After weeks of rehabilitation many of the sea lions rescued from Southern California beaches earlier this year have regained their health and are being released back in the ocean.

Young sea lion pups return to the sea at Point Reyes, California, April 19, 2013. (Photo: The Marine Mammal Center)

    Between January 1 and March 24, the National Oceanic and Atmospheric Administration declared an “unusual morbidity event” during which more than 900 malnourished and weak sea lions were rescued on the region’s beaches. By early April the Marine Mammal Center was providing medical care and nourishment for 165 seals and sea lions, more rescues than in any previous year in the Center’s history.

    Sharp Scissors, one of the sea lion pups rescued from Southern California beaches, returns to the ocean at Point Reyes, CA.. May 24, 2013. (Photo: The Marine Mammal Center)

    So far there is no evidence that the large number of strandings were due to underlying primary infectious disease or toxic insult.

    Young California sea lions at The Marine Mammal Center in Sausalito, CA. (Photo: © Ingrid Overgard/The Marine Mammal Center)

    A preliminary determination of the causes of the strandings points to a simple lack of food. In particular, extremely lows numbers of sardine and anchovies last year which resulted in female adult sea lions having a difficult time providing their pups enough nourishment.

    A stranded and malnourished juvenile sea lion is rescued by Peter Wallerstein, the Marine Animal Rescue director for Friends for Animals. (Photo: Kevork Djansezian / Getty Images)

    The result was a large number of pups either underweight or weaned a month or two early. Those that survived were starving and ended up on the beaches extremely emaciated.

    Mike Remski of Marine Animal Rescue checks for sign of injury after rescuing a malnourished sea lion pup on Dockweiler State Beach in Los Angeles. The pup, was transported to Marine Mammal Care Center at Fort MacArthur for rehabilitation. (Photo: Kevork Djansezian / Getty Images)

    Sea lions are one of the top predators in the ocean. Their suffering is a clear sign something is very wrong with the world’s seas.

    Source: Marine Mammal Center.