Article

Story and photos by Allison Titus

April 22, 2014—Tidal pools at the rocky seashore edges are unique ecosystems that are home to some extraordinary creatures. Because of the constant change in the tides and crashing waves, these organisms are anything but wimps. They are highly adapted to this chaotic environment and employ many different interesting survival strategies.

Tidepools are generally found in three subzones of the rocky shore: the supratidal zone, the intertidal zone and the subtidal zone. These zones are characterized by their different exposures to air, the supratidal being barely moistened by sea spray and the subtidal being submerged under saltwater most of the time.

Different creatures have adapted to live within these microecosystems. The supratidal zone is dry, both literally and in tidepool creatures; here you can expect to see mostly mollusks, such as limpets and black turban snails.

However, in the intertidal zone the party begins. This is a very active part of the rocky shore, which is amazing since it’s also the most tumultuous. Twice a day, it’s covered in water, and twice a day, it’s exposed to air, the waves leaving our tidepool destinations in their wake. Here you can expect to find gooseneck and acorn barnacles as well as mussels attached firmly to the rock. You can also observe giant green sea anemones waving their tentacles through the water and spiny purple sea urchins drawing in kelp for food. Sculpins (small, camouflaged fish) dart amongst the rocks at the bottom of the pools. Hermit crabs meander along edges and in the watery depths. Chitons cling firmly to the mudstone of the pools. The honeycombed structures of sandcastle worms line the small rocky cliffs. Sea stars, the predators of the tidepools, are scattered intermittently amongst the rock. Quite a crowd, huh?
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Read Sea Star Disease A Mystery
Read about Natural Bridges State Beach
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The subtidal zone is only accessible during extremely low tides, but if you’re lucky enough to be out there on one of those days, you’re in for a treat. You can see huge sea anenomes and sea stars here more often than in the shallower pools, and large crabs side-stepping along the edges of the holes. It’s the intertidal zone doubled in size.

After that spiel, you’ve no doubt placed “Visit Natural Bridges Tidepools” on your Google calendar for Saturday. What better way to spend your weekend than exploring one of the most interesting and accessible ecosystems in Santa Cruz County? Before embarking on your tidepooling journey, though, we have 10 tips for the expert tidepooler to make the most of your intertidal experience.


1. Check the tides.
This may seem obvious, but there is no better way to ruin a day of tidepooling than to get there and discover all of the pools are underwater. The best time to explore tidepools is during low tide, especially tides under two feet. Check a tide chart or consult with your surfer friends the morning before to plan accordingly.

2. Equip your feet.
This is another often-overlooked tip that can make or break a tidepooling adventure. Because of tidepools’ proximity to the beach, it’s very tempting to wear flip flops on a detour to the rocky intertidal zone. This can result in stubbed toes, unwanted dives into the pools and a general discomfort that can be very distracting. Do your feet a favor, listen to Mom and wear some sturdy footwear on an expedition to the tidepools. Tennis shoes, closed-toed sandals and sport sandals are good choices.

3. Be patient.
This is a little-known strategy employed by the truly wise tidepooler. Find a nice, well-populated pool, position yourself so your shadow doesn’t fall into it and wait for five to 10 minutes. Your initial stomp up to the pool can scare away many of the creatures hiding within. After a few minutes, those shells that you thought were empty may reveal hermit crabs that scuttle across the bottom, or you may see sculpin fish emerge from dark crevices. Good things come to those who wait.

4. Don’t pick up the sea star (or anything, for that matter).
It is extremely tempting to hold up one of the iconic species of the tidepools for a quick iPhone snap. Please tap into your inner steward and resist. The bottoms of sea stars are covered in tiny tube feet that attach them firmly to the rocks, and picking them up often rips these little suction cups off the sea stars. Ouch!

5. Touch gently.
Many of you have likely said this to or heard this as a child, but it is a very important piece of tidepool etiquette. The creatures of the tidepool are very delicate and deserve to be treated with respect: after all, you are ultimately an invader of their intertidal home.

There is also some solid marine biology behind this overused bit of advice. The sticky feel of the sea anemone is actually the defense mechanism of this sea dweller. A sea anemone tentacle contains cells called nematocysts that actually release a tiny harpoon-looking structure into the attacking organism. This barb then injects the prey with venom, which would normally then paralyze the prey so that the sea anemone could move it into its mouth. However, we are too big and our skin too tough to feel the effects of the venom. Touch the anemones gently with one finger to conserve how many of these weapons they release; their supply is not endless, and they need those mechanisms for capturing prey. If they release all of their barbs on trying to fend off your human curiosity, they may not be able to fend off true predators if they approach.

6. Walk the water line.
This tip is is to protect you and the resident organisms of the tidepools. The wet rocks are a good indicator of where waves are crashing, and it is in your best interest to stay safely above the water line to avoid being knocked by a wave into the sharp, mussel-covered rocks or swept out to sea.

7. Explore the nooks and crannies (and overhangs).
The rocky overhangs of many tidepools are often packed with creatures you can’t see from above. Overhangs, crevices and rocks provide welcome shelter from the burning sun, and these areas often stay moist throughout the day. These conditions are ideal for the average tidepool organism. Check behind you, make sure you are a safe distance from the crash zone, lie on your stomach and get on the animals’ level to check these hidden places; you may be rewarded with that pesky sea star sighting that has eluded you all day.

8. You can’t take it with you.
We have all seen hermit crabs sold in mall stores. However, it is not okay to snatch one of the little guys from a tidepool and put it on display in your room. The creatures, plants and rocks from the tidepools need to stay in the tidepools. A tidepool is a fully functioning ecosystem, and a delicately balanced one at that. As a polite tidepool observer, leave the creatures in their home, not yours, and instead come back to visit often.

9. Bring a guide.
Be it a knowledgable person, book, pamphlet or smart phone, there is no better way to enhance your tidepool experience than by asking “What’s that?” and being able to get an answer. Allow your curiosity to roam, pretend to be a naturalist and next time you visit the tidepools, perhaps you can be the guide!

The National Audobon Society Field Guide to California has a great section on marine invertebrates as well as saltwater fishes that covers many organisms found in tidepools around the Monterey Bay area. The KQED Quest website also has a printable version of a guide (it downloads as a PDF) to tidepooling at Natural Bridges specifically, so you can print it beforehand or bookmark it on your phone before you head out.

10. And finally…
Don’t forget to look around! The view of the ocean from the rocky banks is breathtaking. Feel the mist from the ocean crashing into the shore and take a glimpse of the horizon every now and then. You may even spot an otter, sea lion or whale spout if you are lucky!