Our Mammal Research Institute Whale Unit has launched a satellite tagging programme to follow southern right whales along their migration

Researchers from the MRI Whale Unit have deployed satellite transmitters on four adult female southern right whales, which are enabling them to investigate the migration and feeding behaviour in detail. This research is of paramount importance considering the drastic changes that have been observed in southern right whale migration, reproduction, and body condition in the last 10 years. These changes are most likely as a result of a reduced prey availability in the Southern Ocean due to climate change.

The southern right whale population that breeds off the South African coast has been monitored by the Whale Unit for the past 42 years. This research has highlighted concerning changes in the population in the past decade, including significantly decreased reproductive success and body condition (or “fatness”), and a change in foraging and migration behaviour, all of which have resulted in lower numbers of southern right whales being seen off our shores.

The main food source for hungry southern right whales is found thousands of kilometres away from where they nurse their young, meaning that their successful migration and calving is dependent on them finding enough food during the summer months in the Southern Ocean in order to build up adequate fat reserves so that they can migrate and calve successfully.

The changes observed by the MRI Whale Unit therefore point strongly toward a decreased food availability for these whales in their Southern Ocean feeding grounds. It is therefore of utmost importance to identify these feeding grounds so that the Whale Unit can assess what climatological and/or oceanographic changes may lie at the root of this conservation problem. As one of the first steps to finding these answers, four satellite tags were deployed on adult female southern right whales as a pilot study. These tags will provide us with information on the location of each individual for up to 1 year maximum, allowing the Whale Unit to investigate each animal’s migration and foraging behaviour in more detail. If all goes well, 30 more satellite transmitters will be deployed within the next 2 years.

This research project is in collaboration with Dr Alex Zerbini and Dr Amy Kennedy from the National Oceanic and Atmospheric Administration (NOAA), University of Washington’s Cooperative Institute for Climate, Ocean and Ecosystem Studies (CICOES/UW), and the Marine Ecology and Telemetry Research (MarEcoTel). Funding for this research project is provided by Instituto Aqualie (Brazil) and the MRI Whale Unit.