Authorities are sounding the alarm over the North Atlantic right whale, an extremely rare species that is in increasingly great danger of extinction after another bad year. These whales are already among the most rare marine mammals in the world, and their population is only about 450 individuals in existence.

Just in 2017, 17 North Atlantic right whales have been killed, according to the National Oceanic and Atmospheric Administration. Authorities warn that that the species may not recover if action is taken right away to protect the species. Experts believe only 100 breeding females of the species are still alive.

“You do have to use the extinction word, because that’s where the trend lines say they are,” John Bullard, the Northeast Regional Administrator for NOAA Fisheries, said according to an ABC News report. “That’s something we can’t let happen.”