Tide pools are rocky pools by
oceanAn ocean is a large body of saline water, and a principal component of the hydrosphere. Approximately 75% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
s that are filled with
seawaterSeawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5%. This means that every of seawater has approximately of dissolved salts...
. Many of these pools exist as separate entities only at low tide.
Tide pools are
habitatThe term habitat has a number of meanings:* Habitat , a place where a species lives and grows** Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s of uniquely adaptable animals that have engaged the special attention of naturalists and
marine biologistsMarine biology is the scientific study of living organisms in the ocean or other marine or brackish bodies of water. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment...
, as well as philosophical essayists:
John SteinbeckJohn Ernst Steinbeck, Jr. was an American writer. He wrote the Pulitzer Prize-winning novel The Grapes of Wrath and the novella Of Mice and Men . He wrote a total of twenty-seven books, including sixteen novels, six non-fiction books and five collections of short stories...
wrote in
The Log from the Sea of CortezThe Log from the Sea of Cortez is an English language book written by American author John Steinbeck and published in 1951. It details a six-week marine specimen-collecting boat expedition he made in 1940 at various sites in the Gulf of California , with his friend, the marine biologist Ed Ricketts...
, "It is advisable to look from the tide pool to the stars and then back to the tide pool again."
Tide pools provide a home for hardy organisms. Inhabitants must be able to cope with a constantly changing
environmentThe biophysical environment is the symbiosis between the physical environment and the biological life forms within the environment, and includes all variables that comprise the Earth's biosphere. The biophysical environment can be divided into two categories: the natural environment and the built...
— fluctuations in water
temperatureIn physics, temperature is a physical property of a system that underlies the common notions of hot and cold; something that feels hotter generally has the higher temperature. Temperature is one of the principal parameters of thermodynamics...
,
salinitySalinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
, and
oxygenOxygen Oxygen Oxygen (acid, literally "sharp", from the taste of acids) and -γενής (-genēs) (producer, literally begetter) is the element with atomic number 8 and represented by the symbol O...
content.
Tide pools are rocky pools by
oceanAn ocean is a large body of saline water, and a principal component of the hydrosphere. Approximately 75% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
s that are filled with
seawaterSeawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5%. This means that every of seawater has approximately of dissolved salts...
. Many of these pools exist as separate entities only at low tide.
Tide pools are
habitatThe term habitat has a number of meanings:* Habitat , a place where a species lives and grows** Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
s of uniquely adaptable animals that have engaged the special attention of naturalists and
marine biologistsMarine biology is the scientific study of living organisms in the ocean or other marine or brackish bodies of water. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment...
, as well as philosophical essayists:
John SteinbeckJohn Ernst Steinbeck, Jr. was an American writer. He wrote the Pulitzer Prize-winning novel The Grapes of Wrath and the novella Of Mice and Men . He wrote a total of twenty-seven books, including sixteen novels, six non-fiction books and five collections of short stories...
wrote in
The Log from the Sea of CortezThe Log from the Sea of Cortez is an English language book written by American author John Steinbeck and published in 1951. It details a six-week marine specimen-collecting boat expedition he made in 1940 at various sites in the Gulf of California , with his friend, the marine biologist Ed Ricketts...
, "It is advisable to look from the tide pool to the stars and then back to the tide pool again."
The life in tide pools
Tide pools provide a home for hardy organisms. Inhabitants must be able to cope with a constantly changing
environmentThe biophysical environment is the symbiosis between the physical environment and the biological life forms within the environment, and includes all variables that comprise the Earth's biosphere. The biophysical environment can be divided into two categories: the natural environment and the built...
— fluctuations in water
temperatureIn physics, temperature is a physical property of a system that underlies the common notions of hot and cold; something that feels hotter generally has the higher temperature. Temperature is one of the principal parameters of thermodynamics...
,
salinitySalinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
, and
oxygenOxygen Oxygen Oxygen (acid, literally "sharp", from the taste of acids) and -γενής (-genēs) (producer, literally begetter) is the element with atomic number 8 and represented by the symbol O...
content. Huge
waveIn fluid dynamics, wind waves or, more precisely, wind-generated waves are surface waves that occur on the free surface of oceans, seas, lakes, rivers, and canals or even on small puddles and ponds. They usually result from the wind blowing over a vast enough stretch of fluid surface. Some waves...
s, strong
currentAn ocean current is a continuous, directed movement of ocean water generated by the forces acting upon the water, such as the wind, Coriolis force, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun...
s, exposure to midday
sunThe Sun is the star at the center of the Solar System. The Earth and other matter orbit the Sun, which by itself accounts for about 99.86% of the Solar System's mass....
and
predatorsIn ecology, predation describes a biological interaction where a predator feeds on its prey, . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of the prey...
are only a few of the
hazardA hazard is a situation that poses a level of threat to life, health, property, or environment. Most hazards are dormant or potential, with only a theoretical risk of harm; however, once a hazard becomes 'active', it can create an emergency situation....
s that tide pools' animals must endure to survive.
WaveIn fluid dynamics, wind waves or, more precisely, wind-generated waves are surface waves that occur on the free surface of oceans, seas, lakes, rivers, and canals or even on small puddles and ponds. They usually result from the wind blowing over a vast enough stretch of fluid surface. Some waves...
s can dislodge mussels and draw them out to
seaA sea is any large amount of water filled with animals such as crabs, whales, sharks, and fish, but there is inconsistency as to its precise definition and application. Most commonly, a sea may refer to a large expanse of saline water connected with an ocean, but it is also used sometimes for a...
.
GullGulls are birds in the family Laridae. They are most closely related to the terns and only distantly related to auks, skimmers, and more distantly to the waders...
s pick up and drop
sea urchinSea urchins or urchins are small, spiny, globular animals that compose part of class Echinoidea. They are found in oceans all over the world. Their shell, or "test", is round and spiny, typically from 3 to 10 cm across. Common colors include black and dull shades of green, olive, brown, purple,...
s to break them open. Starfish prey on
musselThe common name mussel is used for members of several families of clams or bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.The...
s and are eaten by gulls themselves. Even
black bearBlack bear may refer to:In mammals:*American Black Bear*Asian Black Bear, including its subspecies** Formosan Black Bear** Himalayan Black BearIn places:*Black Bear Creek, a creek in Oklahoma*Black Bear Ranch, a commune in California...
s sometimes feast on intertidal creatures at low
tideTides are the rises and falls of sea level caused by the combined effect of rotation of the Earth and the gravitation of the Moon and the Sun. The tides occur with a period of approximately 12 and a half hours and are influenced by the shape of the near-shore bottom.Most coastal areas experience...
. Although tide pool organisms must avoid getting washed away into the
oceanAn ocean is a large body of saline water, and a principal component of the hydrosphere. Approximately 75% of the Earth's surface is covered by ocean, a continuous body of water that is customarily divided into several principal oceans and smaller seas.More than half of this area is over 3,000...
, drying up in the
sunThe Sun is the star at the center of the Solar System. The Earth and other matter orbit the Sun, which by itself accounts for about 99.86% of the Solar System's mass....
, or getting eaten, they depend on the tide pool's constant changes for food.
Tide pool zones, from shallow to deep
Spray/splash zone
This zone receives spray from wave action during high tides and storms. At other times the rocks experience other extreme conditions, baking in the sun or exposed to cold winds. Few organisms can survive such harsh conditions.
LichenLichens are composite organisms consisting of a symbiotic association of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
s and
barnacleA barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...
s live in this region. In this zone, different
barnacleA barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...
species live at very tightly constrained elevations. Tidal conditions precisely determine the exact height of an assemblage relative to sea level.
Since the
intertidal zoneThe intertidal zone is the area that is exposed to the air at low tide and underwater at high tide . This area can include many different types of habitats, including steep rocky cliffs, sandy beaches, or wetlands...
periodically desiccates,
barnacleA barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in erosive settings. They are sessile suspension feeders, and have...
s must be well adapted to water loss. Their
calciteCalcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 470°C, and vaterite is even less stable....
shells are impermeable, and they possess two plates which they slide across their mouth opening when not feeding. These plates also protect against predation.
High and mid tide zone
The high tide zone is flooded for hours during each high tide. Organisms must survive wave action,
currentsAn ocean current is a continuous, directed movement of ocean water generated by the forces acting upon the water, such as the wind, Coriolis force, temperature and salinity differences and tides caused by the gravitational pull of the Moon and the Sun...
, and exposure to the
sunThe Sun is the star at the center of the Solar System. The Earth and other matter orbit the Sun, which by itself accounts for about 99.86% of the Solar System's mass....
. The high tide zone is inhabited by
sea anemoneSea anemones are a group of water dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower...
s, starfishes,
chitonChitons are small to large, primitive marine molluscs in the class Polyplacophora.There are 900 to 1,000 extant species of chitons in the class, which was formerly known as Amphineura....
s,
crabCrabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax.Crabs have a soft body covered with a hard shell. They are generally covered with a thick exoskeleton, and armed with a...
s, green
algaeAlgae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds. They are photosynthetic, like plants, and "simple" because they lack the many distinct organs found in...
, and mussels. Marine
algaeAlgae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds. They are photosynthetic, like plants, and "simple" because they lack the many distinct organs found in...
can provide shelter for such organisms as
nudibranchA nudibranch ) is a member of what is now a taxonomic clade, and what was previously a suborder, of soft-bodied, shell-less marine opisthobranch gastropod mollusks, which are noted for their often extraordinary colors and striking forms...
s and
hermit crabHermit crabs are decapod crustaceans of the superfamily Paguroidea. They are not closely related to true crabs. Hermit crabs are quite commonly seen in the intertidal zone: for example, in tide pools....
s. The same
waveA wave is a disturbance that propagates through space and time, usually with transference of energy. A mechanical wave is a wave that propagates or travels through a medium due to the restoring forces it produces upon deformation. There also exist waves capable of traveling through a vacuum,...
s and currents that make the life in the high tide zone so difficult bring food to the
filter feederFilter feeders are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, some fish and sharks, and baleen whales. Some birds, such...
s and other intertidal animals.
Low tide zone
This subregion is mostly submerged — it is exposed only during low tide. This area is teeming with life; this subregion's most notable difference from the other three is that there is much more marine vegetation, especially
seaweedSeaweedSeaweed has antioxidents. Is a loose colloquial term encompassing macroscopic, multicellular, benthic marine algae. The term includes some members of the red, brown and green algae...
s. There is also greater biodiversity. Organisms in this zone generally are not well adapted to dryness and temperature extremes. Low tide zone organisms include
abaloneAbalone are small to very large-sized edible sea snails, marine gastropod mollusks in the family Haliotidae and the genus Haliotis...
,
anemoneAnemone , is a genus of about 120 species of flowering plants in the buttercup family Ranunculaceae in the north and south temperate zones...
s, brown seaweed,
chitonChitons are small to large, primitive marine molluscs in the class Polyplacophora.There are 900 to 1,000 extant species of chitons in the class, which was formerly known as Amphineura....
s,
crabCrabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" , or where the reduced abdomen is entirely hidden under the thorax.Crabs have a soft body covered with a hard shell. They are generally covered with a thick exoskeleton, and armed with a...
s,
green algaeThe green algae are the large group of algae from which the embryophytes emerged. As such, they form a paraphyletic group, although the group including both green algae and embryophytes is monophyletic...
,
hydroid-Marine Biology:Colonial, plant-like animals closely related to jellyfish, with stinging cellsany member of the invertebrate order Hydroida...
s, isopods,
limpetThe name Limpet is used for many kinds of mostly saltwater but also freshwater snails, specifically those that have a simple shell which is more or less broadly conical in shape, and which is either not coiled, or appears not to be coiled, in the adult snail.Thus the word "limpet" is an inexact...
s,
musselThe common name mussel is used for members of several families of clams or bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.The...
s,
nudibranchA nudibranch ) is a member of what is now a taxonomic clade, and what was previously a suborder, of soft-bodied, shell-less marine opisthobranch gastropod mollusks, which are noted for their often extraordinary colors and striking forms...
s,
sculpinA Sculpin is a fish that belongs to the Order Scorpaeniformes, Suborder Cottoidei and Superfamily Cottoidea that contains 11 families, 149 genera, and 756 species according to though these totals will likely change as more molecular work is done...
, sea cucumber,
sea lettuceThe sea lettuces comprise the genus Ulva, a group of edible green algae widely distributed along the coasts of the world's oceans....
, sea palms,
sea starSea stars are echinoderms belonging to the class Asteroidea. The names "sea star" and "starfish" are sometimes differentiated, with "starfish" used in a broader sense to include the closely related brittle stars, which make up the class Ophiuroidea, as well as excluding sea stars which do not have...
s,
sea urchinSea urchins or urchins are small, spiny, globular animals that compose part of class Echinoidea. They are found in oceans all over the world. Their shell, or "test", is round and spiny, typically from 3 to 10 cm across. Common colors include black and dull shades of green, olive, brown, purple,...
s,
shrimpShrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
,
snailThe word snail is a common name for almost all members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word snail is used in a general sense, it includes sea snails, land snails and freshwater snails. Snails lacking a shell or having only a very small one are...
s, sponges,
surf grassPhyllospadix scouleri, or surf grass is a North American flowering marine plant in the family Zosteraceae.This slender, vivid green "grass" has long, flat blades. It grows in large clumps or beds exposed during low tide and submerged at high tide. It is found attached to rocks in the middle to low...
,
tube wormThe name tube worm may refer to any of a number of unrelated tube-dwellingworm-like invertebrates.These include chiefly various polychaetes, specifically the Family Siboglinidae , Serpulidae, and related families of the order Canalipalpata...
s, and
whelkWhelk or welk refers to one of several unrelated groups of marine gastropods found in temperate waters which have historically been used by humans for food:...
s.
These creatures can grow to larger sizes because there is more available
energyIn physics, energy is a scalar physical quantity that describes the amount of work that can be performed by a force, an attribute of objects and systems that is subject to a conservation law...
and better water coverage: The water is shallow enough to allow more
lightSunlight, in the broad sense, is the total spectrum of the electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the atmosphere, and the solar radiation is obvious as daylight when the Sun is above the horizon. Near the poles in summer, the days are longer and the...
for
photosyntheticPhotosynthesis is a process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of Bacteria, but not in Archaea...
activity, and the
salinitySalinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
is at almost normal levels. This area is still protected from large predators because of the wave action and relatively shallow water.
Tide pool fauna
Sea anemoneSea anemones are a group of water dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower...
,
Anthopleura elegantissima clone to reproduce. The process is called longitudinal fission, in which the animal splits in two parts along its length.
Sea anemoneSea anemones are a group of water dwelling, predatory animals of the order Actiniaria; they are named after the anemone, a terrestrial flower...
s,
Anthopleura sola often fight for territory. The white tentacles (acrorhagi) are for fighting. The acrorhagi contain stinging cells. The sea anemones sting each other repeatedly until one (usually) moves.
Some species of starfish have the ability to
regenerateIn biology, an organism is said to regenerate a lost or damaged part if the part regrows so that the original function is restored.Regenerative capacity is inversely related to complexity: in general, the more complex an animal is the less regeneration it is capable of. Whereas newts, for example,...
lost arms in time. 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.
Tide pool flora
Sea palmPostelsia, also known as the sea palm or palm seaweed, is a genus of kelp. There is only one species, P. palmaeformis. It is found along the western coast of North America, on rocky shores with constant waves...
s look very much as palm trees do. 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
musselThe common name mussel is used for members of several families of clams or bivalve molluscs, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.The...
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. Alternatively, the mussels may prevent the growth of competing
algaeAlgae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms. The largest and most complex marine forms are called seaweeds. They are photosynthetic, like plants, and "simple" because they lack the many distinct organs found in...
such as
Corallina or
Halosaccion, allowing
Postelsia to grow freely after wave action removes the mussels.
External links