Recent Harp and Hooded Seal Pup Production Estimates in the Greenland Sea Suggest Ecology-Driven Declines
Pup production of the Greenland Sea populations of harp (Pagophilus groenlandicus) and hooded (Cystophora cristata) seals were estimated based upon aerial surveys in March 2018. One fixed-wing aircraft was used for large-area reconnaissance flights to identify the whelping concentrations and to carr...
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Septentrio Academic Publishing
2022
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ftdoajarticles:oai:doaj.org/article:c52408bf03bc4478958ebe2251dda1db 2023-05-15T15:38:50+02:00 Recent Harp and Hooded Seal Pup Production Estimates in the Greenland Sea Suggest Ecology-Driven Declines Martin Biuw Tor Arne Øigård Kjell Tormod Nilssen Garry Stenson Lotta Lindblom Michael Poltermann Martin Kristiansen Tore Haug 2022-01-01T00:00:00Z https://doi.org/10.7557/3.5821 https://doaj.org/article/c52408bf03bc4478958ebe2251dda1db EN eng Septentrio Academic Publishing https://septentrio.uit.no/index.php/NAMMCOSP/article/view/5821 https://doaj.org/toc/1560-2206 https://doaj.org/toc/2309-2491 doi:10.7557/3.5821 1560-2206 2309-2491 https://doaj.org/article/c52408bf03bc4478958ebe2251dda1db NAMMCO Scientific Publications, Vol 12, Iss 1 (2022) Harp seals hooded seals pup production population assessment population modelling aerial survey Ecology QH540-549.5 article 2022 ftdoajarticles https://doi.org/10.7557/3.5821 2022-12-31T09:59:11Z Pup production of the Greenland Sea populations of harp (Pagophilus groenlandicus) and hooded (Cystophora cristata) seals were estimated based upon aerial surveys in March 2018. One fixed-wing aircraft was used for large-area reconnaissance flights to identify the whelping concentrations and to carry out photographic surveys along systematic transects over the whelping areas. A helicopter, operated from an ice-going vessel, flew more localised reconnaissance flights, deployed GPS beacons within the detected whelping concentrations to monitor ice movements, and determined the proportion of pups in specific age-related developmental stages. While the entire estimated pupping region should ideally be covered during one day, photographic surveys in 2018 were carried out on two consecutive days, March 27 and 28, with slightly different survey designs between the two days to account for potential gaps in coverage caused by changes in visibility and cloud cover. Surveys on the two days were partially overlapping, and pup production estimates were consistent when using different combinations of transects from the two days, suggesting that these photographic counts give a relatively robust estimate of pup production in 2018. The combination of surveys that was deemed most appropriate (in terms of maximum coverage with minimum risk of double coverage) yielded an estimated harp seal pup production of 54,181 (SE=9,236, CV=0.17), which is significantly lower than estimates obtained in similar surveys in 2002, 2007, and 2012. Estimated hooded seal pup production was 12,977 (SE=1,823, CV=0.14), which is lower than estimates obtained from surveys in 2005 and 2007, but similar to estimates from the most recent survey in 2012. The reasons for these declines are unknown, but similar declines in the Barents Sea and White Sea harp seals in the mid-2000s suggest that large-scale environmental or ecological changes affecting the Barents Sea and the Norwegian Sea may be important factors. Article in Journal/Newspaper Barents Sea Cystophora cristata Greenland Greenland Sea Harp Seal hooded seal Norwegian Sea Pagophilus groenlandicus White Sea Directory of Open Access Journals: DOAJ Articles Barents Sea Norwegian Sea White Sea Greenland NAMMCO Scientific Publications 12 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Harp seals hooded seals pup production population assessment population modelling aerial survey Ecology QH540-549.5 |
spellingShingle |
Harp seals hooded seals pup production population assessment population modelling aerial survey Ecology QH540-549.5 Martin Biuw Tor Arne Øigård Kjell Tormod Nilssen Garry Stenson Lotta Lindblom Michael Poltermann Martin Kristiansen Tore Haug Recent Harp and Hooded Seal Pup Production Estimates in the Greenland Sea Suggest Ecology-Driven Declines |
topic_facet |
Harp seals hooded seals pup production population assessment population modelling aerial survey Ecology QH540-549.5 |
description |
Pup production of the Greenland Sea populations of harp (Pagophilus groenlandicus) and hooded (Cystophora cristata) seals were estimated based upon aerial surveys in March 2018. One fixed-wing aircraft was used for large-area reconnaissance flights to identify the whelping concentrations and to carry out photographic surveys along systematic transects over the whelping areas. A helicopter, operated from an ice-going vessel, flew more localised reconnaissance flights, deployed GPS beacons within the detected whelping concentrations to monitor ice movements, and determined the proportion of pups in specific age-related developmental stages. While the entire estimated pupping region should ideally be covered during one day, photographic surveys in 2018 were carried out on two consecutive days, March 27 and 28, with slightly different survey designs between the two days to account for potential gaps in coverage caused by changes in visibility and cloud cover. Surveys on the two days were partially overlapping, and pup production estimates were consistent when using different combinations of transects from the two days, suggesting that these photographic counts give a relatively robust estimate of pup production in 2018. The combination of surveys that was deemed most appropriate (in terms of maximum coverage with minimum risk of double coverage) yielded an estimated harp seal pup production of 54,181 (SE=9,236, CV=0.17), which is significantly lower than estimates obtained in similar surveys in 2002, 2007, and 2012. Estimated hooded seal pup production was 12,977 (SE=1,823, CV=0.14), which is lower than estimates obtained from surveys in 2005 and 2007, but similar to estimates from the most recent survey in 2012. The reasons for these declines are unknown, but similar declines in the Barents Sea and White Sea harp seals in the mid-2000s suggest that large-scale environmental or ecological changes affecting the Barents Sea and the Norwegian Sea may be important factors. |
format |
Article in Journal/Newspaper |
author |
Martin Biuw Tor Arne Øigård Kjell Tormod Nilssen Garry Stenson Lotta Lindblom Michael Poltermann Martin Kristiansen Tore Haug |
author_facet |
Martin Biuw Tor Arne Øigård Kjell Tormod Nilssen Garry Stenson Lotta Lindblom Michael Poltermann Martin Kristiansen Tore Haug |
author_sort |
Martin Biuw |
title |
Recent Harp and Hooded Seal Pup Production Estimates in the Greenland Sea Suggest Ecology-Driven Declines |
title_short |
Recent Harp and Hooded Seal Pup Production Estimates in the Greenland Sea Suggest Ecology-Driven Declines |
title_full |
Recent Harp and Hooded Seal Pup Production Estimates in the Greenland Sea Suggest Ecology-Driven Declines |
title_fullStr |
Recent Harp and Hooded Seal Pup Production Estimates in the Greenland Sea Suggest Ecology-Driven Declines |
title_full_unstemmed |
Recent Harp and Hooded Seal Pup Production Estimates in the Greenland Sea Suggest Ecology-Driven Declines |
title_sort |
recent harp and hooded seal pup production estimates in the greenland sea suggest ecology-driven declines |
publisher |
Septentrio Academic Publishing |
publishDate |
2022 |
url |
https://doi.org/10.7557/3.5821 https://doaj.org/article/c52408bf03bc4478958ebe2251dda1db |
geographic |
Barents Sea Norwegian Sea White Sea Greenland |
geographic_facet |
Barents Sea Norwegian Sea White Sea Greenland |
genre |
Barents Sea Cystophora cristata Greenland Greenland Sea Harp Seal hooded seal Norwegian Sea Pagophilus groenlandicus White Sea |
genre_facet |
Barents Sea Cystophora cristata Greenland Greenland Sea Harp Seal hooded seal Norwegian Sea Pagophilus groenlandicus White Sea |
op_source |
NAMMCO Scientific Publications, Vol 12, Iss 1 (2022) |
op_relation |
https://septentrio.uit.no/index.php/NAMMCOSP/article/view/5821 https://doaj.org/toc/1560-2206 https://doaj.org/toc/2309-2491 doi:10.7557/3.5821 1560-2206 2309-2491 https://doaj.org/article/c52408bf03bc4478958ebe2251dda1db |
op_doi |
https://doi.org/10.7557/3.5821 |
container_title |
NAMMCO Scientific Publications |
container_volume |
12 |
_version_ |
1766370200659165184 |