The deaths of dozens of seals off the coast of Maine has been deemed an “unusual mortality event,” sparking a federal investigation into strandings that appear linked to avian influenza. The seal strandings began in June and 150 have been reported through Monday, the National Oceanic and Atmospheric Administration said. Most of the seals were found dead. NOAA gave the strandings, which have affected harbor and gray seals, the “unusual” designation on Friday. That authorizes a federal investigation to try to determine the cause and minimize deaths. The U.S. Department of Agriculture already has confirmed that samples from four stranded seals tested positive for avian flu, which has been found in more than 40 states since it was detected in winter 2021. The risk to the public from the occurrence of avian flu in seals is low, but beachgoers should take precautions anyway, NOAA representatives said. “We continue to ask the public not to touch ill, stranded or floating dead seals, to keep pets far away from seals, and to call their local stranding network organization to report live or dead stranded seals,” the agency said in a statement.