Doheny State Beach Info
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gravitational pull of both the moon and the sun on the earth’s
oceans causes tides. Most bodies of salt water experience a tidal
change approximately every six hours. The tide may change up to
seven feet and, along California’s rocky shoreline, a low
tide exposes places where marine plants and animals live. Not
do tides change by the day, but there are also times during the
month when the tidal change is greater.
addition, the moon’s revolving around the earth and the earth’s
revolving around the sun affect tides at different times of the
year. Early summer (June-July) and early winter (December-January)
are the months of the year with the greatest tidal change. There
are many days at Doheny when there is not enough tidal change to
uncover our rocky reef and expose tide pools.
tide pools are different from the tide pools found along a rocky
shoreline. San Juan Creek empties into the ocean through our park.
It's flow creates a southward current in front of our campground
and south day use area. The steep drop-off in this area causes the
surf to break right on the sand making wave riding impossible here.
The area directly north of San Juan Creek is rocky because the creek’s
flow causes the sand to move south. The area north of the creek
is where tide pools are found at Doheny. When the tide recedes,
pools are created in the uneven rocky bottom. It is here to look
for the tide pool animals outlined below.
Barnacles are actually
part of the same group of animals, called crustaceans, as crabs,
lobster, and shrimp. Adult barnacles look very different from
crustacean relatives. After birth, barnacle larvae look just like
larvae of other crustaceans; however, when a barnacle metamorphoses,
it attaches it self to a hard surface head first and creates
around its body made of calcium. Its modified legs, called
cirri, filter water for plankton and detritus like little nets.
are the highest living intertidal marine species. Most species
easily spend half of their lives out of water. Some species only
need to be wetted with ocean spray making them well adapted
life along California’s rocky, wave swept shoreline. Since
these organisms are sessile, males may become female and vice versa
in some species
in order to reproduce.
Some of the species
found at Doheny are the common Acorn Barnacle (Balanus
glandus) that would be found on rocks in the surf zone.
Barnacles (Tetraclita rubescens) live alone rather
than in groups. They are brick red in color with only four sides
instead of the usual six, and they like to live under the ledges
Barnacles (Chthamalus dalli) live on rocks in
groups with up to 60,000 individuals per square yard.
Striped Acorn Barnacle (Balanus pacificus) attaches
it self to other marine life, especially sand dollars. They can
live to a depth of 240 feet. They are smooth in texture and pink
to purple striped in color.
that likes to attach to other marine life is the White-Ribbed
Barnacle (Megabalanus californicus). It is similar
to the Red Striped Barnacle in that it has pink to red stripes.
These barnacles prefer to attach to crabs, kelp, mussels, and pier
Goose Barnacles (Pollicipes polymers) are
found in mussel beds only when the tide is the lowest at
barnacles look different from other barnacles because their cupped
feeding appendages are on 3½-inch stalks. The stalks
are edible and are eaten in Spain and Portugal.
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Hermit Crab – (Pagurus samuelis): The bright
blue bands on their walking legs easily identify these little hermit
crabs. They also have bright red antennae. They live in abandoned
black turban and striped dog winkle shells which is why shells should
not be collected anywhere along California’s coastline. They
are strictly an outer coast species found in the rocky high intertidal
areas. Blue Banded Hermit Crabs have compound eyes that adapt to
both day and night. These crabs feed at night on brown algae and
dead animals. Pile Perch, Sheephead, and Kelpfish love to eat them.
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Crabs - There are several different species of porcelain
crabs found at Doheny. These are flat little crabs that easily
the rocks to hide, so you won’t find them unless you look under
a rock. This in the most prolific crab in terms of overall numbers
in our tide pools. A study in Pacific Grove, California, found nearly
900 animals per square meter. They are small, up to ¾ of
an inch, with long antennae. Some rocks at Doheny may have hundreds
them. They live in the high to mid-intertidal areas of our rocky
reef. Porcelain crabs are filter feeders or feed on detritus --
plant and animal matter. This is one of many species that relies
on the protection of the rocks for its livelihood, so never leave
overturned after you look under it. |
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Crab - (Pachygrapsus crassipes): These green to
red or purple crabs with black stripes are active during daylight
hours. They are so well adapted to living out of water that they spend
at least half of the time that way. They have excellent eyesight which
adapts well to both day and night. For the most part, these crabs
feed on land on diatoms and algae. Occasionally they will prey on
hermit crabs and Black Turban snails, and they’ve even been
observed capturing kelp flies with their very dexterous claws. Seagulls,
raccoons, and octopus love to prey on these crabs. Because they are
well adapted to life on land, Striped Shore Crabs will be found in
the rocks along the jetty. But be careful; these crabs may pinch when
handled, so avoid picking them up. Never place them in a container
as they will die and then smell.
Although these crabs
are native to Western North America, scientists believe they may
have been introduced to the Orient in the 1890’s in merchant
ships’ hulls. These hulls may have contained the swimming
planktonic form of this crab in the trapped seawater found in them.
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Green Anemone – (Amthopleura xanthogrammica):
Sea anemones are members of the phylum Cindaria that is the
same phylum as jellyfish and corals because they have
stinging cells. These organisms look like flowers with a central
foot and mouth, as well as multiple tentacles that are used
to capture food ranging from small fish to plankton
to detritus. The tentacles are equipped with specialized
cells called nematocysts. Nematocysts are like mini spear guns
that can harpoon and paralyze prey allowing it to be digested
with ease. The stinging cells are too small to penetrate
There are three
ways a sea anemone can reproduce. First, they can reproduce by
male and female gametes into the
water column. Secondly, they can divide in half, similar
to the way a single cell divides. And thirdly, they can reproduce
by budding. This involves growing a whole new anemone on
the side of their body which will eventually fall off
a clone of the original anemone.
Anemones have a water vascular system, which means they control
their movement by either inhaling or exhaling water.
Solitary Green Anemones are common along California’s
rocky shoreline; however, they are not found very often
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Sea Urchin – (Strongylocentrotus purpuratus):
These animals are completely covered with sharp, brightly colored
purple spines making them easy to recognize. Purple Urchins are
only found during the lowest tides at the farthest edge of our reef.
They need highly oxygenated water to survive, so they are well adapted
to living in the surf. In fact, some excavate an impression in the
rocks with their sharp spines for protection from predators and
strong surf. They are able to regenerate their spines when they
If you look at a
Purple Urchin carefully in the water you’ll notice tube feet
extending beyond the spines. These tube feet are used to snag pieces
of kelp, their favorite food.
Purple Urchins can
do damage to kelp forests when they become overpopulated. They eat
all algae in site and create an urchin barren which is an area of
denuded rocks covered with Purple Urchins. This happens because
only Sea Otters, sea stars, and Sheephead feed on these animals.
Since Sea Otters are no longer found in the waters off Doheny or
anywhere south of Point Conception, Purple Urchins can easily overpopulate
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Star - (Patiria miniata): Commonly found in
the intertidal zone to depths of about 870 feet.
These sea stars
are also found between Sitka, Alaska and Islas
Mexico. These stars are not very large sea stars; in fact,
their arm radius is only four inches. They usually have five arms
but they can have as few as four or as many as nine. They can
be almost any color.
Bat Stars are omnivores and scavengers, which means they will
try to eat almost anything
they can get their tube feet on. Spawning usually occurs
in May and July when the males and females release their gametes
into the water column. This is where the eggs are fertilized. When
the sea stars hatch, they are plankton. A week or two after they
hatch they settle to the bottom where they will spend the rest
of their lives.
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Star – Brittle Stars belong to the class Ophiuroidea,
which consists of over 2,000 different species. Of those,
only 16 species frequent the California coastline. They range
from shallow water species to extremely dense populations
that live in deep water along the continental shelf. Brittle
are easily distinguished from other sea stars because of
their thin, segmented rays and their round central disk.
have the ability to lose arms when disturbed and regenerate
them quickly. Not much is known about brittle stars as they
haven’t been studied yet. However, depending
on the species, it is known that
they can be herbivorous, carnivorous, omnivorous, scavengers
or even detritus feeders. Brittle stars are often
found in masses under rocks in areas of Doheny’s reef
that are usually covered with water. They are best found
on a minus
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Star - (Pisaster gigateus): The Knobby Star
is a relatively large sea star that can reach
inches across. They are found from Vancouver Island,
Canada to Baja California in depths ranging from the intertidal
zone to almost 300 feet. These
sea stars are active predators. They have been known to eat bivalves
clams, scallops and oysters), chitons, snails, and barnacles. When
they eat, they use their extremely strong tube feet to pull open
their bivalves and then digest their prey outside of their bodies.
Spawning occurs between March and April. An interesting side note;
these sea stars are actually trainable. In laboratories,
they have been trained to associate food with a certain light.
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Clingfish – (Gobiesox maeandricus):
The northern clingfish is also known as the flathead clingfish,
common clingfish or scientifically, Gobiesox maeandricus.
The clingfish is an oddly shaped fish that looks similar to a tadpole.
They are commonly found from Guadalupe Island, Baja California
Revillagigedo Island, southern Alaska. These fish are very common
in the tide pools off Doheny though they are rarely seen because
they hide under rocks that are exposed only during the lowest tides
of the year. These small fish have the ability to literally cling
to the rocks by using their specialized pelvic fin as a suction
cup. The largest northern Clingfish on record was 6.5 inches long.
They will feed on small snails, worms and shrimp. Because of its
small size the northern clingfish has no real economic use, so
no one fishes for it. |
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Sculpin – (Oligocottus maculosus):
The tide pool sculpin, also known as Oligocottus maculosus,
is a very common fish from the Sea of Okhotsk, Russia to the
Bering Sea, Alaska, and down the Eastern Pacific to Southern
California. Though these fish only reach about 3.5 inches and
live a maximum of five years, they thrive in the turbulent
waters of the intertidal zone. They also have the ability to
withstand very cold-water temperatures. In the Bering Sea they
been known to live in temperatures as low as 33 degrees Fahrenheit.
Other interesting characteristics of this species, is
their uncanny ability to find their way back to their favorite
tide pool as well as the fact they have no scales. Tide
pool sculpin survive by eating isopods, amphipods, shrimp and
worms. In turn, they are often eaten by larger fish like
the kelp greenling. They range in coloration from gray to brown
and even green with multi-colored speckles.
They are oviparous,
meaning they lay eggs. The coloration of the eggs seems to depend
on where they are laid. Eggs laid in protected areas tend to
be a greenish color, but eggs subject to a lot of water movement
will be a pinkish color.
During the lowest
tides at Doheny you can look for these fish in the pools left behind
as the ocean recedes.
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The abalone is a gastropod mollusk that lives under its ear-like
the three most common species of abalone around Dana Point were
the Black, Pink and Green Abalone. The black abalone was the
common abalone found in the tide pools and surf areas, while the
pink and green abalones were normally found below the tidal
abalones have suffered greatly in recent years. Due to over
and a disease that spread through the different species, their
numbers are just a fraction of what they were 25 years ago.
The black abalone
has taken the biggest hit, with approximately 1% of its former
population remaining. Several years ago, to protect the remaining
California Department of Fish and Game made it illegal to take
any abalone South of San Francisco. The remaining population
slow to recover.
Abalones are herbivores,
feasting on the many different algae types found in the area.
different species come in different sizes with blacks being the
smallest and greens being the largest. The largest abalone along
the California coast is the cold-water loving red abalone, with
some individuals growing to 10 or more inches across.
Abalones are slow
growing and a full size green abalone of 7 or 8 inches might be
15 years old or more. Abalones reproduce sexually by releasing male
and female gametes into the water to meet by chance for fertilization.
The newly formed planktonic abalones eventually settle onto something
hard to live their lives. Abalones are not big travelers, often
moving less than ten feet over a period of months.
There is a host
of animals that prey on abalones including crabs, lobster, octopus,
starfish, cabezon, sea otter and, of course, humans. If you are
lucky enough to see an abalone in the tide pools, please always
place the rock back as you found. This will ensure others will have
that chance and the abalone will have a chance to grow to maturity
and reproduce to replenish the wild stocks.
Chama - (Chama
arcane): The Chama is a type of bivalve -- a class
of mollusk with two shells -- that cements itself onto the
underside of rocks on
reef. They live the majority of their lives attached to these
rocks, only opening their shell enough to extend a siphon to
filter out very fine food particles from the water. They range
from Oregon south to Bahia San Juanico, Baja California. Usually
these animals can be found in small groups, but in some areas
they will be so densely populated they will literally
be cemented on top of each other. Nothing is known about their
reproductive lives other than there are two genders.|
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Chitons - Perhaps
the most mispronounced animal in the ocean is the chiton. It
with a hard “k” sound. Chitons are a type of mollusk
that identified by eight shell plates held together by an outside
oval of tissue called a girdle. Most chitons are light sensitive
so they’ll be found under rocks. Some species are brightly
colored while others are well camouflaged. Chitons are found almost
everywhere in the ocean – from the high intertidal zone to
as deep as 4000 meters. They are at home in cold arctic seas as
well as in the warm tropical waters near the Equator. Most chitons
are vegetarians, but some are carnivorous.
Some species found
at Doheny are the California Spiny Chiton (Nuttallina
californica). California Spiny Chitons are up to two inches
long with a narrow body. The body length is two to three times the
width. These chitons live in depressions in the rocks of Doheny’s
reef. At high tide they feed on a type of red algae called Corallina
which often grow right on their shell plates. Western Sea Gulls
eat these chitons when the tide is low.
Spiny Chiton (Nuttallina scalora) doesn’t
retreat from sunlight and is colorful. Body color varies from green
to brown to black. They are up to an inch in length with a life
span of up to twenty or more years.
(Mopalia ciliata) are covered in soft hairs and are similar
to the Mossy Chiton. The hair makes them more tolerant of daylight;
however, they feed on diatoms at night and stay put during low tide.
Their radula, which is the mouth mechanism for scraping algae off
rocks, can pick up magnetite from the rocks making their mouth magnetic.
A similar looking
species, the Mossy Chiton (Mopalia muscoa),
is covered in stiff hairs making it look fuzzy. They may be found
on the topsides of rocks during low tide, especially if it is overcast.
At night, they feed on red or green algae. Other marine life may
be found living on their bodies.
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are several different species of limpets in the Doheny area.
Limpets are mollusks
closely related to abalones. They range in size from ½ inch
to 3 inches with the Owl Limpet second only to the Giant Keyhole
Limpet in size. The Owl Limpet gets its name from the muscle scar
found on the inside of its shell. This scar resembles the silhouette
of a Great Horned Owl.
Limpets are herbivores
that feed on algae. The shape of their shells often helps them stay
affixed to the rocks in the surf zone. At low tide, the limpet will
grip tight to the rocks and trap small amounts of water under the
shell which the animal will use until water is available again at
the next tidal change.
About half of all
limpets species display homing tendencies. This means that during
high tide when water is covering the animal it will range over
or so of rock in search of food. As the tide recedes, the limpet
will return to its original place on the rock to remain until
next high tide.
Predators of the
limpet include sea stars, crabs, octopus and man. Be careful when
you’re in the tide pools not to crush limpets by stepping
on them or turning rocks on top of them.
Navanax - The navanax is a
medium-sized sea slug with two distinct color forms. One is dark,
the other light. Both have striations of blue, yellow, orange and
white down the length of their body. They can be found in sandy
or muddy bodies of water where it is calm, although they are often
spotted in the tide pools at Doheny nearest lifeguard tower 13.
This sea slug is
carnivorous, feeding on other sea snails and slugs. The navanax
will follow its prey’s mucus trails for its dinner. One of
the navanax’s favorite meals is the Bubble snail. The navanax
will often have so many inside of its soft body that when you pick
it up it will feel very lumpy. This is where its nickname “bag
of marbles snail” comes from.
Although not preyed
upon by too many animals, if disturbed, the navanax will extrude
a bright yellow fluid similar to the purple fluid released by the
sea hare. Also like its cousin the sea hare, each navanax will release
millions of eggs every spring in a clump, similar in color and size
Sea Hare or California Black Sea Hare
– (Aplysia vaccaria): Sea hares are large mollusks
that lack an external shell, and they get their name because their
antennae resemble rabbit ears. These sea hares are very similar
to the Brown Sea Hare and are identified by their uniform black
to dark brown coloration. The most distinguishing feature of these
sea hares is their size as they are the world’s largest gastropod
weighing up to 35 pounds.
too, are found along the water’s edge at Doheny to a depth
of 60 feet. They feed exclusively on brown feather boa kelp so they
don’t produce purple ink.
are also hermaphrodites like Brown Sea Hares except their eggs are
tangled pinkish-white egg strings.
Sea Hare or California Sea Hare –
(Aplysia californica): These sea hares are reddish brown
to greenish brown with some mottling. They have two elongated flaps
with an internal shell. They begin to appear on Doheny’s rocky
reef from May through the summer months living near the water’s
edge to a depth of sixty feet. These animals are active during the
day making them easy to spot in spring and summer.
hares are herbivores, feeding primarily on red algae. They have
a complicated digestive system with three stomachs. Purple ink,
which is their defense system, is derived from the algae they eat.
Be careful when handling, as the ink will stain clothing.
only for a year, these sea hares are hermaphrodites having both
male and female reproductive organs. All they have to do is locate
another sea hare of the same species. They lay up to a million eggs
that look like yellowish spaghetti. The eggs hatch in 12 days. After
hatching, the larvae swim for about a month before settling on red
algae. They then gorge themselves in order to double their weight
every ten days for the next three months.
Snail – (Tegula funebralis): The Black
Turban snail is a common snail at Doheny with a distinctive
found in the upper intertidal zone. In size, its shell is about
1 to 1¼ inches or 3 centimeters in diameter. Black
Turbans eat a variety of algae, especially the microscopic
film that grows
on the surface of rocks. If you examine the snail’s shell
closely, you might find a small Black Limpet, called Collisella
asmi, living on it. Tiny algae live on the Black Turban’s
shell that these Black Limpets eat. During low tide, Black Turbans
will often group together and during this time the Black Limpets
will move from shell to shell. Blue-banded Hermit Crabs love to
live in the abandoned Black Turban shells so never collect shells
when you visit Doheny or any other tide pool.
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Bubble Snail – (Bulla gouldiana): This is
an abundant snail found from Morro Bay, California south to Ecuador.
Living solely in mud and silt substrates, they are generally believed
to be herbivores though this is not well known. This is the largest
species of bubble snail off our coast reaching a maximum size of 5.5
cm and living about a year. These snails cover their shell with their
mantels so the shell will be free from other growth. Believe it or
not, it is not uncommon to find other organisms living in or on these
snails. The pea crab and the crepidula snail can be found in the mantle
cavity of the bubble snail. If you can’t find a bubble snail,
they leave distinctive tracks in the sand. Follow the tracks, and
you might find the snail. |
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