UK researchers will launch a £740,000 investigation into the mysterious deaths of southern right whales (Eubalaena australis), which are among the most threatened endangered marine species in the world. Researchers will tag whales and calves and use satellites to track them, taking DNA samples to identify individuals.
The researchers hope to determine what led to nearly 500 carcasses of the whale species washing up on the Valdés Peninsula of Argentina, over the past decade. The region is one of the species primary calving areas.
Geneticist Jennifer Jackson, with the British Antarctic Survey, and the project’s leader, said:
“There are only a few thousand southern right whales left on the planet. We need to find out what is killing them and we think their sub-Antarctic feeding ground holds the answer.”
Jackson said of the species, “They swim slowly, float when dead, and yield a great deal of oil. They were perfect targets for whalers.”
To make matters worse for the species, the protective mothers swim with their offspring when they are young, exposing themselves in shallow coastal waters, where they can be easily hunted with harpoons.
Southern right whales can weigh as much as 80 tons, and can grow to as long as 18 meters. The global population plummeted from hundreds of thousands in the 18th century, plunging towards extinction until a moratorium in the 1940s slowed the decline. The population fell again when Soviet whalers went after the species again the 1970s. After a period of recovery since then, number have risen to around 12,000.
However, scientists at the Instituto de Conservacion de Ballenas in Argentina have recently seen hundreds of southern right whale carcasses washing up on nearby shores. Jackson said:
“We still do not know why this is happening – though we have ideas. Whatever the cause, it is a worrying development, especially for a species that has been so badly depleted in the past.”
She presented three possible causes of the deaths – lack of food as a result of disappearing krill populations, exposure of calves to toxic algae, and increasingly frequent attacks on whales by kelp gulls, resulting in lesions on the whale’s backs, and declining health.
The research will collaborate with researchers at St Andrews University, and other groups, to use acoustic devices and drones to track whales and investigate the cause of such deaths. The krill population will also be surveyed.
“The aim is to understand how southern right whales live out their lives and what influences their health and reproduction. Once we have done that we hope we will a much clearer idea of what is happening to them and so be able to do something about that.”