The depletion of gray Pacific whales is far more alarming than it has been known until now, as it is pinpointed in new study published online in the Proceedings of the National Academy of Sciences his week.

Almost 118,000 was the number of whales that used to live in the Pacific before human hunting began decimating the population. Moreover, human-caused climate change made the things even worse, whales being confronted with food deprivation.

Detailed analysis of DNA taken from whales living in eastern Pacific revealed the major impact human behavior has had on oceanic ecosystems.

By examining the genetic variability of the present population, scientists at Stanford University and University of Washington at Seattle reached to the conclusion that 76,000 to 118,000 gray whales used to roam the Pacific before the hunting started in the 1800s. A rough comparison between these figures and the present estimated number of 22,000 highlights that human activity has been far more damaging than it was expected.

Though in the mid 1990s it was believed that extinction isn’t jeopardizing gray whales in the eastern Pacific and they ceased to be considered endangered species, deaths among them have increased much lately.

Climate changes were blamed for the decreasing number, as scientists reported: “this decline was due to shifting climatic conditions on Arctic feeding grounds.”

But the reduction in the number was caused by different factors. Local tribes are currently allowed to hunt 125 gray whales per year under the regulations of International Whaling Commission. But if they are to take into consideration the conclusions of the recent study that highlights that extinction rates are outstandingly higher that it has been previously believed, the Commission should reduce the annual number permitted.

Stephen R. Plumbic, a professor of marine sciences at Stanford and a co-author of the study stressed that the population of eastern Pacific gray whales might augment, provided they have the right conditions. On the other hand, it shouldn’t be forgotten that the warming waters of the Bering Sea will constitute a major hindrance in accomplishing this possibility.

Emaciated whales found ashore between 1999 and 2001 were thought to be the result of the exhaustion of the ocean’s “carrying capacity”, but the facts are more complex than that, as global warming might be the gist of he problem.

“It's not a conclusion we can come to. It's a hint. But if humans are affecting the ocean's capacity to support life, it's got to make you worry, it's got to make your wonder," Plumbic explained in an interview.