Guest commentary: Here’s what you can see during Point La Jolla’s seasonal closure, and why it’s needed
On April 8, the California Coastal Commission voted to have seasonal birthing protection for the sea lions at Point La Jolla and Boomer Beach. The San Diego chapter of the Sierra Club and the Sierra Club Seal Society applaud the commission’s decision and conditional requirements for San Diego’s coastal development permit for seasonal closure.
The many beneficial measures incorporated into the CDP will provide critically important safety protections for sea lion mothers and pups and the viewing public.
The La Jolla sea lion rookery is touted as one of the top outdoor places to visit in San Diego, according to Tripadvisor, and brings thousands of tourists to the area — as many as 300 per hour. It is the only sea lion rookery on the California coastline in an urban environment, and over 50 pups are born yearly. The California Coastal Act protects this rookery as an environmentally sensitive habitat area, as does the federal Marine Mammal Protection Act.
Sea lions are pinnipeds, which means fin-footed, and can walk on land by rotating their strong front flippers outward and swiveling their shoulders and hips. They are warm-blooded mammals like us and have small ear flaps, unlike seals, which have no visible outer ears. They often pile on top of one another onshore and are most comical to watch.
The closure dates from May 1 through Oct. 31 will give pups a greater chance of survival and provide visitors and researchers the opportunity to view the sea lions’ life cycle of birthing, breeding and raising their young without human interaction.
After nine months’ gestation, sea lion pups weighing about 16 pounds are born on land from mid-May to mid-July. The closure allows mothers to give birth without human disturbance. If you’re lucky, you may witness a live birth from the short wall overlooking Point La Jolla.
If a mother is about to give birth, she separates herself from the other sea lions. After her pup is born, she calls out to her pup so it recognizes her voice, and the pup makes squealing sounds that allow the mom to distinguish her pup from the others. They also recognize each other by smell; what looks like kissing is really mom and pup identifying each other’s scent. This is called “imprinting.”
Each mom has only one pup and won’t allow other pups to nurse. After birthing, the mother stays onshore with her pup for about eight days. Thereafter, the mom nurses for up to three days before leaving her pup on the cliff above the high-tide line while she goes out foraging for food. During this time, the pup fasts.
Over the next two weeks, the mom leaves to forage more frequently and the pup begins to move around and socialize with other pups.
Sea lion mothers nurse their pups for 11 months. Pups begin to forage for food at around six months, according to Sharon Melin of NOAA [National Oceanic and Atmospheric Administration], but are not adept until eight months. Pups are vulnerable to drowning in rough surf, as they can’t swim well until 3 to 4 months old.
Boomer Beach is where 40 percent of the births take place, and it is the only beach in the rookery where pups can learn to swim. With a closed rookery and rangers present, human disturbance will abate.
The closure also protects the public during sea lion breeding season. After birthing in May to mid-July, bulls weighing 800-plus pounds arrive and fight viciously to defend their territories and the right to mate. If visitors get dangerously close to them, they may growl, lunge at, chase and bite them, causing serious harm. Mothers may bite if people get close to their pups.
With the new closure dates and boundaries and the presence of rangers, the public will be able to safely view wild sea lions in their natural habitat and witness the amazing sea lion life cycle of birthing, caring for their young and mating. It is a treasure to behold!
Special request: If anyone witnesses a pup’s birth, please notify the Sierra Club Seal Society (email@example.com) with the date, time and location to help us document the births.
Carol Archibald is a docent with the Sierra Club Seal Society. ◆
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