Climate change and our neglect of the environment have brought numerous species at the brink of extinction. People have largely contributed to the striking decreasing trend of numerous populations.
Experts maintain that pollution, overfishing, overhunting, land clearing, and the use of various chemicals and toxins have led to horrifying consequences on life on Earth.
Fortunately, we still have time to reverse some of these effects, as shown by the fact that adequate conservation efforts have helped to rebound humpback whales in the South Atlantic from the verge of extinction.
The humpback whale (Megaptera novaeangliae) is one of the most popular mammals in the world, mostly due to the fascinating melodies they sing in the depths of the ocean, their tails fins, and the magnificent leaps out of water.
The whaling industry has made the population of these whales drastically reduced in the early 20th century, to only 450 whales. It was also estimated that within twelve years, approximately 25,000 of them were killed.
The declining trend was noticed in the 1960s, and twenty years later, the International Whaling Commission issued a moratorium on all commercial whalings.
Research by Grant Adams, John Best, and André Punt of the University of Washington’s School of Aquatic and Fishery Sciences showed that the population has rebounded to 25,000.
“We were pleasantly surprised by the comeback; previous studies hadn’t suggested that humpback whales in this region were doing this well.”
The study, published in the journal Royal Society Open Science, opposed a previous assessment conducted by the International Whaling Commission between 2006 and 2015.
This study indicated that the whale population had recovered to about 30% of its pre-exploitation numbers, but new data provides more accurate info on genetics, catches, and life-history.
Adams, a UW doctoral student who helped in the construction of the new model, said:
“Accounting for pre-modern whaling and struck-and-lost rates where whales were shot or harpooned but escaped and later died, made us realize the population was more productive than we previously believed.”
Authors of the study believe that this model can be used to evaluate the recovery of other species as well, and to boost transparency, they made the software available to the public, so anyone can reproduce their findings.
Lead author Alex Zerbini, of the UW’s Joint Institute for the Study of the Atmosphere and Ocean, stated:
“This is good news. Despite all the killing that has happened, conservation efforts can have a positive impact and if you protect animals, this shows numbers can grow.
Wildlife populations can recover from exploitation if proper management is applied.”
The study also evaluated the way the revival of South Atlantic humpbacks may affect the ecosystem. In their quest for krill, which is their primary food source, these mammals compete with other predators, like penguins and seals. Krill populations might also be affected by warming waters caused by climate changes.