Comparison of known spawner abundance from fence counts to visual counts for simplified spawner estimation methods
Many salmon species are monitored by visual counts of spawners in streams; however, there are few data sets where abundance is known and compared to estimates derived from visual counts. We used spawner fences to obtain known kokanee ( Oncorhynchus nerka) spawner abundance (14 stream-years) on strea...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Canadian Science Publishing
2023
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Online Access: | http://dx.doi.org/10.1139/cjfas-2023-0111 https://cdnsciencepub.com/doi/full-xml/10.1139/cjfas-2023-0111 https://cdnsciencepub.com/doi/pdf/10.1139/cjfas-2023-0111 |
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crcansciencepubl:10.1139/cjfas-2023-0111 2023-12-17T10:48:10+01:00 Comparison of known spawner abundance from fence counts to visual counts for simplified spawner estimation methods Askey, Paul J. Ward, Hillary G.M. Weir, Tyler King, Kristen Freshwater Fisheries Society of BC Habitat Conservation Trust Fund 2023 http://dx.doi.org/10.1139/cjfas-2023-0111 https://cdnsciencepub.com/doi/full-xml/10.1139/cjfas-2023-0111 https://cdnsciencepub.com/doi/pdf/10.1139/cjfas-2023-0111 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 2023 crcansciencepubl https://doi.org/10.1139/cjfas-2023-0111 2023-11-19T13:38:40Z Many salmon species are monitored by visual counts of spawners in streams; however, there are few data sets where abundance is known and compared to estimates derived from visual counts. We used spawner fences to obtain known kokanee ( Oncorhynchus nerka) spawner abundance (14 stream-years) on streams that are monitored with annual visual surveys (7 to 9 counts per year) and incorporated similar published data from pink salmon ( Oncorhynchus gorbuscha) (11 stream-years). We investigated the performance of several simplified expansion factor estimation methods with survey life and observer efficiency as unknown nuisance parameters. All visual indices of kokanee and pink salmon spawners from live ground counts were highly correlated to abundance from fence counts ( r 2 ≥ 0.96 and 0.89, respectively). Application of cross-validation on out-of-sample data for both species showed that mean% error could range from 13% to 53% on a previously unsampled stream depending on the species, counting method, and visual index used. Predictive performance metrics were less sensitive to counting frequency than observer efficiency and associated variability, which was influenced by the counting method (aerial versus ground surveys). Article in Journal/Newspaper Oncorhynchus gorbuscha Pink salmon Canadian Science Publishing (via Crossref) Canadian Journal of Fisheries and Aquatic Sciences 80 12 1935 1948 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Askey, Paul J. Ward, Hillary G.M. Weir, Tyler King, Kristen Comparison of known spawner abundance from fence counts to visual counts for simplified spawner estimation methods |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
Many salmon species are monitored by visual counts of spawners in streams; however, there are few data sets where abundance is known and compared to estimates derived from visual counts. We used spawner fences to obtain known kokanee ( Oncorhynchus nerka) spawner abundance (14 stream-years) on streams that are monitored with annual visual surveys (7 to 9 counts per year) and incorporated similar published data from pink salmon ( Oncorhynchus gorbuscha) (11 stream-years). We investigated the performance of several simplified expansion factor estimation methods with survey life and observer efficiency as unknown nuisance parameters. All visual indices of kokanee and pink salmon spawners from live ground counts were highly correlated to abundance from fence counts ( r 2 ≥ 0.96 and 0.89, respectively). Application of cross-validation on out-of-sample data for both species showed that mean% error could range from 13% to 53% on a previously unsampled stream depending on the species, counting method, and visual index used. Predictive performance metrics were less sensitive to counting frequency than observer efficiency and associated variability, which was influenced by the counting method (aerial versus ground surveys). |
author2 |
Freshwater Fisheries Society of BC Habitat Conservation Trust Fund |
format |
Article in Journal/Newspaper |
author |
Askey, Paul J. Ward, Hillary G.M. Weir, Tyler King, Kristen |
author_facet |
Askey, Paul J. Ward, Hillary G.M. Weir, Tyler King, Kristen |
author_sort |
Askey, Paul J. |
title |
Comparison of known spawner abundance from fence counts to visual counts for simplified spawner estimation methods |
title_short |
Comparison of known spawner abundance from fence counts to visual counts for simplified spawner estimation methods |
title_full |
Comparison of known spawner abundance from fence counts to visual counts for simplified spawner estimation methods |
title_fullStr |
Comparison of known spawner abundance from fence counts to visual counts for simplified spawner estimation methods |
title_full_unstemmed |
Comparison of known spawner abundance from fence counts to visual counts for simplified spawner estimation methods |
title_sort |
comparison of known spawner abundance from fence counts to visual counts for simplified spawner estimation methods |
publisher |
Canadian Science Publishing |
publishDate |
2023 |
url |
http://dx.doi.org/10.1139/cjfas-2023-0111 https://cdnsciencepub.com/doi/full-xml/10.1139/cjfas-2023-0111 https://cdnsciencepub.com/doi/pdf/10.1139/cjfas-2023-0111 |
genre |
Oncorhynchus gorbuscha Pink salmon |
genre_facet |
Oncorhynchus gorbuscha Pink salmon |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/cjfas-2023-0111 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
80 |
container_issue |
12 |
container_start_page |
1935 |
op_container_end_page |
1948 |
_version_ |
1785572281551945728 |