Research Document 2020/067

Eclipse sound narwhal (Monodon monoceros) movement and hunt composition and its relevance to stock delineation

By Marcoux, M., and Watt, C. A.

Abstract

The Baffin Bay narwhal population is currently managed as four summering stocks and two tentative stocks based on seasonal distribution, genetic, and contaminant evidence. The rationale for management as discrete stocks was to reduce the chance of depleting narwhal abundance at local harvest sites. This management framework assumes there is a high degree of spatiotemporal site-fidelity, as was originally inferred from limited satellite telemetry data. New data is adding to our understanding of narwhal behavior and suggests site-fidelity may not be as strong as once thought. This document presents recent telemetry data from 2012 and 2016–2018 to provide further information on the division of narwhal summering aggregations particularly between Eclipse Sound and Admiralty Inlet. In addition, we provide information on the composition of the hunt between Eclipse Sound and Admiralty Inlet to further understand the potential linkages between the two current stocks. A total of 30 narwhals were tagged between 31 July-14 September from 2012–2018, with most of the narwhal (n=23) tagged after 10 August. Nine narwhals tagged in Eclipse Sound visited the Admiralty Inlet, Somerset Island, and East Baffin management area. The proportion of female narwhal hunted in Eclipse Sound was higher than in Admiralty Inlet and the tusk size of hunted narwhal in Eclipse Sound was significantly smaller. This may suggest that narwhals are segregated by age and sex between the two areas. This new information suggests that the allocation model which partitions the total allowable landed catch for the Baffin Bay population among hunting communities should allow for mixing among the stocks in the summer. Currently, the allocation model assumes stock mixture only occurs outside the summer season.

Research Document 2020/067 (PDF, 1,437 KB)

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