hen I first learned about the declaration by the United Nations that 2021-2030 would be designated as the Decade of Ocean Science for Sustainable Development, I did a double take, wondering whether some previous decade might also have been so named. It seemed the kind of thing that might cycle around from time to time, that might demand constantly renewed dedication, especially given the spiralingly dire state of world seas. I could not find records of a previous decade, but I did find a couple of years: March 1984-March 1985 had been a U.S. National Oceanographic and Atmospheric Administration-proclaimed “Year of the Ocean” and 1998 had been a United Nations-declared “International Year of the Ocean” (Marine Fisheries Review Staff, 1984; National Oceanic and Atmospheric Administration, Office of Public and Constituent Affairs, 1998). Then there had been weeks: April 29 through May 5, 1984 had been for the United States a “National Week of the Ocean” (Ninety-Eighth Congress of the United States of America 1984). And finally, there was/is World Oceans Day, held every year on June 8, proposed in 1992 by Canada’s International Centre for Ocean Development and officially taken up by the United Nations in 2008. 

These different units of time do different kinds of work. Days, like yearly holidays, invite a recurring reminder about an aspect of the world, perhaps a chance to take stock, celebrate, memorialize. Weeks suggest a more concerted attention, maybe something — like the U.K.’s National Map Reading Week or international sea turtle week — that can be brought into the cadence of a classroom curriculum. Years might find a foothold in academic research initiatives. And decades offer a kind of concerted turning of attention to a matter of concern. For ocean science, a decadal frame might offer a span within which to plan research cruises, programs of long-term sampling, and international collaborations.

The European Research Council “Politics of Marine Biodiversity Data” project, funded from 2018-23, embeds its mission in the UN frame, spelled out on its website in an article entitled “Turning towards the ocean: Launching a decade of Ocean Science” (Tessnow-von Wysocki 2021). The language of the “turn” has appeared before in such initiatives: the United States 1998 Year of the Ocean saw the Clinton administration publish a report entitled “Turning to the Sea: America’s Ocean Future” (U.S. Cabinet, 1999). There is resonance here with the recent “oceanic turn” in environmental humanities (Deloughrey, 2016), but there is more, too; the language of the “turn” resonates with theological definitions, for which “turning is closely connected to the notion of spiritual conversion, … ‘Turning’ is understood as a turning towards someone or something and simultaneously as a turning away from someone or something else” (Dorge, 2017: 369). The oceanic turn is bound up with anxieties about future damnation, hopes to make right what is heading awry. 

Days, weeks, years, decades — these are periodicities tuned to human habits, everyday life, institutional initiatives, lifetimes; some are cyclical, over-and-overing, others are successional, don’t look back-ish. And they curl unevenly into ocean periodicities, which also come in variously scaled cycles: the Atlantic Meridional Overturning Circulation, with its centuries-long conveyance of cold water sinkings and upwellings; the Pacific Decadal Oscillation, with its warm and cool phases; the lunar semi-diurnal tides, with their 12ish hour turns; and many, many more. The UN Decade, then, is an attempt to calibrate, to turn the institutional time of science to some sort of ecological time of consequence. 

Mindful of the multiple and nonlinearly interacting times of the ocean, however, it may be more fitting to call this “oceanic turn” an oceanic churn, where churn is “to agitate, stir, and intermix any liquid, or mixture of liquid and solid matter; to produce (froth, etc.) by this process” (definition 2.a. of churn, v., Oxford English Dictionary). There is more than liquid in this mix, of course; hydrodynamical processes have deep effects on the flow and form of marine life, from plankton to porpoises.

How to grapple with the churning time of ocean days, weeks, years, decades? One smaller scale way in would be to turn to the force and figure of the ocean wave. Waves emerge from ocean-atmosphere interaction — storms and wind — which themselves are also key to larger-scale processes of ocean circulation and oscillation. And waves, though they are often understood as patterns of physical force, are also material things, full of organismic life caught up in their propagative and foaming process. Waves, convolving multiple time streams, are agents of churn. They put hydrodynamics and ecology into nested, partially overlapping orbits with the effects of social relations, politics, economics, and more. Waves offer one window into the state of the Anthropocenic sea.

Oceanographers have lately made wave crashing a diagnostic tool for tracking and predicting changes in ocean chemistry and biology. In June of 2019, during anthropological fieldwork I conducted among ocean wave scientists, I met with atmospheric chemist Kim Prather at the University of California in San Diego, where she and a crew of colleagues and students are seeking to reproduce the shapes, substance, and sound of breaking waves in a 33-meter-long wave tank at the Scripps Institution of Oceanography, similar to those just outside on the Pacific coast. They train their eyes and ears on understanding the climatological effects of sea spray, which aerosolizes compounds of various sorts into the air (Stokes et al., 2013; see also Deane et al., 2017).

Prather told me that, when waves crash, they release telling traces of the bodies of water through which they travel. Sea spray is made largely of particles comprised of sodium chloride, but in areas like the coast of southern California where large pollution run-off occurs, such spray will also contain signs of that effluent. There are also ways to discern the signs of local ecologies of car exhaust in wave splash and mist. The spray from breaking waves therefore contains what Prather calls a “chemical signature” of human impacts. The wake (Sharpe, 2016) of processes like industrial agriculture and fossil fuel use are legible in the wave break (Helmreich, 2021).

There is more than chemistry in the story, too. Wave bubbles pop and transfer a range of organic materials — from lipids in small droplets to heterotrophic bacteria in the larger droplets — so that sea spray carries a complement of microbial bits and bodies. Prather offered a comparison: “Microbes are in your body. You’re comprised of more microbe DNA than human DNA — and some of what they’re trying to do is keep our bodies in a narrow temperature range. Microbes in the environment, to make an analogy, are similarly trying to keep the temperature of the Earth’s climate in a healthy range.” Exactly how well microbes control the temperature of our planet depends on which ones make their way into the atmosphere, to be cycled by humans, animals, and plants, and to be incorporated as seeds for clouds. That process is modulated by transformations in ocean biochemistry, which include changes due to phytoplankton blooms.

Study the scientific portrait of a wave just below, a false color side-view image of a breaking wave (left to right), with warm colors indicating intense bioluminescence from dinoflagellates caught up in the wave. While these organisms’ bioluminescence is here used as a proxy for shear stress, a measure of turbulent energy dissipation, it also indicates that wave crashing has a biotic component. 

False color side-view image of a breaking wave (left to right), with warm colors indicating intense bioluminescence from dinoflagellates caught up in the wave. These organisms’ bioluminescence is here used as a proxy for shear stress, a measure of turbulent energy dissipation. Credit: Deane, Stokes, and Callaghan, 2016. Used with kind permission of authors.

This is the oceanic churn. Breaking waves convey fossil fuel histories and shifting microbial ecologies in their bubbling swirls and now tell a story of a warming ocean, with cascade effects on marine food chains, coral and kelp ecologies, and more. Prather calls microbes “embedded sensors” that deliver accounts of the health of the sea, of possible ocean futures, futures to which her work, funded by the National Science Foundation, seeks to orient — and, importantly, orient students, preparing them to tackle complex environmental problems. In “Insights from a Decade of Ocean−Atmosphere Experiments in the Laboratory,” Prather and colleagues (Mayer et al. 2020) underscore the importance of the work: “the complex interplay of phytoplankton, bacteria, and viruses exerts significant control over sea spray aerosol composition and the production of volatile organic compounds … [and/but] the impact of marine aerosols on clouds represents one of the largest uncertainties in our understanding of climate, which is limiting our ability to accurately predict the future temperatures of our planet.” If the oceanic turn is a turning to face the future, the oceanic churn – symbolized by the deformation and the breaking of the wave face – makes that future hard to see.

How shall we understand the undulating sights, sounds, and signatures of marine biodiversity and what those signs herald for oceanic ecologies? One answer is to tune to the medium of waves, keeping in mind that waves have long been apprehended through, and taken on, qualities of the media used to understand them (see Jue, 2020). The medium of waves can help us understand waves not just as objects for physical oceanography, but also for chemical and biological oceanography, as forms that communicate information about the state of the seas, channeling news of what is and what is to come, of functional and dysfunctional marine biodiversity.



Deane, GB, Stokes D and Callaghan AH (2016) Turbulence in breaking waves. Physics Today 69(10): 86-87.
Deane, GB, Stokes D, Farmer DM, D’Asaro E, and Zhao Z (2017) What can we learn from breaking wave noise? Paper presented at 173rd meeting of the Acoustical Society of America, Boston, Massachusetts, June 26. Available here.
DeLoughrey E (2017) The oceanic turn: submarine futures of the Anthropocene. Comparative Literature 69(1): 32–44.
Dorge C (2017) The Notion of Turning in Metaphysical Poetry. Münster: Lit Verlag.
Helmreich S (2021) Broken ocean. Presented via Midspace at the meetings of the Society for the Social Studies of Science, Toronto, Canada, and worldwide, October 6-9; panel: Becoming with Water V; video here.
Jue, M (2020) Wild Blue Media: Thinking through Seawater. Durham, NC: Duke University Press.
Marine Fisheries Review staff (1984) “Year of the Ocean” Celebrates Marine Importance. Marine Fisheries Review 46(1): 25-26, available here
Mayer, KJ, Sauer JS, Dinasquet J, and Prather KA (2020) CAICE studies: Insights from a decade of ocean–atmosphere experiments in the laboratory.” Accounts of Chemical Research 53(11): 2510-2520.
National Oceanic and Atmospheric Administration, Office of Public and Constituent Affairs (1998) International Year of the Ocean: Fact Sheets, Guide to Additional Resources. 
Ninety-Eighth Congress of the United States of America (1984) National Week of the Ocean. JOINT RESOLUTION Designating the week of April 29 through May 5, 1984, as “National Week of the Ocean.” In United States Statutes at Large, containing the Laws and Concurrent Resolutions Enacted During the Second Session of the Ninety-Eighth Congress of the United States of America, 1984, and proclamations, Volume 98, Part 2. Washington, DC: United States Government Printing Office. 
Sharpe C (2016) In the Wake: On Blackness and Being. Durham, NC: Duke University Press.
Stokes D, Deane GB, Prather K, Bertram TH, Ruppel MJ, Ryder OS, Brady JM, and Zhao D (2013) A marine aerosol reference tank system as a breaking wave analogue for the production of foam and sea-spray aerosols. Atmospheric Measurement Techniques 6: 1085–1094.
Tessnow-von Wysocki I (2021) Turning toward the ocean: Launching a decade of ocean science. MARIPOLDATA, available here
U.S. Cabinet (1999) Turning to the Sea: America’s Ocean Future. Washington, DC: National Oceanic and Atmospheric Administration.

Stefan Helmreich is Professor of Anthropology at the Massachusetts Institute of Technology and author of Alien Ocean: Anthropological Voyages in Microbial Seas (California, 2009) and Sounding the Limits of Life: Essays in the Anthropology of Biology and Beyond (Princeton, 2016).