The Blue Whale is Back
There is some good news in the world of marine biology, the Blue whale population along the west coast of the United States has apparently recovered after being hunted to near-extinction by humans.
A team of researchers at the University of Washington examined the eastern North Pacific (ENP) blue whale population and estimated that the current number of whales is roughly 2,200 animals; 97% of the population sustainable within that ecosystem.
The findings, published in Marine Mammal Science, examined whether collisions with ships are responsible for inhibiting population growth in blue whales. According to the article, approximately 11 whales are killed annually as a result of ship impacts. While the legal limit for “Potential Biological Removal” is set at 3.1 per year, the authors are convinced that this is unlikely to prevent the survival of the species. They instead believe that population growth has slowed due to them approaching their ecological population density limit.
In an article in Nature, Daniel Cressey describes concerns raised by other industry experts in response to these findings. A paper published in July had studied the movement of blue whales and determined that the whales spent substantial time feeding in major shipping lanes. An author of this paper, Daniel Palacios, questions the new data regarding ship strikes given that the strikes vary significantly by year and are difficult to observe and document (whale carcasses sink initially upon death). Michael Fishbach, a co-executive director of the Great Whale Conservancy worries that the latest information may undermine policy efforts to redirect shipping lanes and enforce marine vessel speeds around whale feeding areas by downplaying the ultimate harm to blue whale populations as a result of ship strikes.
There is still much to be done for the blue whale and many more species to save, but this small victory is an excellent example of the efficacy of concentrated, global conservation efforts. For now the largest animal ever known to have lived will live on… provided we don’t muck it up again.
The main image belongs to the Great Whale Conservancy, an excellent resource for more information about this incredible animal.