The not-so-natural beach

The not-so-natural beach

Image 1: Groin in Oceanside California, built in 1961. Photo: Ryan Anderson, 2019.

Growing up, I always imagined the beach to be a natural place. I think it’s safe to say that this sentiment may be pretty common among many beachgoers. It’s easy to think of the beach as being somewhat “natural,” or at least close to that thing some people call “nature.” This is a short piece, so I won’t go down the what is nature!? rabbit hole for now. By natural I mean something along the lines of “not caused or created by human intervention.” So here’s the thing: many beaches are actually far less “natural” than many people assume or know.

I’ll give you an example. Take the beaches of Oceanside, California, where I spent some time doing research this past summer. Oceanside has nice beaches, and lots of people like to visit them. Those beaches bring in tourists, and money. They are also very popular for many local residents, for a variety of uses and purposes. But let’s look back at the more recent histories of Oceanside’s coastline, starting with the first large-scale human-induced coastal changes in the late 19th century.

In 1888, a 1000-foot wharf was built in Oceanside. In 1890, the wharf was destroyed and rebuilt; this structure was in place until around 1920. In 1922, Lake Henshaw was dammed, which resulted in a severe reduction in sand supply. In 1927 a new pier was built, this one at the location where there is still a pier today. Then, in 1942, the Federal government built the Del Mar Boat basin, a process that also included the dredging of 1.5 million cubic yards of sediment. Another 220,000 cubic yards of sand were dredged from the entrance channel of this boat basin in 1945. Another dam, this one at Vail Lake, was completed in 1949. During the same year the city put in a 1000-foot stretch of riprap south of Oceanside pier. In 1952 two groins were installed. In 1957, another 800,000 cubic yards of sand were dredged and placed on downcoast beaches to alleviate erosion problems. The city installed a small groin at the mouth of the San Luis Rey river in 1961 (see Image 1), and a small craft harbor was completed in 1963. This process included the dredging of 2.9 million cubic yards of sand that were placed on beaches to the south. From the 1970s until 2001, more than 8 million cubic yards of sand were pumped onto Oceanside’s beaches.[1]

That was a ton of information, to the point of overkill, but I’ve included all those details to make a point. Oceanside’s beaches, like many beaches around the world, are not simply pristine, untouched natural spaces. They are the results of human interventions that led to cascading effects: The dams and harbors severely reduced the sand supply of downcoast beaches (Kuhn and Shepard 1984), resulting in coastal erosion and shorter beaches over time. As beach tourism demand and popularity grew, cities such as Oceanside sought to maintain their sandy shorelines (and protect coastal properties), often through a combination of armoring (i.e. seawalls, riprap, etc.) and the artificial nourishment of beach sand.

Image 2: Screen shot from Google Earth showing the coast of Oceanside, California. From left to right you can see: 1) The 1942 Boat Basin; 2) The 1960s small boat harbor; 3) The 1961 groin at the mouth of the San Luis Rey River; and 4) the Oceanside pier. Note the buildup of sand on the upcoast sides of the boat basin (the beach on the far left side of the image) and the groin (the beach in the center), in addition to the much shorter beaches on the far right side of the image.

If you look closely at the aerial image of Oceanside’s coast (see Image 2), from left to right you can see 1) the 1942 Del Mar Boat Basin; 2) The small boat harbor that was built in the 1960s; 3) the groin at the mouth of the San Luis Rey River; and 4) the Oceanside pier further down the coast. Notice that there is sand built up on the upcoast sides of these structures (especially the boat basin, harbor, and groin), and that the sandy beaches dwindle as you move to the right. These days, the southernmost coast of Oceanside has little to no sand whatsoever (see Image 3).

Image 3: Riprap-lined beaches along the southern coast of Oceanside, California. This image was taken at a medium high tide in August 2019. Much of the southern coast of Oceanside has a similar profile, with riprap and short to non-existent beaches. Photo: Ryan Anderson.

Such patterns are not uncommon. Today, around 240 km (13.9%) of the state of California’s coastline is armored; in southern California alone that percentage jumps to 38% (Griggs and Patsch 2019). This percentage has grown substantially in the past few decades: in the early 1970s, only around 2.5% of California’s 1760km coast was armored (Griggs and Patsch 2019). Why all this armoring? It’s due to growing coastal populations, increased development, patterns of coastal management, and of course other factors, such as slowly rising seas.

This brings me back to the question of nature. Who cares if the beaches in Oceanside or any other coast around the world is a product of human intervention? Why does any of this matter? Well, around 3 billion people live within 100 miles of a coastline today (Griggs and Patsch 2019), and this isn’t going to change anytime soon. There is indeed a tremendous amount of investment, attachment, and entrenchment in these coastal spaces. And those rising seas aren’t going to be stopping either. What this means, in the future, is that there are going to be many, many more conversations—and conflicts—about sea level rise, erosion, and what should be done. Some of these conversations may be framed in terms of trying to conserve or save natural spaces; in some cases this kind of framing is perhaps appropriate. But in others, where humanity and nature are entangled in more of a complex admixture (which is likely more often then we might assume), the question may rather be more along the lines of whose beach and which nature (as Gesing 2017 puts it) will be protected, created, or maintained. This distinction matters, especially as humanity slowly grapples with the “politics of the anthropogenic” (Sayre 2012)—including those rising tides—in the coming years.

References

Gesing, F., 2017. Whose Beach, Which Nature? Coproducing Coastal Naturecultures and Erosion Control in Aotearoa New Zealand. In Environmental Transformations and Cultural Responses (pp. 125-156). Palgrave Macmillan, New York.

Griggs, G. and K. Patsch, 2019. California’s coastal development: Sea-level rise and extreme events—where do we go from here? Shore & Beach, 87(2), 15-28. https://doi.org/10.34237/1008722

Kuhn, G.G. and Shepard, F.P., 1984. Sea Cliffs, Beaches, and Coastal Valleys of San Diego County: Some Amazing Histories and Some Horrifying Implications. Univ of California Press.

Perdomo, G.A., 2004. Developing a Seawall Algorithm for the Dnr Model with Application to the Oceanside, California, Coastline (Doctoral dissertation, University of Florida).

Sayre, N.F., 2012. The politics of the anthropogenic. Annual Review of Anthropology, 41, pp.57-70.

United States Army Corps of Engineers. 1991. State of the Coast Report, San Diego Region: Coast of California Storm and Tidal Waves Study, Volume II-Appendices, Final.

[1] All the details from this paragraph are based upon the U.S. Army Corps of Engineers (1991) and Perdomo (2004).

One Reply to “The not-so-natural beach”

  1. A timely post, indeed. With Hurricane Dorian crushing the Bahamas, human-nature interactions and the whole big question of what is natural vs anthropogenic change is a very important question, indeed. A really important topic to explore is the continued use of statistical estimates of event likelihood that collapse as black swan events become more frequent.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.