For a while, it seemed as if the North Atlantic right whale was on an upswing. This critically endangered whale saw its population grow between 1990 and 2010, from 270 to 483 whales. That's not a huge increase, but it was a good sign.
But it was perhaps the last good sign for these whales. Since 2015, the population has steadily declined, and the new population estimate from the National Oceanic and Atmospheric Administration (NOAA) is around 458 whales, 17 of which were killed in 2017.
"Science can be complicated, but not in this case," Charles "Stormy" Mayo, director of the Right Whale Ecology Program at the Center for Coastal Studies in Provincetown, Massachusetts, told Yale E360. "It's a simple equation: the number of right whales born every year minus the number that die."
Even more alarming: No new calves have been spotted so far in 2018, and calving season concludes at the end of March.
Scientists from the NOAA fly along the Atlantic Ocean coastline looking for any sign of calves but haven't been lucky yet.
"This is the first time since I have worked with right whales that that has ever happened," NOAA's Barb Zoodsma told NPR. Zoodsma has been studying right whales since the early 1990s and said that out of the approximately 450 whales left, only 94 are breeding females.
"The right whales are at a point where more are dying than are being born," wildlife ecologist Clay George told NPR. "That's just not sustainable long-term."
Why is their population declining?
Several factors are contributing to the population decline. First, there are estimated to be less than 100 breeding females, and that makes it difficult for the species to replace its dwindling numbers. This is especially challenging because many females only giving birth once every six years, instead of every three to four years, which was common in the past.
Then there's the issue of humans. From 2010 to 2014, human-induced right whale fatalities grew to between five or six a year, with fishing gear entanglement, like the whale pictured above, accounting for 80 percent of the injuries and deaths. Of the 17 whales killed in 2017, five died during collisions with ships and at least two were killed after being entangled.
According to a presentation given at the New England Fishery Management Council Meeting in Rhode Island in early December, if marine biologists and fishing companies can work together by changing shipping routes and improving fishing lines, there's a chance the right whales can be saved — but time is running out.
Editor's Note: This article has been updated since it was originally published in December 2017.