Change text size
Choose your language:

Western South Atlantic population of southern right whales

The southern right whale was seriously depleted by whaling during the 1700s and 1800s.  It was fully protected in 1935 but illegal hunting from the 1950s to 1970s delayed any recovery. 

Globally this species is classified as ‘Least Concern’ by the International Union for the Conservation of Nature (IUCN) and recently there has been an encouraging increase in the size of several populations.  The IWC’s Scientific Committee estimates that the total number of southern right whales in 2009 was about 13,600.  This figure is approaching 20% of pre-whaling levels.

The population in the south-west Atlantic (which winters off Argentina and Brazil) was estimated at around 4,000 whales in 2010. Between 1971 and 2010 the population increased at an annual rate averaging about 6%.

Although this long-term increase is good news, a Conservation Management Plan (CMP) is needed to address a number of actual and potential threats to the population’s continued recovery. The main threats are mass die-off events (particularly amongst calves), kelp gull harassment in nursery areas, entanglement in fishing gear, ship strikes and coastal development.

The overall objective of the CMP is to protect habitat and minimise anthropogenic threats to maximise the likelihood that the southern right whale will recover to healthy levels, and recolonize its historical range.  The CMP identifies a series of priority actions to achieve this, including research, coordination and capacity building.  Amongst the key actions are:

  • work to determine movements, migration routes and location of feeding grounds through satellite telemetry;
  • long-term monitoring of abundance, trends and biological parameters through photo-identification and biopsy sampling;
  • enhancement of existing stranding networks including capacity for undertaking necropsies;
  • development and implementation of a strategy to minimise kelp gull harassment;
  • capacity building and raising of public awareness in range states; 
  • development of a database of information on human activities that might have an adverse impact on whales.

Much has been achieved under the auspices of the CMP since its adoption in 2012.  Scientific research has included projects on southern right whale health, aerial and vessel surveys and a satellite telemetry programme.  Several workshops have been held, including on calf mortality and possible links with kelp gull harassment in nursery areas, and on identification of sensitive areas in Argentine waters.  In 2016, a workshop was held to review the CMP.  This assessed progress against each of the key actions, confirming their continuing relevance, and prioritising further work to mitigate kelp gull harassment in Peninsula Valdes, Argentina. 

The CMP for the Western South Atlantic population of southern right whales can be downloaded here

The report of the 2016 workshop to review this CMP can be downloaded here.

You can read about the satellite telemetry programme here.

Also available for download is a press release and full report of the workshop on calf mortality in Peninsula Valdes.