ratio in the second study. Ordination of sites by correspondence analysis showed that, in both studies, benthic communities at unrestored control sites and restored sites were clearly different and did not become more similar through time. A long-term restructuring of the benthic community in the entire brook is suggested by the appearance of silt-intolerant shredders (Lepidostoma, Leuctra) among the most abundant members of the benthos in the second study, replacing silt-tolerant collectors (Tricorythodes, Optioservus) that dominated the earlier study. Habitat factors unaffected by in-stream restoration (frequent high discharge, lack of woody debris) limit benthic communities more than substratum quality. |
format |
Article in Journal/Newspaper |
author |
Têtu, Catherine Mitchell, Sean MacInnis, Charles Taylor, Barry R. |
spellingShingle |
Têtu, Catherine Mitchell, Sean MacInnis, Charles Taylor, Barry R. Restoration of a Nova Scotia stream to enhance Atlantic salmon provides few benefits to benthic invertebrates |
author_facet |
Têtu, Catherine Mitchell, Sean MacInnis, Charles Taylor, Barry R. |
author_sort |
Têtu, Catherine |
title |
Restoration of a Nova Scotia stream to enhance Atlantic salmon provides few benefits to benthic invertebrates |
title_short |
Restoration of a Nova Scotia stream to enhance Atlantic salmon provides few benefits to benthic invertebrates |
title_full |
Restoration of a Nova Scotia stream to enhance Atlantic salmon provides few benefits to benthic invertebrates |
title_fullStr |
Restoration of a Nova Scotia stream to enhance Atlantic salmon provides few benefits to benthic invertebrates |
title_full_unstemmed |
Restoration of a Nova Scotia stream to enhance Atlantic salmon provides few benefits to benthic invertebrates |
title_sort |
restoration of a nova scotia stream to enhance atlantic salmon provides few benefits to benthic invertebrates |
publisher |
Nova Scotian Institute of Science (NSIS) |
publishDate |
2016 |
url |
https://ojs.library.dal.ca/nsis/article/view/nsis48-2tetu,mitchell,macinnis,taylor https://doi.org/10.15273/pnsis.v48i2.6656 |
genre |
Atlantic salmon |
genre_facet |
Atlantic salmon |
op_source |
Proceedings of the Nova Scotian Institute of Science (NSIS); Vol 48, No 2; 211 2292-7743 |
op_relation |
https://ojs.library.dal.ca/nsis/article/view/nsis48-2tetu,mitchell,macinnis,taylor/5848 https://ojs.library.dal.ca/nsis/article/view/nsis48-2tetu,mitchell,macinnis,taylor doi:10.15273/pnsis.v48i2.6656 |
op_doi |
https://doi.org/10.15273/pnsis.v48i2.6656 |
container_title |
Proceedings of the Nova Scotian Institute of Science (NSIS) |
container_volume |
48 |
container_issue |
2 |
container_start_page |
211 |
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1766362400077905920 |