Monday Night Oysters
2017, High School, Prose
It’s a Monday evening. I have just gotten out of work, my older brother has arrived home from college, and my Dad is on his way to meet both of us at a local Irish restaurant–one of our favorite places to eat. We never go out to eat on Monday nights, but tonight is a special night. It’s “Free Oysters from 5-7 pm” night. The sandwich board sign has been on the sidewalk for weeks, and all three of us have been eagerly awaiting this delicious maritime meal all day long.
Eating raw oysters has been a tradition in my family for as long as I can remember. I don’t remember exactly how old I was the first time I ever ate an oyster, but I know it was in Cape Cod, fresh out of the brilliantly blue coastal waters. Served over a bed of ice, I picked up the crusty shell, took a sip of the salty brine, and poured the meat “right down the hatch,” just as my dad instructed. Eating raw oysters is an experience–one that nothing else compares to. They’re slippery and cool, but not slimy; salty; refreshing; fishy, but fresh. Some people eat raw oysters with lemon or mignonette sauce, but my family has always eaten them straight to take in their full flavor. When asked to describe what eating an oyster is like, my dad and have always agreed: It feels like you’re eating the ocean.
Eating oysters with my family has always been a way for us to relax and to connect. I associate eating oysters with the summertime, with being content and carefree, with being outside. I am reminded of how lucky I am to live so close to the ocean, and how fortunate I am to get to enjoy all it has to offer–from early morning swims to late night beach walks, to the delicious, local oysters.
Normally, I don’t eat meat. My family has been mostly vegetarian since I was little, ever since we found out about the humane and environmental impact of the meat and fishing industries. My dad always told me that oysters were different, though. He explained that oysters actually filter the water they’re in, making the water cleaner. I always thought that was really cool, but never did my own research about it. After taking an Environmental Science course at my high school, I started to think more about my favorite seawater snack. I wondered: how are oysters affected by climate change and ocean pollution, and in what ways are oysters beneficial organisms that we should care about saving?
Before answering these questions, it is important to understand the basic biology of these organisms. Oysters are bivalve mollusks, meaning they have two valves, or shells (Massie 1998). The lower valve is thick and attached to a hard substrate, while the upper valve is smaller and more flat (Massie 1998). The two valves are connected to each other by a muscle. When the muscle relaxes, the shell opens, allowing for seawater to fill the inside of the shell, which is called the mantle. When it closes, the mantle fills with the plankton-rich seawater, which is is how the oyster feeds (Massie 1998). Oysters are filter-feeders, which means that as they take in nutrients, they clear the water they are in (Shumway et al. 2003).
One of today’s main issues facing oysters and other mollusks is ocean acidification. Ocean acidification, at its core, is caused by humans. As humans burn fossil fuels, carbon dioxide is released into the atmosphere. Over the past 200 years, the ocean has absorbed 35% of all of those excess anthropogenic carbon dioxide emissions (Garrison et al. 2016). The acidification process begins as the ocean absorbs this carbon dioxide. First, the carbon dioxide reacts with water, which releases hydrogen ions and creates carbonic acid (Garrison et al. 2016). The carbonic acid then quickly dissociates into bicarbonate and hydrogen ions (Garrison et al. 2016). This reaction goes both ways– bicarbonate and a hydrogen ion reacting into carbonate and two hydrogen ions, and vice versa. In healthy ecosystems, the reaction should be in equilibrium. However, as more carbon dioxide is added to the water, the reactions lean towards the left, removing excess hydrogen ions and therefore making the water more acidic (Garrison et al. 2016).
Ocean acidification has harmful impacts on all organisms who depend on carbonate to create their shells. Shelled organisms like oysters make their shells out of calcium carbonate. As CO2 reacts with water to form carbonic acid, that means fewer carbonate ions are available for shell-building (Garrison et al. 2016). At Taylor Shellfish Company in Puget Sound, Washington, one of the most important oyster nurseries in the United States, oysters are being threatened by these increasingly acidic waters (Fletcher 2017). For baby oysters, the lack of carbonate ions prevents them from forming strong, protective shells (Fletcher 2017). Oysters are not the only organisms affected–lobsters, crabs, clams, and corals are suffering as well (Fletcher 2017). Ocean acidification is currently increasing, and projected to get even worse in the coming years. According to the National Oceanic and Atmospheric Administration, ocean acidity will increase five-fold by the year 2100, and most shells would dissolve in 45 days in water that acidic (Fletcher 2017).
The restaurant is crowded tonight, so my brother and dad and I are sitting at the bar. I’m sipping a lemonade, my brother drinks a beer, and my dad has just ordered a Moscow Mule. It feels so good to be here with both of them–it’s been months since I’ve seen my brother, and we have so much to catch up on. I tell him about what’s been going on in high school, and he shares a story about college. A waitress approaches with a tray of oysters.
“Are you folks interested in the free oysters tonight?” she asks.
“That’s why we’re here!” My dad replies, and my brother and I nod along. She sets the tray down in front of us. We cannot wait to wolf them all down.
Why should we care about how ocean acidification is destroying mollusks like oysters? In addition to being one of my favorite foods and at the heart of an enjoyable family tradition, oysters provide valuable ecosystem services. They have significant and beneficial impacts on their ecosystems, making them “ecosystem engineers” (Gazeau et al. 2007). First of all, oysters grow vertically and densely, which creates ideal habitats for mollusks, crustaceans, and other invertebrates (Grabowski et al. 2012) The invertebrates that use oyster reefs as habitats are food for a variety of fish and other mobile crustaceans (Grabowski et al. 2012). Therefore, due to the habitat they create, oyster reefs benefit entire food chains.
Furthermore, the fact that oysters are filter-feeders improves water quality, which benefits the health of marine animals and plants. And oysters are powerful: just one oyster can filter between 30 and 50 gallons of water each day (Smith 2011). In the process, they reduce turbidity and remove excess nutrients from water, filtering out excess organic matter, nitrogen, silt, and harmful bacteria and viruses (Shumway et al. 2003). By filtering out these suspended particles, oysters prevent microbial organisms from dominating the habitat. This, in turn, results in an increase in productivity for organisms at all trophic levels (Grabowski et al. 2012). This filtration is also beneficial to submerged aquatic vegetation, because reducing the turbidity of the water allows sunlight to penetrate more easily and reach the plants (Grabowski et al. 2012). Reducing erosion is yet another ecosystem of oyster reefs–intact reefs keep marine habitats intact as well (Grabowski et al. 2012).
Finally, unlike many types of farming, oyster farming is an environmentally conscious industry. Because oysters take in the water from their habitat, clean water is absolutely essential for oyster cultivation, so oyster farmers, out of necessity, are advocates for clean water standards (Shumway et al. 2003). These standards include monitoring for fecal contamination, algal levels, and heavy metals (Shumway et al. 2003). As a result, shellfish cultivation leads to environmental awareness, and contamination of harvest areas always leads to advocating for improving water quality (Shumway et al. 2003).
By now, we have collectively eaten three whole trays of oysters. Our bellies are full with that salty sea-brine that makes us feel like we’re eating the ocean.
“This is the most amazing night of my life,” I say to my family, meaning it honestly. “I love oysters so much I can’t even believe it.”
“I agree with you there. It’s kind of overwhelming,” my dad pipes in.
“The real question is–if she comes around with another tray, will we say yes?” asks my brother.
“Of course we’ll say yes!” I exclaim. I have to admit I’m starting to feel a little sick, but passing up free oysters would feel like a crime.
Enjoying oysters is something I’ve been doing with my family my whole life, and up until recently, I never even considered that some day that might not be the case. Unfortunately, however, if humans continue burning fossil fuels at the rate we are, the ocean will continue to absorb carbon dioxide, and the waters will become increasingly acidic. As the ocean becomes too acidic for oysters to build strong shells, not only will my family be forced to end our beloved tradition, but all the ecosystem services that oysters provide will diminish. As oyster reefs become less abundant, entire marine habitats will be destroyed. The lack of water filtration that oysters provide will make water more turbid and less habitable for marine organisms. And if the oyster farming industry collapses, some of the most effective clean water activists–oyster farmers–will no longer have the means to advocate.
As humans, we all need to take a step back and realize the ways in which our actions affect our environment. We cannot keep blindly consuming resources and not expect to deal with the consequences. We need to make drastic changes to the way we think about fossil fuels. If we don’t drastically cut our emissions soon, the ocean will become too acidic to sustain the delicious and environmentally beneficial organisms that are oysters. I don’t want my favorite family tradition to become a thing of the past. Even more than that, I don’t want entire marine ecosystems to be destroyed.
Fletcher L (2017). Ocean Acidification Is Killing Baby Oysters. Al Jazeera America.
Garrison T, Ellis R (2016). Oceanography: An Invitation to Marine Science. Cengage Learning, Boston
Gazeau F, Quiblier C, Jeroen JM, Gattuso JP, Middelburg JJ, Heip CHR (2007) Impact of elevated CO2 on shellfish calcification. Centre for Estuarine and Marine Ecology, Netherlands Institute of Ecology, Yerseke.
Grabowski JH, Brumbaugh RD, Conrad RF, Keeler Andrew G, Opaluch JJ, Peterson CH, Piehler MF, Powers SP, Smyth AR (2012) Economic Valuation of Ecosystem Services Provided by Oyster Reefs. BioScience (2012) 62 (10): 900-909
Massie FD (1998) The Uncommon Guide to Common Life of the Narragannsett Bay, 2nd Printing. Save the Bay, Providence
Shumway SE, Davis C, Downey R, Karney R, Kraeuter J, Parsons J, Rheault R, Wikfors G (2003). Shellfish aquaculture– In praise of sustainable economies and environments. University of Rhode Island Environmental Data Center.
Smith B (2011) The Coming Green Wave: Ocean Farming to Fight Climate Change. The Atlantic.
I chose to write about oysters because I have a personal connection to them. Some of my most enjoyable memories involve eating oysters with my family by the ocean, and it is scary for me to imagine a world where the ocean is too polluted for them to thrive. I found out about how oysters are filter-feeders a while ago, but never understood exactly what that meant. While researching for this paper, I was able to learn more in-depth about these amazing mollusks, how they filter water, and additional ecosystem services they provide as well. I found out about ocean acidification this year in my Environmental Science class, and writing this paper allowed me to reflect more deeply about the effects it is having on organisms that I care about.