The Rocky Intertidal Zone

 

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Several people walk on a sandy beach and sandstone cliff near the edge of a large body of water. White waves roll into scattered textured rocks along the beach.

NPS Photo / Dan Zeller

 

The rocky intertidal area, also known as the tidepools, is a favorite spot at Cabrillo National Monument. Each year over 200,000 people visit the tidepools, one of the best protected rocky intertidal areas in California. The best time to visit the tidepools is during the fall and winter months, when we get our great low tides during park hours. During spring and summer, the tide is usually covering the tidepools when the park is open. Please read Prepare for Your Visit to the Tidepools and Protecting the Tidepools before your visit so you will be aware of what to expect.

 
A variety of visitors walking and exploring the tidepools with brown sandstone cliffs in the background
Visitors exploring the tidepools at low tide.

NPS Photo/D. Wieder

 

When is the Best Time to Visit the Tidepools?

Late fall and winter are the optimum times for a visit to the tidepools at Cabrillo National Monument: unlike the summer months, when low tides occur in the middle of the night, the good low tides - including the outstanding negative low tides - in fall and winter occur during daylight hours when the park is open. A general rule of thumb is that the tidepools can be visited approximately two hours before low tide time (when the tide is receding) and two hours after (when the tide is coming back in). Please keep in mind that the tidepool area closes at 4:30 p.m.

You can find information about the low tides at Cabrillo National Monument from the chart below, or from the following links from the Scripps Pier Webcam (courtesy of Ed Parnell at Scripps) which show the tide charts for 2020.

Please note that the following charts are predictions for the Scripps Pier in La Jolla. Tide predictions are based on the charts you are using. They should all be used as guidelines.

2020 Tide Charts
2021 Tide Charts
2022 Tide Charts

 
2020 Aug Tides
 

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It’s Summer! Time To Hit Up The Tidepools, Right?

Well, yes and no. You can still visit our tidepool areas in the summertime, but you might not see too many tidepool creatures! Extreme low tides in the summertime happen in the middle of the night, making it impossible to see without any sunlight. Extreme low tides in the winter tend to happen in daylight hours! This means your best chance to see critters out and about in the tidepools is in the wintertime. While we still have low tides during the summertime, they are generally still too high for us to be able to see much else besides water. At Cabrillo, a 0.7 tide or lower will give you the best ability to explore the actual tidepools.

Don’t fret! You can still explore the coastal area along the tidepools in the summer and enjoy the beautiful ocean views and blooming flowers along the Coastal Trail. Just save the tidepool critter searches for the winter.

Keep in mind that parking can fill up on the weekends at the tidepools. If parking fills up, Park Rangers will start to manage the road for ease of traffic. Simply come back towards the middle or end of your visit to Cabrillo National Monument to see if there is parking available. Another option: come early to avoid any crowds! The park opens at 9 am every day.

 
 
 
Boots in the Tidepools

  • Please be aware that cell phone service is not available at the tidepools. If you use a driver for hire for transportation, make arrangements to pick you up at a certain time and location. Otherwise you will not be able to reach anyone, and you may have to hike up the road to the top of the park.

  • The road to the tidepools may be closed if the area hits capacity in order to maintain conditions appropriate for social distancing. The road to the tidepool area will be closed (usually around 30 minutes) until sufficient capacity in the parking areas becomes available. This temporary closure of the road allows for traffic to flow freely and allows a more pleasant experience for the visitor by reducing the number of people and reducing the damage to the fragile ecosystem. Please plan your trips to allow for this delay, and thank you for your patience.

  • A vehicle is the best way to get to the lower area of the park where the tidepools are located; once parked, it's a short walk and scramble down into the tidepools. We discourage visitors from walking down Cabrillo Road for safety reasons. The road is narrow without shoulders and drivers may not see you.

  • Please plan for appropriate clothing and footwear. Shoes with good gripping soles are best, as rocky areas become slippery with water and algae. Closed toe shoes are recommended. Sandals or flip flops are strongly discouraged due to their inability to provide a good grip on the slippery rocks.

  • Please keep small children close - a child's enthusiasm and excitement over being in this natural wonderland can quickly translate into a slip or tumble.

Tidepool Permit May Be Required

In order to protect this distinct and delicate ecosystem, Tidepool Permits are required for groups of ten or more to visit the tidepools at Cabrillo National Monument during low tides of 0.7' and lower. If your group numbers less than ten, no permit is required.

Tidepool Permits

 

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Protecting the Tidepools

To ensure that current and future visitors experience and enjoy the healthy and diverse tidepools at Cabrillo National Monument, guidelines are needed to minimize the human impacts on organisms. To protect tidepool inhabitants, the following guidelines have been prepared:

Collection of any natural item, including living and dead organisms, shells or rocks, is strictly prohibited in any areas within or under the administration of Cabrillo National Monument. Similarly, approaching or engaging with any marine mammal is prohibited by the Marine Mammal Protection Act.

Many tidepool animals can be safely touched as long as it is done with great care and respect. A general guideline is to only touch animals as gently as you would touch your own eyeball. For example, anemones should not be poked and sea hares should not be squeezed.

No organism attached to a surface should be removed by force, however slight. Many animals, such as limpets, chitons, barnacles, mussels, seastars, and urchins are attached directly to rocks (permanently or temporarily) and using force to remove them would be harmful to them.

Animals that are actively swimming, moving away from people, hiding under rocks, or that resist being handled, should not be pursued or picked up.

Rocks should not be moved and should be left in their original location and orientation. Organisms living under the rocks have adapted to a certain environment, and rock-turning can harm them.

Nothing, especially rocks, should be thrown in any area of the park. Rocks can do great damage when they land in the water, and continue to do damage as they are tossed by wave action.

The following should not be introduced into the tidepool area: Containers (such as buckets or cups); nets, scraping, probing, or prying instruments (such as spatulas, trowels, knives, screwdrivers or sticks).

With your help, the tidepools at Cabrillo National Monument will remain a healthy environment for marine life, and will continue to be a prime example of this precious ecosystem for generations to come.

 

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What is a Tidepool?

Tidepools are depressions in rocks that are formed over millions of years through a combination of biological, physical, and chemical processes. Tidepools need a rocky coastline to form. As the tide goes from high to low, pools of water are left behind among the rocks, forming tidepools. As the water moves away from the shoreline during a low tide, water and critters are trapped in these tidepools.

 
The tidepool area covered with the ocean during a high tide with the sandstone cliffs rising above the water
High tide at the tidepools

NPS Photo

 
The tidepool area uncovered with the ocean receding during a low tide.
Low tide at the tidepools

NPS Photo

 

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Zonation

The tidepool area at Cabrillo is divided into several zones, where different types of animals and plants struggle to live. Depending on the height of the tide, some of these zones may not be visible. These zones are called the High, Middle, and Low zones.

 
A graph with a diagonal line from upper left to bottom right showing the different zones (high, middle and low) in relation to the shoreline at the top
The different intertidal zones relative to the shoreline

NPS

 
A photo of a low tide with the high middle and low intertidal zones labeled
An example of the different intertidal zone locations in the tidepools

NPS Photo

 

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High Zone

The high or splash zone is located at the highest part of the tidepools. Here some animals can live with just the occasional splash from the high tides. Some of the animals you can find in the high zone are barnacles, limpets, chitons, crabs and mussels.

Take a closer look as you notice things on the rocks. Some of these creatures look dead or like fossils but they are all alive, trying to survive until the tide rolls back in. Please do not try to remove anything from the rocks as this will disturb or possibly kill the animals.

 
 

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Middle Zone

The middle zone is the zone between the high and low zones. There is an opportunity to see more critters in this zone compared to the high zone, due to the varying tides.

Some of the animals found here are anemones, keyhole limpets, Black tegula snails, Kellet’s whelks and Sandcastle worms. In this zone you can find surf grass, the only true plant in the tidepools, as well as some algae such as sponge weed, kelps and red algae.

 
A photo collage of 3 rows and 3 columns with tidepool animals found in the middle intertidal zone.
An example of tidepool animals found in the middle intertidal zone. Top row: Solitary Sea anemone, Brooding anemone, Kellet's whlek. Middle row: Black tegula snails,Giant keyhole limpet, Sandcastle worms. Bottom row: Aggregating anemones, Scaly tube snail, Dead Man's fingers.

NPS Photos

 

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Low Zone

The lower zone is only available during the lowest of tides. Here you have the chance to find octopus, sea stars, nudibranchs, sea hares, spiny lobsters, urchins and various types of fish.

 
A photo collage of 3 rows and 3 columns with tidepool animals found in the lower intertidal zone.
An example of animals found in the lower zone in the tidepools. Top row: Two spot octopus, Knobby sea star, Bat star. Middle row: Spanish shawl nudibranch, Black sea hare, Wooly sculpin. Bottom row: Hopkins rose nudibranch, Purple sea urchin, Spiny lobster.

NPS Photos

 

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Other Tidepool Features and Resources

The tidepools are more than just the critters you can find in the water and between rocks. You can also learn about the geology that helped create the intertidal area that we see today. You can also learn about types of seaweeds, mammals, birds, plants, reptiles and the kelp forests that you might see along the Coastal trail.

We encourage you to read about what to expect as well as the rules for exploring the tidepools before you visit. You can also access our Life in the Intertidal Zone and the Intertidal Field Guide.

 

Last updated: August 11, 2020

Contact the Park

Mailing Address:

1800 Cabrillo Memorial Drive
San Diego, CA 92106

Phone:

(619) 523-4285

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