Sierra
Article also available at: http://www.sierraclub.org/sierra/200405/tidepools.asp
Tidal Attraction
Strange, delicate, and sometimes delicious, tidepool creatures never cease to fascinate–until they’re gone.
by Blair Tindall
In the 1930s, the whir of Monterey’s canneries echoed down desolate shores to Point Pinos, in the neighboring community of Pacific Grove. As the tide receded, John Steinbeck and marine biologist Ed Ricketts would scramble to the water’s edge and peer through a shallow window to the deep.
"When the tide goes out, the little water world becomes quiet and lovely . . . the bottom becomes fantastic with hurrying, fighting, feeding, breeding animals," wrote Steinbeck, immortalizing "Doc" Ricketts and Point Pinos’s "Great Tide Pool" in his novel Cannery Row. Here, pounding surf nourished the band of life at ocean’s edge, where sea foam washed over rocky pockets stuffed with purple urchin spines and plump emerald anemones. Ropes of seaweed lazed in green-gray eddies, translucent lettuce leaves shifted in the current, and iridescent blades shimmered just beneath the surface of pools teeming with limpets, eight-legged crabs, and rosy sea slugs. Spiny orange, pink, and purple sea stars, big as plates, plastered the rocks.
Ricketts resumed his studies whenever the low tide bared seashore life. He also made a business of the bounty, selling tidepool creatures to schools and laboratories. Even so, he recognized that those fragile marine regions–beginning to be understood as ecosystems–could be depleted and destroyed. "We are, alas, no longer in the halcyon days of carefree collecting and unspoiled abundance," wrote Ricketts in 1939. "The life of the seashore was never adapted to withstand the pressure of hordes of people."
Ricketts’s predictions must have sounded odd at the time; tidepooling was not a Depression-era recreation, and save for teenagers prying abalones loose with old car springs, the Monterey peninsula’s rocks were unpeopled. The intertidal zone was an unthreatened, infinite source of life. Jim Willoughby–the son of a 1940s caretaker at Pacific Grove’s Hopkins Marine Station–remembers Ricketts’s pools firsthand, and even Ricketts chatting with his dad about the ocean temperatures he took daily for station scientists. The tidepools on Hopkins’s rocky shore, less than two miles from Point Pinos, were Jim’s action-packed playground, where the boy chased seven-inch crabs and caught blennies in a coffee can. It was a weird world, crammed with strange animals, and it was all his.
Poking through Point Pinos today, Willoughby, now a retired biology teacher, sees a big change. "It still looks like a fairyland, with wonderful clean sand, gravel, and clear water," says Willoughby, who co-chairs the Coalition to Preserve and Restore Point Pinos Tidepools, "but the abundance of invertebrates and fishes is no longer there."
The intertidal zone is where the riches of the ocean are most vulnerable to the creatures of the land. Today, with more than half the U.S. population clustered along the coasts, the sheer number of visitors is placing terrific pressure on tidepools’ delicate structures and complex communities. Whether through careless trampling, avaricious collecting, or wholesale climate change, we’ve risked depleting a treasure chest whose wonders we so recently discovered.
even if Monterey Bay’s tidepools aren’t what they were in 1930, they can still hook any youngster. And they come in droves: On a summer weekend, Point Pinos’s broad mesa blazes with neon buckets as children prowl the water’s edge for surreal creatures. Beneath jumbled boulders, sunlight dapples onto brilliant-red strawberry anemones and dripping volcano barnacles. Two sisters count a lined chiton’s eight armor plates, all spotted with crimson and cream. More discoveries: Striped green shore crabs peek from a stage curtain of feather-boa seaweed, a camouflaged rock louse rests on a dry surface, and a shy octopus’s tentative tentacle creeps around a stone.
"Kids see what a habitat is; they can watch the behavior of predators and herbivores, and talk about cooperative adaptation and natural selection," says Bob Breen, manager of the Fitzgerald Marine Reserve, 60 miles north of Monterey, which hosts 22,000 schoolchildren each year. At the Monterey pools, a woman visiting her parents’ Pacific Grove retreat says, "My kids love to tidepool because they can actually see living things, even touch abalone." A snail crawls across the palm of her one-year-old daughter, who gurgles with delight before the woman gently replaces it in the water.
Not all of Point Pinos’s 97,000 annual visitors are so careful. Some damage is innocent; tiny white Spirorbis snails die on overturned rocks, a toddler strands a brown six-armed sea star far from the water, or a beachcomber pockets silvery abalone shells crusted with live barnacles. In some cases, well-meaning tourists put animals back, but in the wrong place. A delicate, mucus-spinning snail thriving in high "spray" territory will soon perish in the rough wave zone inhabited by hardy bat stars. Even without foraging, trampling demolishes populations of rockweeds, plants with reproductive structures at their tips.
Other damage, however, is more deliberate. At Point Pinos, orange-billed oystercatchers pick at keyhole limpets, but they’re not the only ones looking for a meal. Two men hack at mussel beds with metal paint-scrapers. Toting three plastic grocery bags, they scramble ashore to their car, past a sign–in English, Spanish, and Vietnamese–prohibiting collecting in the Pacific Grove Marine Gardens Fish Refuge. Many world cuisines prize tidepool animals as expensive delicacies, says Bob Van Syoc, an invertebrate biologist at the California Academy of Sciences. French and British cooks favor periwinkle snails, Portuguese chefs parboil the fleshy stalks of gooseneck barnacles, Hawaiians pickle limpets, South Americans broil barnacles’ adductor muscles, and dried sea cucumbers are crumbled as seasoning in France and Japan. A 2001 cookbook on seafood foraging recommends Limpets Klallam, Sweet Fried Kelp Chips, and Neng Kook, a Korean cold seaweed soup. Noting that steamed sea palm is considered a special treat in San Francisco’s Chinatown, the book warns that California prohibits its collection.
On the Fourth of July, a Chanel-clad woman minces across the Point Pinos tidepools, ripping enoughMastocarpus algae from the rocks to fill three one-gallon Ziploc bags. "You cook it, then put the slimy side on your face to purify the skin," she says. Her mother, visiting for the first time from Seoul, displays a double handful of turban snails and a wide smile. "We boil them, then serve them with toothpicks," says the daughter, who admits her snail-collecting is illegal. Even gelatinous green anemones–which otherwise are prey mostly to sea slugs, leather stars, and sea spiders–are apparently delectable. At Fitzgerald Marine Reserve, one couple was caught poaching 72 of them.
Tidepool food foraging can deplete a species. At one Southern California park, owl limpets declined by 23 percent between 1990 and 1995, with survivors measuring 10 percent smaller. "I hear the owl limpet is delicious–tastes like abalone," says Willoughby. "But they morph from male to female as they grow, so harvesting desirable larger specimens wipes out reproductive capacity." Similarly, taking large turban snails leaves only a slow-growing community of tiny juveniles. A sea palm colony can be wiped out by one brief collecting trip, because its spores only disperse short distances. And the scraped mussel colony at Point Pinos may take a decade to restore, says John Pearse, a biology professor at the University of California at Santa Cruz, whose own mussel-study plot took over six years to regenerate.
Though dinner-table poachers risk a $1,000 fine, they’re small fry next to the commercial harvester, says John Ewald, a now-retired warden with the California Department of Fish and Game. While on midnight shore patrol, he trailed a suspect home, and eventually to a freezer that held some 500 abalones–costing a local restaurateur his business and a $25,000 fine. Because overharvesting and shellfish disease have decimated abalone beds since the 1980s, taking even one abalone south of San Francisco has been illegal since 1997. While most respect these restrictions, it’s weekend "starfish violations" that top a warden’s duties. "If every visitor took a sea star home, there would be nothing left," Ewald says, peering at distant boulders through the scope mounted on his car window. Just offshore from where we are parked, sea stars, bat stars, and 21-rayed sunflower stars feed voraciously along the ocean floor, unseen by all but the occasional scuba diver.
A vision of what Point Pinos used to be like–and could be like again, if left to recover–lies 300 miles north along California’s "Lost Coast." Four miles from any road, rocky fingers reach into the frigid, violent Pacific. Three tectonic plates grind together here in the most seismically active spot in the Lower 48, bulldozing tidepool platforms from beneath the ocean floor and carving bluffs with periodic tsunamis. On a lonely shore punctuated by sea lion carcasses, wind shrieks through Punta Gorda’s abandoned lighthouse, and the rare beachcomber thinks twice about turning away from the moody sea to poke at starfish.
Luxuriant seaweed carpets these wild gardens, fertilized by arctic currents. Robust sea stars line surge channels, where water roars over gargantuan anemones. Purple sea urchins rest in vertical condominiums–carved in the soft rock by rasping teeth and spines–and crabs flirt from old holes left vacant. On a high mesa, crustose coralline algae line deep pink pools left behind by ravenous urchins who devour everything else. Out where the waves howl, mussels frost every surface, and gumboot chitons, resembling deflated footballs, are flung across rocks and jammed into crevices.
Yet little more than a decade ago, this ecosystem suffered a fate worse than tourist-mauling when a 7.1 quake heaved its pools nearly a meter in a moment. As the earth fell silent, delicate algae bleached and wilted, barnacles dried, sea urchins languished a foot above water, and mussels sealed themselves with mucus, self-cannibalizing within a month. Seals, weak from eating rotting sea life, hauled out on the crusty white platform to die. But just days after the catastrophe, scientists noticed new organisms colonizing the area, followed in succeeding years by complete restoration. It’s a message of hope to ravaged intertidal communities around the world.
While it’s clear that over-visitation and harvesting are major management problems for California’s tidepools, wardens and rangers are often left scratching their heads over exactly what is allowed and where. The Pacific Grove Marine Gardens Fish Refuge, where fishing is permitted even in the tidepools, is under the jurisdiction of California’s Department of Fish and Game. It’s also subject to rules from the city of Pacific Grove and the Monterey Bay National Marine Sanctuary. For example, Fish and Game regulations allow our Chanel lady 35 snails in unprotected areas. But Pacific Grove would cite her for taking a single shell fragment. Compounding the problem, this refuge is but one stitch in a patchwork of 62 California marine protected areas along 1,100 miles of coast. Of their 5,600 square nautical miles, only 140 enjoy total protection for all species.
Since 1999, California’s Marine Life Protection Act has attempted to iron out this crazy quilt, despite devastating budget cuts and funding shortfalls. The first legislation of its kind, the act created a network of protected areas with common goals, regulations, and administration. The state’s coast was reorganized into seven regions with distinct regulatory classifications, each with its own constituent working group, including professionals from sport and commercial fishing, kelp harvesting, recreational diving and boating, science, education, and environmentalism–people who understand and use ocean resources regularly.
Willoughby’s coalition, which successfully lobbied Pacific Grove to ban most invertebrate collection in the Point Pinos pools, is one example of the grassroots involvement that many feel is key to tidepool preservation. "There are so few wardens and rangers, we appreciate people being our eyes and ears," says Ewald. Tipped off by license plate information from a shoreline observer, Ewald once drove away from a local apartment with hot evidence–a cauldron steaming hundreds of turban snails. The uninvited officer also found 12 abalones hastily crammed between a garbage pail and a Hefty bag. Some 300 volunteer docents make this kind of enforcement possible in Pacific Grove through the sanctuary’s "Bay Net" program. Patrolling Point Pinos in blue jackets, the volunteers also offer educational talks, pamphlets, and gentle guidance on tidepooling etiquette.
Larger marine organizations augment grassroots efforts. At the spectacular Monterey Bay Aquarium, 1.8 million visitors a year get to stroke critters in petting pools. The aquarium’s program teaches respect for marine life, while satisfying some enough to stay out of the wild pools. The staff also leads field training for teachers and rangers. Ninety miles north of Monterey at Fitzgerald Marine Reserve, naturalists experiment with limiting access. At each low tide, rangers cone off 12 square yards, comparing it with an adjacent, trampled plot. Despite nearly 100,000 annual visitors, after four years this reserve’s biodiversity has begun to increase. And the University of California at Santa Cruz has expanded its intertidal monitoring program, which recruits students and volunteers to evaluate the health and stewardship of sites along the state’s rocky central coast.
Human behavior may also be shaking up intertidal communities in more fundamental ways, even in distant refuges where beachcombers never venture. Stanford professor emeritus Chuck Baxter first suspected something amiss when he spied a loneSerpulorbis snail cemented to a rock far north of its usual habitat. Soon, he saw their coiled tubes tangled atop rocks everywhere. "The pools were starting to look an awful lot like Southern California," says Baxter, who recognized the calcareous shell from research in San Diego. There were other clues. Once rare, ragged pink volcano limpets sprouted throughout the lower intertidal, while the Petrolisthes cinctipes crab disappeared. "There used to be a riot of life under the rocks–brittle stars, peanut worms, chitons, flatworms, and sea cucumbers–and it was gone," says Baxter. Since he now found plenty of southerly species instead, Baxter suspected that he was witnessing the effects of global warming, but needed a way to quantify his hunch.
The evidence came in an old doctoral dissertation from Steinbeck’s day. From 1931 to 1933, Stanford student Willis Hewatt counted and observed organisms in pools behind Pacific Grove’s Hopkins Marine Station. At each low tide, he outlined a 108-yard transect, stretching a cord along four brass bolts pounded into the hard rock. First, he scrutinized the uppermost rocks scattered with tiny mollusks and microalgae. Noting distinct "stripes of life," he worked his way to the tunicates, sponges, isopods, and sea stars nestled amid thick brown algae and fine surf grass in the lowest tidepool zone. At that time, marine scientists usually concentrated on one particular species. But Hewatt took a broader view toward understanding the world Ed Ricketts would describe in Between Pacific Tides, his landmark 1939 study of intertidal zonation and ecology.
Some 60 years later, Stanford researcher Rafe Sagarin points out one of Hewatt’s bolts, nestled in the marine station’s dense seaweed canopy. While he was still an undergraduate, Baxter, his advisor, had told him about Hewatt’s study. Changes in tidepool diversity are hard to measure: Small ecosystems a few hundred feet apart differ because of currents, substrate, wave action, and human interaction. But Hewatt’s plot was ideal. Its hard rocks resisted erosion, and no tidepooler had waded through the restricted shore since 1917. Sagarin could draw conclusions by directly comparing his data with Hewatt’s.
Sagarin reanalyzed Hewatt’s plot, measuring his 58,000-animal count against data from 1933. He was amazed by what he saw. "It’s like a shotgun blast," he says. The pools were still richly diverse, with the same number of plants and animals from 1933. They just weren’t the same species: Eight of nine warm-water species increased, while five of eight cold-water ones decreased. Cold-loving ochre sea stars, for example, were being driven north, with sunburst anemones, green urchins, and other southern species taking over. In 60 years, local water temperature had risen 1.3 degrees Fahrenheit year-round, and nearly 4 degrees in the summer. Sagarin, along with Baxter and two other researchers, published the results in Science.
"The strongest pattern is warming," says Sagarin. The study supported Baxter’s hypothesis. "I’m afraid it’s not the kind of thing I’d hoped for," he says. With Hopkins strictly off-limits to tidepoolers, Sagarin believes direct human impact can be ruled out. But at Little Corona del Mar, a site 400 miles south of Point Pinos, scientists cite not only warm-water episodes, but major coastal development, sewage discharge, and human predation–including as many as 15,000 visiting during tidepooling field trips. At Little Corona, substantial declines in rockweeds, brown kelps, predatory sea stars, nudibranchs, and abalones have occurred, according to a University of California, Fullerton, study by Julie Bursek and Dr. Steve Murray.
Back at Pacific Grove, the tide is turning. A sea otter rests in the gentle swells of distant kelp, but frothy surges rush over the lowest tidepool zone. A Bay Net volunteer, teaching tidepool manners and safety, guides a father and son back to shore as a channel floods. On higher ground, a woman from Arizona and her 20-year-old daughter watch (but don’t touch) anemones open like flowers as the pools come to life and then disappear beneath the waves. Sunlight burns down on a swarming pool of sculpins and scurrying hermit crabs flaunting costume-party shells. "I’m surprised we’re allowed out here, what with the deluge of tourists," says the woman, smiling at her daughter. "Someday, you’ll tell your kids you were able to see this."