Scientists Employ Satellite Tags To Solve Whale-Sized Mystery
For the first time, scientists working in the waters of Patagonia are using satellite tags to remotely track southern right whales from their breeding/calving grounds in the sheltered bays of Península Valdés, Argentina, to unknown feeding grounds somewhere in the western South Atlantic. This could eventually provide clues to the cause of one of the largest great whale die-off ever recorded.
The international effort for answers includes members from the Wildlife Conservation Society (WCS), the Aqualie Institute of Brazil, the National Oceanic and Atmospheric Administration (NOAA), and Cascadia Research Collective, working in cooperation with Fundación Patagonia Natural, Instituto de Conservación de Ballenas / Ocean Alliance, the University of California, Davis, the Dirección de Flora y Fauna (Wildlife Service), la Secretaría de Turismo, el Ministerio de Ambiente (Ministry of the Environment) of Argentina’s Chubut Province.
The announcement was made as conservationists are holding the 2014 IUCN World Parks Congress in Sydney, Australia – a once-in-a-decade global forum on protected areas.
Said Dr. Graham Harris, Director of WCS’s Argentina Program: “A provincial protected area and a key area with a long history of work by WCS, Peninsula Valdés was declared a UNESCO Biosphere Reserve in June of 2014 due to its importance to protect both terrestrial wildlife and marine species along its waters. As the World Parks Congress in Sydney is underway, it is imperative to highlight the importance of protected areas like Peninsula Valdes to safeguard unique wildlife and habitats.”
Over the past month, the team succeeded in affixing satellite transmitters to five southern right whales, a difficult task conducted during varying weather conditions in Golfo Nuevo, one of the two protected gulfs of Península Valdés and an important breeding ground for the southern right whale.
Vicky Rowntree, director of Ocean Alliance’s Right Whale Program comments: “It’s incredibly exciting to follow the daily movements of individual whales which we usually see only one day a year, at most, when we conduct our annual photo-identification surveys. The tagged whale that traveled southwest for a bit and then retraced its path was fascinating–why did it change its direction, what was it looking for and what did it find? By matching photographs of right whales taken in places far from the Peninsula Valdes, we’ve known for years that some PV mothers calve off Brazil in alternate years and that three PV whales traveled to feed in the krill-rich waters in the western South Atlantic off the island of South Georgia. These snapshots in time have been extremely important in delineating the population’s habitat but satellite tracking is allowing us to follow day-to-day movements and understand they make, the paths they follow and if the tags keep transmitting, hopefully, their feeding destinations. I can’t wait to search for the tagged whales in our PV catalogue of 3,000 individuals that have been photographed at PV over the past 44 years and attach life histories to their journeys.”
Over the past decade, southern right whale calves have died in unprecedented numbers (more than 400 between 2003-2011) for reasons still unclear to scientists. Different hypotheses for this mortality have been considered, including disease, certain types of contaminant, and harassment and wounding by kelp gulls, a frequent occurrence in Península Valdés.
This new research will help assess where the whales are feeding, namely if there could be any threats to the whales along their migration route or on their feeding grounds and if the research team can conduct additional tagging and studies to determine any issues associated with food or nutritional stress causing calf loss by some mothers.
Said Mariano Sironi, Scientific Director of the Instituto de Conservación de Ballenas in Argentina: “This project follows the recommendations made by the International Whaling Commission when it analyzed the recent increase in right whale calf mortality in Península Valdés. It is the result of the cooperation between non-governmental organizations, universities and government agencies. The scientific data resulting from this project will provide a new scale to our understanding of southern right whale behavior. Differences in movement patterns among the tagged individuals will certainly be fascinating.”
The deployed tags will transmit the geographical position and behavioral information of the animals up to Earth-orbiting satellites multiple times a day, allowing researchers to follow whales remotely. The researchers selected calving females and solitary juveniles for satellite tagging in order to glean insights into habitat use and migratory movements for different sex and age groups.
Data accumulated thus far reveal unprecedented information for southern right whales: real-time information on long-range movements across marine regions. Two of the five whales have remained in the waters of Golfo Nuevo, while the other three have already left the bay. One of the animals is currently in deep waters of the South Atlantic, one has been spending its time over the continental shelf, and another has moved into deep offshore waters, but has returned to the continental shelf break. Movements from all whales have lead researchers to some areas where the tagged animals are likely feeding, and further discoveries of feeding grounds for this population may be revealed as the team tracks the movements of tagged animals.
Growing up to 55 feet in length and weighing up to 60 tons, the southern right whale is the most abundant species of the world’s three species of right whale. Unlike the North Atlantic and North Pacific right whales (both Endangered), southern rights have managed to rebound from centuries of commercial whaling, with populations that have grown by as much as approximately seven percent annually since 1970. Of the estimated total population of southern right whales found throughout the entire Southern Hemisphere, around one third use the protected bays of Península Valdés as a breeding and calving habitat between the months of June and December.