Today, much of the land surrounding Elkhorn Slough near Monterey, California, is managed to reduce nitrogen input. Nevertheless, there is still 150 times more nitrogen in the slough than a century ago. Because of those levels, Elkhorn Slough mudflats are often covered in a thick, green sludge of nitrogen-loving algae. Algae could also be growing on eelgrass, blocking its access to light. Instead, the slough harbors beds of healthy, dark green eelgrass. So what’s the secret? It turns out to be everyone’s favorite keystone predator, the California sea otter.

Otters help keep kelp forests healthy and also contribute to healthy eelgrass habitat. Photo: Bart Selby

Brent Hughes from the University of California, Santa Cruz was first to make the connection between a charismatic carnivore and an unassuming perennial marine plant. He looked at 50 years of historical data that compared areas with and without otters and discovered that areas with larger populations of sea otters had healthier beds of eelgrass (Zostera marina).

Everyone’s favorite keystone predator, the California sea otter. Photo: Bart Selby

The reason: Otters love to eat crabs, which love to eat grazing invertebrates such as sea slugs, which love to eat the algae that grow on eelgrass.

This pup will learn to eat crabs from its mom, indirectly protecting eelgrass habitat. Photo: Bart Selby

This top-down management of species is known as a trophic cascade. A top predator alters the abundance of its prey, which in turn reduces predation on the next trophic level down the food chain.

The trophic cascade at Elkhorn Slough. The top predator is the sea otter (E. lutris), the mesopredators are crabs (Cancer spp. and Pugettia producta), the epiphyte mesograzers are primarily an isopod (I. resecata) and a sea slug (P. taylori), and algal epiphyte competitors of eelgrass primarily consist of chain-forming diatoms, and the red alga Smithora naiadum. Solid arrows indicate direct effects, dashed arrows indicate indirect effects, and the plus and minus symbols indicate positive and/or negative effects on trophic guilds and eelgrass condition. C, competitive interaction; T, trophic interaction. Image: Original artwork by A. C. Hughes and used with permission of the Proceedings of the National Academy of Science 2013 (see full citation below)

You can see the difference between an area with otters and one without when you look at Elkhorn Slough compared to Tomales Bay. Even though Tomales Bay has lower levels of nutrients (such as nitrogen from fertilizer), it has significantly fewer otters. The result is brown eelgrass covered in algae. Without as many otters preying on the crabs, the crustaceans are four times as abundant and 30% bigger than the crabs in Elkhorn Slough. This leaves very few sea slugs to keep the eelgrass grazed clean of algae.

Otters hard at work, keeping Elkhorn Slough’s ecosystem balanced. Photo: Bart Selby

Where to See the Sea Otters

For the best view of sea otters, visit the Moss Landing Wildlife Area (on the east side of Highway 1) or Moss Landing State Beach (on the west side of Highway 1, just off Jetty Road). At the beach on the same side as the harbor, you can often see a raft of male otters floating together out on the open water.

Keep any eye out for otters when you visit the slough. Photo: Bart Selby

Elkhorn Slough – A Protected Place for Otters and More

Elkhorn Slough is one of the few coastal wetlands remaining in the state, second in size to San Francisco Bay. At nearly 7 miles long, this estuarine waterway shelters an abundance of marine life, providing essential habitat for over 700 species, including aquatic mammals, birds, fish, invertebrates, algae, and plants. It is also part of California’s statewide program to establish Marine Protected Areas (MPAs). MPAs are a lot like our landlocked state parks except that they extend many miles off our coastline. These “underwater parks” are established in areas that are biologically diverse (lots of different marine species), culturally rich (think sunken ships like the S.S. Palo Alto and buried anthropological treasure), and economically important (fishing and tourism are a big deal to these coastal communities).

The MPAs in Santa Cruz County. Image: California Marine Sanctuary Foundation

Elkhorn Slough is home to three marine protected areas—Elkhorn Slough State Marine Conservation Area (SMCA), Elkhorn Slough State Marine Reserve (SMR), and the Moro Cojo Slough SMR. There are several different types of MPAs, and each one has its own set of rules. See the California Department of Fish and Wildlife website for details.

Image: Courtesy the Ocean Conservancy via the California Marine Sanctuary Foundation.

Take the Self-Guided Mobile Tour

This piece is part of the Santa Cruz Marine Protected Areas Beaches Tour made possible by the Santa Cruz Collaborative with support from the California Marine Sanctuary Foundation and the Resources Legacy Fund. Download the free app with many tours of the Santa Cruz area and beyond.

1. Sources

   • Sea Otters: Your Defence Against the Algal Apocalypse. Ed Young. National Geographic. August 26, 2013.
   • Sea otters promote recovery of seagrass beds. Tim Stephens. August 26, 2013. University of California Santa Cruz Newscenter Website.
   • Recovery of a top predator mediates negative eutrophic effects on seagrass Brent B. Hughes, Ron Eby, Eric Van Dyke, M. Tim Tinker, Corina I. Marks, Kenneth S. Johnson, and Kerstin WassonProc Natl Acad Sci, September 17, 2013. Issue 38:15313–15318.

]]> /santacruz/elkhorn-slough-sea-otters-offset-agricultural-runoff/feed/ 0 /santacruz/surfing-over-kelp-forests-at-cove-beach/ /santacruz/surfing-over-kelp-forests-at-cove-beach/#respond Thu, 08 Sep 2016 00:00:41 +0000 /?p=9749

Surfing with the kelp. Photo: Steven Tyler PJs

Marine Protected Areas (MPAs) run along the coastline of California. They were created to maintain the precarious balance between keeping places wild and allowing people to interact with the landscape. In the Año Nuevo MPA, 55 miles south of San Francisco and 20 miles north of Santa Cruz, lies Cove Beach. This is a popular spot for seasoned surfers who fear the loss of this rugged coastline more than the great white sharks cruising the waters in search of fat seals. Gary Strachan, a park ranger and wildlife biologist, is often one of these surfers. He has seen firsthand how the waters have changed over the decades.

Surfer at Cove Beach, April 2015. Photo: Mike Merritt

A typical central California kelp forest community at 40 foot depth, Pebble Beach, California, June 2010. Photo: Chad King/NOAA BMNS

The Loss of Kelp Forests and a Killer Surf Break at Cove Beach

In the summer of 1967, large kelp harvesting boats anchored in the bay and started harvesting kelp. By the end of the summer, the surfers noticed that the waves were choppy or “blown out” on windy days and could be hard, even dangerous, to surf. It seemed that the removal of the kelp patches was affecting the surf. Who knew what implications this massive harvesting could have on the marine ecosystem? Anecdotal evidence from fishermen says that the fishing was much better before the harvest, but scientific data on kelp forests goes back only to 1984. Even recent data does little to clear up the mystery.

Giant kelp (Macrocystis pyrifera) draped over the ocean surface, August 2011. The R/V Fulmar, a research vessel, is in the background. Photo: Chad King/NOAA MBNMS

A 2008 baseline data collection study surveyed the species found in kelp forests at 14 central coast MPAs. Surprisingly, their data showed that the density of a kelp canopy was not related to the number of species found within the canopy. In fact, sometimes more species are found in areas of sparse kelp canopy cover than in areas with dense canopy cover.

Image: Courtesy the Ocean Conservancy via the California Marine Sanctuary Foundation.

Harvesting of kelp at Año Nuevo Bay, by hand, was allowed until early 2016, when it’s status changed from a State Marine Conservation Area to a State Marine Reserve. As a Reserve, it has the highest level of protections and the take of all living, geologic, or cultural marine resources is prohibited. Blown-out waves or not, plenty of surfers still flock to this section of coastline in addition to hundreds of elephant seals.

Image: Courtesy California Marine Sanctuary Foundation

Take the Self-Guided Mobile Tour

This piece is part of the Santa Cruz Marine Protected Areas Beaches Tour made possible by the Santa Cruz Collaborative with support from the California Marine Sanctuary Foundation. Download the free app with many tours of the Santa Cruz area and beyond.

Aerial image of El Jarro Point in 1993. This is area is about 3.5 miles south of Greyhound rock. The buildings in the center-top portion are what is now Swanton Berry Farms. Photo: © Kenneth and Gabrielle Adelman, California Coastal Records Project .http://www.Californiacoastline.org

​Greyhound Rock lies right next to one of the major faults within the San Gregorio Fault Zone. This fact might be no big surprise in earthquake-prone California, but what is startling is how ridiculously close we came to building a huge nuclear power plant right on top of this active fault zone.
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In 1969, Pacific Gas and Electric (PG&E) announced it had leased 6,800 acres of Coast Dairies and Land property and intended to build a 6,000-megawatt-generating nuclear power plant at El Jarro Point, a wide marine terrace between Scott Creek Beach and Davenport Landing. The plant would have stood approximately where Swanton Berry Farm is now and required a major rerouting of Highway 1.

Geologist Gerald Weber standing in the field where El Point Nuclear Power Plant was to have been built. Photo: Julia Gaudinski/Mobile Ranger

“It is a classic exposure of fault movement. The fault had been completely covered by vegetation for probably hundreds of years. If not for the El Niño storms of 1972 and 1973, no one would have ever noticed it.”

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The entire zone between the two black arrows is the Frijoles Fault at Año Nuevo/Cove Beach. Notice that it is a “zone” about 70 feet wide. To find it when you go to our Año Nuevo/Cove Beach stop, look for the trees and the slumped area. If you see the dark tilted layer in the cliffs, above the right-most arrow, you know you have found the fault. Image: Julia Gaudinski/Mobile Ranger

In the 1970s, the San Francisco Bay Area was well-known for earthquakes along the San Andreas Fault, of course. But the San Gregorio Fault, which extends from San Francisco to south of Santa Cruz all along the coast, was just being discovered and mapped. Weber’s work was crucial in detailing the faulting around Año Nuevo State Park and Greyhound Rock.

Faults in the San Francisco Bay Area and Santa Cruz coast region. Image: Courtesy Gerald Weber

By 1971, a passionate group of people was already on the move to stop the nuclear power plant at El Jarro Point. In September 1971, the Santa Cruz County Board of Supervisors voted 3 to 2 for a moratorium “in principle” on a permit for the plant. But it was really Weber’s discovery of the Frijoles Fault and other faults in the San Gregorio Fault Zone at Cove Beach that stopped the El Jarro Nuclear Power Plant dead in its tracks.
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For a nuclear power plant to be approved, there can be no nearby active faults and, in geologic terms, “active” means a surface rupture within the last 10,000 years. By using radiocarbon dating of plant remains at the base of the cliffs at Cove Beach, Weber was able to prove clear movement within the San Gregorio Fault Zone at Año Nuevo/Cove Beach in the last 10,000 years.

A map of the many faults in this area. The fault exposed at Greyhound Rock is still not well mapped. Image: Created by and courtesy of Gerald Weber

Faults from the San Gregorio Fault Zone continue north and south and can be seen in the beach cliffs at Greyhound Rock. Greyhound Rock itself is not faulted.

These cliffs at Greyhound beach clearly show fault movement. The two black arrows point to the most obvious places where rocks have slid past each other. There are likely two other faults in this area two but they are a bit harder to see. Image: Julia Gaudinski/Mobile Ranger

One way to cope with the threat of earthquakes: poke fun at the threat with a t-shirt!

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As you enjoy the California coast, keep in mind that it could start moving and shaking at any time. The San Gregorio Fault Zone has moved in the last 10,000 years and it will move again. We just don’t know when. Geologist Gerald Weber admits that he hopes the San Gregorio Fault Zone, which he spent much of his life laboriously mapping, might show some modest sign of movement while he is still alive.

Take the Self-Guided Mobile Tour

This piece is part of the Santa Cruz Marine Protected Areas Beaches Tour made possible by the Santa Cruz Collaborative with support from the California Marine Sanctuary Foundation and the Resources Legacy Fund. Download the free app with many tours of the Santa Cruz area and beyond.

1. Sources

   • The Geology from Santa Cruz to Point Año Nuevo, with the San Gregorio Fault zone and Pleistocene Marine Terraces. Gerald E. Weber and Alan O. Allwardt. University of California, Santa Cruz

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   • Personal communication with Dr. Gerald (Jerry) Weber, Lecturer Emeritus University of California, Santa Cruz, Geologic Consultant. May and June 2016.

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]]> /santacruz/greyhounds-almost-nuclear-powerplant/feed/ 2 /santacruz/keeping-a-strawberry-farm-protecting-the-elkhorn-slough/ /santacruz/keeping-a-strawberry-farm-protecting-the-elkhorn-slough/#respond Wed, 20 Jul 2016 20:00:13 +0000 /?p=11742

The crops at Azevedo Strawberry Ranch used to run right up to the water’s edge. Photo: Elkhorn Slough Foundation

Row crops were introduced to the areas around Elkhorn Slough in the late 1800s. The majority of these crops were strawberries because the slough’s perimeter has ideal growing conditions with a moderate climate and well-drained soils.

Strawberries are farmed in abundance around Elkhorn Slough due to the ideal growing conditions. Photo: Sharon Mollerus

The Azevedo Ranch, just about one mile up the slough from the Wildlife Viewing Area, was one such strawberry farm. They grew their berries next to the Azevedo Marshes, a series of pocket wetlands that were cut off from the slough in the 1870s with the construction of a railroad embankment. The strawberries were grown right to the edge of the slough, and like all berry farmers of the day, they applied chemical fertilizers containing high levels of nitrogen to the crops.

Sediments and chemicals from strawberry fields used to run off directly into the marshes. Photo: Elkhorn Slough Foundation

If runoff goes unchecked, the addition of nitrogen can lead to massive algal blooms that deplete the oxygen in the water, making it impossible for almost any other species to survive.

Today, there is a buffer zone of native vegetation that traps agricultural runoff before it reaches the Azevedo Marshes. Photo: Elkhorn Slough Foundation

In 1991, the Nature Conservancy acquired the ranch with funding from the Coastal Conservancy. Soon after, they took the strawberry fields adjacent to the slough out of strawberry production. Instead, they planted a native vegetation buffer. Today, the ranch has 24 acres of native plants between its strawberry producing crops and the marshes. This creates a natural buffer zone that traps nutrients and sediments and decreases nitrogen input into the slough. Azevedo Ranch is still owned by the Nature Conservancy, but it is managed by the Elkhorn Slough Foundation. This is a working example of how agriculture can co-exist next to a natural ecosystem without too much negative impact.

The view from the overlook at the research reserve. Photo: Elkhorn Slough National Estuarine Research Reserve

A Great Side Trip

We recommend a visit to the Elkhorn Slough National Estuarine Research Reserve at 1700 Elkhorn Road. They have a visitor center and a wonderful overlook where you can view much of the Elkhorn Slough. There are also five miles of trails to enjoy the grasslands, oak woodland, and wetlands of the Elkhorn Slough. There is a small admission fee for people over the age of 16. If you have a hunting or fishing license, you’ve already paid.

Take the Self-Guided Mobile Tour

This piece is part of the Santa Cruz Marine Protected Areas Beaches Tour made possible by the Santa Cruz Collaborative with support from the California Marine Sanctuary Foundation and the Resources Legacy Fund. Download the free app with many tours of the Santa Cruz area and beyond.

1. Sources

   • Coastal Conservancy Azevedo Marshes Wetland Enhancement. Coastal Conservancy. September 15, 2004. Coastal Conservancy

    

   • Elkhorn Slough Foundation Property: Azevedo Ranch. Elkhorn Slough Website.

    

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]]> /santacruz/keeping-a-strawberry-farm-protecting-the-elkhorn-slough/feed/ 0 /blog/why-is-the-golden-gate-bridge-orange/ /blog/why-is-the-golden-gate-bridge-orange/#comments Mon, 13 Apr 2015 01:00:00 +0000 /?p=2840

International Orange, the color chosen for the Golden Gate Bridge, is a perfect complement to the warm tones of the surrounding hills of Marin. Photo courtesy of Molly Lautamo.

When driving across the Golden Gate Bridge how often have you asked yourself “Why is the Golden Gate orange?” Or, “Why is an orange bridge called the “Golden Gate”? The answer lies in Istanbul and in an architect named Irving Morrow.

The Golden Gate Is Not a Bridge, It’s a Strait

The Golden Gate Bridge is named after the entrance to San Francisco Bay from the Pacific Ocean, which is a narrow passage of water connecting two large areas of water, otherwise known as a strait. This stretch of water was named “Chrysopylae” or Golden Gate in 1846 by Army Captain John C. Fremont because it reminded him of a strait in an Istanbul harbor called Chrysoceras, or Golden Horn. When the construction of the bridge began in 1933, it took on the name of the strait.

The most recognizable strait in the world: the Golden Gate of San Francisco, August 2006. Photo courtesy of NASA.

Many people were concerned that a bridge spanning the wide Golden Gate Strait would mar the beauty of the bay.  Irving Morrow, the project’s consulting architect who designed the lighting and art-deco styling of the bridge, took the people’s concerns seriously and thought long and hard about the right color for the 4,200 feet of suspended steel.

But what color would add, not detract, beauty to the bay and do justice to such an impressive architectural feat?

The Chosen Color: International Orange

Several colors were considered for the Golden Gate Bridge. Among them were black (Morrow thought it would diminish the bridge’s size), silver (more well-suited for a dirigible), gray (too drab for this marvel of engineering), and the worst by far … black and yellow stripes (the U.S. Navy’s preference for visibility). Morrow knew that none of these options would do justice to the world’s longest suspension bridge.

In order to be visible to ships, the U.S. Navy wanted the Golden Gate Bridge covered in yellow and black stripes! Photo courtesy of Official U.S. Navy Page. (October 13, 2011)

Finally, the perfect color presented itself when Morrow noticed one of the bridge’s painters applying an orangish primer to one of the towers. The vermilion orange went well with the surrounding Marin hills and was a stark contrast to the gray fog that enveloped the bridge almost daily. The community echoed Morrow’s preference as well. As the orange primer covered more of the bridge, local citizens wrote eloquent letters to Morrow, emphasizing the area’s natural beauty and pleading that the final coat of paint match that of the undercoat. Morrow prepared a 29-page report, “The Report on Color and Lighting,” to convince the bridge’s Board of Directors to paint the bridge “International Orange.”

His report underscores the natural beauty of the area and thus the importance of choosing exactly the right color for the bridge:

“The Golden Gate [Strait] is a scenic feature which demands all possible respect because of (a) its intrinsic beauty; (b) its great renown; and (c) its strong long-standing sentimental attachment in the minds of inhabitants of the San Francisco Bay region. Many people, sincerely believing that a bridge must of necessity mar this landscape, opposed bridging the Golden Gate for no other reason. Poorly chosen color may actually create disharmony between the structure and the site.”

Luckily, Morrow succeeded in winning support for his daring color choice. While this stunning art deco suspension bridge is no longer the world’s longest, it now holds the title of the world’s most photographed. This is not hard to believe if you’ve ever found yourself catching your breath at the sight of the bridge peeking out above a thick layer of fog, the bold orange brush strokes of color in bright contrast to the cold, gray sky.

Imagine how hard it would be to see the Golden Gate Bridge in the fog if it were gray (the second color choice) and not orange! Photo courtesy of Frank Kovalcheck. (May 31, 2010)

How to Maintain 10 Million Square Feet of Paint

If you grew up in California, you’ve probably heard that the Golden Gate Bridge is repainted from end-to-end every year. Well, this mind boggling rumor is nothing more than just that — a rumor. In an article on NPR superintendent Rocky Dellaroccato joked, “Yeah, you start at one end, and when you get to the other end, you retire.” We are talking about 10 million square feet of steel after all! The paint does require routine touch-ups on a continual basis by a team of 34 painters and 16 ironworkers. (The ironworkers move along with the painting crew, removing pieces of steel to make painting possible and replacing parts as needed.) These touch-ups require 5,000 to 10,000 gallons of International Orange every year.

Touch-ups on the Golden Gate Bridge require 5,000 to 10,000 gallons of International Orange paint every year. Photo courtesy of Anita Dikinme. (Dec 19, 2005)

How To Get Your Hands on a Can of International Orange

There is enough International Orange paint for everyone if you’re as smitten with the color as the rest of the world. So many people have asked for a paint sample over the years that it can now be found on the Highway and Transportation District’s website. Just give your local paint store these instructions: CMYK colors are: C= Cyan: 0%, M =Magenta: 69%, Y =Yellow: 100%, K = Black: 6%.

Now the next time you’re driving across the famous Golden Gate Bridge, you can impress your passengers by telling them about the strait in Istanbul and how the color was chosen because an architect and local citizens liked the orange hue of the bridge’s primer. Oh and don’t forget to mention that we should all be grateful to Irving Morrow for ensuring the bridge did not end up covered in black and yellow stripes!

One of two picnic tables made from the original 1864 packing crate for the 3,800 pound cheese made by the Steele family. Seated at table is Mrs. Catherine Steel. Photo circa 1950; courtesy of the Santa Cruz Museum of Art & History.

There are many ways to show support for your country’s troops, but would you ever think of making the world’s largest cheese to raise money for hungry soldiers? In the early summer of 1864, a farming family by the name of Steele did just that: They produced a 3,800 pound wheel of cheese to raise money for the soldiers of the Army of the Potomac.

The Steele family of Pescadero was at that time one of the most well-known dairy operations in California. They began in Petaluma and wound up at Rancho Punta del Año Nuevo, or “cow heaven” according to Isaac Steele. The ranch was owned by Loren Coburn, a very wealthy and notoriously greedy man who owned most of the land in Pescadero. Despite his bad reputation, a lease was arranged and the Steeles moved 1,100 cattle to the ranch in 1861. The family earned $17,000 (almost half a million today!) on cheese alone within the first year at the ranch.

Imagine a wheel of cheese weighing almost 4,000 pounds! Photo courtesy of Loseitlady.

A Unique Show of Support for the Union

When the Civil War was declared in April of 1861, Isaac’s brother Frederick joined the army and became a general. With a close family member fighting in the war, the Steele family wanted to contribute something special to the United States Sanitary Commission (the Civil War equivalent of the Red Cross). What better way for dairy farmers to show support for their troops than to produce for them the world’s largest cheese?

Notice of an address by Rev. Dr. Bellows upon presentation of cheese to the Sanitary Commission. Photo courtesy of the New York Public Library Digital Collections.

In the early summer of 1864, with this ambitious goal in mind, the Steeles enlisted the help of their neighbors to milk 1500 cows, make curds, and press the curds together to produce a 3,800 pound wheel of cheese. The cheese, worth $800 then ($11,900 today), was presented to the Sanitary Commission by Reverend Dr. Bellows. It was met with wonder and amazement and became the central attraction of that year’s Industrial Fair of the Mechanics Institute of San Francisco.

Held in San Francisco’s Union Square, the Fair’s pavilion featured a 108-foot-high dome. The seven foot wide by two foot deep cheese was displayed at the center, hidden inside a Chinese pagoda ringed with potted flowers and called the “floral temple.” To see the massive cheese, people paid 25 cents to one of several wounded soldiers who had fought bravely for the Union. The money raised all went to the National Sanitary Fund and after a month on display, the cheese wheel had raised $1500 (equal to $22,400 today).

Mark Twain Reports on the Monster Cheese

Samuel Clemens reported on the great cheese in the Daily Morning Call on September 10, 1864:

Mark Twain, Brady-Handy photo portrait. February 7, 1871. Photo courtesy of the United States Library of Congress.

“It is the contribution of two whole hearted brothers, and it is worth twenty-five cents to look upon such a monument of kindly Christian charity. After that cheese has gone the rounds of the States and collected a quarter of a million for the Sanitary Fund, it will be cut up in New York and sold by the slice [to benefit the Sanitary Fund].”

Samuel Clemens wrote several pieces about the monster cheese but he failed to fact check his work and the Call’s editor-in-chief, George Barnes, let him go in October saying,

“You’re out of your element, Clemens. The position requires persistence and a certain attention to detail. I believe you are unsuited to it. Besides, you’re obviously capable of greater things in literature.”

And indeed he was. Samuel Clemens moved on from reporting on the world’s largest cheese to writing some of America’s greatest literature under his pen name, Mark Twain.

President Lincoln Gets a Bite of the Big Cheese

The cheese wheel’s final destination was meant to be New York so that the soldiers of the Army of the Potomac could enjoy the delicious creation. Sadly, only samples of the cheese made the trip. It was decided that by the end of the journey, planned to be made by steamship, the cheese would no longer be edible and would go to waste. So instead, most of the cheese remained in San Francisco and was sold for 50 cents a pound to anyone interested in trying the world’s largest cheese and supporting the Sanitary Fund. Some of the cheese did make it all the way to New York (a special sample box was sent to Reverend Dr. Bellows) and to the White House so that President Lincoln could try a piece. In the end, the massive cheese raised $2,820 and was enjoyed at Thanksgiving dinner by many San Franciscans that year.

Special thanks to Randall Brown for writing the article that was the main source for this piece.

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Creation of the Santa Cruz Mudstone

The Santa Cruz Mudstone was created about 7-9 million years ago (late Miocene) by the settling of fine grained silts, clays and the silicate remains of billions and billions of single-celled plankton called diatoms. It varies in thickness but has been measured to be 8,900 feet thick in at least one location.

The sediments accumulated offshore of the ancient (paleo) coast, on the continental shelf or slope, in ocean water about 450-600 feet deep. This is nearly the same type of condition we have today half a mile off our modern coast. The silts and clays came from nearby rivers, and as the amounts coming from each source varied over time, so did the composition of the layers. With time, these sediments became very thick.

Hardening to Rock

Over millions of years, thousands of feet of sediment were deposited on top of the Santa Cruz Mudstone sediments. With burial, the sediment warms up and some of the silica from those billions of diatoms dissolves and later re-precipitates as cement that binds the particles together; this is called lithification.

During and after lithification, the sediments are also subjected to regional tectonic stresses from huge tectonic plates moving around, which can cause folding and faulting. Thus the original sediment composition, the degree of lithification, and the amount of tectonic stress all combine to determine how hard a rock is and how it will erode. In and around Santa Cruz, the Santa Cruz Mudstone is not very deformed, with just some tilting, jointing, and faulting.

Take the Self-Guided Mobile Tour

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To help guide you through the history, a cultural preserve lies within the park. There are restored farmhouses and workshops from a century of dairy farming. Docents dressed in period clothing are often available for interpretive tours and living history demonstrations. It is very family friendly with a large chicken coop and a great “climbing tree.” Call (831) 426-0505 for hours and tours.

The restored Wilder Ranch Farm House. Photo by Grey3K.

Native Americans

The native peoples of this area refer to the region as Cotoni and call themselves the Awaswas. Most folks today think of them as the “Ohlone” people but this is a misnomer and not how they identify themselves. Today the descendants of the area’s indigenous forbearers who were “missionized” at Santa Cruz and San Juan Bautista, are organized as the Amah Mutsun Tribal Band. The Cotoni-Awaswas nourished themselves from the sea and tidal zone as well as harvesting, gathering and taking game from the coastal uplands. Though not “agricultural” as we tend to think of it, California Indians thrived by actively managing the environment for productivity.

Europeans

The Spanish first came to Monterey Bay in the mid-1500s, but they did not establish settlements until sometime after the expedition of Gaspar de Portolá in 1769/70.

During this period, the Spanish laid claim to the land as their property, divided it into land grants called ranchos, and offered it to Spanish speaking settlers from Mexico. In 1849 the region became part of the United States but the land grants left a framework by which future subdivisions were made. In many cases, outlines of the original grants are still marked by the fences and roads of today.

From 1791 to 1835, all of the land west of Mission Santa Cruz was used by the Mission for hunting and agriculture. In 1835 it became Rancho Refugio. The huge land grant had various owners and was subdivided into smaller sections. Deloss D. Wilder bought the section on which the park stands today, in 1885. He and his descendants operated a dairy farm here until the 1930s when financial pressures necessitated a switch to beef and vegetable production.

One of the spectacular views you can see along the Old Cove Loop Trail. The rock type here is the Santa Cruz Mudstone. Note the shore platforms formed by erosion of the mudstone and the large pocket beach half in shade.

The same spot as above from a postcard circa 1913. You can see a large arch (left) and two caves. Image courtesy of the Santa Cruz City-County Library System.

In 1969 the Wilder family sold the property to the Moroto Investment Company who proposed to develop up to 10,000 housing units over 30 years. The land was included in a plan developed by the Santa Cruz City Council to extend the city limits 3.5 miles to the north along the coast, thereby doubling the cities population.

Local residents opposed the plan and formed groups such as Operation Wilder to fight it. Similar to the battle to save Lighthouse Field, Santa Cruz County citizens voted to protect the open space. In 1974, California State Parks acquired the property to preserve the land’s natural environment and cultural history.

Open Space

Much of the open space along the coast north of Santa Cruz is the result of many struggles between development and other priorities. Large tracts of land including Wilder Ranch, Gray Whale Ranch, Scaroni Ranch (now part of Wilder), Coast Dairies Property and very recently the CEMEX Redwoods area surrounding the Davenport Cement plant, are all development-free because of the work of many conservation organizations.

Since 1994 this beach at Wilder Ranch has undergone restoration efforts to create a more native habitat. It is currently closed to visitors.

Human Impacts on Ecosystems

European settlement caused significant changes to the landscape and ecology as new plants and animals were introduced. Grazing lands were created, by burning on lowland slopes, to support large numbers of cattle, horse and sheep.

Prior to European settlement, grasses in the Monterey Bay area were perennial bunch grasses such as purple needle grass. Patches of native grasses can still be found on rougher terrain that is inaccessible to grazing and cultivation. These grasses, though able to recover from a burn, do not tolerate repeated grazing. Thus exotic plants, originating in the Mediterranean, took hold and spread outward from Monterey—the main site of Spanish activity.

Accounts show that by 1846 landscapes had been noticeably changed and new species had taken hold. Some of the most common plants now associated with rural California landscapes are non-native wild oats, filaree, wild mustard, wild radish, foxtail, and bur clover.

Fields of rosemary being cultivated within Wilder Ranch State Park.

Ecosystem Restoration

Today Wilder Ranch is managed to support a variety of activities including recreation, agriculture, cattle grazing, and cultural preservation. Recently 110 acres has been restored to pre-Spanish habitat conditions with native vegetation.

Restoration work began in 1994. Some of the agricultural fields have been returned to wetland and riparian habitats with their native tree, shrub and plant species.

Wetland birds and hawks now nest in this habitat. Red-legged frogs and other wetland animals have also moved into the area. The riparian corridor was planted with dogwood, alder, cottonwood, and willows. It will take constant vigilance to keep out weedy plant species such as hemlock and thistle. The hope is that Wilder Ranch will become a showcase coastal wetland restoration site.

Marine Terraces

Have you ever wondered why much of the Westside of Santa Cruz and all the agricultural fields just north of it are so flat, or why many of the hills climb upwards like a staircase to flat tops? It’s because the local landscape is made up of ancient marine terraces which formed as sea level rose and fell over the millennia. These terraces are clearly visible from Western Drive north to Año Nuevo State Reserve. Once you recognize them they will always pop-out at you. The second marine terrace runs along Highway 1 very clearly from Western Drive to Davenport.

View looking north from the Old Cove Trail. You are standing on the first marine terrace. The second marine terrace is clearly visible. To the right of the middle white arrow, you can see the third marine terrace.

The story of how the marine terraces formed begins long ago when the west coast of the United States, as far inland as the state of Utah, was under the ocean. Most all rocks west of Utah are either marine sediments or volcanic in origin.

Here, on the north coast of Santa Cruz, the marine terrace sequence consists of a series of platforms or “terraces” cut into the ocean facing slope of our local mountain (Ben Lomond Mountain). Each terrace is an ancient ocean floor that has since been slowly uplifted by large scale tectonic movements along the San Andreas Fault System. The higher the terrace, the older it is. The steep surfaces that separate each terrace are ancient beach cliffs eroded away by waves when sea level was high. For a more detailed explanation about marine terraces click here.

Map showing the Santa Cruz marine terraces. The first through fifth terraces are shaded purple, blue, green, yellow and red, respectively. The black arrow points to the fifth marine terrace. The image is modified from a 2008 paper by Art White and colleagues (cited below).

Many thanks to Archer Koch of MultirotorCam.com for permission to use of his video at the start of this post.

Further Information

Save the Redwoods League

Take the Self-Guided Mobile Tour

This piece is part of the North Coast Tour. Download the free app with many tours of the Santa Cruz area and beyond.

1. Sources Used

   • California State Parks Website. Wilder Ranch Pamphlet. 2009.
   • Chemical weathering of a marine terrace chronosequence, Santa Cruz, California I: Interpreting rates and controls based on soil concentration–depth profiles. A F White, M S Schulz, D V Davison V. Vivit, et al. Geochimica et Cosmochimica Acta. 2008;72:36–68.
   • Monterey Bay Area: Natural History and Cultural Imprints, Second Edition. Burton Le Roy Gordon. Boxwood Press; 1977.
   • The Monterey Bay Shoreline Guide. Jerry Emory. University of California Press; 1999.
   • Ocean Cliffs at Wilder Beach Circa 1913. Santa Cruz Public Libraries Website Website. http://www2.santacruzpl.org/gallery2/v/postcards/v3-013.jpg.html.
   • Personal Communication with Jim Keller, Director of Conservation and Land Initiatives, Amah Mutsun Tribal Band, November 28, 2012.
   • A Santa Cruz County Century: The Sentinel takes a journey through the past 100 years. Santa Cruz Sentinel. Santa Cruz Sentinel Publishers Co. 2000.
   • Wilder Ranch State Park. Wikipedia. http://en.wikipedia.org/wiki/Wilder_Ranch_State_Park.

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]]> /santacruz/wilder-ranch-coastal-california-in-a-nutshell/feed/ 0 /blog/collecting-ancient-rocks-in-bloomers-at-pescaderos-pebble-beach/ /blog/collecting-ancient-rocks-in-bloomers-at-pescaderos-pebble-beach/#comments Thu, 12 Feb 2015 04:19:17 +0000 /?p=2312 Many thanks to Barry Blanchard for permission to use this video.

Women in bloomers and children in search of treasure once flocked to Pebble Beach to spend hours hunting for the best pieces of agate, opal, jasper, and carnelians polished by the waves to shiny perfection. Also known as Bean Hollow State Beach North, the beach is located along California’s scenic Highway 1, about 30 miles north of Santa Cruz and 17 miles south of Half Moon Bay. It was a famous tourist destination in the late 1800s and the place of failed dreams for a greedy local millionaire, dead-set on privatizing Pebble Beach.

 

The Ocean Shore Railroad & Pockets Full of Pebbles

 

The Ocean Shore Railroad was originally designed to connect Santa Cruz and San Francisco by rail. Building began in 1905 at both ends. Between the years of 1907 and 1920, passengers could catch this rail line starting in either town but a gap remained between Tunitas (south of Half Moon Bay) and Swanton (north of Davenport), with Pebble Beach and Pescadero solidly in this gap.

 

The town of Pescadero, three miles from Pebble Beach, still managed to have a thriving tourist industry: Visitors from San Francisco could take the train to Tunitas and then board the Stanley Steamer stage and finish their journey by stagecoach to reach Pescadero. (It’s not clear if folks from Santa Cruz had this option.) Swanton’s Hotel in Pescadero provided lodging for the travelers and transported folks by the wagonload to Pebble Beach everyday.

 

The writer of a report in the Alta California (May, 1867) describes the extreme popularity of the beach’s pebbles:

 

“The whole conversation at the [Swanton] hotel is pebbles. The house is full of them; one steps on them in the parlor or on the stairs; visitors carry them in their pockets and compare them at the breakfast table; they are, in fact, in everybody’s mouth! I verily believe they carry them to bed, and dream of pebbles all night …”

 

Rock Collecting in Bloomers

 

The writer also describes the “ludicrous” scene of folks in their finery (including many pairs of bloomers) sprawled on the piles of pebbles, their heads stuck in holes that they’d dug in their passionate search. It is said in one account that these collections could be found in all the upper class houses in San Francisco and along the coast. Today’s beachgoers are no longer allowed to collect the pebbles, but you can still lay face down on top of them (wearing your bloomers if you like) and look and touch to your heart’s delight.

 

Women in their bloomers at the beach in 1898. Original image is in the public domain.

“Coburn’s Folly” & The Gate Debate

 

A wealthy man named Loren Coburn owned most of Pescadero, including Pebble Beach. He had plans to build a hotel overlooking the beach and a town called “Coburnville.” According to the late local historian and 35-year San Mateo County resident, June Morrall, Coburn was an uncharitable millionaire who had few friends in the Pescadero community. In addition to his sour temperament, Coburn was accused of murdering a well-liked Pigeon Point wharf employee in a shootout. Coburn proved he was a most disagreeable fellow by putting up a locked gate on his property, barring the public from accessing their beloved Pebble Beach.

 

A group of locals were enraged by this greedy act and banded together to storm the gates. Morrall writes that “the mood was one of vengeance as Pinkham [County Roadmaster and the group’s leader] sized up the pine bridge planks, fastened with long wire spikes, that sealed the entrance. Methodically, the roadmaster slashed away at the offensive chains and padlocks and the gate opened.”

 

The Pebble Beach War

 

This started what was called “The Pebble Beach War.” Every time someone tore down Coburn’s barricades he would put them up again. Eventually Coburn charged his longtime adversary, local business-man Joe Levy, with a misdemeanor for taking part in breaking into his private road. Pescaderans finally pushed for the beach to be dedicated as a San Mateo County public park. The legislation passed in 1893 but it did not ensure that Coburn’s road be made public.

Loren Coburn’s Hotel and livery stables at Pebble Beach. Photo © California Views Collection. Used with permission.

Coburn continued to fight for private ownership of the land. Despite it now being a public park, he somehow managed to build his grand hotel above the beach that offered modern luxuries like hot water. He had hopes of large profits and huge success as there were still solid plans for the Ocean Shore Railroad to pass through Pebble Beach. These hopes and dreams never came to fruition, and it is said that the only person to stay overnight at Coburn’s hotel was the watchman.

The hotel’s failure was in small part due to the 1906 San Francisco earthquake which damaged much of the rail line. Funding for completing the tracks largely dried up soon after. The main barricade to success though was probably his widespread unpopularity. Supposedly, tales of the “gate debate” spread and slowed tourism to the area for a time. The fine folks of San Francisco had probably heard of Coburn’s selfish and inhospitable nature and decided to avoid the new hotel. The failed hotel burnt down in 1920 and is remembered as “Coburn’s Folly.”

An Uplifting Beach

Like most of the beaches in coastal California, the sea cliffs here were once loose sediments on the bottom of the ocean floor. The flat cliff tops that you can see in the opening video are part of the first marine terrace.

An example of marine terraces along the coast north of Santa Cruz. The numbers correspond to the generally accepted numbering of each terrace—from the first marine terrace (agricultural fields) to the fourth (highest set). Picture © Kenneth and Gabrielle Adelman, California Coastal Records Project www.Californiacoastline.org

If you go to Pebble Beach, keep an eye out for these wide, flat stairs, or marine terraces, rising out of the skyline as you drive along Highway 1. Each terrace is an ancient ocean floor that has since been slowly uplifted by large tectonic movements on the San Andreas Fault System. The higher the terrace, the older it is. The steep surfaces that separate each terrace are ancient beach cliffs eroded away by waves when sea level was high.

At Pebble Beach the modern sea cliffs are Quaternary in age, about 100,000 years in this case, and the sediments are beach sands or deposits from fairly near the paleo-shoreline.

Pebble Beach with Quaternary sandstones in the foreground.

Underwater Landslides of the Cretaceous

The flat beach surface, or “beach platform” is totally different than the sea cliffs. Those rocks are late Cretaceous in age, or 60 to 100 million years old, and show the story of much tectonic activity through their 63 degree tilt. These tilted sediments were originally deposited far from their paleo-shoreline in water about a mile deep. What’s odd is that normally in such deep water the sediments are fine-grained silts and muds, but these sediments are mostly coarse pebbles!

Why Are There Pebbles on Pebble Beach?

So how did the pebbles end up in deep water? They were essentially the deposits of repeated underwater landslides called turbidity currents. Turbidity currents are plumes of sediment (dense gravel, sand and mud) that rush downslope, often triggered by an earthquake. They carve out everything in their path and carry the debris for long distances. They usually set up a channel that transports sediments out into deep water over and over again. Sometimes it’s a mix of really coarse stuff, sometimes its finer grained muddy stuff. This is essentially what is happening right now south of here in Monterey Bay Submarine Canyon. Once these deposits turn into rock, they are called turbidites. The beach platform at this beach is composed of turbidites. The pebbles on the beach and in the younger sea cliffs are reworked and recycled from these Cretaceous turbidites. They likely get stuck here due to the deeply convex shape of the beach.

The multi-color pebbles of Pebble Beach. Photo courtesy of John Kim. (June 2009)

Tafoni: Rock Art Created by Salt & Air

 

Looking south across the parking lot of the official Pebble Beach is another section of coastline covered in an amazing display of tafoni or honeycomb weathered rock. The sandstone here looks like abstract hunks of swiss cheese—it’s filled with holes and undulates along the beach in subtle waves and dramatic peaks of latticed stone. These “honeycombs” in the rocks are caused by the salty air wearing away weaker sections of the rock. Because this is an inter-tidal area, the rocks are subject to wetting and drying cycles as well as wave action. Once a small hole forms, it accumulates ocean water and other debris that accelerates the erosion process and expands the cavity, creating what looks like a honeycomb.

Tafoni or “honeycomb” weathering at Pebble Beach. Photo courtesy of Dawn Endico. (Dec 2011) 

What Could Have Been

Pebble Beach may not offer seaside accommodations as it did over one hundred years ago, but it still offers an abundance of geologic wonders as well as tide pools filled with fascinating invertebrates and coastlines teaming with marine life like harbor seals, Brandt’s cormorants, and whales. In fact, we’re lucky that this historically popular tourist destination was never developed the way Loren Coburn would have liked. Instead of “Coburnville” and private roads guarded by locked gates, we have a beautiful state beach for everyone to enjoy.

Take the Self-Guided Mobile Tour

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1. Sources Used

   • South from San Francisco: The Life Story of San Mateo County by Frank M. Stanger. 1963. San Mateo County Historical Association.
   • History of Pescadero, California. From: The Story of San Mateo County, California. Roy W. Cloud. S.J. Clarke Publishing Company. 1928. http://history.rays-place.com/ca/sm-pascadero.htm
   • Half Moon Bay Memories: The Coastside’s Colorful Past Paperback. Jun Morrall. 1978. http://www.halfmoonbaymemories.com/?p=159
   • Pescadero Memories: The Battle Over Pretty Pebbles at Pescadero. June Morrall. Posted on Jan 17, 2008. http://www.pescaderomemories.com/?p=335 and http://www.pescaderomemories.com/?p=335
   • Geological Outings Around the Bay: Pebble Beach. Quest Website. Andrew Alden. March 3, 2011. http://science.kqed.org/quest/2011/03/03/geological-outings-around-the-bay-pebble-beach/
   • Bean Hollow State Beach, Pebble Beach. Coastside State Parks Website. http://www.coastsidestateparks.org/pages/bean-pebble.htm
   • What is a turbidity current? NOAA Website. http://oceanservice.noaa.gov/facts/turbidity.html
   • Geology of the Marin Headlands and the Half Moon Bay coast. Saturday, May 19, 2001 California Rocks! Field Trip Guide. Instructor: Mary Leech GEO 116, Continuing Studies Stanford University. http://www.sanandreasfault.org/coastalgeology.pdf
   • The Geology from Santa Cruz to Point Año Nuevo—The San Gregorio Fault Zone and Pleistocene marine terraces. By Gerald Webber and Alan Allwardt. In: Stoffer PW, Gordon LC, eds. Geology and natural history of the San Francisco Bay Area: a field-trip guidebook: 2001 Fall Field Conference, National Association of Geology Teachers, Far Western Section: September 14-16. USGS Bulletin 2188; 2001:194.
   • Canyon Processes. Monterey Bay Aquarium Research Institute Website.http://www.mbari.org/canyon/.
   • Our Ocean Backyard: Grand canyons on the seafloor. Gary Griggs. Santa Cruz Sentinel. November 21, 2009. http://www.santacruzsentinel.com/ci_13839171.
   • Our Ocean Backyard: Submarine Canyons: Going Deeper. Gary Griggs. Santa Cruz Sentinel. December 19, 2009. http://www.santacruzsentinel.com/localnews/ci_13933346.
   • Our Ocean Backyard: Why Monterey Submarine Canyon? Gary Griggs. Santa Cruz Sentinel. January 2, 2010. http://www.santacruzsentinel.com/ci_14109831.

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]]> /blog/collecting-ancient-rocks-in-bloomers-at-pescaderos-pebble-beach/feed/ 5 /blog/beach-bowling-paleo-style/ /blog/beach-bowling-paleo-style/#comments Mon, 12 Jan 2015 05:33:32 +0000 /?p=1948

Bowling Ball Beach. Photo courtesy of John ‘K’. (December 2012)

Aptly named Bowling Ball Beach (part of Schooner Gulch State Beach), the geologic wonders here are plenty and plenty strange. Low tide reveals spherical rocks, two to three feet in diameter, resting in rows within naturally occurring ‘lanes’ within the surf. And if the giant paleo-bowling alley were not enough, just to the north, massive english muffins decorate the sandstone cliffs and wet sand.

The rocks on this remote Northern California beach in Mendocino County are sandstones and mudstones that were deposited on the sea floor during the Miocene (5-25 million years ago).

Image courtesy of Ted from geologictrips.com.

So just how do these massive bowling balls form?

These round rocks are unusually large concretions. Concretions form when minerals like silica or calcite concentrate around a common center and cement the grains of sand, silt or clay into hardened spheres. The concretions grow larger and larger over millions of years and can withstand weathering better than the surrounding material within the rock formation. Thus as the surrounding rock is eroded away by wind and waves, the concretions remain. Those in the cliff faces fall to the beach, those on the beach surface, largely stay put.

Bowling Balls in neat rows on the beach. Photo courtesy of Chris de Rham. (June 2008)

A bowling ball protrudes from the upturned sandstone bed.
Photo courtesy of Ted from geologictrips.com.

A concretion on the beach is still surrounded by sandstone from the host rock formation.
Photo courtesy of Ted from geologictrips.com.

It’s Not a Dinosaur Egg, It’s a Concretion!

Concretions have been mistaken for dinosaur eggs before, most famously in Chechnya in 2012. Dinosaur eggs are much smaller, however and too fragile for so many to remain intact like the rocks at Bowling Ball Beach. Another way you can tell the bowling balls are not dinosaur eggs is that wave patterns in the sand that formed as the sand was originally deposited can be followed from within the “host” sandstone into the round concretions (see photo above).

 

Rock concretions have been mistaken for fossilized dinosaur eggs like these ones from the fossil exhibit in the Kunming Natural History Museum of Zoology in Yunnan, China. Photo courtesy of Daderot. (August 2011)

From Horizontal to Vertical: Formation of the Lanes

What makes this beach really stand out is the combination of both the bowling balls and the amazingly straight and repeating bowling lanes that run right into the cliff face. While all sedimentary rocks are deposited laying fairly flat, these layer cake sandstones and mudstones were tilted upward by 90 degrees. If you look at the map above, you will see the San Andreas Fault is just to the east of Bowling Ball Beach. The uplift and tilting happened by movement and squeezing of the rocks along the San Andreas Fault system. Once tilted 90 degrees, slight differences in erosion of the layers make the lanes really stand out.

The “bowling alleys” of Bowling Ball Beach. As waves crash into the cliff, the sandstone erodes away and form the ‘lanes’. Photo courtesy of Ted from geologictrips.com.

 

English Muffin Rocks

In addition to the natural bowling alley, Bowling Ball Beach features what could be described as a giant game of shuffleboard. Towards the north end of the beach, a bed of gray shale hosts concretions that have been cemented by silica and resemble massive english muffins, five to six feet across. Some rest high up in the cliffside while others have slid down towards the sand like giant pucks in a game of vertical shuffleboard that has lasted for millennia.

The “muffin” rocks. Photo courtesy of Ted from geologictrips.com.

Have you visited Bowling Ball Beach or been to another beach with cool geologic concretions and stratifications? Let us know in the comments or on Facebook, and share photos if you have any!

Also, a special thank you to Ted of Geologic Trips for allowing Mobile Ranger to use his photos. Check out his website for a more detailed description of the geologic processes that formed Bowling Ball Beach.

 

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1. Sources Used

   • Geologic Trips, Sea Ranch and Bowling Ball Beach. Ted Konigsmark. GeoPress; 1995. http://www.geologictrips.com/sr/gtsr.pdf
   • Bowling Ball Beach. http://www.geologictrips.com/bbb/bbb.pdf
   • Compaction and Cementation. The Geological Society Website. http://www.geolsoc.org.uk/ks3/gsl/education/resources/rockcycle/page3559.html
   • Bowling Ball Beach Redux. Phil Wendt Website. Published March 6, 2013. http://philwendt.com/2013/03/06/bowling-ball-beach-redux/

This aerial photo taken about 3.5 miles north west of Western Drive on Highway 1 shows four marine terraces. The numbers correspond to the generally accepted numbering of each terrace—from the first marine terrace (agricultural fields) to the fourth (highest set). Picture © Kenneth and Gabrielle Adelman, California Coastal Records Project www.Californiacoastline.org

Have you ever wondered why much of the Westside of Santa Cruz and all the agricultural fields just north of it are so flat, or why many of the hills climb upwards like a staircase to flat tops? It’s because the local landscape is made up of ancient marine terraces, which formed as sea level rose and fell over the millennia. They are clearly visible from Western Drive north to Año Nuevo State Reserve.

The flat foreground is the first marine terrace. The second marine terrace is clearly visible. To the right of the middle white arrow, in the background, you can see the third.

The Santa Cruz marine terraces are a series of platforms cut into the ocean-facing slope of our local mountain (Ben Lomond Mountain). Each terrace is an ancient ocean floor that has since been slowly uplifted by large-scale tectonic movements. The higher the terrace, the older it is.

The first marine terrace is 105,000 years old and the fifth is about 550,000 years old. The steep surfaces that separate each terrace are old beach cliffs eroded away by waves during high stands in global sea level that occur during glacial cycles. The Westside of Santa Cruz and the many agricultural fields to the northwest are on the first marine terrace (also known as the Highway 1 Terrace). The second terrace parallels Highway 1 on the inland side all the way to Davenport. It is very easy to spot once you know it.

Map showing the Santa Cruz marine terraces. The purple is the first marine terrace. The blue is referred to here as the second, green the third, yellow the fourth and red the fifth marine terrace. The black arrow points to fifth marine terrace. Image is modified from a 2008 paper by Art White and colleagues on chemical weathering (listed at bottom).

How Do They Form?

Marine terraces can be found in many places around the globe but just the right conditions must be present for them to form. These are:

• Slow and steady tectonic uplift (rates of about 0.02 inches per year)
• Repeating cycles of rising and falling sea level (rise and fall of up to 400 feet!)
• Just the right rate of erosion for a wave cut platform to form and a sea-cliff to be preserved

To understand how marine terraces are created, begin by thinking about the beaches of today. Each of the terraces you see once looked like a modern beach.

Schematic showing how a modern beach platform evolves into a marine terrace. Figure from a 2001 USGS paper by Gerald Webber and Alan Allwardt .

Normally, most of the ocean’s wave energy is used in leveling the wave-cut platform. But during winter storms and high tides large energetic waves erode into the sea cliff. In order for a marine terrace to form from a modern sea cliff, two things must happen:

• Sea level falls by 10 to 100s of feet, leaving the cliff free from further wave erosion.
• Continuous tectonic uplift then isolates it from the next high sea level stand.

Once the ocean recedes during a low stand in sea level, the process starts over again. The beach slowly rises becoming the new elevated sea cliff and terrace platform, and when the ocean advances again it slowly cuts a new wave-cut platform into the terrace. Erosional processes during uplift round out and bury much of the original beach deposits and sharp contours.

Another key factor is the erosion rate of the rock that makes up the mountain. It has to be hard enough to hold a cliff edge. In Santa Cruz, it is the Santa Cruz Mudstone that forms the modern sea cliffs and most of the marine terraces. It makes a hard and durable sea cliff that takes time to erode. In fact, the waves need to be focused in one location for a long time — thousands of years — to form a sea cliff. Also, sea level must rise at a rate just slightly greater than the tectonic uplift rate. If sea level rises too fast or too slow, wave action will not be focused on one location long enough to create a wave-cut platform and a sea cliff.

Geek Details: How Many Terraces and How Old?

The number of marine terraces found on Ben Lomond Mountain is still debated in scientific papers. Papers in the 1960s reported up to nine. Since the mid-1970s, five or six are generally reported. Part of the reason for the disagreement is that the higher terraces are older, more modified by erosion and harder to identify conclusively. Also, not all of the terraces run contiguously along the length of the coast. For example one terrace is found only in the Davenport area. It is above the Highway 1 Terrace but below the second terrace (as it is shown in the image above).

The ages of the terraces from youngest (lowest) to oldest (highest) are reported to be 105, 213, 320, 430 and 545 thousand years. Terrace age is debated in scientific studies, in large part because of the different dating methods used:

• Uranium series dating, which measures the amount of short-lived decay products resulting from radioactive decay of Uranium in fossil corals and mollusks over time
• Amino-acid racemization, which measures the degradation of proteins in fossilized organisms into suites of amino acids over time
• Cosmogenic dating, which measures the buildup of beryllium-10 and aluminum-26, naturally occurring isotopes found in dust and known to be created at a fairly constant rate

Each method includes some unavoidable assumptions and has limitations. Their application to the terraces results in ages that vary 20-50 thousand years for the first terrace and 200+ thousand years for the third and higher terraces. I have given the ages from a 2001 paper by Gerald Webber and Alan Allwardt because the authors discuss all of the available studies and make a good case for their choices.

Picture of the Monterey Canyon. Vertical relief has been exaggerated to better show the Monterey Canyon and mountains on either side of the bay. Image by David Fierstein, courtesy of and © 2000 MBARI.

Picture the Grand Canyon under water. Then you’ll have the right scale in your mind when thinking about the Monterey Canyon in California. It is truly a huge underwater feature! It is the largest submarine canyon along the coast of North America.

Just Another River?

Initially scientists thought submarine canyons were carved like river canyons on land. They thought the process just happened at low stands in sea level during a glacial period, and that the canyon was later submerged during an inter-glacial period, when the sea level rose. The problem with this theory is that through all known glacial periods, sea level never dropped the required thousands of feet to expose the land so a river could carve the deep canyon.

Turbidity Currents to the Rescue

Today it has become clear that submarine canyons may indeed start forming during a low stand in sea level, like a normal river, but once sea level rises again, the main canyon cutting happens underwater by turbidity currents.
Turbidity currents are plumes of sediment (dense gravel, sand and mud) that rush downslope after being triggered by an earthquake or even large storms. In the picture above, red arrows indicate the general direction of sediment transport along the edges of the bay down into the canyon. The top-left arrow is from the San Lorenzo River, the center arrow is the Pajaro River and the right one is the Salinas River.

A Very Old Canyon

An underwater remotely operated vehicle used by The Monterey Bay Research Institute to explore the Monterey Canyon. Photo by Kim Fulton-Bennett; courtesy of and © 2004 MBARI.

Research in the Canyon

Much of the understanding of the Monterey Canyon comes from research done by the Monterey Bay Aquarium Research Institute (MBARI). MBARI specializes in combining scientific research with engineering design. This combination has allowed them to see and measure what no other scientists have seen and measured before — both within the Monterey Canyon, and all over the world.

Within the submarine canyon, MBARI uses underwater robots called remotely operated vehicles (ROVs) to explore and perform research experiments in the deep waters. The photo above shows a launch of the ROV Ventana on board the research vessel Point Lobos. Launching and recovering a 2-ton, 10-foot long ROV is a tricky business in the open waters of Monterey Bay.

Vampyroteuthis infernalis, better known as the “vampire squid.”
Photo courtesy of and © 2004 MBARI.

A Home for Diversity

Submarine canyons extend from shallow to very deep waters, and thus contain a wide range of habitats and a very diverse array of organisms. Each habitat is home to its own set of fishes and invertebrates.

One example of an interesting creature is Vampyroteuthis infernalis, which means “vampire squid from hell.” It spends most of its time lurking in the always dark, low-oxygen waters about half a mile below the surface. It has a dark red body, huge blue eyes, and a cloak-like web that stretches between eight arms. If threatened, it will turn itself inside out, flaunting rows of evil-looking “cirri.”

Protecting the Canyon

Controlling pollution entering the Monterey Bay is very important to the health of the canyon ecosystem because it is the gravitational low point and is where trash and pollutants accumulate. Comparisons between surface and deep fish in the Monterey Canyon find deep fish to have much higher concentrations of persistent organic compounds such as PCBs and DDT.

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Further Information

MBARI

1. Sources Used

   • About MBARI.
   • A Coast to Explore: Coastal Geology and Ecology of Central California. Miles O. Hayes, Jacqueline Michel. Pandion Books; 2010.
   • Canyon Processes. Monterey Bay Aquarium Research Institute Website. http://www.mbari.org/canyon/.
   • MBARI researchers discover what vampire squids eat (it’s not what you think). Monterey Bay Aquarium Research Institute Website.
   • Our Ocean Backyard: Grand canyons on the seafloor. Gary Griggs. Santa Cruz Sentinel. November 21, 2009. http://www.santacruzsentinel.com/ci_13839171.
   • Our Ocean Backyard: Submarine Canyons: Going Deeper. Gary Griggs. Santa Cruz Sentinel. December 19, 2009. http://www.santacruzsentinel.com/localnews/ci_13933346.
   • Our Ocean Backyard: Why Monterey Submarine Canyon? Gary Griggs. Santa Cruz Sentinel. January 2, 2010. http://www.santacruzsentinel.com/ci_14109831.
   • Our Ocean Backyard: Why Submarine Canyons? The Evidence Accumulates. Gary Griggs. Santa Cruz Sentinel. December 19, 2009. http://www.santacruzsentinel.com/news/ci_14031738.
   • Monterey Bay National Marine Sanctuary Submarine Canyons. Simon: Sanctuary Integrated Monitoring Network. Sanctuary Simon.

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]]> /blog/monterey-submarine-canyon-an-amazing-traveling-canyon/feed/ 1 /santacruz/the-waddell-bluffs-the-wall-keeps-tumbling-down/ /santacruz/the-waddell-bluffs-the-wall-keeps-tumbling-down/#comments Mon, 17 Nov 2014 14:11:51 +0000 /?p=1560 Along Highway 1, sandwiched between the elephant seals at Año Nuevo State Park and the colorful kite surfers at Waddell Beach, is a 1.4-mile stretch of coastline called the Waddell Bluffs. These near vertical bluffs, made of Santa Cruz Mudstone, are so steep and prone to erosion that they simply defied safe and reliable traversing for almost a century.

The bluffs and adjacent creek and valley are named after William Waddell who conducted timber operations there in the 1860s. At that time, stagecoaches could only pass the bluffs by waiting for low tide and using the hard packed sands of the beach. During winter, passage by beach crossing or even in a boat was essentially impossible and residents couldn’t reasonably reach the county seat in southerly Santa Cruz. In a surprising nod to geography over politics, Santa Cruz County allowed the area north of the bluffs to be annexed to its northerly neighbor, San Mateo County, in 1868.

An Engineering Nightmare

Even with the development of heavy machinery, engineers struggled for several more decades with how to construct safe passage over or past the cliffs at a reasonable cost. The Ocean Shore Electric Railway couldn’t complete a continuous railroad between San Francisco and Santa Cruz during 1905 to 1908 because of the Waddell Bluffs. The State of California acquired the land in 1933 but didn’t come up with a viable roadway design until 1941. The project was delayed due to WWII, but did begin in 1947 and was completed in 1948.

The design essentially cut into the slope and then used the material as fill to create an adjacent, flat roadbed along the beach. A massive 600 foot long retaining wall was built to protect the section exposed to the worst wave erosion. The retaining wall consisted of huge boulders weighing up to 11 tons each (called rip-rap). The original rip-rap was quarried granite from 8 miles away. The excavation of the bluffs alone moved 1.1 million cubic yards of material (52 football fields filled to a depth of 10 feet).

Erosion Never Stops

A debris trench 15 feet wide, 4 feet high, with a 2 foot berm separating it from the highway, was also constructed to catch falling pieces of rock. This design took advantage of a fortuitous property of the Santa Cruz Mudstone; it rarely falls as large blocks. Instead, it tends to break apart in small chunks. This produces a relatively manageable rain of debris, which can be removed periodically from the trench.

Unfortunately, large blocks do occasionally come down and bounce onto highway one. In the 1990s, a man traveling north in a passenger truck was killed by a rock that bounced through his front window. Litigation after the accident accused Caltrans of improper maintenance and emptying of the debris trench. Thus in 1994, Caltrans installed the steel-wire and rope-net barrier fence that is there today.

To maintain the depth of the trench, Caltrans annually removes 15 to 30,000 cubic yards of rock (0.7 to 1.4 football fields filled to 10 feet) and places it onto the beach. Winter storms entrain it into the ocean currents and carry it southward. Without the highway the rock would have fallen onto the beach and moved into the ocean currents naturally. Studies mandated by the California Coastal Commission have not found any adverse ecological impacts from this method of rock removal.

Erosions Many Forms

Not only are the rocks falling from the Waddell Bluffs a constant hazard, the roadbed is essentially on an active beach and is attacked by waves. The El Niño storms of 1983 removed all of the loose rock and fill protecting the highway at their southern half. This section was repaired and reinforced with rip-rap within that year.

Whenever I drive on those bluffs, I can’t help but imagine falling rocks or a huge slide. I always wonder how that weird fence will react and if that circled wire will really provide the needed flexibility to hold in the kinetic energy. I think my foot gets a little heavy in an effort to get me out of there fast.

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1. Sources Used

   • Calculations for Volume Analogies. Math Central Website. http://mathcentral.uregina.ca/QQ/database/QQ.09.13/h/john1.html
   • The Geology from Santa Cruz to Point Año Nuevo—The San Gregorio Fault Zone and Pleistocene marine terraces. By Gerald Webber and Alan Allwardt. In: Stoffer PW, Gordon LC, eds. Geology and natural history of the San Francisco Bay Area: a field-trip guidebook: 2001 Fall Field Conference, National Association of Geology Teachers, Far Western Section: September 14-16. USGS Bulletin 2188; 2001:194.
   • Living With the Changing California Coast. Gary B. Griggs, Kiki Patsch, Lauret E. Savoy. University of California Press; 2005.
   • Rancho Del Oso Nature and History Center Website. http://ranchodeloso.org/history/
   • Wadell Bluffs, Illustrated. California Highways and Public Works. Official Journal of the Division of Highways, Department of Public Works, State of California. Kenneth C. Adams Editor. September-October 1948. Volume 27, Number 9, 10.

The inland view of the earthen berm on which the railroad tracks sit. The two arrows show the limits of the native bedrock, i.e., the Santa Cruz Mudstone. In between the arrows is all fill for the embankment.

Grandiose Railroad Plans

At the turn of the twentieth century, railroads were king and still expanding with easy money from business tycoons of the day. The railroad embankments we see today were originally part of the Ocean Shore Electric Railway (Ocean Shore) which was begun in 1905 and was to be a grand line from Santa Cruz to San Francisco. It was to have two parallel electric lines to run both passengers and freight and be completed in 1907. Southern Pacific (SP) was also building rail to Davenport at about the same time and there was definitely some hard ball and power politics between the two companies.

A More Humble Reality

Fate intervened. The 1906 quake caused huge damages to the northern end of the Ocean Shore line and their easy funding largely dried up. Construction continued though money had to be raised by local bonds. Southern Pacific secured the contract to transport cement and materials for the Davenport Cement Plant, taking away much needed revenue from Ocean Shore.

Construction of the Ocean Shore line circa 1905. Image from the collection of Alverda Orlando.

The details on how the collaboration ultimately occurred are hard to pin down but both Ocean Shore and SP did collaborate in building the embankments north to Davenport. The embankments are so wide because they were designed for three tracks (two for Ocean Shore and one for SP). They consist of wooden trestles filled in with local material to allow the structures to support the extreme weight of the cement cars.

This 1906 photo shows the wooden railroad trestle that crosses San Vincente Creek, at Davenport, partially filled in. There are many of these filled trestles between Davenport and Santa Cruz, including the one at Bonny Doon Beach. Photo from the collection of Gary Griggs and courtesy of Sandy Lydon.

By 1908 only portions of the rail on each end of the Ocean Shore line were running: Santa Cruz to Swanton, which is just north of Davenport, and San Francisco to Tunitas Creek, a few miles south of Half Moon Bay. The railroad never fully connected Santa Cruz to San Francisco. Ocean Shore stopped running trains by 1920 and never laid their second line. The Southern Pacific line was eventually sold to Union Pacific, who ran freight for the cement plant until the plant closed in 2010.

An aerial view of Bonny Doon Beach. The black rectangle encompasses the embankment made by the filled railroad trestle. The arrow on the left points to the tunnel through which Lidell Creek drains to the sea. Picture © Kenneth and Gabrielle Adelman, California Coastal Records Project . http://www.Californiacoastline.org

Embankments and the Local Creeks

Creation of the railroad embankments meant completely blocking off the creeks and any associated estuaries and lagoons. Water flow was routed through tunnels made through the Santa Cruz Mudstone. The tunnels are on the north side of each beach and, despite large storms, have eroded little and have been adequate to handle the flow. In the picture above, the black arrow points to a tunnel where Liddell Creek comes out of the Santa Cruz Mudstone. You can follow the water to its exit at the ocean. The black rectangle shows the very linear railroad embankment that now defines the back of the beach.

Liddel Creek draining through the man-made tunnel (drilled in 1907/1908) in the Santa Cruz Mudstone

The Rail Line’s Future

The railroad right of way from the Davenport to Santa Cruz and even beyond to Watsonville (a 32 mile stretch known as The Santa Cruz Branch Line) has been bought by the the Santa Cruz County Regional Transportation Commission (SCCRTC). Planning and negotiating between several parties took more than a decade, but finally came together in 2012. The line is to be used for recreational, rail preservation, and future transportation uses, including passenger rail service, transit, bicycle and pedestrian facilities, and freight rail service.

Iowa Pacific Holdings will run freight and passenger trains on the line. Iowa Pacific ran a special train to celebrate public ownership on November 17, 2012. For the latest information on rail plans go to Santa Cruz Branch Line Acquisition.

The Iowa Pacific Holdings train at the Westside of Santa Cruz during the November 17th, 2012 event to celebrate public acquisition of the Santa Cruz Branch Line.

Take the Self-Guided Mobile Tour

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The town of Davenport with the very important train in the foreground in 2008. Photo: Drew Jackson

Settlement in the area of today’s Davenport got its start in 1868 when Captain John Davenport, a sea-based whaler by trade, built a 450 foot wharf off what became to be known as Davenport’s Landing (near El Jarro Point). The wharf was used to export local timber by boat to San Francisco.

Captain Davenport also used a practice developed in the Azores Islands of Portugal called shore-based whaling. Scouts on the bluffs would alert men to go out from shore in a boat, kill the whale, and tow it back to shore for processing. It allowed the crew to stay with their families and was easier than processing the blubber at sea. By 1880 the high cost of operation forced Davenport to abandon the landing and move to Santa Cruz.

A Cement Town

The history of the modern town of Davenport is wholly wrapped up with the Davenport Cement Plant. The town was built in 1905 by the Coast Dairies and Land Company to house workers for the cement plant. On the shores of San Vicente Creek, it is located about a mile south of Davenport Landing. The town was originally called San Vicente, but when the post office was moved from Davenport Landing to the new town in 1907, it retained the name of Davenport. In those days the power of the post was great. San Vicente slowly faded away as a name, to be officially replaced by Davenport.

By 1915 Davenport had a population of about 1800 people, with 60 homes, two hotels, a school, a hospital, a church, and a hotel. The cement from the plant was used to rebuild San Francisco after the 1906 quake, build one of the Panama Canal locks, and even construct the dry docks in Pearl Harbor. Though it was bought and sold by several different companies over the decades, the plant continued to supply cement for major construction projects up and down the West Coast. It was the main employer in Davenport for over 100 years.

Davenport circa 1908. The modern day Roadhouse is located in the upper left where you see a white building to the left of the cement plant. The hotel and many homes in the center right are along San Vicente Creek and are mostly all gone now. Image: Courtesy of Alverda Orlando

A Community of Immigrants

In the first third of the 20th century getting into and out of Davenport was a big deal. There were over 700 turns on the road from Davenport to Santa Cruz. As such the town was isolated and developed a close-knit community. It was made up of a very culturally diverse group of people. Most of the managers were Swiss, because the Coast Dairies and Land Company was owned by four Swiss families, but the workers were from all over the world. Italian and Greek families were very prominent but workers apparently came from all over Europe and the Middle East. Prior to World War I, over 20 different languages were spoken in the town.

By the 1930s the roads and cars had improved such that many people moved to Santa Cruz and commuted to Davenport to work at the cement plant. The cement plant apparently chartered with Greyhound to bus workers back and forth daily. By the 1940s it was a much smaller town with a population less than five hundred.

During World War II the US government brought in Mexican workers, under the Bracero Program, to do agricultural work. Many worked in the Davenport area. After the war several Mexican workers came back and the town’s cultural makeup began to include more people of Mexican decent and lose the influence of previous Italian and Greek cultures.

Alverda Orlando, a Davenport resident from 1945 to 1975, tells a story about one Mexican man, known as Pancho, who walked up the stairs of the cement plant one day looking for work. At the same moment the best shift worker, an Italian American was walking down having just quit. The superintendent hired Pancho on the spot. Pancho went on to work at the cement plant for years, brought his whole family up from Mexico, and bought seven homes, eventually giving one to each child.

Dust covering cars in Davenport circa 1950. Image: Courtesy of Alverda Orlando

The End of a Long Run

In 2005, CEMEX, a Mexican company, acquired the plant and kept it operational until 2010, when a bad economy and high operation costs (the highest of its 14 cement plants in the US) forced it to close. At the time it employed about 120 people. Its closure was a big blow to the town in loss of jobs and other services. For example, CEMEX was paying about $185,000 annually for operation and maintenance of the local water and sewage treatment facilities. After the closure, the community had to absorb those costs, on top of the many job losses in a weak economy.

The Church

The Saint Vincent De Paul Church was built in 1914-1915 with donated materials and the labor of Davenport residents, workers from the Coast Dairies and Land Company, and the cement plant. It is at the end of Davenport Avenue, on the Santa Cruz side of the Davenport Roadhouse.

The Jail Museum

Originally constructed in 1914 as a two-cell county jail, the Davenport jail was used only once before it was decommissioned in 1936. It was converted into a museum of north coast history in 1987. It features a permanent exhibition on the natural environment, native peoples, major local industries and early families and community life. From June to September, the museum is open on the first Sunday of the month between 11 am and 4 pm. Contact phone is (831) 429-1964.

The jail is located just behind the Davenport Roadhouse. The correct address is 1 Center Street. For years the jail’s address was incorrectly listed as 2 Davenport Avenue by just about everyone, including the fire department and planning commission. Luckily Alverda Orlando cleared this up in 2012 and the fire department now has the correct address.

St. Vincent De Paul Church in 2012. Photo: Julia Gaudinski/Mobile Ranger

The Davenport Jail Museum in 2012. Photo: Julia Gaudinski/Mobile Ranger

Backside of the defunct Crocker Hospital in 2012. Photo: Julia Gaudinski/Mobile Ranger

The Hospital

The Crocker Hospital was built in 1910 by the Davenport Cement Company to care for its workers and the community. It is located just across from the entrance to the cement plant. William H. Crocker was one of the original investors along with William Dingee the “Cement King.”

Updated August 9, 2016

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A sandstone dike that cuts across the Santa Cruz Mudstone. The blue line parallels the dike just above it.

If you look in the northern most cove at Bonny Doon Beach, (yes, it’s the clothing-optional section), you will see a tall skinny dike of sandstone that cuts across the cliffs-which are made of Santa Cruz Mudstone. A dike is essentially loose material, in this case, the older and deeper Santa Margarita Sandstone, that was squirted up under pressure through the younger but harder mudstone. The dikes and the Santa Margarita Sandstone in general contain bituminous (asphalt-like) material in varying quantities. There are many similar dikes in the sea cliffs along the north coast of Santa Cruz. This one is unusual in how skinny and rectangular it is.

Bonny Doon Beach.

Some of the bituminous sandstones just a few miles south of Bonny Doon Beach, at Majors Creek, were quarried for paving material. Apparently about 600,000 tons, valued at over 2 million dollars, were quarried and sent by boat to pave San Francisco between 1888 and 1914.

Photo from the collection of Gary Griggs. See his article on these intrusions.

In the 1950s the Husky Oil Company ran an experimental project to get oil and gas out by heating the sandstone in the drill hole and then recovering what melts. Over three years they pulled out 3,000 barrels of oil and some gas. In general, costs were too high to make it economically viable.

Take the Self-Guided Mobile Tour

This piece is part of the North Coast Tour. Download the free app with many tours of the Santa Cruz area and beyond.

An aerial view of Pigeon Point Lighthouse. Photo © Jitze Couperus via Flickr Commons.

Almost 30 miles north of Santa Cruz stands Pigeon Point Lighthouse. The story behind its origins is not a pleasant one. The lighthouse was built in 1871 after a series of shipwrecks stirred public outcry.

Pigeon Point’s first victim was the ship “Carrier Pigeon.” In 1853, carrying 1,300 tons of cargo, the ship departed on her maiden voyage from Boston to San Francisco. A painting of a carrier pigeon was painted on her bowsprit as a sign of good luck. But luck was not with the ship in June of that year. After traveling 15,000 miles, it was thrown off course by heavy fog and tumultuous waves and crashed into the coast. Settlers from nearby Pescadero saw the foundering ship and flocked to the water. The entire crew was rescued and the ship bobbed in the water for a few days before sinking. To commemorate the young vessel, the ship’s captain named the area Pigeon Point.

In the 1860’s, the ships “Coya” and “Hellespont” shared the same fate as the Carrier Pigeon. They were sturdy ships but mother nature still got the best of them and the crews of these ships mostly drowned. With 37 dead and only a handful of survivors, the public had had enough. They banded together and petitioned the U.S. Lighthouse Service Board to construct a lighthouse equipped with a fog horn to prevent further disasters. While ships continued to sink along the coast of Pigeon Point until 1953, there has not been a wreck since then – likely due to better navigation aides.