Tide pool

Tide pools or rock pools are shallow pools of seawater that form on the rocky intertidal shore. Many of these pools exist as separate bodies of water only at low tide.

Many tide pools are habitats of especially adaptable animals that have engaged the attention of naturalists and marine biologists, as well as philosophical essayists: John Steinbeck wrote in The Log from the Sea of Cortez, "It is advisable to look from the tide pool to the stars and then back to the tide pool."[1]

Tide pools in santa cruz
The site of a tide pool in Santa Cruz, California showing sea stars, sea anemones, and sea sponges.
Porto Covo February 2009-2
A tide pool in Porto Covo, west coast of Portugal

Zones from shallow to deep

Tide pools in Santa Cruz from Spray-splash zone to low tide zone
Tide pools in Santa Cruz, California from spray/splash zone to low tide zone

Tidal pools exist in the intertidal zones. These zones are submerged by the sea at high tides and during storms, and may receive spray from wave action. At other times the rocks may undergo other extreme conditions, baking in the sun or exposed to cold winds. Few organisms can survive such harsh conditions. Lichens and barnacles live in this region.[1] In this zone, different barnacle species live at very tightly constrained elevations. Tidal conditions precisely determine the exact height of an assemblage relative to sea level.

The intertidal zone is periodically exposed to sun and wind, which desiccate barnacles, which need to be well adapted to water loss. Their calcite shells are impermeable, and they possess two plates which they slide across their mouth opening when not feeding. These plates also protect against predation.[2]

High tide zone

The high tide zone is flooded during each high tide. Organisms must survive wave action, currents, and exposure to the sun. This zone is predominantly inhabited by seaweed and invertebrates, such as sea anemones, starfish, chitons, crabs, green algae, and mussels. Marine algae provide shelter for nudibranches and hermit crabs. The same waves and currents that make life in the high tide zone difficult bring food to filter feeders and other intertidal organisms.

Pteropurpura trialata is laying the eggs 1
Low tide zone in a tide pool

Low tide zone

Also called the lower littoral zone. This area is mostly submerged and is exposed only during unusually low tide. Often it teems with life and has much more marine vegetation, especially seaweeds. There is also greater biodiversity. Organisms in this zone do not have to be as well adapted to drying out and temperature extremes. Low tide zone organisms include abalone, anemones, brown seaweed, chitons, crabs, green algae, hydroids, isopods, limpets, mussels, and sometimes even small vertebrates such as fish. These creatures can grow to larger sizes because there is more available energy and better water coverage: the water is shallow enough to allow more sunlight for photosynthetic activity, and the salinity is at almost normal levels. This area is also relatively protected from large predators because of the wave action and shallow water.


Tide pools provide a home for hardy organisms such as starfish, mussels and clams. Inhabitants must be able to deal with a frequently changing environment — fluctuations in water temperature, salinity, and oxygen content. Hazards include waves, strong currents, exposure to midday sun and predators.

Waves can dislodge mussels and draw them out to sea. Gulls pick up and drop sea urchins to break them open. Starfish prey on mussels and are eaten by gulls themselves. Even black bears sometimes feast on intertidal creatures at low tide.[3] Although tide pool organisms must avoid getting washed away into the ocean, drying up in the sun, or getting eaten, they depend on the tide pool's constant changes for food.[1]


The sea anemone Anthopleura elegantissima reproduces clones of itself through a process of longitudinal fission, in which the animal splits into two parts along its length.[4] The sea anemone Anthopleura sola often engages in territorial fights. The white tentacles (acrorhagi), which contain stinging cells, are for fighting. The sea anemones sting each other repeatedly until one moves.[5]

Some species of starfish can regenerate lost arms. Most species must retain an intact central part of the body to be able to regenerate, but a few can regrow from a single ray. The regeneration of these stars is possible because the vital organs are in the arms.[6]


Sea palms look similar to palm trees. They live in the middle to upper intertidal zones in areas with greater wave action. High wave action may increase nutrient availability and moves the blades of the thallus, allowing more sunlight to reach the organism so that it can photosynthesize. In addition, the constant wave action removes competitors, such as the mussel species Mytilus californianus.

Recent studies have shown that Postelsia grows in greater numbers when such competition exists — a control group with no competition produced fewer offspring than an experimental group with mussels; from this it is thought that the mussels provide protection for the developing gametophytes.[7] Alternatively, the mussels may prevent the growth of competing algae such as Corallina or Halosaccion, allowing Postelsia to grow freely after wave action removes the mussels.[8]

Anthopleura sola is consuming Velella velella

A large sea anemone (Anthopleura sola) consuming a "by-the-wind-sailor" (Velella velella), a blue hydrozoan

Postelsia palmaeformis 2

Postelsia palmaeformis at low tide in a tide pool


Sea star, Pisaster ochraceus consuming a mussel in tide pools

Close-up of clone war of sea anemones

Sea anemones, Anthopleura sola engaged in a battle for territory

See also


  1. ^ a b c "NPCA Tide pools". npca.org. September 5, 2008. Archived from the original on 2008-09-24. Retrieved 2008-09-06.
  2. ^ Connell, Joseph H. "Community interactions on marine rocky intertidal shores." Annual Review of Ecology and Systematics3.1 (1972): 169-192.
  3. ^ "Botanical Beach Tide Pools". juandefucamarinetrail.com. September 5, 2008. Archived from the original on 2008-07-24. Retrieved 2008-09-06.
  4. ^ "Sea Anemones". homepages.ed.ac.uk. September 5, 2008. Archived from the original on 2008-10-17. Retrieved 2008-09-06.
  5. ^ "Snakelocks Anemone". British Marine Life Study Society. September 5, 2008. Retrieved 2008-09-06.
  6. ^ "Biology:Regeneration". Dana Krempels, Ph.D. September 5, 2008. Archived from the original on August 6, 2009. Retrieved 2008-09-05.
  7. ^ Blanchette, Carol Anne (1995). "Seasonal patterns of disturbance influence recruitment of the sea palm, Postelsia palmaeformis". Department of Zoology, Oregon State University. Retrieved 13 July 2007.
  8. ^ Paine, R.T. (1998). "Habitat Suitability and Local Population Persistence of the Sea Palm Postelsia palmaeformis". Ecology. 69 (6): 1787–1794. doi:10.2307/1941157. JSTOR 1941157.

External links

Big Talbot Island State Park

Big Talbot Island State Park is a state park in Florida, United States. It is located on Big Talbot Island, 20 miles east of downtown Jacksonville on A1A North and immediately north of Little Talbot Island State Park along the Atlantic coastal plain.

The park is a nature preserve and a location for nature study, bird-watching, or photography. Other activities include hiking, bicycling, fishing, boating, canoeing, kayaking, and picnicking. Amenities include picnic pavilions, nature trails, a fishing pier, a boat ramp, bike trails and beaches. The park is open from 8:00 am till sundown year round.

The coastal landscape and beach at Big Talbot Island is unique within the state of Florida for its rock-like sedimentary hardpan soil deposits underlying the surface. Where these formations are exposed in the shallow waters surrounded the island they provide habitat for molluscs, crabs, oysters, and other tide pool creatures. The formations and sand on Blackrock Beach are much darker in contrast to the coquina formations at Washington Oaks State Gardens, about 60 miles southward on the coastal highway A1A, and the limestone outcroppings at Blowing Rocks Preserve over 250 miles further south. The beach can be accessed through the park entrance or through the trailhead parking area adjacent to the Blackrock Trail. At the end of the Blackrock Trail is Boneyard Beach. Here, skeletons of oaks sit along the shoreline. Big Talbot's Boneyard Beach is not recommended for swimming but is popular with photographers.Big Talbot and Little Talbot are two of only a few remaining undeveloped barrier islands within Florida. They were first inhabited by a Native American group called the Timucua. Beginning with the arrival of the French in 1562, France, England, and Spain claimed the islands as colonial territory. In 1735, General James Oglethorpe named the Talbot Islands in honor of Charles Talbot, Lord High Chancellor of England. Along with the bordering Timucuan Ecological and Historic Preserve, the islands are representative of several ecosystems and support a number of diverse natural habitats abundant with wildlife.

Birch Aquarium

Birch Aquarium at Scripps (sometimes referred to as Scripps Aquarium or Birch Aquarium) is an aquarium and the public outreach center for Scripps Institution of Oceanography at the University of California, San Diego. Accredited by the Association of Zoos and Aquariums, Birch Aquarium at Scripps has an annual attendance of more than 439,000, including more than 40,000 school children, and features more than 3,000 animals representing 380 species. The hilltop site provides views of the Scripps Institution of Oceanography campus and the Pacific Ocean. The mission of the aquarium reads: "At Birch Aquarium at Scripps, we connect understanding to protecting our ocean planet".

Body of water

A body of water or waterbody (often spelled water body) is any significant accumulation of water, generally on a planet's surface. The term most often refers to oceans, seas, and lakes, but it includes smaller pools of water such as ponds, wetlands, or more rarely, puddles. A body of water does not have to be still or contained; rivers, streams, canals, and other geographical features where water moves from one place to another are also considered bodies of water.Most are naturally occurring geographical features, but some are artificial. There are types that can be either. For example, most reservoirs are created by engineering dams, but some natural lakes are used as reservoirs. Similarly, most harbors are naturally occurring bays, but some harbors have been created through construction.

Bodies of water that are navigable are known as waterways. Some bodies of water collect and move water, such as rivers and streams, and others primarily hold water, such as lakes and oceans.

The term body of water can also refer to a reservoir of water held by a plant, technically known as a phytotelma.

Bodies of water are affected by gravity which is what creates the tidal effects on Earth.


Chathamiidae is a family of case making caddisflies more commonly known as the marine caddisflies. Chathamiids are unique among insects in their invasion of the tide pool environment. Larvae construct their cases of coralline algae. The four described species are distributed along the coasts of New Zealand, New South Wales, and the Chatham Islands.

Clinocottus analis

Clinocottus analis is a species of fish in the family Cottidae, one of the families of sculpins. It is known commonly as the woolly sculpin in English and the charrasco lanudo in Spanish. It is native to the eastern Pacific Ocean, where it occurs along the coastline of California and Baja California.This fish reaches up to 18 centimeters in length.This species lives on the seabed of intertidal waters up to 18 meters deep. It is commonly found in tide pools amidst algaes, but it leaves the tide pool area at will. It can breathe air and has been known to survive out of water for up to 24 hours.The diet of this species includes mainly crustaceans, especially amphipods, as well as fish eggs and larvae, polychaetes, and molluscs. Most of its food items are light-colored or clear, suggesting that these are easiest for the fish to see against the dark background of its habitat.This fish has green blood plasma, the color caused by biliverdin tightly bound in protein complexes.

Clinocottus globiceps

Clinocottus globiceps, commonly known as the mosshead sculpin or globe-headed sculpin, is a species of fish in the family Cottidae, native to the northeastern Pacific.

C. globiceps is a resident (non-migratory) intertidal species which exhibits homing behavior. It generally inhabits tidal pools and shallow rocky areas, often in strong surf. C. globiceps can leave a tide pool if conditions become inhospitable, since it can also breathe air. It sometimes rests on rocks out of water, but usually under rocks or among seaweed. C. globiceps is most commonly found in the eastern Pacific from Kodiak Island (Alaska) to Gaviota (southern California). This fish prefers a temperate climate from latitude 60°N. to 32°N. and is usually in a marine, demersal environment.

Davenport tide pools

The Davenport Tide Pools are located just past the town of Davenport, California in the United States. They are located off Davenport Landing, which is a street off Highway 1. The tide pools are unique due to the ridges that run up and down the tide pools, allowing for different organisms to live close, even though in a normal habitat they would be unable to do so. The Beach is open sunrise to sunset, and is day use only.

Labrisomus pomaspilus

Labrisomus pomaspilus is a species of labrisomid blenny only known from the Pacific coast in the area of Esmeraldas, Ecuador and from some locations in Colombia. This species is known to be a tide pool denizen. A female of the species measured 8.4 centimetres (3.3 in) SL.

Notheia anomala

Notheia anomala is a macroalgae in the family Notheiceae and the order Fucales. It is native to New Zealand and Australia.

It is an obligate epiphyte that is commonly found growing on Hormosira (although there is a single unconfirmed observation of Notheia being attached to Xiphophora chondrophylla).Hormosira is also from the order Fucales - and it is rare to have an epiphyte so closely related to its host.

It appears Notheia growth is entirely dependent on being attached to Hormosira. For example, attempts to grow Notheia in culture were unsuccessful until Hormosira extracts were added. However, there are few suggestions as to whether Notheia has a parasitic effect on Hormosira.

When Hallam et al. (1980) studied natural populations of Hormosira in Australia they found that tide pool populations had a consistently higher proportion of infected plants (with Notheia) than the low shore reef populations. This suggests that Notheia has a much narrower tolerance limit than its host. They found that sexually mature Hormosira plants carried more infections and the infections were most abundant on the reproductive conceptacles usually close to the osteoles. When looking at the settlement preferences of Notheia, Hallam and colleagues (1980) discovered that it did not show any partiality towards a particular sex of its dioecious host.


Ocynectes is a genus of tide pool dwelling sculpins native to the northwestern Pacific Ocean.

Otter Rock, Oregon

Otter Rock is an unincorporated community in Lincoln County, Oregon, United States. It is located on U.S. Route 101 along the Oregon Coast. Otter Rock is 5.4 miles south of Depoe Bay and 8 miles north of Newport, Oregon. Otter Rock takes its name from a rock located about 1⁄2 mile (0.8 km) offshore and 3.25 miles (5.23 km) north of Yaquina Head where sea otters formerly lived.There are various activities to do around Otter Rock throughout the year such as surfing, wine tasting, whale watching, tide pool exploring, and beach combing. The Devils Punch Bowl State Natural Area is located in Otter Rock.

As of 2019 the population of Otter Rock is approximately 225, up from 193 occupants in 2010.

Pacific Grove Marine Gardens State Marine Conservation Area

Pacific Grove Marine Gardens State Marine Conservation Area is one of four small marine protected areas located near the cities of Monterey and Pacific Grove, at the southern end of Monterey Bay on California’s central coast. The four MPAs together encompass 2.96 square miles (7.7 km2). Within the SMCA fishing and take of all living marine resources is prohibited except the recreational take of finfish and the commercial take of giant and bull kelp by hand under certain conditions. According to the Frommer's guide, the Marine Gardens area is "renowned for ocean views, flowers, and tide-pool seaweed beds."


Pagoo is an illustrated children's book by Holling C. Holling that was published in 1957.The book tells the story of a hermit crab who is guided by instinct presented in the form of a voice called "Old Pal". In the process it presents a study of tide pool life.

Like most of Holling's works, it is lushly illustrated, containing many full-page color paintings. Pages with text in them are also generously illustrated, with black-and-white pen-and-ink drawings in the margins, many with explanatory captions.

Queen's Bath

Queen's Bath is a unique tide pool on the island of Kauaʻi, Hawaii. The pool is a sinkhole surrounded by igneous rock. It is located on the north shore of Kauaʻi in the town of Princeville, at 22°13′44.9″N 159°29′15.0″W. Small fish and tiny sea life also live in the tide pool, such as Hawaiʻian sea urchins, angelfish and the so-called "ghost fish".The original "Queen's Bath" was located in Kalapana on the Big Island of Hawaiʻi.

It was formed after a lava tube collapsed and filled with fresh water supplied by natural springs. In ancient times only the Aliʻi (Royalty) were permitted entry to the sacred waters. In 1983 Kilauea Volcano erupted and in 1987 the original site was destroyed by lava flow.

Only after the original site on the Big Island of Hawaiʻi was destroyed did the location on Kauai become better known as "Queen's Bath". This tide pool was used for what it sounds like; it was a royal bathing place. It was also used as a place of relaxation when an Aliʻi needed to "wash off the stress".

R. W. Gray

Robert (R. W.) Gray is a Canadian writer, filmmaker and academic.

Originally from Prince Rupert, British Columbia, he was educated at the University of Victoria, the University of Manitoba and the University of Alberta. He taught screenwriting at the Vancouver Film School in the early 2000s, and published two serialized novels, Tide Pool Sketches (2001) and Waterboys (2004), in Xtra! West during this era.His debut short story collection Crisp was published in 2010, and was shortlisted for the Danuta Gleed Literary Award in 2011.His second short story collection, Entropic, followed in 2015, winning him the Thomas Head Raddall Award. He has also published both poetry and short stories in Arc, Grain, Event, The Fiddlehead, Malahat Review and dANDelion. His poems "How this begins", "Flutter", "Bite" and "Outside the Café" appeared in John Barton and Billeh Nickerson's 2007 anthology Seminal: The Anthology of Canada's Gay Male Poets.As a screenwriter, he has written six short films, of which he directed two. He has also produced several short films for other directors.

He is currently based in Fredericton, New Brunswick, where he teaches in the film studies department at the University of New Brunswick and is an organizer of the annual Fredericton 48-Hour Film Competition. He is also a senior editor and film critic for the web magazine Numéro Cinq.

Stephen Hillenburg

Stephen McDannell Hillenburg (August 21, 1961 – November 26, 2018) was an American animator, voice actor, and former marine science educator. He was best known as the creator of the Nickelodeon animated television series SpongeBob SquarePants (1999–), which he also directed, produced, and wrote. It has gone on to become the fifth-longest-running American animated series.

Born in Lawton, Oklahoma and raised in Anaheim, California, Hillenburg became fascinated with the ocean as a child and developed an interest in art. He started his professional career in 1984, instructing marine biology, at the Orange County Marine Institute, where he wrote The Intertidal Zone, an informative comic book about tide-pool animals, which he used to educate his students. In 1989, two years after leaving teaching, Hillenburg enrolled at the California Institute of the Arts to pursue a career in animation. He was later offered a job on the Nickelodeon animated television series Rocko's Modern Life (1993–1996) after his success with The Green Beret and Wormholes (both 1992), short films that he made while studying animation.

In 1994, Hillenburg began developing The Intertidal Zone characters and concepts for what became SpongeBob SquarePants. The show has aired continuously since its premiere in 1999. He also directed The SpongeBob SquarePants Movie (2004), which he originally intended to be the series finale. However, Nickelodeon wanted to produce more episodes, so Hillenburg resigned as the showrunner. He went back to making short films, with Hollywood Blvd., USA (2013). In 2015, The SpongeBob Movie: Sponge Out of Water was released; the second film adaptation of the series, it marked Hillenburg's return to the franchise, wherein he co-wrote the story and acted as an executive producer on the project.

Besides his two Emmy Awards and six Annie Awards for SpongeBob SquarePants, Hillenburg also received other recognition, such as an accolade from Heal the Bay for his efforts on elevating marine life awareness, and the Television Animation Award from the National Cartoonists Society. Hillenburg was diagnosed with amyotrophic lateral sclerosis (ALS) in 2017, but stated he would continue to work on SpongeBob SquarePants as long as possible. He died due to complications of the disease on November 26, 2018, at the age of 57.

Stew pond

A stew pond or stew is a fish pond used to store live fish ready for eating. During the Middle Ages, stews were often attached to monasteries, to supply fish over the winter.

Surf zone

As ocean surface waves come closer to shore they break, forming the foamy, bubbly surface called surf. The region of breaking waves defines the surf zone. After breaking in the surf zone, the waves (now reduced in height) continue to move in, and they run up onto the sloping front of the beach, forming an uprush of water called swash. The water then runs back again as backswash. The nearshore zone where wave water comes onto the beach is the surf zone. The water in the surf zone, or breaker zone, is shallow, usually between 5 and 10 m (16 and 33 ft) deep; this causes the waves to be unstable.

Triopha maculata

Triopha maculata, common name spotted triopha or speckled triopha, is a species of colorful sea slug, a nudibranch, a shell-less marine gastropod mollusk in the family Polyceridae. This species is very variable in color.

Aquatic ecosystems
Food webs
Example webs
Ecology: Modelling ecosystems: Other components
Ponds, Pools and Puddles
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