Unusual Mortality Event

Mass Die-Offs Continue to Threaten Marine Life

Balmy temperatures can lead to conditions perfect for the spread of infectious diseases, Sanderson said. When sea ice melts too early in the season, seal pups must enter the water before they are ready to be weaned, leaving them weaker and more vulnerable to disease. Vanishing sea ice also means that seals and sea lions in cold regions will have less space to emerge from the water to rest, breed, or escape predators, forcing them to crowd more tightly together.

A Sea Bird Dead Zone

In a study published Wednesday in the journal PLOS ONE, a group of scientists from various state and federal agencies, universities and bird rescue organizations documented the die-off and concluded from the data that it was caused by a record-breaking ocean heat wave in 2014 through 2016 that triggered systemic changes throughout the ocean ecosystem.