A metapopulation model for Canadian and West Greenland narwhals

Abstract A model of the metapopulation structure of narwhals M onodon monoceros in B affin B ay, H udson B ay and adjacent waters is proposed based on satellite telemetry data collected over two decades from six coastal aggregations of narwhals in the eastern C anadian high A rctic, H udson B ay and...

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Bibliographic Details
Published in:Animal Conservation
Main Authors: Heide‐Jørgensen, M. P., Richard, P. R., Dietz, R., Laidre, K. L.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2012
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Online Access:http://dx.doi.org/10.1111/acv.12000
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Facv.12000
https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1111/acv.12000
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Summary:Abstract A model of the metapopulation structure of narwhals M onodon monoceros in B affin B ay, H udson B ay and adjacent waters is proposed based on satellite telemetry data collected over two decades from six coastal aggregations of narwhals in the eastern C anadian high A rctic, H udson B ay and W est G reenland. In addition, data on seasonal catches of narwhals in 11 I nuit communities are used to provide information on the occurrence of narwhals. The tracking data suggest that disjunct summer aggregations of narwhals are, to some extent, demographically independent subpopulations, with minimal or no exchange with other summering aggregations. We propose that these should be considered separate stocks for management purposes. Year‐round satellite tracking of individuals demonstrates that whales return to the same summering areas the following year, suggesting inter‐annual site fidelity. We propose that the narwhals in C anada constitute five separate stocks, with limited exchange between three of the stocks. C oastal summer aggregations in G reenland constitute two stocks in addition to two fall and winter aggregations supplied by narwhals from several summering areas. Several narwhal stocks mix on the wintering areas in B affin B ay, but the metapopulation structure is likely maintained through a combination of life‐history traits and migratory routes, as mating most likely occurs after the initiation of the return migration toward summering areas. The metapopulation structure in B affin B ay narwhals will be impacted differentially by I nuit subsistence hunting, depending on the migratory schedule of narwhals and dates at which whales occur in different seasonal hunting areas. It is therefore important to identify which narwhal stocks contribute to which subsistence hunts in order to assess the sustainability of those hunts. This paper proposes a preliminary stock model for this purpose.