Population Dynamics and Management of the Northwest Atlantic Harp Seal ( Phoca groenlandica )
Previous methods of estimating population size and natural mortality rate in harp seals (Phoca groenlandica) are reviewed. Excepting the method of Beddington and Williams (Marine Mammal Comm., Washington, DC., Rep. MMC 79-03, 1980) all previous methods rely heavily upon the survival index method of...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
1983
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1139/f83-118 http://www.nrcresearchpress.com/doi/pdf/10.1139/f83-118 |
id |
crcansciencepubl:10.1139/f83-118 |
---|---|
record_format |
openpolar |
spelling |
crcansciencepubl:10.1139/f83-118 2023-12-17T10:31:18+01:00 Population Dynamics and Management of the Northwest Atlantic Harp Seal ( Phoca groenlandica ) Roff, Derek A. Bowen, W. Don 1983 http://dx.doi.org/10.1139/f83-118 http://www.nrcresearchpress.com/doi/pdf/10.1139/f83-118 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 40, issue 7, page 919-932 ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 1983 crcansciencepubl https://doi.org/10.1139/f83-118 2023-11-19T13:39:34Z Previous methods of estimating population size and natural mortality rate in harp seals (Phoca groenlandica) are reviewed. Excepting the method of Beddington and Williams (Marine Mammal Comm., Washington, DC., Rep. MMC 79-03, 1980) all previous methods rely heavily upon the survival index method of estimating pup production. We describe the mathematical rationale underlying this method and indicate potential sources of bias. Beddington and Williams' analysis produces a combination of vital rates for 1952 that would not enable a population to persist in the absence of hunting. This suggests that the method may not be able to estimate these parameters accurately. This conclusion is supported by several unpublished analyses. We present an alternative method of analysis that is based on the concept of maximum likelihood. We estimate the rate of natural mortality and trend in 1 + population size from 1967 to 1980, using mark–recapture estimates of pup production in the late 1970s and the observed ratio of the survival of adjacent cohorts in the late 1960s and early 1970s to constrain population trajectories from a simulation model. From this analysis we conclude that the population is increasing and that the present total catch may be substantially smaller than the replacement yield. Article in Journal/Newspaper Harp Seal Northwest Atlantic Phoca groenlandica Canadian Science Publishing (via Crossref) Canadian Journal of Fisheries and Aquatic Sciences 40 7 919 932 |
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 Roff, Derek A. Bowen, W. Don Population Dynamics and Management of the Northwest Atlantic Harp Seal ( Phoca groenlandica ) |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
Previous methods of estimating population size and natural mortality rate in harp seals (Phoca groenlandica) are reviewed. Excepting the method of Beddington and Williams (Marine Mammal Comm., Washington, DC., Rep. MMC 79-03, 1980) all previous methods rely heavily upon the survival index method of estimating pup production. We describe the mathematical rationale underlying this method and indicate potential sources of bias. Beddington and Williams' analysis produces a combination of vital rates for 1952 that would not enable a population to persist in the absence of hunting. This suggests that the method may not be able to estimate these parameters accurately. This conclusion is supported by several unpublished analyses. We present an alternative method of analysis that is based on the concept of maximum likelihood. We estimate the rate of natural mortality and trend in 1 + population size from 1967 to 1980, using mark–recapture estimates of pup production in the late 1970s and the observed ratio of the survival of adjacent cohorts in the late 1960s and early 1970s to constrain population trajectories from a simulation model. From this analysis we conclude that the population is increasing and that the present total catch may be substantially smaller than the replacement yield. |
format |
Article in Journal/Newspaper |
author |
Roff, Derek A. Bowen, W. Don |
author_facet |
Roff, Derek A. Bowen, W. Don |
author_sort |
Roff, Derek A. |
title |
Population Dynamics and Management of the Northwest Atlantic Harp Seal ( Phoca groenlandica ) |
title_short |
Population Dynamics and Management of the Northwest Atlantic Harp Seal ( Phoca groenlandica ) |
title_full |
Population Dynamics and Management of the Northwest Atlantic Harp Seal ( Phoca groenlandica ) |
title_fullStr |
Population Dynamics and Management of the Northwest Atlantic Harp Seal ( Phoca groenlandica ) |
title_full_unstemmed |
Population Dynamics and Management of the Northwest Atlantic Harp Seal ( Phoca groenlandica ) |
title_sort |
population dynamics and management of the northwest atlantic harp seal ( phoca groenlandica ) |
publisher |
Canadian Science Publishing |
publishDate |
1983 |
url |
http://dx.doi.org/10.1139/f83-118 http://www.nrcresearchpress.com/doi/pdf/10.1139/f83-118 |
genre |
Harp Seal Northwest Atlantic Phoca groenlandica |
genre_facet |
Harp Seal Northwest Atlantic Phoca groenlandica |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 40, issue 7, page 919-932 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f83-118 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
40 |
container_issue |
7 |
container_start_page |
919 |
op_container_end_page |
932 |
_version_ |
1785584524721127424 |