By: Rachel Wu
When Russian astronaut Yuri Gagarin became the first man to see Earth from space, he was astounded by the majesty and beauty of the planet. Since then, thousands of images of the great wonders of Earth—whether the jeweled parrots on lush green carpet of the Congo rainforest, the clusters of monarch butterflies on Canadian trees, or the frosty crystalline icebergs populated by penguins, have been used as fuel to argue for climate change. Should we not work to preserve this astounding wonder? In our desperate dash to exhibit the most visually stunning pieces of Earth to preserve, we have overlooked the smallest details; the most seemingly insignificant organisms whose presence created life as we know it today and could be the key to save our perishing planet. Green algae are not what most people first think of when they hear “ecological artifact,” but to me, this clade fits into all three dimensions of Earth’s timeline: past, present, and future. Through this dissertation on the significance of this photosynthetic protist, I hope to draw your mind to the small details by using detailed scientific research on algae to raise questions on ecological awareness. Of course, every living organism on Earth has much to offer about how we should act ecologically. However, few organisms span as many generations as any algae, whose history dates back to billions of years ago–long before the dinosaurs, mammoths, or even vascular plants. We need not look to Antarctica or the Amazon to find reasons to save the planet. Perhaps the perfect exemplar could be found at the edge of a sewer.
What is so remarkable about algae? Most people today believe that algae are just the irritating green scum that collects in their child’s goldfish bowl, but the history and significance of algae far extend that of the human imagination. The development of autotrophic green algae from cells that engulfed photosynthetic bacteria 3.5 billion years ago was a major milestone in the development of present-day land plants, since it gave these organisms the ability to synthesize organic molecules from the inorganic environment (Yoon 2008). Another important turning point in the history of eukaryotic life—also mediated by algae—is the colonization of land by around 500 million years ago.
With this event, the atmospheric oxygen concentrations skyrocketed as a result of photosynthetic activity aboveground, and a path to terrestrial life was established (Wodniok 2011). Over millions of years, algae developed into the first nonvascular land plants, which evolved into the complex seed plants like gymnosperms and angiosperms we see in botanic gardens today (de Vries, 2018). Even if these early algae and land plants are not as prevalent as they were millennia ago, their existence created the diverse flora that are so admired by many environmentalists.
One flaw in most ecological arguments is the overlooking of the small details of the past. We only look toward the future—which organisms can replace bees as pollinators? Out of all these endangered species, which animals should we prioritize saving? How much should each person have to contribute to scale back carbon emissions by a certain year? The past is what led us to today—the mass panic we feel over the future is a consequence of our failure to appreciate the Earth’s rich resources and use them accordingly and responsibly in our day-to-day life. Our very existence on Earth depends on past organisms’ evolution. If one single cellular organism could give rise to every plant we see outside our window, should we not consider the effect our smallest actions? We are an incredible species, but our powerful sphere of influence could lead to the closing chapter of the history of life on Earth. The actions we do are irreversibly written into history—who will we be remembered as by our descendants? Or will there be no one left to remember us by?
Though algae have given us the gift of life as we know it today, it may also be our downfall. Given the previously outlined importance of algae to life as we know it today, one might question why this abundance of algae could be detrimental. As it is with most science, a delicate equilibrium is essential to an ecosystem’s survival. Runoff of phosphorus-rich fertilizers into lakes and streams from agricultural engineering projects have caused a problem known as eutrophication. “Eutrophication” deriving from the Greek root “eutrophos,” meaning well-nourished, is a phenomenon where overabundance of minerals and nutrients causes excessive algal growth (Anderson 2008). These algal blooms accumulate in surface water, where they produce toxins that kill fish and other aquatic life. (Schindler 2006). Algal blooms also pose a danger to our societies and economies: it has been estimated that such harmful algae blooms cost the fishing economy more than $2.2 billion annually in the U.S. alone (Chislock 2013).
Hypoxic areas are caused by algae that monopolize all the oxygen in an aquatic ecosystem. As seen in the map above from 2011, the number of eutrophic and hypoxic coastal are becoming much more prevalent around the world.
With the development of large scale commercial farming needed to sustain the growing global population, agricultural runoff has not only increased the frequency of algal blooms in the Beibu Gulf of China from six events between 1985 and 2000 to approximately twenty between 2011 to 2017, but has also increased the surface area of such blooms from tens to hundreds of square kilometers (Xu 2019). As seen in the persisting problem of eutrophication, it is evident that although a single alga may not be able to significantly impact our day-to-day life, a teeming colony could have detrimental effects on society as well as ecology.
A common argument I hear against climate change is how it’s “just one person,” or it’s “just one time.” What difference does one thing make? Like algae, we are a community species, where parts add up to a whole. Eutrophication is a problem caused by the additive effects of many algae releasing toxins, and global warming is a problem caused by billions of people failing to utilize the Earth’s resources effectively. We must bring our focus from “my actions, my future” to “our actions, our future.” One person choosing to drive instead of walk may not have contributed that much to the carbon emissions—certainly not enough to raise the global temperature by an appreciable amount, but what happens if the seven billion others also choose to do so? On the contrary, one person’s decision to shower for a minute less than usual might not seem to conserve much water, but what happens if everyone in the family saves water for that one minute every day of the year? Like how small viruses cause global pandemics, and how small algae destroy aquatic ecosystems, miniscule actions by humans can cause extinctions. We must tread carefully: there is no room for error, and we do not have much time left to undo our wrongs.
Eutrophication is not the only problem endangering us. With the rise of industrialization during the close of the nineteenth century, fossil fuels have been harvested at record rates, depleting the Earth’s accumulated store of petroleum and natural gases within mere decades. Scientists desperately attempted to search for new sources of renewable energy, such as wind, water, or even the sun and tides. Though none of these sources are efficient enough to support the global economy, one is of rising interest to researchers: algae. It came as a great shock to many biologists when they realized that applying an environmental stress—such as limiting the presence of key nutrients—to an algal culture caused the cells to accumulate energy-rich triacylglycerides like oleic, palmitic, and linoleic fatty acids that closely resembled fossil fuels (more about this here). (Park et al 2014). The development of such a fuel could reduce global carbon emissions by two billion tons per year if as little as 27% of consumed energy were derived from biofuels by 2050 (Singh et al 2014). This development is obviously monumental in emphasizing the significance of algae on the world’s future, but there is as much deeper lesson behind this.
Algae being grown for biofuels are often grown in large reservoirs like these. Compared to growing the same amount of corn for ethanol, algae growing and harvesting takes up far less arable land.
The ability of algae to adapt to such stressors in their environment not only provides us with a hope to produce more sustainable energy, but it also is a lesson on resilience: if a small strain of eukaryotic cells could so easily survive under harsh conditions, why are we not trying our best to adapt to the future that we created? We have caused more damage to the Earth in our existence than any other species during theirs. The biosphere as we know it is merely a few steps away from ceasing to exist. However, all hope is not lost–nature has endowed itself with the extraordinary ability to recover and grow in response to drastic changes like major extinction events. If we were powerful enough to wreak such destruction, we also must be innovative enough to find ways to reverse it. We have not yet found the answer, but with perseverance and a continued thirst to preserve our home, we will find the cure one day—but only if we don’t give up.
So what does algae contribute to the life we are so familiar with? Well, it does seem like they contribute everything, doesn’t it? Without the evolution of algae, there would be no path to multicellular plants and animals—we would not have even evolved in the first place. Algal blooms threaten to suffocate wild aquatic ecosystems due to overfertilization and poor water runoff infrastructure. But algae also seem to hold the key to creating more sustainable energy to power our future. It does seem confusing: are algae the reason we live, or the reason we die? The answer is not quite so black and white. Our roles within the environment likewise cannot be reduced to just “big ideas.” Every action we have comes with its own costs and benefits. Although an economist would certainly perform countless mathematical operations to find the equilibrium that neutralizes externalities, the Earth is not a market. It cannot be reduced to graphs, figures, or equations. There is no right answer, because every smallest detail constantly alters the course of the future. The complex web of relationships that connect every living thing to the first common ancestral cell emphasize how each organism is here for a reason. Natural selection favored their propagation because they have something important to contribute to their population, their community, their ecosystem, and ultimately the entire biosphere. Likewise, each person on Earth has a responsibility to contribute something for the environment. Every action, no matter how small, is significant. So will your actions lead to the survival of the next generation, or will it lead to the death of this one? Will you open more doors for life, or will you destroy them? Like it or not, you play a part in this decision simply by living. You decide.
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- Chislock, Michael, et al. “Eutrophication: Causes, Consequences, and Controls in Aquatic Ecosystems,” Nature Education Knowledge. 4(4): 10 (2013). https://www.nature.com/scitable/knowledge/library/eutrophication-causes-consequences-and-controls-in-aquatic-102364466/
- De Vries, Jan, and Archibald, John. “Plant evolution: landmarks on the path to terrestrial life.” New Phytologist. 217(4): 1428-1434 (2018). https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.14975
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- Park, Jeong-Jin, et al. “The response of Chlamydomonas reinhardtii to nitrogen deprivation.” The Plant Journal. 81(4): 611-624 (2015). National Library of Medicine. https://pubmed.ncbi.nlm.nih.gov/25515814/
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- Wodniok, Sabrina, et al. “Origin of land plants: Do conjugating green algae hold the key?” BMC Evolutionary Biology. 11: 104 (2011). https://doi.org/10.1186/1471-2148-11-104
- Xu, Yixiao, et al. “Historical Occurrence of Algal Blooms in the Northern Beibu Gulf of China and Implications For Future Trends.” Frontiers in Microbiology. 10:451 (2019). https://www.frontiersin.org/articles/10.3389/fmicb.2019.00451/full
- Yoon, Hwan Su, et al. “A Molecular Timeline for the Origin of Photosynthetic Eukaryotes.” Molecular Biology and Evolution. 21(5): 809-818 (2004). Oxford Academic. https://academic.oup.com/mbe/article/21/5/809/1014069