Editor's note: The next king tide in the Santa Cruz area takes place on Friday, Feb. 9. Tide pool viewing will be extra-good from Wednesday through the weekend. Learn more from Visit Santa Cruz.
By Liz Broughton
Jan. 30, 2024—As the tide goes in and out along our coast, unseen worlds are revealed, home to some otherworldly creatures. From bright giant green anemones to slimy iridescent kelp and rough orange bat stars, tide pool life is a colorful and complex ecosystem.
A tide pool is an isolated pocket of seawater found in the ocean’s intertidal zone, and Santa Cruz County has numerous locations you can explore, from Capitola to further up the coast by Natural Bridges and Wilder Ranch. Depending on the season, the time of day and the tides themselves, what you can observe in our local tide pools is ever-changing.
In the intertidal zone, life is arranged vertically depending upon organisms’ abilities to compete for space, avoid predators from above and below, and resist drying out. This community is adapted to extreme conditions in tide pools, where the temperature, oxygen content, salinity, and water levels are constantly in flux.
Tide pools contain tremendous diversity and are important and delicate ecosystems. They are also important to larger ocean creatures as both a source of food and as a nursery for young animals.
In recent years, scientists have observed that global rises in ocean temperatures have caused the conditions in tide pools to change rapidly, and their inhabitants must quickly adapt, or risk dying off. Warmer waters can lead to bacterial growth that, for example, caused the devastating seastar wasting disease of 2013.
Increased amounts of CO2 in our atmosphere is driving the acidification of the ocean. This in turn leads to dissolving shells for creatures like snails and bivalves, weakening their built-in protection from predators. Changing conditions in our coastal environment has already caused some tide pool creatures to move, either further north to cooler waters, or higher up the tideline, often throwing off the delicate balance of ecosystems.
The Science of Tides
Tides are one of the most reliable phenomena in the world, partially because they are dependent upon astronomical systems that are also fairly reliable, like the sun and the moon. Every new and full moon, we experience “spring tides,” a term which has nothing to do with the season and is more about the tides “springing” back and forth between higher highs and lower lows. When these spring tides are especially high or low, they’re often called “king tides.”
King tides are an important indicator of what sea level rise will do to our coastline. According to NOAA, “Sea level rise will make today’s king tides become the future’s everyday tides.” For our coastal communities, king tides often mean water overwhelms inadequate infrastructure or intrudes where floods had not historically occurred.
Higher high tides, in combination with winter storms, have also increased erosion of the coastline, as we saw with West Cliff Drive in early 2023. A Scripps Institution of Oceanography study found that California waves have grown, on average, a foot taller in the last 50 years, which may at least be exciting for surfers looking to catch big waves. Given this outlook, humans and tide pool residents alike, will have to contend with what the future holds for the California coastline.
Tide Pooling as a Naturalist
The Monterey Bay has long fascinated residents who sought to understand and protect this fragile ecosystem. Early Santa Cruz Lighthouse keeper, Laura Hecox, grew up exploring the tide pools below Lighthouse Point and her collection of shells and other curios led to the formation of the city’s first public museum, what is today the Santa Cruz Museum of Natural History.
In her honor, the museum has exhibited an intertidal touch pool since the 1970s, introducing generations of visitors to some of the common species that can be observed in our local tide pools. For those who are new to tide pools or who have barriers to accessing tide pools out in nature, this exhibit is a wonderful way to connect with a local habitat and its residents.
The intertidal zone is a window into the ocean, rich with opportunities to hone the observational skills any naturalist needs. Go to the tidepools at different points in the tidal cycle and record what you see in the pools, but also what larger animals are present and where. To record your findings, consider starting a field journal, use an app like iNaturalist, or start your own phenology wheel to make note of changes over time. Early naturalists and scientists like Ed Ricketts started in just the same way — making observations of a single habitat over time, you never know what you might discover!
While intertidal explorations are one of the many perks of living in or visiting Santa Cruz, it’s also our responsibility to protect this critical ecosystem. Good tide pool etiquette means we should make as little of an impact as possible:
- Watch where you step — not only are rocky surfaces slippery, they’re also often covered in living organisms.
- Touch gently — If you must touch something, do so carefully. Moving rocks or seaweed should also be done with care and put back how you found them.
- Don’t take anything home — while some seaweeds can be foraged in small amounts, it is illegal to collect any living marine creatures from the coast without a permit. Remember that Monterey Bay is a marine sanctuary!
As John Steinbeck once wrote in his book The Sea of Cortez, “It is advisable to look from the tide pool to the stars and then back to the tide pool again,” meaning we are all connected, to each other and to the many ecosystems around the world.
Here on the Central Coast we are so lucky to have tide pools ready and available for us to explore, to learn from, and to connect us with the ocean. Tide pools are a great example of resilience and adaptability to change, but they also remind us that the world’s ecosystems exist in a delicate balance and they need our help.
To learn more about marine ecosystems and to touch some tide pool creatures, visit the Santa Cruz Museum of Natural History, an independent nonprofit organization that has been bringing the delights and wonders of the natural world to life for locals and visitors alike since 1905. The Museum regularly hosts tide pool walks for its members and the general public—visit their website to learn more about their upcoming events.
Liz Broughton is the Visitor Experience Manager at the Santa Cruz Museum of Natural History.
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