Status Review and Extinction Assessment of Cook Inlet Belugas (Delphinapterus Leucas)

Résumé du livre

"The contraction of the range of this population northward into the upper Inlet makes it far more vulnerable to catastrophic events with the potential to kill a significant fraction of the population. The population is not growing at 2% to 6% per year as had been anticipated since the cessation of unregulated hunting. The population is discrete and unique with respect to the species, and if it should fail to survive, it is highly unlikely that Cook Inlet would be repopulated with belugas. This would result in a permanent loss of a significant portion of the range for the beluga species. The importance of anadromous fish runs in Cook Inlet to belugas is evident. The bulk of their annual nutrition is acquired during the summer months. The PVA shows a 26% probability of extinction in 100 years and 68% probability of extinction in 300 years (for the model assuming one predation mortality per year and a 5% annual probability of an unusual mortality event killing 20% of the population). It is likely that the Cook Inlet beluga population will continue to decline or go extinct over the next 300 years unless factors determining its growth and survival are altered in its favor."--Page xiii-xiv.