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Our region is pretty legendary for its extensive open spaces with breathtaking views. I like feeling like a tiny speck in a vast, natural universe. However, it’s also neat to marvel at the itty-bitty wonders of nature. Tidepooling is a fun activity that invites you to crouch down and observe some fascinating sea creatures up close. In rocky areas along the coast, you’ll find entire worlds in shallow, isolated pockets of saltwater.
In this blog, you’ll find tips to make your tidepooling experience a splash, as well as a lineup of tidepool dwellers you’ll likely encounter in these unique habitats. Let’s get our feet wet and explore!
Be sure to head out to the tidepools during low tide. Specifically, tides should be between -1.0 feet and -1.4 feet — you can find the right time for these water levels by checking tide charts for your location. Our favorite website to do so is the aptly named TideCharts.
Just because it’s low-tide doesn’t mean tidepool conditions will be perfect — you should also consider the weather and ocean conditions. Rain can be a danger, especially if rocky surfaces become slick. You should always check in with the National Weather Service’s Bay Area page for warnings about swells, high wind, and beach flooding before heading out.
You don’t need very much equipment to enjoy the tidepools, but it’s important to wear appropriate gear. Try to wear shoes with treads on the bottom to give you traction and prevent slipping and falling. Waterproof shoes are ideal, since they’re likely to get a little wet. Other than that, all you need are your own senses and a camera if you want to document the critters you see! It can also be nice to bring a friend.
Remember that the tidepools are sensitive ecosystems, and that disrupting their flow can be harmful to the living creatures within them. These organisms are delicate and vulnerable, so while you look at them, remember never touch the plants and animals, and please don’t ever remove or take anything with you from the tidepools.
There’s a long list of living beings you might find in a tidepool, but some oceanic inhabitants are shyer than others. Here’s a list of five fascinating tidepool dwellers that are more likely than others to make an appearance, complete with a lineup of fun facts and our recommendations about where to find them.
Did you know that anemones, due to their bright color and flashy forms, were named after a blossom? It’s true! Often found nestled into the curves of a tidepool, sea anemones take after their equally stunning terrestrial counterpart, the anemone flower. And their look-alike status makes sense — sea anemones have a cylindrical central body encircled by petal-like tentacles. With over 1,000 species of anemone, their vast array of colors cover all the hues of the rainbow. Sizes vary too, ranging from half an inch to six feet! In tidepools, you’ll be more likely to catch the smaller kinds, but even these boast flashes of color. But be warned, it’s better to keep your hands away from sea anemones. Some species have stinging cells in their tentacles — after all, they’re part of the Cnidaria phylum, whose other notable member is the jellyfish.
Bean Hollow State Beach in Pescadero is a reliable destination to see a full lineup of tide pool critters. Chances of getting a good glimpse at an anemone here are high.
“Starfish” is out, “sea star” is in! Marine scientists have attempted to “re-name” this beloved sea creature, because, shocking as it may be, the “starfish” is not a fish. But regardless of what you call it, it’s hard not to be charmed by this five-armed echinoderm. With calcified skin that is bony for protective reasons, sea stars are known for their array of vibrant colors. In some cases, the coloring is for camouflage, but the dramatic brights can also be a tactic to scare off a predator! Though we often perceive them as cute, the sea star is a formidable predator itself. To feed, the sea star’s stomach emerges from their mouth, envelops prey and begins to digest it outside of its body. Still cute? Well, at least it’s interesting. Fun fact — while five arms is the most common sea star configuration, alternate varieties exist, including those with 10 arms, 20, and even 40!
Of all the tidepool creatures, sea stars are more difficult to spot. Though they frequent tide pools, they tend to prefer deeper waters — sometimes even the cold, hard ocean floor! However, sea star sightings are fairly common at tidepools in Half Moon Bay, so if a sea star is who you most want to see, we recommend Fitzgerald Marine Reserve.
Of all the flamboyant critters crawling through the tidepool crevices, the nudibranch may be the most eye-catching of all – and perhaps the most elusive. These shell-free mollusks are part of the sea slug family, but there’s so much more to them than their slime. Their jelly-like bodies take on many forms, hues, and patterns. With more than 2,000 known species of nudibranch (and even more being discovered!), there’s a seemingly endless range of nudibranch appearances. Some may have spots and others stripes. Some have spike-like protrusions all over their body and some are entirely smooth! Check out some examples of nudibranch species who reside in California here. Remember, you’re most likely to see them at extremely low tide. So if you’re bent on seeing a nudibranch, plan your tidepooling journey accordingly!
Privates Beach, Santa Cruz — At low tide, the tidepools of Privates Beach are bristling with activity. Nudibranchs are known to have been spotted here, so it’s a good bet to explore this place if it’s them you’re seeking out.
Barnacles may not be the cutest denizens of the sea, but beneath their crusty outward appearance, we find a fascinating and determined crustacean! Known for sticking to the sides of ships, tops of whales, and the contours of rocky shores, barnacles are admirable for their tenacity. They secrete a cement-like substance that works as a powerful natural glue (so powerful that scientists have studied how to use this glue commercially!). Once they’ve chosen a place to stick themselves, they feed through a feather-like appendage called a cirri. It emerges from the top of the barnacle and feels around for microscopic organisms. Coarse calcium plates cover the barnacle’s exterior, protecting it from threats. There are more than 1,400 species of barnacles, but the most common type is the acorn barnacle.
You’re practically guaranteed to find barnacles on any solid surface that gets covered by ocean water, so the chances of spotting them are highest at rockier beaches. We recommend visiting China Beach in San Francisco.
Hermit crabs are an especially crafty crustacean. If you see these critters scampering across the rocks of tidepools, you’ll notice that their shells may cover a vast range of shape, size, and color. That’s because hermit crabs don’t grow their own shells — they find discarded shells of other creatures and use them second-hand (or second claw?). Hermit crabs are technically not true crabs. They lack the hard exoskeleton that keeps other crabs protected on the outside. Instead, they have a hard exoskeleton in front, and a soft skinned tail. Thus, they need extra protection. Though there are over 800 kinds of hermit crabs, the most common in our region are blueband hermit crabs, named for their bright blue stripes on their legs. Despite being called hermits, they’re actually known to travel in groups — so keep your eye out for a clique of these inch-long scuttlers!
Robert W. Crown Memorial Park in Alameda is host to Crab Cove at its northern end. This area is a protected marine reserve, and a good place to search for hermit crabs as well as other tide pool crustaceans.
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Tidepools remind us that amazing, complex ecosystems are found in all corners of our world. They’re a great chance to get an up-close view of some amazing creatures. Just remember, look but don’t touch!
Peninsula Open Space Trust (POST) protects open space on the Peninsula and in the South Bay for the benefit of all. Since its founding in 1977, POST has been responsible for saving more than 89,000 acres as permanently protected land in San Mateo, Santa Clara and Santa Cruz counties. Learn more
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