An insight into the populations of blainville's and curvier's beaked whales off El Hierro (Canary Islands)

Abstract

Beaked whales (Fam. Ziphiidae) appear to be highly sensitive to some acoustic sources, which can lead to mass strandings. The lack of knowledge about the population dynamics and reproductive parameters of these species impedes the assessment of potential population-level effects of stranding mortalities. Estimating the abundance and density of beaked whales is more difficult than for many other cetacean species, due to the difficulty in identifying most beaked whales to species level in visual surveys. All this has resulted in few population estimates in the published literature. El Hierro (Canary Islands) harbours resident populations of Blainville’s and Cuvier’s beaked whales in deep waters close to the shore. This has made possible to perform one of the few long-term monitoring of beaked whale populations taking place in the world (on-going since 2003).