Parks / Coast / Environment
Children’s Pool Frequently Asked Question
Regarding the Biology of Harbor Seals at the La Jolla Children’s Pool:
Answered by Dr. Doyle Hanan
Former Senior Biologist 27 years, California Department of Fish and Game
Is the Children’s Pool Beach biologically necessary for the survival of this group of seals?
No, the population is doing well, not ESA (Endangered Species Act) listed nor depleted under MMPA
(Marine Mammal Protection Act). You have to look at the whole population since the seals mix all along the coast.
Where else do the Harbor Seals haul out, how many sites are there and what kinds
of population numbers are at these different sites?
California has at least 1200 sites. Numbers at the sites range from one to one
thousand and average less than 100 per site.
Is the Children’s Pool a necessary location for the breeding habits of the harbor
They breed and pup all along the US west coast and offshore islands.
Where will the Harbor Seals go if they are deterred from the Children’s
Pool by the dredging plan?
They will move to other sites along the coast or at the offshore islands.
Are the numbers of Harbor Seals increasing? What is OSP and what does that mean?
Seals are still increasing. OSP (Optimum Sustainable Population) is a range between
their maximum population growth rate and about 70% of carrying capacity of the
This is thought to be a range where the population is insured of being sustainable
in the current environment, and it is the primary goal of the MMPA for these pinnipeds.
Since there have been documented sightings of different pinnipeds-Sea Lions and
Elephant seals – at the Children’s Pool, is there a chance that in long term use
of this beach that the Sea Lions could actually squat-out the Harbor Seals?
This is a possibility as the sea lion and elephant seal populations continue to grow.
Harbor seals tend to leave a site rather than compete with the other pinnipeds.
Are there any adverse biological issues to be concerned with regarding the seal
feces on the beach especially if the children come down to use the beach?
The major concern should be for transmittal of internal parasites through their feces.
Predation is a concern to many. What predators are currently here and what will
the result be if the Seals continue to stay in a “natural haul out and rookery”
Seals are preyed upon by various species of sharks and killer whales. These predators
will likely be present where seals frequent an area.
Re-habilitated seals from Sea World and other re-hab facilities?
Some of these seals have become accustomed to people during their period of captivity
and may not be as leery of humans as “wild” seals. Other seals might adapt this
If more and more pinnipeds become accustomed to using the La Jolla area as though
it were a natural haul-out, will the excess seals start to use other beaches in the
same way. Could La Jolla Cove become another example of the same situation?
Yes, as they fill up a site they will start to use others.