Is the length distribution of C1 and C3 humpback whale catches consistent with an age-structured version of the resident model

• Main Authors: Müller, Andrea, Butterworth, Doug S, Johnston, Susan J
• Format: Report
• Language: English
• Published: Marine Resource Assessment and Management Group 2009
• Subjects: humpback whale; age-structured version of the resident model; Humpback Whale
• Online Access: http://hdl.handle.net/11427/18442

A sex- and age-structured BALEEN II population model is fitted to population abundance and trend as well as photo-id capture-recapture data for the C1 and C3 humpback whale breeding sub-stocks. The model is of the “Resident” type, i.e. no interchange between breeding grounds, though the whales do mix on the feeding grounds. Uniform selectivity on the 1+ population is assumed for both regions. A particular aim is to address the question of whether length distribution differences between the two regions are a reflection of different levels of past exploitation. Comparison with length distribution data for both regions does however indicate a greater proportion of larger males than anticipated in the C3 catches, and the reverse effect for both males and females in the C1 catches.