DISCOVER MAGNIFICENT MORRO
ROCK
Explore the beauty of Morro Rock and learn about its geology and history and
the species that live on and around the rock. Meet near the rest rooms at the
northeast parking lot in front of the Rock. Bring binoculars and a jacket. (E)
.5 mi., 1-1.5 hours
·
Welcome
and Introductions
·
Hand
out binoculars
·
THEME: Magnificent Morro
Rock, standing as a sentinel at the entrance to Morro Bay harbor for centuries,
supports a unique ecosystem and several endangered and threatened species that
live in its shadow. Please enjoy your visit here and help us preserve its
beauty and its many species for future generations to enjoy.
·
The
name El Moro or Morro means domed turban, knob or knoll and was given to the
rock by Portuguese explorer Juan Cabrillo who sailed into Estero Bay in 1542.
·
The
nine sisters the Morros of San Luis Obispo County
There are actually 14 peaks extending from Morro Rock to south San Luis Obispo near Tank Farm Road and the SLO airport but only 9 have names.
(If asked, they are: Islay Hill, (775 ft.), San Luis Mtn. (1292 ft), Bishop Peak (1559 ft), Chumash Peak (1257 ft.), Cerro Romualdo (1306 ft.), Hollister Peak (1404 ft), Cerro Cabrillo (911ft.), Black Hill (665 ft.) and Morro Rock).
·
Morro
Rock is about 576 feet and covers about 55 acres, the small rock in front is
Pillar Rock.
·
Lets
move onto the beach area for a better look at the Rock on the north side.
(Move
to Morro Strand State Beach near the rock and the water)
·
Born
20+ million years ago in Southern California near Baja, California Rock est. -
22 million years, others older. The area was then undersea.
·
Plate
tectonics offshore Pacific Plate moving under the North American Plate
scraping rock forming the sisters and the coastal ranges. Plates moving past
each other at San Andreas Fault (east of Paso Robles & Atascadero) causing
earthquakes and moving the sisters northwest.
·
When
the seas subsided about 10 million years ago, the peaks became visible. No ones
knows how active they were but the cones eroded over the centuries, rock dust
filled crevices and seeds took hold sprouting plants to provide shelter for
animals and birds.
·
Dacite
rock Morro Rock is dacite, an igneous (volcanic) rock similar to granite. It
is composed of potash, feldspar, calcite and quartz.
·
The
local Chumash Indians used the Rock as a navigational tool in their canoe trips
along the coast but did not camp here. It was thought of as sacred in their
culture. The closest village was near where the power plant is today.
·
After
Cabrillos visit in the mid-1500s, the next European explorer was Captain Don
Gaspar de Portola travelling by horseback from San Diego to Monterey in 1769.
Fr. Juan Crespi, the diarist for the trip noted in his journal that Rock was
completely surrounded by water and about 200 meters offshore (photo of Morro
Rock before blasting).
·
Degradation
of the Rock by man began about 20 years after the founding of the town of Morro
when blasting of the rock began (1891).
(Info about planned tunnel and blasting party).It provided building
materials for a breakwater at Port San Luis near Avila, the causeway to connect
the Rock to the mainland (1933-35), breakwaters for Morro Bay and to repair the
breakwater here (photo of blasting at Morro Rock and use of same plan as Long
Beach harbor and result). About 1.2 million tons of rock was blasted.
·
Mans
devastation of Morro Rock finally ended in 1963, 70+ years after it began,
after public outcry over the degradation to the rock and its environment. You
can see significant damage from here and we will see more on the other side
(photo after).
·
In
1968, Morro Rock became a California State Historical Landmark and five years
later an Ecological and Natural Preserve protecting the endangered Peregrine
Falcon. Climbing has been prohibited since then.
·
Peregrine
Falcons (photo) nest on the rock every year from late February through June or
early July. They have nested here for centuries. The Chumash revered the
Peregrine as a god. There were two nests (called eyrie) on the Rock this year,
one on the southwest side and one on the northeast side. The falcon is a medium
sized bird about 18 inches (female, male 2 inches shorter) long with a wingspan
of over 3 feet. They weigh 1.5-2 lbs. It has a dark gray back and gray and
white barred under parts and a squared-off tail. The head is black above and
white below and it looks like it has sideburns! The young fledglings are tiny
when born (1 oz.) and have white down but at a month they start sprouting their
brown and white feathers. The falcon is the fastest animal in the world, diving
at 200 mph for prey that it catches in the air. They were once fairly common
along the coast but suffered from the introduction and widespread use of DDT
beginning in the 1950s, which caused thin eggshells that did not hatch
successful young. Although DDT was banned in the US in the early 1970s, it is
still sold in Mexico and Central America where the falcons prey live in the
winter and it is still present in the food chain. Extinction was averted with
the help of the Santa Cruz Predatory Bird Research Center at UC Santa Cruz and
other research facilities in the Mid West and East Coast where baby falcons were
hand-raised and replaced thin and broken eggs in the nests. Many local bird
fanciers in Morro Bay also helped by guarding the nests. Today the falcon is
making a comeback. There were two nests on the Rock with 4 fledglings in 2001
and 2002. The birds use a different nest site each year in the same area and
when they form a pair they will often close to the areas where they were born.
Males claim territories, generally large ones of several miles so it is unusual
to have 2 nests on Morro Rock even though they were on opposite sides.
What can we do to help the Peregrine Falcon? Please make sure you properly dispose of dangerous household and agricultural chemicals so they do not get into the environment where they can affect wild animals as DDT did to the Peregrine Falcon. Also make sure you do not drop lit cigarettes near the rock as the vegetation that we will see on the next stop is very dry particularly in summer and can easily catch fire.
·
There
is another threatened species nesting further up Morro Strand beach and on the
sand spit across from the rock that we will see later the Western Snowy
Plover (photo). This small shorebird weighs about 1 to 2 ounces and is
approximately 6 to 6.5 inches long. It is gray-brown, white, and black. The
Plover nests from March-September on the Pacific coast beaches. There are only
about 1500 left due to the degradation of their nesting grounds and
interference from man and his pets. (No dog signs) (Birds & Nature at Morro
Strand)
·
There
is a small tide pool at the base of the rock facing the beach that is visible
at a minus tide. There you can see surf grass, sea stars, mussels, anemones,
snails, algae, small fish and many other tiny creatures. Now lets move closer
to the rock on the causeway. (Other tidepool walks)
(Move to the path head on the northeast side of the
rock)
·
The vegetation on and around the rock is
chaparral that is tolerant of the windy, salty and sometimes dry conditions.
Plant life here includes white and golden yarrow, fennel, California sagebrush,
nightshade (white and purple), black mustard flower, blackberry, fog lichen (on
the rocks), sticky monkey flower coast salt bush, chamise, arroyo willow,
cactus, sea rocket and poison oak. Sometimes we will see butterflies, moths and
dragonflies in these vegetated areas. During the winter breeding season, the
Monarch butterfly (photo) is often seen here. What can we do to help the
butterflies and other insects? You can see how dry the vegetation is here a
real fire hazard so be careful with lighted cigarettes. Plant native plants
that butterflies & other insects can nest upon. They visit our garden flowers to collect nectar but nest on
native plants. And remember not to step
on caterpillars they turn into beautiful butterflies.
·
Gull
and cormorant nests are visible here and cormorants (Brant and pelagic) out on
Pillar Rock. Males of these species vie with each other for the best, most
protected nesting sights and this can lead to some loud fights, conducted in the
air. The cormorants are great fishing birds with heavy bones so they can stay
under water longer but need to dry out their wings by spreading them when they
land on the Rock.. Double crested
cormorants we see flying and fishing here near the rock nest at the rookery.
·
We
can now see the Dacite (igneous) rock Lets examine it closely. You can
clearly see the colors of the dacite here when wet and dry. The orange
highlights are iron oxides. We can also see clearly and up close the scars of
the seventy plus years of blasting.
·
Lets
move to the other side of the causeway.
(Stop by plaque on way and point out falcon nest on South side.)
(Move
to the parking area on the side of the road facing the harbor near the kelp beds)
·
{Sea
otters may be present fishing in the channel or resting in the kelp beds.} The
sea otter is a member of the weasel family who took to the sea millions of
years ago (photo). This marine mammals relatives include the river otter, the
weasel, the American badger, the mink and the skunk (yes the skunk!). This
animal was hunted nearly to extinction for its beautiful warm fur coat which
helps it to stay warm in our 50 + degree water. Other marine mammals have a
layer of thick blubber to stay warm but the otters fur, which it keeps well
groomed, serves this purpose. It also must eat a lot of food to help stay warm
more than 20% of their body weight each day (60-80lbs average weight of
adults)! It is listed as a threatened species as there are only about 1900
2000 left in the Central California range, extending from near Santa Cruz to
South of Pt. Conception. There is
another colony of slightly larger size in Alaska and a small one offshore
Russia. Sea otters swim on their backs,
eating clams, abalone, sea stars, octopus, sea urchins and other crustaceans.
They help keep the kelp forests healthy by eating the urchins that destroy the
kelp beds. Sea otters are one of only a very few mammals to use tools, rocks to
pound clams and abalone shells off their rocky resting-places and to open clams
and other bivalves. We often see otters here in the kelp beds near the causeway
and feeding in the harbor channel. Many are males but sometimes a female with a
pup will appear near the Embarcadero area across the Bay. Other places to see
sea otters are offshore off Montana de Oro, in the kelp beds north of Cayucos,
sometimes offshore of Morro Strand Beach and near the rocks and kelp beds close
to the Sea Otter Research Station at Piedras Blancas Lighthouse north of San
Simeon. (Sea otter and forest walk)
·
What
can we do to help the sea otters and other marine mammals? Please pack your
trash when you go to the beach clean up after your pets on the beach; be
careful when disposing of chemicals and used oil and do not harass or try to
feed these lovely wild animals. They, like all sea mammals, are very sensitive
to oil spills so if you are boating, make sure your engines are well maintained
and use public restroom pumping stations at the wharfs. Many of these charming
animals from the Alaska population were killed during the Exxon Valdez oil
tanker spill when oil fouled their coats and they died from exposure and
ingesting oil. They are also very
susceptible to diseases carried by improperly treated sewage and animal wastes.
·
Another
sea mammal often seen feeding in Morro Bay is the harbor seal (photo). There is
a resident colony south of the marina in Morro Bay State Park. They can also be
found at Port San Luis near Avila Beach, hauled out on the rocks at Corallina Cove
in Montana de Oro State Park and also on rocks north of Cayucos. Harbor seals
are gray with darker spots and a rounded cat-like head. They have their young
on sandbars or mud flats and the pups can swim within a few hours of birth.
· Franklin Riley founded the town of Morro (now Morro Bay) across the Bay from where we are standing, in 1870. Another early settler and town father was the Rev. Alden B. Spooner I who ministered to the Protestant population in the region, served as town constable and piloted ships entering treacherous Morro Harbor. He died outside the harbor entrance in 1877 while trying to pilot a ship into harbor. The town was incorporated as a city in 1964.
·
The
large electricity plant with the 3 tall stacks in front of us is the Duke
Energy, constructed by PG&E in mid-1950s, sold to Duke in 1990s.
·
The
Sand spit across the harbor entrance is the 7 mile long Morro Dunes Natural
Preserve (another snowy plover nesting area and usually has lots of brown
pelicans on the beach resting).
· Discuss other birds visible
· Brown & white pelicans fly overhead and rest on the sand spit (brown) and Grassy Island near the marina (white). (photos)
· Great & Snowy Egrets & Great Blue Herons are often seen flying (photo) overhead or feeding in the bay as they nest in the Heron rookery across the Bay near the Museum. Nesting season is January- June.
· The annual Audubon Christmas count shows many bird species using the Rock and surrounding beaches as this is part of the Pacific flyway for birds migrating from Mexico to the Arctic. These include the black crowned night herons, double crested Brant & pelagic cormorants, red shouldered hawks, surf and black scooters, the common loon, grebes, oyster catchers, several species of owls, gulls and shorebirds and many land species such as chickadees, finches, wrens, warblers, bushtits, cliff swallows and even turkey vultures.
·
Other
animals include many ground squirrels, lizards and insects, including moths,
butterflies and dragonflies.
·
Lets
move to the south side near the beach.
(Walk
to rocky area above the beach and near the breakwater point out falcon nest)
·
The
harbor entrance and breakwater areas are very dangerous places because of the
high waves and strong ocean currents. Often there are rogue waves that crash
over the rocks and breakwater even on a seemingly calm, sunny day. Many sailors
have lost their lives in boating accidents here and other people have been
washed out to sea from the rocks near the breakwater and the south area of the
Rock. Wave trains come down the coast from the Gulf of Alaska and their impact
on the breakwater can be 3000 lbs. per square foot of breakwater. A wave train
can take 2 days to travel the 2000 miles over deep water.
·
Morro
harbor is 4 miles long by 1.75 miles wide and includes about 1450 acres of mud
flats, eelgrass, pickle weed marsh and salt marsh. It is one of the last
relatively unspoiled estuaries on the Pacific Coast. The harbor entrance is dredged every 2-3 years due to the
positioning of the breakwaters, the closure of the north entrance, silting from
creeks entering the Bay and sand blowing from the sand spit. The harbor
entrance was dredged last winter (2001).
·
Gray
whales (photo), the California marine mammal, pass Morro Bay from December to March
on their 12,000-mile journey from the Arctic to Mexico and return. They are
usually not visible from the Rock due to the fog but it is fun to go out on a
whale watching boat from Morro Bay.
·
Sea
lions (photo) can sometimes be seen in the harbor especially in the fall during
the anchovy season (July & August). They can also be seen offshore on rocks
north of Morro Bay. The humpback whales (photo) also come from Hawaii to feed
on the anchovy. We can see them blowing
from the rock and the beach and again from the whale watching vessels. The huge elephant seals (photo) haul out on
the beach near Piedras Blancas lighthouse north of San Simeon and it is worth
the trip to see them.
·
On
this side of the Rock we can see many holes formed from erosion by sand and
wind. The nesting birds take advantage of them by building their nests in them
since they are better protected from the weather than those on the ledges. The
bird droppings we see aid in fertilization of plant material growing on the
rock here.
·
What
can we do to help the birds and animals on and around the rock? Remember to
pack your trash and be careful with lit cigarettes. Please do not feed the
birds and animals, french fries and bread are not a normal part of their diets
and some of our foods might make them sick. The many ground squirrels here may
carry fleas that can transmit plague so keep your children away from them. If you come to the Rock or the small beach
here with your animals, please keep them leashed and pick up after them. Don't
throw rocks or other objects at the sea otters, birds or other animals and
certainly do not shoot at them.
·
CONCLUSION
(Return
to starting point or at harbor entrance area)
·
Thank
you for visiting Morro Rock. Remember
that the Rock supports a unique ecosystem and several endangered and threatened
species. Please enjoy your visit here and help us preserve the Rock and its
many species for future generations to enjoy. We hope youll come again. We ask
that you take only photos and leave only foot prints.
·
Retrieve
binoculars, answer any other questions
·
Handout
CCNHA newsletter, application
·
Other
handouts (Welcome map. Morro Bay National & State Estuary)
·
Encourage
a visit to the museum give directions
Sources:
Gates
& Bailey, Morro Bays Yesterdays
Krause,
Anthony, Wildlife Watches Guide to San Luis Obispo County
Dickerson,
Sharon, Mountains of Fire
Items
needed:
(Refer to the Morro Walk photo archive (this is a password protected directory only, no web page) of photos for docent training and visitor education for Morro Rock walk (docents can request a user-id and password to browse this directory))
Photos
of:
·
Peregrine
falcon
·
Snowy
plover
·
Sea
otter
·
Harbor
seal
·
Gray
whale/ Humpback whale
·
Sea
lions & elephant seal
·
Blasting
at Morro Rock
·
Morro
Rock without causeway and breakwaters
·
Morro
Rock after
CCNHA
newsletters
Other
handouts
morro-bay.com
Docent Pages
Revised
Monday, February 18, 2008 01:27:44 PM