. La Canadian field-naturaliste. 212 Le Canadian Field-Naturalist Vol. 105 Iqaluit Pangnirtung m Lake Harbour.  .   Illlllllll 76 77 78 79 80 81 82 83 84 85 86 87 88 89 Figure 5. Les captures annuelles récentes le béluga dans la baie Cumberland, de la baie Frobisher et autour de Lake Harbour, le MPO (1976-1989 statistiques de captures annuelles). année (Figure 3), plus de 17  % de la taille du stock 1986 Southeast Baffin ("moins de 500") qui, une fois corrigée pour un 10 % à 30 %. La chasse, la perte annuelle indique un taux d'élimination de 92 à 119 animaux ou plus de 18 à 24  % de la taille du stock de 1986. Si une prise annuelle de Lake Harbour tha

• Contributeur: Book Worm / Alamy Banque D'Images
• ID de l’image: RG3DB2
• Taille du fichier: 7,1 MB (153,5 KB Téléchargement compressé)
• Autorisations: Modèle - non | Propriété - non
• Dimensions: 1573 x 1588 px | 26,6 x 26,9 cm | 10,5 x 10,6 inches | 150dpi

Informations supplémentaires

Cette image appartient au domaine public, ce qui signifie que le droit d’auteur a expiré ou que le titulaire du droit d’auteur a renoncé à ses droits. Les frais facturés par Alamy couvrent l’accès à la copie haute résolution de l’image.

Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.

. The Canadian field-naturalist. 212 The Canadian Field-Naturalist Vol. 105 Iqaluit Lake Harbour m Pangnirtung. _ â .â â â Illlllllll 76 77 78 79 80 81 82 83 84 85 86 87 88 89 Figure 5. Recent annual Beluga catches in Cumberland Sound, Frobisher Bay, and around Lake Harbour, 1976-1989 (DFO annual catch statistics). year (Figure 3), more than 17% of the 1986 Southeast Baffin stock size ("less than 500") which, when adjusted for a 10% to 30%. hunting loss, indicates an annual removal rate of 92 to 119 animals or more than 18 to 24% of 1986 stock size. If a Lake Harbour annual catch that could be between 10 (July 1989 catch) and 21 Belugas (average annual catch 1987-1989) is added, the total annual removal could be as large as 100 or more. At rates of 2 to 3%, the growth potential of the stock is already slight. If there was no hunting, the Southeast Baffin population might increase slowly and double its present size in half a century or more, but even then it would still not sustain the present annual catch. Low population si/c can accelerate oreven cause extinction by random occurrences of high death rates and low birth rates (Gilpin and Soule 1986). Small populations run the risk of random loss of genetic variance which, in turn, can reduce birth rate, and increase mortality and the likelihood of demographic extinction. These processes can be exacerbated by random changes in the quality ol the environment or by catastrophic events. The recent phocmc distemper epidemic which wiped Mm , ii leasl hall i>t the North Sea Harboui Seal population in six months (llarwood I9S°) is a good example ol such a catastrophic event. ol ionise, there are examples ol overharvested in.nine mammals rebounding to large numbers ill- i .i period ol protection, foi example Northern Elephant Seals (Mirounga angurostris), hut i.ii I in:1 .i pool ol genet i< variability with which to adapt lo (hanging conditions, these species are especially vulnerable to environmental mo

Recherche dans la banque de photos par tags

• bookauthorottawafi
• bookcentury1900
• bookdecade1910
• bookyear1919