Rehabilitated California sea lions Grace and Evanora will be released back into the wild this weekend by the Pacific Marine Mammal Center, whose staff and volunteers saved many lives during an unprecedented stranding epidemic this spring.

Starting in January, the Laguna Beach-based center witnessed an influx of sea lion pups coming ashore, suffering from severe malnourishment and starvation. During the next four months, center volunteers responded to more than 340 rescue calls, a record for the 42-year-old center and 10 times the number of patients typical during the spring season.

At the peak, the center housed 167 sea lion pups, including Grace and Evanora. Grace was rescued on Feb. 26 from San Clemente, weighing just 26 pounds, less than half of what is considered normal. She was in such a critical condition that it took her more than two months before she was able to eat on her own, spokeswoman Melissa Sciacca said. Evanora was a similar case with her rescuing occurring on March 13, also from San Clemente, weighing just 22 pounds and suffering from starvation and lacerations on her face.

“It was the most catastrophic event we’ve ever seen,” Executive Director Keith Matassa said. “We did everything we could to rescue each animal in need, and have been working tirelessly for the last six months to get them all well enough to return home.” Even so, about a third of the rescues were unsuccessful, Sciacca said.

While the National Oceanic and Atmospheric Administration declared the extraordinary number of starving sea lions “an unusual mortality event” in April and the larger scientific community are still gathering data on what has caused this mass stranding in the first place, PMMC continues to focus its efforts on each individual case, with one animal rehabilitation at a time, Sciacca said.

Since the height of the crisis, PMMC has since returned more than 120 sea lions back to the ocean, with many more still recovering at the hospital. “We do whatever it takes to give each animal a second chance,” said Michele Hunter, animal care director. “We have many animals that were on the brink of death, but fought hard for their lives, and are now making their way back home.”

The center has also gone to new lengths to ensure that their efforts to save marine mammal patients hasn’t been in vain. Each animal is traditionally tagged on their flipper with a very small orange tag with a code number. This year four animals were released with satellite tags to watch their travels in the wild. One of those patients, Roscoe, was tracked off the coast of Newport, and later spotted by rescue teams to monitor his body weight and health. “We were pleased to see Roscoe doing so well in the wild,” Matassa said. “He’s been on his own now for a few months, and the fact that he looks healthy and has a good weight indicates that he is doing well out there, and that our efforts are allowing him to being successful.”

The center’s patients are still going through more than 300 pounds of fish a day, down from a peak of 600 pounds, a significant cost to its animal care budget.

For more info: www.pacificmmc.org.