Research Document - 2016/023
Historical abundance of Eastern Canada - West Greenland (EC-WG) bowhead whales (Balaena mysticetus) estimated using catch data in a deterministic discrete-time logistic population model
By Jeff W. Higdon and Steven H. Ferguson
Abstract
Applying a Precautionary Approach to marine mammal harvesting requires knowledge of abundance trends, population dynamics, and carrying capacity of the target species. We use historical catch data to model bowhead whale (Balaena mysticetus) population abundance trends over the past 500 years. The analysis provides an estimate of the historic (i.e., pre-exploitation) population level that can be used as a carrying capacity (K>) estimate in identifying limit reference points in management. A standard discrete time logistic growth model used by the International Whaling Commission to understand past and future population abundance projections was developed for the Eastern Canada-West Greenland bowhead population. A number of model runs investigated parameter estimation and sensitivity and provided confidence in the approach. The model results provided an historical population size estimate of about 18,500 whales as the most plausible solution (mean = 18,495; 95% CI = 18,022-18,972; SD = 289 for a model with input K = 18,000-19,000 and with mean rmax = 0.0400; SD = 0.0029; 95% CI = 0.0352-0.0448). 18,500
Accessibility Notice
This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.
- Date modified: