With their distinctive black-and-white markings and dramatic breaching habits, orcas have long been among the most iconic coastal mammals of the Pacific Northwest. But they are now in danger of vanishing from the region, The New York Times reports. The population has reached a 30-year low of just 75 whales, researchers from the National Oceanic and Atmospheric Administration (NOAA) report, and no calves have been born into the group in the past 3 years. The most likely cause is the near disappearance of the Chinook, or king salmon, the orcas’ main food source, due to overfishing and stream pollution. The researchers say inbreeding, increased oil tanker traffic, water contamination from farm and factory runoff, and diseases passed on from humans could also be to blame.