Spatial and temporal structure of the western North Pacific minke whale distribution inferred from JARPN sightings data

The density of minke whales (Balaenoptera acutorostrata) in the western North Pacific was examined using a generalized additive model order to investigate spatial and temporal distribution patterns. data used were subset JARPN sightings collected from 1994 1999. process for estimating divided into two parts: detection estimation effective search half-width; encounter rate. Model selection carried out information criteria. selected included ‘sightability’, synthetic index detectability, as covariate, interaction between latitude longitude month latitude. trend surface transformed predicted by each revealed no clear gaps. monthly transition also suggested northward seasonal feeding migration whales.