Urchins, anemones and other assorted sea life abound at this crown jewel of the Norcal coastline

By Kate Bradshaw

A submerged view of a tide pool teaming with sea life at Fitzgerald Marine Reserve, in Moss Beach. (Photo by Rob Cala)

Sea stars that develop a mysterious disease and dissolve without a trace. Mollusks that resist the pull of the tides by clinging to rock using their layers of teeth. Sea slugs that weaponize anemone stingers to shoot at their enemies.

These funky aquatic critters and their adaptations to survive point to a simple precept, which San Mateo County Park Ranger Rob Cala delivers with a smile: “The ocean is brutal. It’s all warfare.”

In this sense, the inherent beauty of the tide pools and the joy of exploring them belies the stark Darwinism at play just below the water’s surface.

But that’s the fun of it.

The mollusks and urchins and other cohabitants of the rock-lined niches of Northern California’s intertidal zone are all part of the colorful cast of characters that reside at Fitzgerald Marine Reserve, a federally-protected sanctuary for sea life along a pristine stretch of coastline in San Mateo County. It provides a unique glimpse into the spectacular — and yes, often brutal — ocean ecosystem, and, as a result, has come to be known to generations of locals and visitors alike as one of the premier tidepooling spots on the California coast.

Curious crustacean: a crab is seen above the waterline during low tide at Fitzgerald Marine Reserve, in Moss Beach. (Photo by Adam Pardee)

Fitzgerald Marine Preserve was established in 1969, and over the course of decades of advocacy by watchdog neighbors, the reserve has attained one of the highest levels of federal protection. Today, it is part of the Montara State Marine Preserve and Pillar Point State Marine Conservation Area.

Since its start, scientists have discovered 25 new invertebrate and plant species there, according to the San Mateo County parks department.

Over the years, the access to and abundance of sea life readily on display during low tide makes the reserve a prime destination for tourists, nature lovers and local science classes anxious to see the teeming-with-life tide pools.

Visitors view the inhabitants of tide pool this past spring at Fitzgerald Marine Reserve. (Photo by Adam Pardee)

In addition to the regular inhabitants of crabs, anemone and sea stars, sometimes the tide washes up new surprises. Cala says that rare species, like the leatherback turtle, lancetfish, pacific octopus and monkeyface eel have made appearances at Fitzgerald’s tide pools.

“You never know what the ocean will deposit,” he explains.

The reserve’s popularity means that it can routinely attract upwards of a thousand visitors on weekend days. For the small staff tasked with preserving the mission of the place — to offer protection for the marine life that survives there and provide education for the humans who visit it — it can be challenging when some visitors seem to have trouble reading signs and following directions.

The tidal zone is a delicate environment even without human interference, Cala says. That’s why the rangers have a pretty strong no-nonsense policy when it comes to rule enforcement.

The rules can seem strict, he admits — albeit common-sensical — compared to more recreationally-focused beaches. No collecting sea creatures. No crossing into demarcated territory designated for the local colony of harbor seals.

A young harbor seal pup in the water near the beach at Fitzgerald Marine Reseve. (Image by Rob Cala)

And no dogs. Especially no dogs. Just this past April, a dog escaped from its owners, swam into the reef and reached an outcropping of rocks where it attacked and killed a harbor seal. The dog’s owner is now being prosecuted by the National Oceanic and Atmospheric Administration, a federal agency.

Over time, the small cadre of rangers at Fitzgerald have imbued the place with a staunch DIY ethos, acting as Jacks and Jills-of-all-trades, as comfortable wielding a chainsaw to maintain trails as pointing out signs of tidal life to bright-eyed, curious kids (and adults). In recent years, the rangers, frustrated with operating out of a tiny hut of an office, applied for a San Mateo County Measure A Grant for funding and built themselves a new rangers’ office. They converted the old hut into a museum, which features a collection of sea life curios and an impressive series of marine life videos that Cala has produced, drawing on his background in video production.

An assortment of underwater organisms found at Fitzgerald, including (clockwise from top) a jelly fish, sea anemone and sea star. (Photos by Rob Cala)

The rangers are helped in their educational efforts by a robust and eager cohort of volunteers culled from the Friends of Fitzgerald Marine Reserve group. On a recent afternoon at the reserve, nearby resident Mary Larenas carries her long hair and soft-spoken demeanor with a set of magnifying binoculars. She eagerly demonstrates how the binoculars can magnify a bee on a flower closely enough to see its legs gum up with pollen. She suggests to Cala the reserve buy some and set them up to enable visitors an intricate glimpse of life in the tide pools.

Larenas says that as a volunteer, she’s given tours to a range of student groups and has seen the place bring out the inner kid in just about everyone. One was a group of kids from East Palo Alto, some of whom had never been to the ocean before, and started out acting tough and indifferent to what the reserve had to offer. By the end, their barriers had come down, and they were visibly in awe of the ocean, impressed by its majesty.

The view of the coastline southward from atop the bluffs at Fitzgerald Marine Reserve. (Photo by Charles Russo)

Another key part of the experience of Fitzgerald are the bluffs overlooking the tide pools, which provide stunning views of both the coastline and the seals. From the parking lot, there’s a side trail that’ll take you up to some gorgeous vistas likely to trigger a degree of déjà vu — since the site has been photographed extensively. The first bluff along the trail was featured in the film adaptation of “Memoirs of a Geisha,” Cala notes.

Proceed apace and you’ll find yourself atop a clearing shaded by a neat row of cypress trees. The trees were likely planted in the late 1800s, according to Cala. Farther back in history, the clearing was once home to middens, or Native American dumping grounds, he adds.

The very photogenic cypress grove at Fitzgerald Reserve. (Photo by Charles Russo)

If you look closely, you’ll see that some of the cypress trees have an orangish substance growing on them. That, Cala says, is a type of marine algae called trentepohlia that gets the water it needs from the moist air. In the right light, the algae makes the trees look like they’re on fire.

In a more reflective moment, Cala speaks about the place with a sense of wonder and reverence — places where rivers meet the sea, like this juncture between San Vicente Creek and the Pacific Ocean, have an air of magic about them, he asserts.

“This place has a special energy. You have to respect it,” he says.

The sea star population has made a comeback in recent years after suffering from “wasting syndrome” which caused the creatures to lose limbs and mysteriously disintegrate. (Photo by Rob Cala)

What to look for

At low tide, walk past the beach and onto the cragged, pocked rocks, and take a peek at some of the marine flora and fauna that live in this rugged environment.

Sea star

Once the mascot of tide pools, nowadays, sea stars are rare finds — due mainly to a tragic disease that decimated the population in 2013. Over the course of just a couple of weeks that year, Cala said, the reserve’s population of sea stars was ravaged by a mysterious illness, called sea star wasting disease, which caused the sea stars’ limbs to fall off and disintegrate. The 24-armed sunflower sea star hasn’t been seen at the marine reserve since, Cala said.

Most recently, there have been positive signs that the sea star population is in recovery — a recent study found that an accelerated natural selection process has yielded more disease-resistant starfish offspring, and that they have begun to appear in growing numbers along California’s coast.

A marine mollusk that looks like the ocean’s take on the “roly poly” or pill bug.

Tar spot algae

This algae grows on rocks. When wet, it gets VERY slippery, Cala says. Visitors should take care when walking over rocks not to slip on this slick stuff.

Closeup of a spiny sea urchin found near the Mavericks surf break immediatley south of Fitzgerald Marine Reserve. (Photo by Charles Russo)

Sea urchins

Also known as “sea hedgehogs,” the sea urchin has a globular shape, is covered with spines and possesses a unique, symmetrical anatomy. Its mouth, which has five teeth, is at the bottom in an organ called “Aristotle’s Lantern.”

Irradia kelp

Irradia kelp have thin fronds that shine with an almost oily, iridescent gloss through the water.

Rock-boring clams

Spy a rock punctured with round holes? That’s probably the work of rock boring clams, which live in holes they carve out of the soft coastal stone, Cala says. The rocks’ softness along the coastal bluffs makes the area particularly prone to erosion.

A brightly colored nudibranchs seen in a Fitzgerald Reserve tide pool. (Photo by Rob Cala)


The fancy word for sea slugs, nudibranchs are essentially soft-bodied or unshelled sea snails. One variant, the Hopkins’ Rose nudibranch, comes in a vibrant pink hue and is endemic to Southern California. In recent years, it has been spotted farther and farther up the California coast — a clarion, some scientists say, of warming waters and shifting oceanic conditions. According to Bay Nature, these slugs have teeth shaped like crochet hooks and get their color from their diet of microscopic pink bryozoan zooids.

Nudibranchs sometimes feed on animals with stingers, like jellyfish and sea anemone. In the process, they take on the stingers as part of their own armor, and discharge them when attacked.

Coralline algae

This form of algae contains calcium carbonate, which gives it a “bony” appearance, especially as it turns white when it is dried. Underwater, its pinkish hue makes it look like coral.

Lounging harbor seals as seen from atop the bluffs at Fitzgerald Marine Reserve. Access to the section of the beach where the seals congregate is typically cordoned off by rangers. (Photo by Charles Russo)

Harbor seals

These marine mammals don’t live in the tide pools exactly, but the Fitzgerald Marine Reserve beach is home to a year-round colony of about 250 harbor seals. During the spring, the seals “haul out” of the water at the beach to birth and raise their pups — about 80 pups were born this year. The pups are especially vulnerable typically between March and June as they grow bigger along the shore. Visitors must keep away from the pups, Cala says, because if a mother seal thinks her baby seal has been disturbed by a human, she may abandon it. The beach is clearly marked with cones telling visitors where the boundaries are. It’s best, Cala says, to “stay back and let them do their thing.” The reserve also has a partnership with the Marine Mammal Center in Sausalito, where hurt or abandoned seals are rehabilitated.

Explorers of all ages investigating the tide pools at Fitzgerald Marine Reserve. (Photo by Adam Pardee)

Tips for Visiting

Visitors should plan to come to the tide pools at the lowest tide of the day, ideally when the low tide is at one foot or less, according to Friends of the Fitzgerald Marine Reserve. Daily tide reports are available here. The park opens daily at 8 a.m. and closes at different times, depending on the season.

To make a day of a visit to the reserve, Cala recommends taking a walk along the beach at a negative tide and then along the bluffs about a mile and a half to Pillar Point Harbor, where you can see the famous Maverick surf breaks, which are some of the biggest in the country.

For food, there’s the Moss Beach Distillery (140 Beach Way, Moss Beach), which offers waterfront dining in walking distance of the reserve. For more casual options, he recommends heading north to Gherkin’s Sandwich Shop (171 7th St. in Montara), or south to the popular Ketch Joanne at Pillar Point Harbor (17 Johnson Pier, Half Moon Bay.)

A vibrantly colored sea anemone seen just below the waterline at Fitzgerald Marine Reserve. (Photo by Rob Cala)

What time of year is best? Cala says there’s really no wrong time to plan a trip. The tidepools are at their most vibrant in the winter, he says, while spring offers sights of seal pups. Regardless, visitors should assume fickle coastal weather and dress accordingly, in layers.

A harbor seal pokes its head above water near Pillar Point Harbor in El Granda, just south of the marine reserve. (Photo by Charles Russo)

Visitors are also advised to keep some rules in mind: do not disturb or remove plants or animals, do not fish and stay at least 300 feet from all marine mammals. No dogs are allowed.

Groups of 10 or more must make reservations in advance for a docent-led tour. Call (650) 363–4021 for reservations or (650) 363–4020 for more information.

James V. Fitzgerald Marine Reserve | 200 Nevada Ave., Moss Beach, CA 94038

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