Many pups were washed away as their mothers barked helplessly.
Storms pushed normal high tides even higher. King tides, the highest tides of the year, washed over the beaches on Saturday and Sunday.
Elephant seals return to the beach in the winter to give birth to their pups, nurse them for a month, mate and then return to the ocean. Many of those that gave birth before the storms lost their pups.
Pregnant seals continue to arrive and give birth. They have been safe so far, but recent king tides may affect those later arrivals.
The atmospheric rivers that drenched California also affected the rookery. Beaches that were above high tide lines were inundated by waves that washed away sand and the pups that were born here days before.
The entire north beach at the viewpoint was under water. Pups struggled valiantly, washed out and making their way back up to their mothers, but ultimately lost the battle.
By the time the storms had passed in mid-January, no pups remained on that beach.
The south beach fared somewhat better, with its dunes at the far south end providing some high ground.
Most of the beach was under water at least part of the time, but niches in the rocks gave some pups safe harbor.
These pups, now fat weanlings, are likely the pups that were settled in the kelp pile early in January. They found a way to survive.
Seal pups can’t swim to save themselves. They don’t have enough blubber to stay warm. Those that have had a week or so to nurse and gain weight have an advantage in surviving.
Newborns are most at risk.
Mothers Can Get Separated from Pups
Having so many seals on the beach inevitably causes some confusion, and some pups get separated from their mothers. They may reunite, but if they don’t, the pup can starve and die. Maternal-pup separation is the most common cause of pup death.
With the chaos of rain, wind and tides, many pups are separated from their mothers. The mothers who have lost their pups may adopt an orphan pup.
Heather Liwanag, Cal Poly associate professor and principal investigator at the Vertebrate Integrative Physiology lab, and her Team Ellie, survey the seals on the beach regularly and record data.
“We can estimate losses when we analyze the data at the end of the season,” she said.
What Will Be Long-Term Effect of Storms?
Researchers are observing the seals to assess how this loss of pups will affect the Piedras Blancas rookery.
Overall, San Luis Obispo County’s elephant seal population is doing well. Other rookeries have been similarly affected.
Typically, elephant seal mothers come into estrus about a month after they give birth, mate and return to the ocean. Researchers expect mothers whose pups were swept away to remain on the beach and complete that cycle, getting pregnant with next year’s pups.
How to See Elephant Seals
Subdominant bulls find refuge from the rigors of the breeding beaches at Hearst Memorial Beach in San Simeon and on other local beaches.
Give them plenty of space. They are recovering from battles and will soon depart for their ocean home, and next year’s breeding season.