78 results on '"Nilssen, Kjell Tormod"'
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2. Pup production of Harp Seals in the Northwest Atlantic in 2017 during a time of ecosystem change
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Stenson, Garry, primary, Gosselin, Jean- François, additional, Lawson, John, additional, Buren, Alejandro, additional, Goulet, Pierre, additional, Lang, Shelley, additional, Nilssen, Kjell Tormod, additional, and Hammill, Mike, additional
- Published
- 2022
- Full Text
- View/download PDF
3. Functional relationship between harp seal body condition and available prey in the Barents Sea
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Øigård, Tor Arne, Lindstrøm, Ulf, Haug, Tore, Nilssen, Kjell Tormod, and Smout, Sophie
- Published
- 2013
4. Report From Surveys To Assess Harp And Hooded Seal Pup Production In The Greenland Sea Pack-Ice In 2022
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Biuw, Martin, Nilssen, Kjell Tormod, Kristiansen, Martin, Lindblom, Lotta, Poltermann, Michael Tino, Haug, Tore, and Johansson, Malin
- Abstract
Source at https://www.hi.no/en/hi/nettrapporter/toktrapport-en-2022-7. Cruise no.: 2022703 : The 2022 survey of harp and hooded seal pup production in the Greenland Sea was carried out to obtain updated estimates to be used to assess current status of these two seal stocks. Since a similar survey in 2018 indicated a 40% reduction in harp seal pup production since the 2012 survey, and the continued lack of increase in pup production of the severely depleted hooded seal stock despite its protection from hunting since 2007, a new survey after a period of only 4 years was urgent. The survey was carried out using well established methodologies for these species, including 1) reconnaissance of the drift ice breeding habitat from a helicopter based on the research icebreaker R/V Kronprins Haakon and a fixed-wing aircraft stationed at Constable Pynt in East Greenland, 2) deploying GPS beacons around the identified breeding areas to monitor its displacement in the East Greenland Current, 3) carrying out staging surveys to monitor the pup age structure and estimate the optimal day of pup counting as well as correction factors accounting for pups not present on the ice at the time of counting, and 4) conducting aerial photographic surveys using the fixed-wing aircraft. Ice conditions in the Greenland Sea were similar as those experienced in 2018, with a relatively narrow band of pack ice over the shelf break near the coast of East Greenland. Seal whelping patches were initially discovered on March 21 & 22nd, within an area stretching from 72°53’N / 16°42’W in the north to 71°51’N / 17°30’W in the south. Five GPS beacons were deployed at the main whelping patches within this area, allowing us to track the continuous drift due to strong northerly winds during the period between initial reconnaissance and the final pup counting. Pup staging surveys were carried out on March 22nd, 23rd, 25th, 28th and 30th, providing us with a solid dataset with which to assess the development of pup age dynamics, determine the optimal day for photographic surveys, and to estimate correction factors to account for pups absent from the ice during the photographic surveys. The final photographic surveys were carried out on March 28th in a relatively narrow (20-30 nm) N/S band stretching from 71°00’N / 20°00’W in the NE to 69°34’N / 20°36’W in the SW. In total, 2,463 images were obtained during the aerial photographic survey, and following pre-processing (georeferencing and ortorectification), these will be analysed both manually and using dedicated machine learning systems, to determine the number of pups present in images. Results will be used to estimate the total 2022 pup production for each species and will also be combined with estimates from previous years to estimate the population sizes using the dedicated population dynamics model. The entire updated dataset will be made available to the upcoming ICES benchmarking meeting for harp and hooded seal population modelling, and results will finally be evaluated at the upcoming meeting of the ICES WGHARP working group in 2023.
- Published
- 2022
5. Recent Harp and Hooded Seal Pup Production Estimates in the Greenland Sea Suggest Ecology-Driven Declines
- Author
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Biuw, Martin, primary, Øigård, Tor Arne, additional, Nilssen, Kjell Tormod, additional, Stenson, Garry, additional, Lindblom, Lotta, additional, Poltermann, Michael, additional, Kristiansen, Martin, additional, and Haug, Tore, additional
- Published
- 2022
- Full Text
- View/download PDF
6. Working Group on Marine Mammal Ecology (WGMME)
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Ahola, Markus, Authier, Matthieu, Benjamins, Steven, Brasseur, Sophie, Brownlow, Andrew, Carlström, Julia, Evans, Peter, Fariñas, Andrea, Fernandez , Ruth, Geelhoed, Steve, Haelters, Jan, Hammond, Philip, Jüssi, Ivar, Jüssi, Mart, Lundstrøm, Karl, Nilssen, Kjell Tormod, Pawliczka, Iwona, Petitguyot, Marie, Pierce, Graham J., Plikshs , Maris, Prieto, Rui, Ransijn, Janneke, Rumes, Bob, Russell, Debbie, Smout, Sophie, Penas, Camilo Saavedra, Vazquez Bonales, Jose Antonio, van Neer, Abbo, Verevkin, Mikhail, Verutes, Gregg, Vetemaa, Markus, Vincent, Cécile, Waggitt, James J., Galatius, Anders, and Gilles, Anita
- Published
- 2021
7. Forskerutvalg om sjøpattedyr 2020 - Tilrådning om forskning og forvaltning
- Author
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Bjørge, Arne Jostein, Øien, Nils Inge, Haug, Tore, Nilssen, Kjell Tormod, Biuw, Martin, Sivle, Lise Doksæter, and Kvadsheim, Petter Helgevold
- Abstract
Forskerutvalg om sjøpattedyr som ble opprettet i 2009, består av femten forskere fra syv forskningsinstituttet i Norge. Utvalget møttes 22.-23. oktober i Tromsø for å utarbeide anbefalinger om forvaltning, vern og forskning på sjøpattedyr i 2021.
- Published
- 2021
8. Forskerutvalg om sjøpattedyr 2021 - Råd om forskning og forvaltning
- Author
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Bjørge, Arne Jostein, Øien, Nils Inge, Biuw, Martin, Haug, Tore, and Nilssen, Kjell Tormod
- Abstract
Forskerutvalg om sjøpattedyr som ble opprettet i 2009, består av femten forskere fra syv forskningsinstituttet i Norge. Utvalget møttes 21.-22. oktober i Tromsø for å utarbeide anbefalinger om forvaltning, vern og forskning på sjøpattedyr i 2022. Det foreligger et nytt bestandsestimat for vågehval basert på tellinger i 2014-2019. Dette estimatet som er ca 50% høyere enn i tidligere telleperioder, skal behandles av IWC’s Vitenskapskomité våren 2022 og legges til grun for et nytt Implementation Review. Anbefaling om kvoter for 2022 må utarbeides før IWC’s behandling foreligger. HI må derfor gjøre simuleringene selv som grunnlag for kvoteråd. For grønlandssel i Vesterisen ga Utvalget sin tilslutning til anbefalingene fra ICES om en kvote på 11 548 dyr i 2021. Utvalget gir også sin tilslutning til anbefalingen fra ICES om en kvote på 21 172 grønlandssel i Østisen for 2021. (Den Blandede Norsk-Russiske Fiskerikommisjonen allokerte i et virtuelt møte den 12.-16. oktober 2020
- Published
- 2021
9. Working Group on Marine Mammal Ecology (WGMME)
- Author
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Galatius, Anders, Gilles, Anita, Ahola, Markus, Authier, Matthieu, Benjamins, S., Brasseur, S.M.J.M., Brownlow, Andrew, Carlström, Julia, Evans, Peter, Farinas, Andrea, Fernandez, Ruth, Geelhoed, S.C.V., Haelters, Jan, Hammon, Philip, Jussi, Ivar, Jussi, Mart, Lundstrom, Karl, Nilssen, Kjell Tormod, Pawliczka, Iwona, Petitguyot, Marie, Pierce, Graham J., Plikhs, Maris, Prieto, Rui, Ransijn, J., Rumen, Bob, Russell, D., Smout, Sophie, Penas, Camilo Saavedra, Bonales, Jose Antonio Vazquez, van Neer, Abbo, Verevkin, Mikhal, Verutes, Gregg, Veetema, Markus, Vincent, Cecile, and Waggitt, James
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Onderz. Form. D ,Business Manager projecten Midden-Noord ,Life Science ,Business Manager projects Mid-North - Published
- 2021
10. From pup production to quotas: current status of harp seals in the Greenland Sea
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Øigård, Tor Arne, Haug, Tore, and Nilssen, Kjell Tormod
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- 2014
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11. Estimation of hooded seal (Cystophora cristata) pup production in the Greenland Sea pack ice during the 2005 whelping season
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Salberg, Arnt-Børre, Haug, Tore, and Nilssen, Kjell Tormod
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- 2008
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- View/download PDF
12. Working group on marine mammal ecology (WGMME)
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Ahola, Markus, Authier, Matthieu, Brasseur, Sophie, Carlström, Julia, Chaudry, Farah, Culloch, Ross, Evans, Peter, Galatius, Anders, Geelhoed, Steve, Gilles, Anita, Hammond, Philip, Kavanagh, Ailbhe S., Lundstrøm, Karl, Macleod, Kelly, van Neer, Abbo, Nilssen, Kjell Tormod, Pierce, Graham, Ransijn, Janneke, Rumes, Bob, Begona Santos, M., Galatius, Anders, and Gilles, Anita
- Published
- 2020
13. Potensielle effekter av havvindanlegg på havmiljøet
- Author
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de Jong, Karen, Steen, Henning, Forland, Tonje Nesse, Nyquist, Daniel, Utne-Palm, Anne Christine, Nilssen, Kjell Tormod, Albretsen, Jon, Falkenhaug, Tone, Biuw, Martin, Buhl-Mortensen, Lene, and Sivle, Lise Doksæter
- Abstract
I denne rapporten er dagens kunnskap om potensielle effekter av vindkraftanlegg på det marine økosystemet oppsummert, med fokus på oppdatert kunnskap siden forrige rapport fra 2008. Potensielle fysiske endringer er beskrevet i kapittel 2, og potensielle effekter på det marine økosystemet er delt inn i potensiell effekt av innføring av nye strukturer (kap. 3), elektromagnetisme fra kablene (kap. 4) og lyd produsert under konstruksjon og drift av vindturbinene (kap. 5). Konklusjoner finnes i kapittel 6, og Havforskningsinstituttets nåværende råd i kapittel 7.
- Published
- 2020
14. Forskerutvalg om sjøpattedyr 2019 - Anbefalinger om forskning og forvaltning
- Author
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Bjørge, Arne Jostein, Biuw, Martin, Haug, Tore, Nilssen, Kjell Tormod, and Øien, Nils Inge
- Abstract
Forskerutvalg om sjøpattedyr som ble opprettet i 2009, består av femten forskere fra syv forskningsinstitutter i Norge. Utvalget møttes 24.-25. oktober 2019 i Tromsø for å utarbeide anbefalinger om forvaltning, vern og forskning på sjøpattedyr i 2020. Utvalget anbefalte at ‘Potential Biological Removal’ (PBR) burde legges til grunn for å beregne høstingskvoten for grønlandssel ved Jan Mayen (Vesterisen) og den anbefalte kvoten ble dermed 11 548 sel i 2020. Dette er i samsvar med råd fra ICES. Utvalget anbefalte å opprettholde full fredning av klappmyss ved Jan Mayen, dog slik at et mindre antall dyr kan tas til vitenskapelige formål. For grønlandssel i Barentshavet (Østisen) anbefalte Utvalget at kvoten skulle baseres på PBR med en konservativ ‘Recovery factor’ på 0,25. Den anbefalte kvoten for 2020 blir da 21 172 sel. Dette er i samsvar med råd fra ICES. For havert og steinkobbe på norskekysten anbefalte Utvalget jaktkvoter på henholdsvis 200 og 467 sel. Full fredning av havert mellom Stad og Lofoten og fredning av små, isolerte bestander av steinkobbe ble anbefalt opprettholdt. For høsting av vågehval anbefalte Utvalget at kvoten fortsatt bør baseres på ‘Revised Management Procedure’ som ble utviklet for forvaltning av bardehval av Vitenskapskomiteen til Den internasjonale hvalfangstkommisjonen (IWC). Alle andre hvalarter forblir fredet i Norge. Utvalget anbefalte videre obligatorisk bruk av akustiske alarmer på noen garnfiskerier og områder for å avbøte høye bifangster av nise. Endelig vedtok Utvalget en rekke anbefalinger om videre forskning for å styrke kunnskapsgrunnlaget for forvaltning, vern og dyrevelferd av sjøpattedyr i Norge og for å øke forståelsen av sjøpattedyrenes roller i økosystemene.
- Published
- 2020
15. Modelling the abundance of grey seals (Halichoerus grypus) along the Norwegian coast
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Øigård, Tor Arne, Frie, Anne Kirstine, Nilssen, Kjell Tormod, and Hammill, Mike Osborne
- Published
- 2012
- Full Text
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16. Diet composition and biomass consumption of harbour seals in Telemark and Aust-Agder, Norwegian Skagerrak
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Sørlie, Maria, primary, Nilssen, Kjell Tormod, additional, Bjørge, Arne, additional, and Freitas, Carla, additional
- Published
- 2020
- Full Text
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17. Diet and prey consumption of grey seals ( ) in Norway
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Nilssen, Kjell Tormod, Lindstrøm, Ulf, Westgaard, Jon Ivar, Lindblom, Lotta, Blencke, Taija-Riitta, and Haug, Tore
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0106 biological sciences ,Consumption (economics) ,Fishery ,Geography ,010604 marine biology & hydrobiology ,Aquatic Science ,Oceanography ,010603 evolutionary biology ,01 natural sciences ,Seal (mechanical) ,Ecology, Evolution, Behavior and Systematics ,Predation - Abstract
To obtain knowledge of feeding habits and prey consumption of grey seals, data were sampled in selected areas along the Norwegian coast. Prey were recovered from 182 grey seal gastrointestinal trac...
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- 2019
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18. Seasonal distribution, condition and feeding habits of Barents Sea harp seals (Phoca groenlandica)
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Nilssen, Kjell Tormod, primary
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- 1995
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19. Ecological implications of harp seal Phoca groenlandica invasions in northern Norway
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Huag, Tore, primary and Nilssen, Kjell Tormod, additional
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- 1995
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20. Diet and prey consumption of grey seals (Halichoerus grypus) in Norway
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Nilssen, Kjell Tormod, primary, Lindstrøm, Ulf, additional, Westgaard, Jon Ivar, additional, Lindblom, Lotta, additional, Blencke, Taija-Riitta, additional, and Haug, Tore, additional
- Published
- 2019
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21. Status of harbour seals (Phoca vitulina) in mainland Norway
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Nilssen, Kjell Tormod, Skavberg, Nils-Erik, Poltermann, Michael, Haug, Tore, Härkönen, Tero, and Henriksen, Gunnar
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abundance ,surveys ,Norway ,lcsh:QH540-549.5 ,harbour seals ,lcsh:Ecology ,biology ,ecology - Abstract
Harbour seals were counted along the entire Norwegian coast at known moulting haulout sites in the period mid-August to early September 2003-2006. In 2003-2005, almost all known moulting areas from Finnmark to Vestfold counties were covered by aerial photo surveys flown at altitudes of approximately 800-900 ft (243-274m), and at low tide (± 2 hours). Surveys in the Østfold County were flown in 2003-2006 at 300 ft (91m), and the small tidal amplitudes permitted counts to be carried out irrespective of the tidal cycle. In some sub-areas, two or three independent surveys were conducted. Visual counts using binoculars from smaller boats and islands were carried out in some selected areas. The surveys revealed a total minimum population of 6,705 harbour seals in Norwegian waters. Harbour seals were most abundant in the Nordland and Sør-Trøndelag counties with minimum estimates of approximately 2,500 and 1,500 seals, respectively. The presented minimum estimate is approximately 800 seals lower than an estimate obtained in a comparable study carried out during the moult in 1996-1999. Increased anthropogenic removals, and the phocine distemper virus (PDV) epidemic in the Skagerrak region in 2002, may have contributed to the current lower estimate.
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- 2010
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22. Haulout behaviour of harbour seals (Phoca vitulina) during breeding and moult in Vesterålen, Norway
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Mogren, Hanne-Grethe, Lindstrøm, Ulf, Nilssen, Kjell Tormod, and Haug, Tore
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harbour seals ,Norway ,haulout behavior ,lcsh:QH540-549.5 ,lcsh:Ecology ,biology ,ecology ,behaviour - Abstract
Haulout behaviour of harbour seals (Phoca vitulina) in Vesterålen, Norway, was investigated from1 July to 23 August 2003 using a combination of high- and low-tide counts performed from boat and elevated land positions, and hourly counts from the land positions through 12- or 24-h cycles at specific haulout sites. There were obvious contrasts in haulout patterns of the seals throughout the period. The number of seals hauled-out was considerably higher in the area in July (the pupping period) than during August when the moulting period started. Contrasting July, when numbers of seals hauled-out at low tide was clearly higher than at high tide, there were virtually no systematic differences in haulout numbers between high and low tides in August. Circadian patterns were weaker in August than in July as well. Low temperatures had significant adverse effects on haulout numbers both in July and August, whereas increased cloud cover resulted in fewer seals hauled-out in July, but more seals in August.
- Published
- 2010
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23. Status of grey seals (Halichoerus grypus) in Norway
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Nilssen, Kjell Tormod and Haug, Tore
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Norway ,lcsh:QH540-549.5 ,grey seals ,population status ,lcsh:Ecology ,biology ,ecology - Abstract
During the period September-December in 2001-2003, ship based surveys of grey seal (Halichoerus grypus) pups, including tagging, counting and staging of pups, were conducted along the Norwegian coast. All known and other potential breeding areas were surveyed from Rogaland county in the south to Finnmark county in the north. Most of the breeding sites were surveyed only once, but some sites were surveyed 2-4 times. The investigations resulted in a total minimum estimate of 1,159 grey seal pups born in Norwegian waters. Nordland county was the most important breeding area where about 50% of the pups were born. Total population estimates were derived from the recorded number of pups born using a range of multipliers (4.0-4.7), based on observed annual growth rates of approximately 7-12% in other grey seal populations. This gave a total estimate of about 5,800-6,600 grey seals including pups in Norwegian waters. However, the total pup production was probably underestimated due to only one pup count in most of the breeding sites. Observed mean pup mortality was 1.1% during the breeding season along the Norwegian coast.
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- 2007
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24. Utredning av Havforskningsinstituttets framtidige infrastrukturbehov for innhenting av marine data
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Huse, Geir, Nieuwejaar, Per, Bruvoll, Annegrete, Godø, Olav Rune, Taranger, Geir Lasse, Nilssen, Kjell Tormod, Knutsen, Jan Atle, Axelsen, Bjørn Erik, and Ibenholdt, Karin
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marine data - Published
- 2015
25. Testing UAVs to perform aerial photographic survey of harp and hooded seals in the West Ice area
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Nilssen, Kjell Tormod, Storvold, Rune, Stødle, Daniel, Solbø, Stian André, Johansen, Kjell-Sture, Poltermann, Michael, and Haug, Tore
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hooded seal ,cruise report ,klappmyss ,toktrapport ,"Svalbard" - Abstract
Survey report – KV “Svalbard” 16-26 March 2014 The aim of the KV “Svalbard” survey was to test two UAVs (Unmanned Aerial Vehicles) to perform aerial photographic surveys of harp and hooded seal whelping patches on the drift ice in the West Ice area in the Greenland Sea. Digital cameras and a thermal infrared (IR) camera were used. We aimed to explore various survey altitudes and camera settings to obtain an optimal altitude and camera set up for photographing seal pups. Simultaneous use of digital and IR cameras enable us to explore combinations of those to detect and classify seals. Experience obtained from using the UAVs and the quality of the images taken, are promising. Both harp and hooded seals, including pups, were easily identified on the images taken at a flight altitude of 300 m. Also preliminary results from the IR camera are promising. It is, however, necessary to improve the range of the largest UAV and the methods for landing the aircraft on ice floes. Also some technical improvements on both aircrafts and operational equipment should be performed
- Published
- 2014
26. Recent summer diet of hooded Cystophora cristata and harp Pagophilus groenlandicus seals in the drift ice of the Greenland Sea
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Enoksen, Solveig, primary, Haug, Tore, additional, Lindstrøm, Ulf, additional, and Nilssen, Kjell Tormod, additional
- Published
- 2016
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27. Report from surveys to assess harp and hooded seal pup production in the Greenland Sea pack-ice in 2012
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Haug, Tore, Nilssen, Kjell Tormod, and Øigård, Tor Arne
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cruise report ,toktrapport - Published
- 2012
28. Utredningsområder for havvindkraft: effekter på marine organismer og ressurser
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Dalen, John, Hjelset, Elin, Nilssen, Kjell Tormod, Steen, Henning, and Søvik, Guldborg
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environmental effects ,vindfarmer ,VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 ,wind farms ,miljøeffekter - Abstract
De 15 foreslåtte utredningsområdene ligger spredt i norsk økonomisk sone fra sentrale Nordsjøen ved ca. 56°N til Vest-Finnmark ved ca. 71°N. Områdene ligger i varierende avstander fra kysten, og hvert område er øremerket enten bunnfaste eller flytende installasjoner. Der utredningsområdene er innenfor eller nærheten av særlig verdifulle områder og/eller marine verneområder, er dette påpekt. Vi har vurdert og oppsummert relevante marinbiologiske og bunnfaunaforhold av registrerte forekomster av viktige og sårbare marine organismer og ressurser i forhold til alle utredningsområdene for vindkraftanlegg. Basis for dette har vært å vurdere eventuell overlappende arealbruk eller nærhet mellom utredningsområdene og gytefelt, oppvekstområder og konsentrert utbredelse av fisk, reker, sjøkreps, sel og kval. Vurderingene er i hovedsak utført med hensyn på: gytefelt og konsentrerte gytevandringsruter opp mot disse for fisk. fiskeriområder for reke og sjøkreps innenfor eller tett inntil utredningsområdene. områder med betydelige forekomster av kvalarter inkl. fødeområder. områder med betydelige forekomster av selarter inkl. kasteområder. korallrevområder. Etablering av vindkraftanlegg til sjøs kan også ha gunstige påvirkninger og effekter på visse organismer og ressurser et i havet. For eksempel kan vindturbinparkene ha beskyttende virkninger for fisk og krepsdyr og sågar bidra til artsmangfold i områdene og eksempel på dette er vist. Avslutningsvis er det foretatt en oppsummering av viktige sammenhenger og tilrådinger for det videre arbeidet på nasjonalt nivå. Havforskningsinstituttet fraråder at det åpnes for vindkraftutbygging i 9 av vindkraftområdene slik de er definert pr i dag. Dette rådet er gitt med bakgrunn i å beskytte gytefelt og gyteaktiviteter for sild, tobis og lodde; arter som er bunngytere og som trenger spesielle substrat for å kunne gyte. Bunngytere er mer sårbare for påvirkning av habitatet enn arter som gyter pelagiske i vannmassene (eks. torsk og makrell). Tobis er den arten som er aller mest sårbar, med geografisk begrensede gytefelt som i tillegg utsettes for allerede høy menneskelig belastning fra fiske og petroleumsvirksomhet. For tobis og sild er det kun deler av de foreslåtte vindkraftområdene som overlapper med gytefeltene. Dersom disse områdene justeres slik at de ikke omfatter gytefeltene, kan de resterende delene av områdene åpnes. For lodde omfatter hele de foreslåtte vindkraftområdene Auvær, Vannøya nordøst og Sandskallen – Sørøya, loddegytefelt og bør i sin helhet ikke åpnes. Opprinnelige geografiske referanser bygger på Anon. (2010). Mer generell arts- og faktainformasjonen om hver art er hovedsakelig hentet fra Anon. (2011) med supplering fra Anon. (2008b), (2009a) og Dalen et al. (2010). Rapporten skal refereres til som: Dalen, J., Hjelset, E., Nilssen, K.T., Steen, H. og Søvik, G. 2011. UtredUtredningsområder for havvindkraft: effekter på marine organismer og ressurser. Rapport til Norges vassdrags- og energidirektorat. Rapport fra Havforskningsinstituttet, Bergen, nr. 10-2011, juli 2011. 54 s.
- Published
- 2011
29. Kystvann (bunn og pelagisk)
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Oug, Eivind, Christie, Hartvig, Eikrem, Wenche, van der Meeren, Gro, Nilssen, Kjell Tormod, and Lorentsen, Svein-Håkon
- Subjects
coastal resources ,biologisk mangfold ,kystressurser ,VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 ,biodiversity - Abstract
Norge har en kystlinje på ca. 2500 km målt langs den såkalte grunnlinjen fra svenskegrensen til Grense Jakobselv. Grunnlinjen trekkes mellom ytterpunktene på landformasjoner som stikker opp over vannflaten. Målt langs land inkludert øyer, fjorder og bukter er kystlinjen mer enn 80 000 km, som tilsvarer to ganger jordens omkrets ved ekvator. Som kystvann regnes i denne forbindelse alle indre farvann og sjøområdene innenfor en nautisk mil (1852 m) utenfor grunnlinjen. Denne avgrensningen er en praktisk grense som er definert i forbindelse med EUs vanndirektiv og som derfor vil bli benyttet i framtidig miljøovervåking av norsk kystvann. Kystvannet omfatter et spekter av naturtyper fra fjæresonen til store dyp (1301 m dyp i Sogne fjorden). Vannmassene utgjøres i hovedsak av den norske kyststrømmen som strømmer nordover langs hele kysten, og Atlanterhavsvann utenfor og under denne (Brattegard & Holthe 1995; Rinde et al. 1998). Vannet i kyststrømmen oppblandes med tilført elvevann og har lavere saltinnhold enn Atlanterhavs vannet. Inne i fjordene kan vannmassene være markert sjiktet med et ferskvannspreget overflatelag som kan bli betydelig oppvarmet om sommeren, og et betydelig saltere dypvann som holder lav temperatur året rundt. Organismesamfunnene i de frie vannmassene er preget av forholdsvis korte næringskjeder fra planteplankton og dyreplankton til fisk, sjøfugl og sjøpattedyr. Produksjonen i vannmassene står i nær forbindelse med havområdene omkring, men er generelt høyere i kystvannet på grunn av tilførsler av næringsemner fra land. Bunnsystemene i kystvannet kan grovt inn deles i hardbunn (fjell og stein) og bløtbunn (leire, mudder, sand, grus). Utformingen bestemmes av lokale strømforhold og bølgepåvirkning. I tillegg til bunnforholdene er faktorer som lys, oksygentilgang, saltholdighet og temperatur avgjørende for hvilke organismer som forekommer. I norske farvann er det tilstrekkelig lys for plantevekst ned til 30-40 meter dyp. Hardbunn på grunt vann domineres av tang, tare og andre fastsittende alger, mens bløtbunn kan ha tett vegetasjon av sjøgress. Bunnområder med velutviklet vegetasjon av tare eller sjøgress har stor biologisk produksjon og er ofte svært artsrike. I fjorder og indre kystområder hvor det tilføres ferskvann er saltholdigheten ofte nedsatt i de øverste vannlagene. Disse systemene kan ha helt spesielle organismesamfunn. I brakkvann med permanent nedsatt saltholdighet kan få arter klare seg, men disse er gjerne spesialiserte og finnes ikke andre steder. Det foreligger ikke sikre tall for antall arter i kystvannet, men overslag antyder opp mot 10 000 arter. Disse inkluderer mer enn 1000 encellede alger, hvorav drøyt 700 lever fritt i vannmassene, og 1000-2000 encellede dyr, omkring 500 fastsittende flercellede alger og opp mot 5000 flercellede virvelløse dyr (Brattegard & Holthe 2001; Bakken et al. 2005). Av fisk forekommer omkring 150 arter i kystvannet, hvorav riktignok en god del er tilfeldige gjester fra mer sydlige farvann. Av fugl er det omkring 60 arter som i større eller mindre grad er knyttet til kysten, mens det for pattedyr kan regnes et titall arter av sel, hval og landpattedyr (oter, mink). Kystsonen har stor betydning for produksjon av marint materiale, for rekreasjon og opplevelse og for produksjon av oppdrettsorganismer. Samtidig er kystsonen utsatt for en rekke påvirkninger fra menneskelig virksomhet. De viktigste påvirkningene utgjøres av forurensninger, overgjødsling av nærings salter (eutrofi), ødeleggelse av arters leveområder og overbeskatning av bestander. I senere år er man blitt klar over at ødeleggelse av leveområder er viktigere enn tidligere antatt og rammer både arter i spesielle miljøer og vanlig forekommende arter som i deler av sin livssyklus er knyttet til visse naturtyper. I tillegg er kyst vannet i endring som følge av stigende temperatur og mulig framtidig forsuring. Nye trusler kommer også fra fremmede arter som i økende grad finner innpass i kystsonen. Kystsonen er utsatt både for langtransporterte påvirkninger som forurensning og næringssalter som tilføres med havstrømmer og fra lokale kilder ved utslipp til sjø.
- Published
- 2010
30. Marine indikatorer
- Author
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van der Meeren, Gro, Øigård, Tor Arne, Øien, Nils, Nilssen, Kjell Tormod, Oug, Eivind, Sunnanå, Knut, Jakobsen, Tore, Mehl, Sigbjørn, Kvamme, Cecilie, Torstensen, Else, Stenevik, Erling Kåre, Planque, Benjamin, Helle, Gunnar, Gjøsæter, Jakob, Skiftesvik, Anne Berit, Aglen, Asgeir, Johannessen, Tore, Dommasnes, Are, Naustvoll, Lars-Johan, Moy, Frithjof E., Falkenhaug, Tone, Melle, Webjørn, Knutsen, Tor, Eriksen, Elena, Jørgensen, Lis Lindal, Fosså, Jan Helge, Bannister, Raymond, Buhl-Mortensen, Lene, Buhl-Mortensen, Pål, Strand, Øivind, Søvik, Guldborg, Jelmert, Anders, Knutsen, Jan Atle, Enersen, Svein Erik, Edvardsen, Hanne, Kroglund, Tone, Pedersen, Atle, Eikrem, Wenche, Bekkby, Trine, and Tveite, Stein
- Subjects
VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ecology: 488 ,biologisk mangfold ,økosystemer ,VDP::Agriculture and fishery disciplines: 900::Agriculture disciplines: 910::Management of natural resources: 914 ,ecosystems ,biodiversity - Abstract
The Nature Index (NI) is established to get an overview of the state and development of biodiversity within the major ecosystems of Norway. It includes marine, limnic and terrestrial ecosystems. The aim of the index is to measure if Norway manage to halt the loss of biodiversity by the end of 2010. A number of indicators are chosen to represent the state of biodiversity. 125 scientists from various disciplines of research have contributed with data, expert judgements or modeled data for 310 indicators representing different aspects of biological diversity, such as trophic levels, key species and threatened and common species. In order to assemble all the data to an index, a reference value has been estimated for each indicator. The reference value reflects an ecological sustainable value for the indicator, and the indicator values displays eventual divergence from this state. This report describes how data on reference values, uncertainty and values for 1950, 1990, 2000 and 2010 has been set for each indicator. Furthermore this report documents the data sources for each of the indicators that are included in the data set.
- Published
- 2010
31. Merketokt, grønlandssel i Svalbardområdet [25/5 - 12/6, 2010]
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Nilssen, Kjell Tormod, Poltermann, Michael, and Shafikov, Ilias
- Subjects
"Kvitbjørn" ,cruise report ,toktrapport - Published
- 2010
32. Report of the Working Group on Marine Mammal Ecology (WGMME), 12-15 April 2010, Horta, The Azores
- Author
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Brasseur, Sophie, Brensing, Karsten, Clarke, Malcolm, Duck, Callan, Geelhoed, Steve, Haelters, Jan, Hall, Ailsa, Härkönen, Tero, Hasselmeier, Ilka, Jauniaux, Thierry, Jepson, Paul, Jüssi, Mart, Lens, Santiago Lens, Lesage, Veronique, Lonergan, Mike, Nilssen, Kjell Tormod, Pierce, Graham, Pinn, Eunice, Prieto da Silva, Rui Conde de Araújo Brito, Santos, Ricardo Serrão, Notarbartolo di Sciara, Giuseppe, Silva, Mónica, Sipilä, Tero, Tougaard, Jakob, Uranga, Raúl Castro, Waring, Gordon, Werner, Stefanie, and Murphy, Sinead
- Published
- 2010
33. Marinøkologiske ringvirkninger av vindmølleparker til havs
- Author
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Steen, Henning, Nilssen, Kjell Tormod, Agnalt, Ann-Lisbeth, Alvsvåg, John, Asplin, Lars, Jelmert, Anders, Dahl, Einar, and Dalen, John
- Abstract
There is an increasing need for energy. Considerable efforts are being made to develop environmentally friendly energy sources. Generating electric energy using wind turbines is one of the methods that has gained widespread, international acceptance. In Norway wind turbine farms are established as well, and more farms are planned for the coming years. Most farms are land based, but from several reasons there are increasing interests in offshore wind farms.
- Published
- 2008
34. Report from surveys to assess hooded and harp seal pup production in the greenland sea pack-ice in March - April 2007
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Haug, Tore, Nilssen, Kjell Tormod, and Øigård, Tor Arne
- Subjects
cruise report ,toktrapport ,"Nordsyssel" - Published
- 2007
35. Prey consumtion by Barents sea harp seals in the period 1990-2005
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Lindstrøm, Ulf, Nilssen, Kjell Tormod, and Haug, Tore
- Subjects
VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ecology: 488 ,VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 ,grønlandssel ,biologisk mangfold ,harp seal ,biodiversity - Abstract
The Barents Sea ecosystem has experienced major fluctuations in species abundance in the past 20-30 years. The mechanisms behind these fluctuations are complex and arise from numerous interactions between species and the environment. Previous and present attempts to assess multi-species interactions in the Barents sea ecosystem has resulted in increased focus on the foraging ecology of the most conspicuous high trophic-level predators in the ecosystem. The Barents Sea stock of harp seals Pagophilus groenlandicus is, along with Arctic cod Gadus morhua, considered as the most conspicuous high trophic-level predator in the Barents Sea ecosystem. The abundance and feeding ecology of the Barents Sea stock of harp seals has been monitored the past 15 years. Previous prey consumption estimates suggests that harp seals consume range between 3.3 and 5 million tonnes of prey annually, depending on the choice of input parameters in the bioenergetic model. There were a considerable amounnt of uncertainty attached to the input data in the consumption model, in particular the important harp seal diets during summer (May-August). Also, uncertainty estimates of the prey consumption were not given in the previous study. An important objective of this study was to estimate the uncertainty of the prey consumption estimates by using a standard Monte-Carlo framework; random draws from probability distributions of diet and abundance were performed. Additionally, new diet data from May-July has become available and is included in the analysis. The summer consumption was to a large extent dominated by krill, whereas polar cod also contributed importantly. All sampling were performed in a period with low capelin abundance – this may have influenced the results.
- Published
- 2006
36. Use and selection of prey by harp seals during summer in the northern Barents Sea
- Author
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Nilssen, Kjell Tormod and Lindstrøm, Ulf
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VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ecology: 488 ,grønlandssel ,VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 ,harp seal - Abstract
The aim of this study was analyse harp seals prey use and selection during summer in Svalbard waters. A total of 41, 34 and 58 (including 24 faeces samples) from animals were sampled in 1996, 1997 and 2004. Krill was the overall dominant prey species (63%) followed by polar cod (16%) and other fish species (10%) in terms of a combined index (frequency occurrence and weight). Resource mapping was performed in two areas simultaneous with the seal sampling, in 1996 and 1997 by using standard acoustic methods. These surveys suggested that krill was the most abundant prey in both areas and years; krill constituted 84% and 69% of the total prey biomass in 1996 (99.7 tonnes/nm2) and 1997 (21.4 tonnes/nm2), respectively followed by parathmisto sp. (13 and 18%) and Gammarus sp. (2 and 12%). The prey preference results suggest that harp seals are not particular prey selective, i.e., harp seals display a random feeding behaviour.
- Published
- 2005
37. Estimation of hooded seal pup production in the Greenland Sea pack-ice during the 2005 whelping season
- Author
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Haug, Tore, Nilssen, Kjell Tormod, Frie, Anne Kirstine, Lindblom, Lotta, Poltermann, Michael, Salberg, Arnt-Børre, Skavberg, Nils Erik, and Fagerheim, Kjell Arne
- Subjects
"Polarsyssel" ,cruise report ,toktrapport - Published
- 2005
38. Diets of hooded seals in coastal and drift ice waters along the east coast of Greenland
- Author
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Haug, Tore, Nilssen, Kjell Tormod, Lindblom, Lotta, and Lindstrøm, Ulf
- Subjects
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 ,greenland halibut ,klappmyss ,tobis ,lodde ,blåkveite ,arktisk torsk ,capelin ,hooded seal ,VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 ,arctic cod ,squid ,akkar ,sandeel - Abstract
To provide data on the feeding habits of hooded (Cystophora cristata) seals in the Greenland Sea, seals were collected for scientific purposes on expeditions with R/V”Jan Mayen”, conducted in the pack ice belt east of Greenland in September/October 1999 and 2002 (autumn), July/August in 2000 (summer), and February/March in 2001 and 2002 (winter). Results from analyses of stomach and intestinal contents from captured seals revealed that the diet was comprised of relatively few prey taxa. The squid Gonatus fabricii and polar cod Boreogadus saida were particularly important, whereas capelin Mallotus villosus, and sand eels Ammodytes spp contributed more occasionally. G. fabricii was the most important food item in autumn and winter, whereas the observed summer diet was more characterized by polar cod, however with important contribution also from G. fabricii and sand eels. The latter was observed on the hooded seal menu only during the summer period, while polar cod, which contributed importantly also during the autumn survey, was almost absent from the winter samples. During the latter survey, also capelin contributed to the hooded seal diet. Samples obtained in more coastal waters indicated a more varied and fish based (polar cod, redfish Sebasetes sp., Greenland halibut Reinhardtius hippoglossoides) hooded seal diet.
- Published
- 2005
39. Distribution and number of marine mammals in the open Barents Sea and their connection with capelin and polar cod distribution
- Author
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Zabavnikov, V.B., Zyryanov, S.V., Tereschenko, V.V., Nilssen, Kjell Tormod, and Lindstrøm, Ulf
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VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ecology: 488 ,VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 - Abstract
Ecosystem dynamics and optimal long-term harvest in the Barents Sea fisheries. Proceedings of the 11th Russian-Norwegian Symposium. Murmansk, 15-17 August 2005. This paper presents the data on the character of distribution and the assessment of the number of marine mammals in the open part of the Barents Sea in autumn 2001-2004 by the results from PINRO’s aerial surveys using the airborne laboratory AN-26 “Arktika” and the annual joint Russian-Norwegian vessel ecosystem survey for pelagic fish including capelin and polar cod. The aerial surveys were carried out being combined with the vessel surveys and their tacks coincided or crossed in several points.
- Published
- 2005
40. Estimation of harp seal pup production in the Greenland Sea using spatial analysis on aerial survey data
- Author
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Salberg, Arnt-Børre, Stenson, Garry B., Haug, Tore, and Nilssen, Kjell Tormod
- Subjects
VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ecology: 488 ,grønlandssel ,VDP::Mathematics and natural science: 400::Zoology and botany: 480::Marine biology: 497 ,harp seal ,VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 - Abstract
From 14 March to 6 April 2002 aerial surveys were carried out in the Greenland Sea packice to assess the pup production of the Greenland Sea population of harp seals Pagophilus groenlandicus. One xed-wing twin-engined aircraft was used for reconnaissance rights and photographic strip transect surveys of the whelping patches once they had been located and identifed. A helicopter assisted in the reconnaissance rights, and was used subsequently to by visual strip transect surveys over the whelping patches. The helicopter was also used to collect data for estimating the distribution of births over time. Three harp seal breeding patches (A, B and C) were located and surveyed either visually and/or photographically. Using traditional strip-transect analysis, the total estimate of pup production, including the visual survey of Patch A, both visual and photographic surveys of Patch B, and photographic survey of Patch C, was calculated at 98 500 (SE = 16 800), giving a coencient of variation for the survey of 17.9%. A new approach in analysis of this type of data, using a spatial analysis method, has been developed recently. It is the aim of this work to apply this new method to the data obtained in the 2002 photographic surveys (i.e., patches B and C), and to compare the results obtained (both point estimates and variances) with previous results obtained in the traditional strip-transect analysis.
- Published
- 2005
41. Distribution and number of marine mammals in the open Barents Sea and their connection with capelin and polar cod distribution [presentation]
- Author
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Zabavnikov, V.B., Zyryanov, S.V., Tereschenko, V.V., Nilssen, Kjell Tormod, and Lindstrøm, Ulf
- Subjects
VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ecology: 488 ,VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 - Published
- 2005
42. Status for havertbestandens ungeproduksjon langs norskekysten i 2001-2003
- Author
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Nilssen, Kjell Tormod, Corkeron, Peter, Haug, Tore, Skavberg, Nils Erik, Jenssen, Bjørn Munro, and Henriksen, Gunnar
- Subjects
havert ,grey seal - Abstract
During September-October 2001-2003, registrations of grey seal (Halichoerus grypus) pups, including tagging, counting and staging of pups, were conducted along the Norwegian coast from Rogaland county in the south to Finnmark county in the north. Also other possible whelping areas along the Norwegian coast were surveyed. By combining results from 2001-2003 a total of 1184 pups were recorded. Froan in Sør-Trøndelag county and Koiøyene and Kongsfjord in Finnmark county were surveyed 3-4 times during the investigations, which made it possible to estimate a total number of 303 and 105 pups born in Froan and Koiøyene/Kongsfjord, respectively. The investigations resultet in a total minimum estimate of a grey seal pup production of about 1200 pups in Norwegian waters. Total population estimates were derived from estimates of number of pups born by estimating a range of 2 multipliers (4.28-5.35), based on observed annual growth rates of 12 % in other grey seal populations. This gave a total estimate of 5150-6440 one year and older (1+) grey seals in Norwegian waters. However, it is obvious that this is an underestimate of the pup production but data on on the lengths of pup stages are not available to estimate pup production based on one single count. Natural pup mortality during the whelping season was 1.2 %, and 49.5 % of the pups born were males. NORSK SAMMENDRAG:I løpet av september-desember 2001-2003 ble det gjennomført merkinger, tellinger og stadiebestemmelser av havertunger langs norskekysten fra Rogaland i sør til Finnmark i nord. Mulige nye kasteområder og områder i geografisk nærhet av kjente kasteområder ble også gjennomsøkt. Ved å kombinere resultatene i 2001-2003 ble det totalt registrert 1184 fødte havertunger på de ulike deler av norskekysten som var omfattet av dette studiet. De sørlige deler av Nordland, inkludert Hortavær i Nord-Trøndelag viste seg å være det området med størst tetthet av havert langs norskekysten med en produksjon på 345 havertunger. I Froan i Sør-Trøndelag og ved Koiøyene og Kongsfjorden i Finnmark ble det gjennomført flere tellinger i samme år slik at det der var mulig å estimere total ungeproduksjon, henholdsvis 303 unger i Froan og 105 unger tilsammen ved Koiøyene og Kongsfjorden. Dette ga et totalt estimat på landsbasis på rundt 1200 fødte unger. Det er nokså klart at ungeproduksjonen er noe høyere enn dette estimatet fordi mange områder kun er undersøkt en gang. Eksisterende data omkring havertungenes alder i de forskjellige utviklingstadier er imidlertid for unøyaktige til å kunne gi tilfredstillende estimater for ungeprodusjonen ved kun en telling. Basert på observerte vekstrater i havertbestander i andre områder på 12 % i året ble det estimert faktorer på mellom 4.28 og 5.35 for omregning mellom ungeproduksjon og bestanden av ett år og eldre dyr (1+). Dette resulterte i et estimat for totalbestanden på 5150-6440 havert (1+). Naturlig ungedødelighet under kasteperioden var 1.2 % og kjønnsfordelingen av havertungene var 49.5 % hanner og 50.5 % hunner.
- Published
- 2004
43. Improving time budget estimates through the behavioural interpretation of dive bouts in harbour seals
- Author
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Ramasco, Virginie, primary, Biuw, Martin, additional, and Nilssen, Kjell Tormod, additional
- Published
- 2014
- Full Text
- View/download PDF
44. Current status of hooded seals in the Greenland Sea. Victims of climate change and predation?
- Author
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Øigård, Tor Arne, primary, Haug, Tore, additional, and Nilssen, Kjell Tormod, additional
- Published
- 2014
- Full Text
- View/download PDF
45. From pup production to quotas: current status of harp seals in the Greenland Sea
- Author
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Øigård, Tor Arne, primary, Haug, Tore, additional, and Nilssen, Kjell Tormod, additional
- Published
- 2013
- Full Text
- View/download PDF
46. Report from aerial surveys of ice breeding seals in the Greenland Sea pack-ice during the 2002 whelping season
- Author
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Haug, Tore, Corkeron, Peter, Nilssen, Kjell Tormod, and Stenson, Garry B.
- Abstract
In the period 14 March to 6 April 2002 aerial surveys were performed in the Greenland Sea pack-ice (the West Ice), to asssess the pup production of the Greenland Sea population of harp seals Pagophilus groenlandicus and, if possible, hooded seals Cystophora cristata. One fixed-wing twin-engined aircraft (stationed in Scoresbysound, Greenland, but permitted also to use the Jan Mayen island as base) was used for reconaissance flights and photographic surveys along transects over the whelping patches once they had been located and identified. A helicopter, stationed on and operated from the applied research vessel (R/V”Lance”), assisted in the reconnaissance flights, and subsequently flew visual transect surveys over the whelping patches. The helicopter was also used for other purposes, such as age-stageing (also performed along transects over the patches) and tagging of the pups. Logistical restrictions and the unusually wide distribution of the hooded seal pups made it impossible to survey both species simultaneously, and therefore hooded seal pup production was not assessed. Three harp seal breeding patches were located and surveyed. The results from the aerial surveys will be used to estimate the 2002 harp seal pup production. Subsequently, the status of the stock will be assessed by fitting population models to the pup production estimate. Report from aerial surveys of ice breeding seals in the Greenland Sea pack-ice during the 2002 whelping season
- Published
- 2002
47. Registrering av havertunger i Nord-Trøndelag, Nordland og Finnmark i oktober-november 2001
- Author
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Nilssen, Kjell Tormod, Corkeron, Peter, Haug, Tore, Skavberg, Nils Erik, and Lindblom, Lotta
- Abstract
Hovedmålsetningen for de båtbaserte undersøkelsene under havertens kasteperiode i oktober-november 2001 var å gjennomføre tellinger og aldersbestemmelse av havertunger i Nord-Trøndelag og Nord-Norge.Undersøkelsene skulle særlig prioritere viktige kastelokaliteter og estimere ungeproduksjonen ved disse. Dette skulle gi grunnlag til å evaluere status for havertbestandene i det aktuelle området. Aktiviteten ble noe begrenset i de nordlige deler av Nordland og kastelokalitetene i Lofoten og Troms måtte utelates på grunn av dårlig vær. I Nord-Trøndelag ble det totalt registert 84 havertunger, med størst konsentrasjon i Hortavær. Dette er ca. 25% mer enn antallet registrerte unger basert på flyfotograferinger i 1998. I Nordland ble havertens kasteområder mellom fylkesgrensen i sør til Vega svært godt dekt. De viktigste kastelokalitetene er Bindalsflesa,Terjan, Horsvær, Hensteinen og Storbraken hvor det ble registrert 252 havertunger. Dette er ca. 20% mer enn resultatene fra flytellingene i 1998. Om økningen i antall registrerte havertunger skyldes en økning i bestanden eller om det er et resultat av forskjellig metodikk brukt til å registrere unger er uklart. Kastetoppen ble funnet å være omkring 1. oktober. Totalbestand (inkludert unger) ble estimert til å være 1725-2070 havert i området Hortavær- Storbraken. Videre nordover langs nordlandskysten var dekningen for dårlig til foreta noe bestandsanslag. I Finnmark er kastetoppen omkring 12. november på Kamøyene og 17. november i Kongsfjorden. De viktigste kastelokalitetene er Kamøyene, Koifjord og Kongsfjord. Det ble totalt registrert 142 havertunger Finnmark, mot 117 unger under tilsvarende undersøkelser i 1998, altså en økning på ca. 21%. Observasjoner gjort i lokaliteten i Kongsfjorden i 1998-2001 tyder på at det kan være stor årlig variasjon i antall fødte unger. Det er ønskelig å gjennomføre ytterlige undersøkelser for å avklare disse forhold før det blir gjort en ny bestandsvurdering for Finnmark. Registrering av havertunger i Nord-Trøndelag, Nordland og Finnmark i oktober-november 2001
- Published
- 2002
48. Report of joint Russian/Norwegian aerial surveys in the Barents Sea in September 2001
- Author
-
Zabavnikov, V.B., Nilssen, Kjell Tormod, Zcharikov, K. A., and Frie, Anne Kirstine
- Subjects
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 - Abstract
The distribution of harp seals in the Barents Sea has been recorded based on incidental sightings from Norwegian and Russian research vessels, Norwegian fishing and coast guard vessels, from Russian aerial surveys (Haug et al. 1994), and from satellite tagged seals (Erling Nordoey, University of Tromsoe, pers. commn.). However, possible overlap in the distribution of harp seals and capelin in early autumn has not been studied. Data on potential harp seal predation on capelin are important in multispecies modelling. Therefore, in September 2001, aerial surveys aimed to study possible overlap between harp seals and capelin were conducted simultaneously with the annual joint Norwegian/Russian acoustic survey of pelagic fish in the Barents Sea. Two Norwegian and two Russian research vessels took part in the survey which covered most of the Barents Sea
- Published
- 2002
49. Recent age compositions and aberrant migration patterns of the Barents Sea stock of harp seals Phoca groenlandica
- Author
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Nilssen, Kjell Tormod, Haug, Tore, Øritsland, Torger, Lindblom, Lotta, and Kjellqwist, Sten Anders
- Subjects
grønlandssel ,VDP::Mathematics and natural science: 400::Geosciences: 450::Oceanography: 452 ,aldersbestemmelse ,migration patterns ,age determination ,harp seal ,vandringsmønster ,VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 - Abstract
Since 1978, and in particular in 1986-1988, large numbers of harp seals Phoca groenlandica have invaded coastal waters of North Norway during winter and spring. After 1988 the harp seal invasions have been restricted to the northeastemmost parts of the coast of Norway. In 1995, however, a significant increase occurred in both the magnitude and the spatial extent of the harp seal invasions. Sampling of stomach contents, teeth for age determinations and body condition parameters were carried out on seals taken as by-catches in Norwegian gillnet fisheries during winter and spring in 1995. In early winter the seal herds comprised immature animals (mainly from the 1994 year class), while mature females dominated in the spring. Analyses of stomach contents suggested that the diet mainly contained fish, in particular saithe Pollachius virens, haddock Melanogrammus aeglefinus and cod Gadus morhua. Body condition parameters revealed that the one year old seals taken in February 1995 were in significantly poorer condition than harp seals of the same age taken in the southeastem Barents Sea in February 1993. Also the mature females taken in April 1995 had significantly lower condition compared to adult females collected in April 1992. Recaptures of 39 immature harp seals tagged in the White Sea (mainly in 1994) suggest that the invading young harp seals in the winter of 1995 belonged to the Barents Sea stock. Age compositions of the Barents Sea harp seals based on material collected during Norwegian commercial sealing in the East Ice moulting lairs in 1995 suggest a low recruitment to this stock of the 1993 and in particular the 1994 year classes.
- Published
- 1996
50. Tagging and recoveries of grey seals Halichoerus grypus in north Norway and on the Murman Coast, Russia
- Author
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Henriksen, Gunnar, Haug, Tore, Kondakov, Andrej, Nilssen, Kjell Tormod, and Øritsland, Torger
- Subjects
VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920 - Abstract
A total of 787 grey seal pups were tagged between Vestfjorden in North Norway and the White Sea in North West Russia from 1989 to 1994. A majority of them (542) were tagged at the Ainov archipelago on the Murman coast. Thirty-six ( 4.6 %) of the tagged seals were recovered, almost all taken as bycatches in fishing gear. Thirty-three of the recaptures were made during the first seven months after tagging. Of the remaining three, two were in their second year, and one in its third year. The pups seem to disperse considerably. Ten pups were recovered less than 100 km from the tagging site, 8 pups between 100 and 200 km and 15 pups more than 400 km from the tagging site. Two pups tagged at Seven Islands in Russia 21 November 1994, were recovered in Norway on 1 March and 10 April 1995 respectively. The first one in Lyngen (Troms county) 790 km from the tagging site, and the second one outside Myre (Nordland county) 1010 krn from the tagging site. The pups may disperse both east- and westwards. The lack of recoveries from the Russian coast are most likely due to the lack of coastal fisheries and hunting of grey seals in the area.
- Published
- 1996
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