Dynamics of Exploited Whitefish Populations and their Management with Special Reference to the Northwest Territories
Available data on mortality, growth, reproduction, and stock size in exploited and unexploited populations of lake whitefish (Coregonus clupeaformis) are reviewed with a view to understanding the dynamics of exploited populations and improving their management. Natural mortality ranged from about 0....
Published in: | Journal of the Fisheries Research Board of Canada |
---|---|
Main Author: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
1975
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1139/f75-053 http://www.nrcresearchpress.com/doi/pdf/10.1139/f75-053 |
id |
crcansciencepubl:10.1139/f75-053 |
---|---|
record_format |
openpolar |
spelling |
crcansciencepubl:10.1139/f75-053 2024-05-19T07:46:17+00:00 Dynamics of Exploited Whitefish Populations and their Management with Special Reference to the Northwest Territories Healey, M. C. 1975 http://dx.doi.org/10.1139/f75-053 http://www.nrcresearchpress.com/doi/pdf/10.1139/f75-053 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Journal of the Fisheries Research Board of Canada volume 32, issue 3, page 427-448 ISSN 0015-296X journal-article 1975 crcansciencepubl https://doi.org/10.1139/f75-053 2024-05-02T06:51:25Z Available data on mortality, growth, reproduction, and stock size in exploited and unexploited populations of lake whitefish (Coregonus clupeaformis) are reviewed with a view to understanding the dynamics of exploited populations and improving their management. Natural mortality ranged from about 0.20 to 0.80 in unexploited populations. In exploited populations total mortality was as high as 0.94. Unexploited populations showed a wide range of growth rates. Growth rate increased with increasing exploitation, and growth rate in all heavily exploited populations was similar to the most rapid growth rate shown by unexploited stocks. Heavily exploited whitefish matured at a younger age and possibly also at a smaller size than those which were unexploited. Limited data on stock size suggest that although total population size declines under heavy exploitation, the vulnerable population remains of similar size.It is concluded that whitefish respond to fluctuations in population size through compensatory changes in growth rate, the difference between growth rate in a population and maximum growth rate is a measure of its scope for compensating for increased mortality. Populations with slow growth rate and low mortality should, therefore, have the best fishery potential, while those with high growth rate and high mortality have a low fishery potential. Further, it is possible to judge the fishery potential of a population or its stage of exploitation from relatively simple measurements of mortality, growth, age structure, and maturity. Article in Journal/Newspaper Northwest Territories Canadian Science Publishing Journal of the Fisheries Research Board of Canada 32 3 427 448 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
description |
Available data on mortality, growth, reproduction, and stock size in exploited and unexploited populations of lake whitefish (Coregonus clupeaformis) are reviewed with a view to understanding the dynamics of exploited populations and improving their management. Natural mortality ranged from about 0.20 to 0.80 in unexploited populations. In exploited populations total mortality was as high as 0.94. Unexploited populations showed a wide range of growth rates. Growth rate increased with increasing exploitation, and growth rate in all heavily exploited populations was similar to the most rapid growth rate shown by unexploited stocks. Heavily exploited whitefish matured at a younger age and possibly also at a smaller size than those which were unexploited. Limited data on stock size suggest that although total population size declines under heavy exploitation, the vulnerable population remains of similar size.It is concluded that whitefish respond to fluctuations in population size through compensatory changes in growth rate, the difference between growth rate in a population and maximum growth rate is a measure of its scope for compensating for increased mortality. Populations with slow growth rate and low mortality should, therefore, have the best fishery potential, while those with high growth rate and high mortality have a low fishery potential. Further, it is possible to judge the fishery potential of a population or its stage of exploitation from relatively simple measurements of mortality, growth, age structure, and maturity. |
format |
Article in Journal/Newspaper |
author |
Healey, M. C. |
spellingShingle |
Healey, M. C. Dynamics of Exploited Whitefish Populations and their Management with Special Reference to the Northwest Territories |
author_facet |
Healey, M. C. |
author_sort |
Healey, M. C. |
title |
Dynamics of Exploited Whitefish Populations and their Management with Special Reference to the Northwest Territories |
title_short |
Dynamics of Exploited Whitefish Populations and their Management with Special Reference to the Northwest Territories |
title_full |
Dynamics of Exploited Whitefish Populations and their Management with Special Reference to the Northwest Territories |
title_fullStr |
Dynamics of Exploited Whitefish Populations and their Management with Special Reference to the Northwest Territories |
title_full_unstemmed |
Dynamics of Exploited Whitefish Populations and their Management with Special Reference to the Northwest Territories |
title_sort |
dynamics of exploited whitefish populations and their management with special reference to the northwest territories |
publisher |
Canadian Science Publishing |
publishDate |
1975 |
url |
http://dx.doi.org/10.1139/f75-053 http://www.nrcresearchpress.com/doi/pdf/10.1139/f75-053 |
genre |
Northwest Territories |
genre_facet |
Northwest Territories |
op_source |
Journal of the Fisheries Research Board of Canada volume 32, issue 3, page 427-448 ISSN 0015-296X |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f75-053 |
container_title |
Journal of the Fisheries Research Board of Canada |
container_volume |
32 |
container_issue |
3 |
container_start_page |
427 |
op_container_end_page |
448 |
_version_ |
1799486435474014208 |