Oyster Shells: Petaluma’s “Secret Sauce”

Gunerius “George” Aanunsen, standing center, in the first Aanunsen Oyster Shell Yard at the southwest corner of the D Street Bridge, with brother Pete seated on wagon, 1906 (Petaluma Historical Library & Museum)

On the evening of September 9, 1909, Gunerius Aanunsen sailed up the Petaluma River on his schooner the Fearless with a cargo of oyster shells, docking at his supply yard beside the D Street Bridge. Returning the next morning, he found the boat submerged. During evening low tide its hull, weighted by the shells, cracked on a hidden silt mound.1

The sinking of the Fearless illustrated the perils of using a tidal estuary as a shipping channel. The genesis of Petaluma’s founding, the waterway came with a congenital birth defect—instead of flowing like a stream, it rose and fell with the ocean tides twice each day, making it prone to silting up.

At the time of the mishap, only the Sacramento and San Joaquin rivers exceeded the estuary as a waterway for shipping commercial tonnage in California.2 Two steamers and more than 60 flat-bottomed schooners plied its 18 miles to and from San Pablo Bay with an annual 200,000 tons of goods, including 100 million eggs, Petaluma’s new agent of wealth as the self-proclaimed “Boss Chicken Town of the Pacific Coast.”3

Steamer Gold steamer traveling up the Petaluma River, circa 1900 (Petaluma Historical Library & Museum)

But with economic prosperity came more silt. The expansion of farmlands led to the elimination of wetlands and rechanneling of tributary streams, sending erosion from the plowed fields into the estuary during rainy seasons, where it trapped boats like the Fearless in its muddy grasp. 4

Having a clogged artery at the heart of town raised the perennial question, according to local historian Skip Sommer, as to whether Petaluma wanted to be known as a river town or a mud town.5 For more than a century, the answer turned on the secret sauce of the Boss Chicken Town—oyster shells.

The arrival of oyster shells coincided with the Army Corps of Engineers’ first dredging of the estuary in 1880. Petaluma previously funded two dredgings of the upper channel north of Haystack Landing in 1859 and 1866, along with cuts made by ferryboat operator Charles Minturn.6 The arrival of the San Francisco and North Pacific Railroad in 1870 however made dredging an existential imperative.  

Having bypassed Petaluma, the railroad created its own shipping terminus on the estuary south of town near Lakeville. Fearing a transportation monopoly, local business leaders successfully lobbied Congress in 1880 for $28,000, or $875,000 in today’s currency, to have the Army Corps dredge the estuary and re-channel some of its 80 serpentine bends.7

The dredging coincided with the invention in Petaluma of an efficient egg-hatching incubator by Isaac Dias, a dentist from New Orleans. He was later joined in perfecting and marketing it by one of his patients, Lyman Byce.8

In 1880, Christopher Nisson, a Danish immigrant, purchased one of Dias’ incubators, and employed it to launch the country’s first commercial egg hatchery on his ranch in Two Rock.9

Christopher Nisson’s Pioneer Hatchery Ranch in Two Rock (Sonoma County Library)

The one ingredient Nisson lacked in his transformation of the chicken from pastoral farm animal to egg assembly line was calcium. If his hens were to dramatically increase their egg production, they needed many times their natural amount of calcium to avoid brittle bones and soft-shelled eggs. For a calcium supplement, Nisson turned to oyster shells.10

Crushed oyster shells were already being used in feed for backyard chickens, but not on the industrial scale he envisioned. Fortunately for Nisson, large mounds of ancient oyster shells, or middens, had been preserved beneath the waters of the South San Francisco Bay near San Mateo, built up by indigenous tribes over thousands of years.11

Sacks of “Egg Food” with oyster shells being loaded for delivery at George P. McNear’s Oriental Flour Mill on Petlauma Boulevard North across from Penry Park, 1895 (Sonoma County Library)

In 1880, Nisson persuaded Petaluma grain merchant George P. McNear to ship oyster shells up the estuary from the South Bay. The shells enabled him to quickly increase his flock to 2,000 hens, and begin selling incubated baby chicks to his neighbors.12 Within a decade, six additional hatcheries were operating in Petaluma, drawing hundreds of aspiring chicken ranchers to the area.13

Gunerius “George” Aanunsen immigrated to San Francisco from Norway in 1889.14 At the turn of the century, he and his brother Pete opened a supply yard in Petaluma for oyster shells, coal, and wood at the southwest corner of the D Street Bridge. The brothers dissolved their partnership un 1907, with Pete retaining the coal and wood supply business while Gunerius opened the South Bay Shell Company on the southeast side of the D Street Bridge. The site would remain an oyster shell facility for the next 110 years.15

Schooner on Petaluma River just north of D Street Bridge, circa 1900 (Sonoma County Library)

In 1907, the brothers dissolved their partnership, with Pete retaining the coal and wood supply business while Gunerius opened the South Bay Shell Company on the southeast side of the D Street Bridge.16 The site would remain an oyster shell facility for the next 110 years.

The opening of Aanunsen’s new shell yard coincided with the third major dredging of the estuary by the Army Corps, the second having taken place in 1892.17 In the River and Harbor Act of 1904 Petaluma was provided a $7,500 ongoing annual appropriation for dredging ($234,000 in today’s currency).18 The Army Corps recommended accumulating the annual allocation to fund a thorough dredging of the channel every four or five years.19

Dredger on the Petaluma River, 1920s (Sonoma County Library)

But, as the Fearless’ sinking demonstrated just two years later, Petaluma couldn’t wait that long. After only one or two heavy rain seasons, enough silt filled the estuary’s upper channel to make it a mud trap for vessels at low tide. As a result, the annual funding allocation was eaten up by regular maintenance dredging. The exception was the River and Harbor Act of 1930, which allocated $200,000, or $4.4 million in today’s currency, to fully dredge and straighten parts of the estuary to Cloudy Bend.20

1930 also saw Aanunsen’s retirement from the oyster shell business. After resurfacing the sunken Fearless, he converted it into a sloop-rigged barge, purchasing a tugboat to pilot it up and down the creek.21 The tugboat also served as his home. For the next 30 years, he helped keep the Boss Chicken Town supplied with shell as annual egg production soared to half a billion eggs.22

Gunerius “George” Aanunsen aboard his tugboat Solano docked in Petaluma, circa 1930 (Sonoma County Library)

At the age of 70, Aanunsen set sail for the San Diego Bay, where he devoted a year to collecting sea shells for museum collections before his body was found floating in the bay, the apparent victim of an unsolved murder.23

Aanunsen’s shell yard beside the D Street Bridge changed hands a few times before being purchased in 1948 by the Pioneer Shell Company, which constructed a processing plant on the site capable of crushing 10 to 12 tons of oyster shell an hour. By then, oyster shells were being used not only for poultry feed, but horse feed, fertilizer, and landscaping.24

Pioneer Shell Company plant, southeast corner of D Street Bridge, 1954 (Sonoma County Library)

Other shipments on the estuary were decreasing however, due to the rise of trucking and the demise of Petaluma’s chicken industry. After World War II, more efficient caged factory farms were springing up around the county, putting the area’s small chicken ranches out of business.25

In an attempt to turn the tide, Petaluma presented Congress with two bold proposals. The first was a name change for the estuary from the Petaluma Creek, which it was commonly called, to the Petaluma River. Contrary to popular lore, the name change was not required to maintain federal funding for the dredging. Instead, Petaluma believed that “river” would carry more prestige than “creek” in helping the town attract new industries in need of water transportation.26

Petaluma River stretching south from Petaluma to San Pablo, with arrow pointing to oyster shell plant beside the D Street Bridge (photo courtesy of Scott Hess)

The second proposal, which carried a price tag of $6.5 million ($58 million in today’s currency), called for a major reengineering of the estuary in hopes of attracting new commercial traffic and also recreational boats.27 Congress quickly passed the name change in 1959, but the reengineering proposal was eventually ruled out as cost prohibitive.28

The city succeeded however in attracting a handful of enterprises that used the river for transporting heavy construction materials like gravel and concrete. Together with the oyster shell plant, then owned by Jerico Products who diversified to also transporting sand for construction, there was sufficient commercial tonnage to qualify for continued dredging by the Army Corps.29

Mitch Lind, owner of Jerico Products (later renamed Lind Marine), at the oyster shell plant beside the D Street Bridge, 1981 (photo courtesy of Murray Rockowitz)

After the Corps’ dredging in 2003, the Petaluma River was classified as a “low use” waterway, placing future dredging in jeopardy. At that time, barge traffic was largely dependent on just two companies, a concrete plant and the oyster shell plant. In 2006, the concrete plant closed, leaving only oyster shells to justify future dredging.30

It wasn’t enough. Lind Marine, the new name of Jerico Products, steadily reduced the tonnage of shells and sand on their barges to navigate the increasingly shallow channel until 2017, when it proved no longer profitable to do so.31

By then, river traffic consisted almost entirely of recreational boats which, while contributing tourism revenues to the city, didn’t figure into the Corps’ criteria for dredging. By 2020, even they were unable to safely navigate the muddy channel. Thanks to local lobbying, the Army Corps returned that year for a $9.7 million dredging of the river, with the understanding that it would be their last.32

By that time, most of the industrial sites on the riverfront that once neighbored Aanunsen’s oyster shell yard had been converted to infill housing, shopping malls, and office space, reflecting Petaluma’s transformation from an agricultural shipping hub to a suburban community.

In 2022, Lind Marine announced plans to replace its historic shell plant with an infill housing development called Oyster Cove.33

Proposed design of new Oyster Cover development at the southeast corner of the D Street Bridge (courtesy of Urban Design Associates)

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A version of this story appeared in the Petaluma Argus-Courier, May 20, 2022.

Video of Proposed Oyster Cove Development:

FOOTNOTES

[1] “Local Brevities,” Petaluma Courier, December 1, 1902;“Schooner Fearless Sinks,” Petaluma Argus, September 7, 1909.

[2] Adair Heig, History of Petaluma: A California River Town (Scottwall Associates, 1982), p. 78.

[3] 200,000 annual tons is cited in “Saw the Engineers,” Petaluma Argus, January 18, 1908, but 155,000 annual tons in “Official Report of Government Engineer on River Improvements,” Petaluma Courier, November 24, 1909; egg production volume is from an advertisement from the Petaluma Chamber of Commerce, Pacific Rural Press, April 10, 1910; “Boss Chicken Town of the Pacific Coast” was first used in an 1898 issue of the Petaluma Weekly Budget, as cited in Thea  Lowry’s Empty Shells: The Story of Petaluma, American’s Chicken City (Novato, CA: Manifold Press, 2000), p. 27.

[4] Petaluma Valley Historical Hydrology and Ecology Study”. SFEI Contribution No. 861, 2018. https://www.sfei.org/documents/petaluma-valley-historical-hydrology-andecology-study.

[5] “Petaluma River Dredging Due,” Petaluma Argus-Courier, June 1, 1983.

[6] “Approved,” Sonoma County Journal, April 15, 1859; “Improvement of the Creek,” Sonoma County Journal, October 14, 1859: “Act to Improve the Creek,” Sonoma County Journal, April 13, 1860; “Straightening the Creek,” Petaluma Argus, February 11, 1862; “Notice To Contractors,” Petaluma Argus, August 23, 1866; “Contract Awarded,” Petaluma Argus, August 30, 1866.

[7] “Petaluma Creek,” Petaluma Argus, December 4, 1876; “Straighten the Creek,” Petaluma Courier, January 1, 1879; “Petaluma Creek,” Petaluma Argus, December 5, 1879; “Of Interest to Us,” Petaluma Courier, March 8, 1880; “Improvement of Petaluma Creek,” Petaluma Argus, August 27, 1880; “Work Commenced,” Petaluma Argus, October 8, 1880; “Local Brevities,” Petaluma Argus, October 22, 1880; “Important Change,” Petaluma Argus, May 13, 1881; “Petaluma Creek,” Petaluma Courier, November 15, 1882; “Petaluma Township,” Petaluma Argus, January 5, 1884. “Petaluma Creek,” Petaluma Argus, August 9, 1884.

[8] Lowry, pp. 33-34 (after Dias’s death in a mysterious 1884 hunting accident on the estuary, Byce wrote him out of the incubator’s origin story).

[9] Lowry, pp. 49-51; p. 146; “Nisson’s Famous Poultry Yard,” Petaluma Courier, November 11, 1891.

[10] Lowry, p. 156.

[11] N.C. Nelson, “Shellmounds of the San Francisco Bay Region,” University of California Publications in Archaeology and Ethnology, Vol. 7, No. 4, Berkeley, The University Press, 1909, pgs. 337, 346. https://digitalassets.lib.berkeley.edu/anthpubs/ucb/text/ucp007-006-007.pdf; Lydia Lee, “Olympian Dreams,” Alta magazine, January 4, 2022. https://www.altaonline.com/dispatches/a38325907/west-coast-native-oyster-lydia-lee/ Charles H. Townsend, “Report of Observations Respecting the Oyster Resources and Oyster Fishery of the Pacific Coast of the United States,” Report of the Commissioner of Fish and Fisheries for 1889 to 1891,United States Commission of Fish and Fisheries, 1893. https://penbay.org/cof/cof_1889_91.html;

[12] “Local Brevities,” Petaluma Argus, March 18, 1881; “Courierlets,” Petaluma Courier, August 31, 1881.

[13] Lowry, p. 50; “Nisson’s Famous Poultry Yard,” Petaluma Courier, November 11, 1891.

[14] Ancestry.com: Norway Select Baptism 1634-1927 (Gunerius Aanunsen’s birth: May 10, 1862, Ostre Moland, Aust-Agder, Norway); Hamburg Passenger Lists (Hamburg departure date: May 2, 1889); San Francisco Directory, 1889.

[15] Note: It appears that the Aanunsens formed their first shell yard along the river near Washington Street Bridge by 1902, before moving to the First and D street location a few years later; “Local Brevities,” Petaluma Courier, December 1, 1902; “Briefs,” Petaluma Courier, August 31, 1906; “Has Sued for Accounting,” Petaluma Argus, October 21, 1907.

[16] “Briefs,” Petaluma Courier, July 24, 1907; “Has Sued for Accounting,” Petaluma Argus, October 21, 1907; Ad, Petaluma Courier, January 22, 1908; “Opinion in Local Case,” Petaluma Argus, April 24, 1908; The 1914 Petaluma City Directory lists George Aanunsen as owner of the South Bay Company, Petaluma Historical Library & Museum.

[17] “Local News,” Santa Rosa Press Democrat, March 9, 1889; “Local Brevities,” Santa Rosa Press Democrat, June 3, 1891; “Official Report of Government Engineer on River Improvements,” Petaluma Courier, November 24, 1909.

[18] “Official Report of Government Engineer on River Improvements,” Petaluma Courier, November 24, 1909; “Who Got the Money,” Petaluma Argus, October 22, 1914; “City Dredging Woes Date to 1890,” Petaluma Argus-Courier, September 7, 1983.

[19] “Official Report of Government Engineer on River Improvements,” Petaluma Courier, November 24, 1909.

[20] “Saw the Engineers,” Petaluma Argus, January 18, 1908; “Official Report of Government Engineer on River Improvements,” Petaluma Courier, November 24, 1909; “River & Harbor Committee Reports to the C. of C. Board,” Petaluma Argus-Courier, September 10, 1930 “Dredging Crew Start $200,000 River Cut Here,” AC, January 24, 1933; “Extensive River Improvements Coming to River Channel,” Petaluma Argus-Courier, April 4, 1959.

[21] “Schooner Fearless is Now a Sloop Rigged Barge,” Petaluma Argus, April 29, 1910; “Briefs,” Petaluma Argus, October 8, 1908.

[22] Heig, p. 115; “Poultry Industry in Upward Trend,” Petaluma Argus-Courier, March 4, 1929.

[23] “Has Taken Over Shell Business,” Petaluma Argus-Courier, May 28, 1930; “George Aanunsen Meets Mysterious Death in San Diego Bay,” Petaluma Argus-Courier, September 10, 1931; Findagrave: https://www.findagrave.com/memorial/142750468/george-aanunsen

[24] Note: Aaunensen sold his shell yard to William Cartensen. Jerry Hannigan purchased it in 1939, renaming it Jerry’s Shell Yard. In 1945, he moved the yard across the river to 735-741 Third Street. In 1948, Pioneer purchased the yard; Ad, Petaluma Argus-Courier, May 20, 1939; Ad, Petaluma Argus-Courier, December 4, 1945; “City Council,” Petaluma Argus-Courier, October 5, 1948; “Oyster Shell Processing Plant Opens In Petaluma,” Santa Rosa Press Democrat, February 22, 1950.

[25] “Poultry Must Organize,’” Petaluma Argus-Courier, October 2, 1959; Lowry, Empty Shells, pp. 229-233.

[26] “Creek Naming and Dredging Supported,” Petaluma Argus-Courier, January 14, 1959; “Miller Submits Bills, Works on More,” Petaluma Argus-Courier, January 23, 1959; “River Name Bill Sails To Senate,” Petaluma Argus-Courier, June 16, 1959.

[27] “Creek Naming and Dredging Supported,” Petaluma Argus-Courier, January 14, 1959; “Extensive Improvements Coming to River Channel,” Petaluma Argus-Courier, April 4, 1959.

[28] “Petaluma Might Get River Yet,” Petaluma Argus-Courier, August 20, 1959; “International Scoop,” So They Tell Me Column, Petaluma Argus-Courier, September 24, 1959; “River Dredging Should Be Completed by September,” Petaluma Argus-Courier, May 8, 1964; “River Project Gets a Boost,” Petaluma Argus-Courier, October 26, 1965; “City records Progress and Problems in 1967,” Petaluma Argus-Courier, December 30, 1967.

[29] “Oakland Firm Given Contract to Dredge the River,” Petaluma Argus-Courier, June 4, 1964; “River Project Gets a Boost,” Petaluma Argus-Courier, October 26, 1965 “City Records Progress and Problems in 1967,” Petaluma Argus-Courier, December 30, 1967.

[30] “The Ebb and Flow of the River Industry,” Petaluma Argus-Courier, April 19, 2006:

[31] “Nearly $10 million Petaluma Dredging Project Begins after 13-year Wait,” Santa Rosa Press Democrat, September 5, 2020; “River Dredging Crucial for City,” Petaluma Argus-Courier, February 27, 1992; Katherine J. Rinehart, “Processing Oyster Shells Along the Petaluma River,” Sonoma County Farm Bureau Newsletter, February 11, 2022. https://sonomafb.org/processing-oyster-shells-along-the-petaluma-river/

[32] “Nearly $10 million Dredging Begins After 13-year Wait,” Santa Rosa Press Democrat, September 5, 2020; John Shribbs, “Dredging,”2021,  Petaluma Wetlands Alliance, petalumawetlands.org. https://petalumawetlands.org/dredging/

[33] “Oyster Cove Project,” a video presentation by UrbanMix Development and Urban Design Associates. https://www.youtube.com/watch?v=RTg6JZcx1Ms&list=PLtMVX2ASLE4rwOq9VROofcEcGpFkfnk6e&index=2