Whales survived centuries of indiscriminate hunting

“At the end of the 17th century, it is estimated that there were fifty-eight thousand whales in the Southwest Atlantic. Currently, the population is recovering. There are about five thousand, which represents less than ten percent of the estimated total prior to removal by hunting. In 1830, for instance, there were less than two thousand,” Alejandra Romero comments. She is an associate researcher at the del Centro de Investigación Aplicada  y Transferencia Tecnológica en Recursos Marinos “Almirante Storni” (CIMAS-CONICET). Romero is part of a group led by a researcher of the Centro para el Estudio de Sistemas Marinos (CESIMAR-CONICET), Enrique Crespo. The main objectives are to discover the history of exploitation of different marine organisms that inhabit Patagonia and study the mechanisms of recovery that allow the animals to continue to exist.

For the study, which was published in Scientific Reports, Romero had to gather information from different sources and interview several references to be able to reconstruct the number of whales captured by vessels from different countries in this region of the world.

“After collecting a large amount of information, we have managed to reconstruct the series of historical catches of whales from the 17th century to the present. Going through all that data was hard work. For instance, we gained access to UK customs books. The handwritten record of everything that was imported during the 19th century from different regions of the world is there. It took me around four months to discriminate the data on the number of whales captured in the South Atlantic and that arrived in the United Kingdom,” Romero explains.

The study reveals that the whale and other marine animals, such as wolves and elephants, were exploited because of their fat, which had a high commercial interest. “The first ones who began to capture whales were the Basques. They started it in the 6th century and the most important activity was between the 13th and the 18th centuries. They went from the Bay of Biscay to Terranova and the Labrador peninsula. These people had bases where they spent the winter and then returned with the rendered fat and other by-products of the whale. The fat, among other things, was used in oil lamps. During the Middle Ages, all of Europe was illuminated with the fat of these animals,” Crespo adds.

Besides, it is worth mentioning that in the beginning the capture of whales was an activity that was carried out manually. “They were hunted with a hand harpoon from small rowing boats and the Basques captured about fifty whales per year. It was an extremely risky activity and those who hunted were at great risk of suffering injuries, freezing limbs and amputations,” Crespo explains.

Over the years and as technology and fishing gear improved, the number of whales captured increased so much that at different times various species of whale were on the verge of extinction.

“In the case of right whale hunting in the Southwest Atlantic, the first capture records date back to 1602 and were carried out by the Portuguese crown. Later, whaling ships with American, British, French and Spanish flags were added. It is estimated that in total about fifty thousand whales were removed between the 17th and 20th centuries,” Romeo explains. In 1935, the southern right whale was protected by international law, “but in 1962, for example, 1,335 whales were illegally captured by Soviet vessels in international waters,” Crespo affirms.

The hunting moratorium policies implemented in 1986 by the International Whaling Commission allowed all species to recover their populations to a greater or lesser degree. “Currently, the population growth rate of the whales that inhabit the Southwest Atlantic is positive, and our study projects that by 2030 there will be about 5,500 individuals. Although it is still far from the maximum number of its original population, understanding the dynamics of the whale populations is essential to manage and diagram conservation strategies,” Romero concludes.