Southern Right Whale Eubalaena australis in the Golfo San Matías (Patagonia, Argentina): An update of recolonization process

Abstract

1. Southern Right Whales is thought to be experiencing a density-dependent process while expanding its distribution range in Patagonia.2. The recovery of the species and the increase in the number of SRW sightings in GSM created a new opportunity to develop the whale-watching activity in Bahía San Antonio Marine Protected Area.3. This paper reports an update of the population growth trend and changes in the age and sex classes of the right whale in the Golfo San Matias estimated from a data set collected through both aerial censuses and on-board whale-watching surveys.4. Aerial counts show showed a high variability between years, and consequently no significant change in abundance was recorded over the years.5. For the first time in the last 9 years of monitoring the whale-watching activity, mother calf pairs were the predominant group sighted during all months of the season.6. The increase in sightings of mother calf pairs in in Bahía San Antonio Marine Protected Area indicates the beginning of a new stage in the recolonization process.7. The differences observed between the aerial and on-board surveys underlining the significance of monitoring both the coastal zone and the offshore area.