Infographic: California’s Sea Lion Die-Off

In December 2014, sick sea lion pups began stranding in record numbers along California's shores. According to the National Oceanic and Atmospheric Administration (NOAA), the number of California sea lion strandings for 2015 alone surpassed the total number of strandings from 2004 to 2012 combined. The pups are severely emaciated and dehydrated, showing up underweight for their age, and weighing less than half of what they should normally weigh at 8 or 9 months of age.

Although scientists are still trying to determine what's causing the unique spike in strandings for 2015, it's known that warming ocean temperatures and changes in prey availability are likely contributors to this unusual mortality event. As a result, sea lion mothers are being forced to travel further offshore to find food, and many pups are left to fend for themselves before they are ready.

Watch the VICE News documentary, California's Sea Lion Die-Off:

With more than 3,100 strandings to date, marine mammal centers up and down the California coast are overwhelmed, and struggling to keep up with the number of rescue calls they receive on a daily basis. According to NOAA, there are only seven stranding network rehabilitation facilities available to care for stranded sea lion pups, a low number considering California's coastline extends 840 miles.

Despite the growing crisis and record numbers this year, researchers and scientists believe it is too soon to predict how these strandings will affect California's sea lion population, which currently sits at an estimated total of 300,000. Although the long-term affect on the population remains unknown warming ocean temperatures, and a lack of cold nutrient-rich water could prolong the crisis.