Ocean Acidification: The Chesapeake Bay Oyster’s Next Battle?


Acid ReactionThe Chesapeake Bay Oyster is now potentially entering its newest fight in what could prove to be an epic battle against ocean acidification.

The crash of the heralded Chesapeake Bay’s oyster fishery has been told countless times. First came mass deforestation during the colonial era which led to enormous sedimentation runoff smothering the bay’s historic beds. With no tree roots to hold the earth in place, large quantities of dirt ran straight into the bay, burying billions of oysters.

Then came the overzealous Victorian businessmen of the Gilded Age. These entrepreneurs got rich quick during the bay’s oyster gold rush. Oysters were harvested in unfathomable quantities to meet Euro-American demand. Mountains of discarded oyster shell collected at shucking houses and was turned into roads, lime, sidewalks, and countless other materials. These businessmen did not realize however, that they were destroying their own livelihood in the process. We now understand we must return oyster shell to the water so that baby oysters have the critical shell substrate they need to which to attach so that they can settle above the muck, forming oyster reefs. Sadly during this Victorian era, countless baby oyster larvae could find no shell. Rather, these baby oysters settled into the mud where they suffocated and died by the trillions.

Then disease entered the picture. In an attempt to save the fishery, scientists experimented by introducing non-native Asian oysters into the Bay as a possible replacement candidate for the struggling native Eastern Oyster (Crassostrea Virginica). In so doing, the scientists all but ensured the destruction of the oyster fishery they were trying to save. Asian oysters brought unfamiliar disease, MSX and Dermo to be specific. The native Eastern oyster had no tolerance to these unfamiliar invaders. Mass die offs ensued.

Nearly all the shucking houses of the Chesapeake Bay closed. A way of life was all but lost. Today we are left with less than 1% of the historical Chesapeake Bay’s oyster stocks.

Aquaculture to the Rescue
America’s first cage based oyster farm appeared on the York River in the late 1930s. Ivy League scientists experimented with tray systems keeping the oysters out of the muck. Chefs and high end restaurants paid top dollar for these cultured oysters and their pretty shells. But then World War II came, and America forgot about oyster farming. The war effort and the military’s need for the lower Chesapeake Bay took precedence.

But there has been a recent resurgence of oyster aquaculture and chefs around the country couldn’t be happier. Just drop in for dinner at your local gastropub. You are almost certain to see an artisanal oyster listed on the special board, if not permanently and prominently featured atop the menu.
Us oyster farmers proudly use sophisticated techniques as part of this oyster renaissance in order to grow precious strains that have shown signs of disease resistance. We have built large oyster nurseries in an attempt to return the almighty oyster to its rightful place. While growing, our oysters filter enormous quantities of water. At Anderson’s Neck Oyster Company, our oysters have filtered 20 Billion gallons of water alone in just the last three years creating a cleaner, healthier Chesapeake Bay for everyone to enjoy. During grow out, our oyster’s shells also act as a natural base moderating the acidity level of the water. Both living and deceased oyster shells essentially act as an antacid for the bay, regulating the water’s PH level and gradually dissolving over time.

But is Farming Enough?
Unfortunately, our oyster farms pale in comparison to the vast quantity of oysters that once existed. We simply don’t have enough oysters in our farms to regulate the acidity level of the entire Chesapeake Bay. If you consider the carbon production since the time of the Industrial Revolution, that vast output is now partially stored in the oceans as carbonic acid. According to the National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Laboratory, the acidity of the ocean has already increased a whopping 28.8% since the time of the Industrial Revolution. This is problematic since the oceans are slowly but surely turning corrosive. Acidic water works to reduce the amount of calcium carbonate in the ocean, which is what shellfish need to form their shells. Baby shellfish are therefore stressed as they expend tremendous amounts of energy just trying to form shell which in turn leads to premature death. Whitman Miller, a research scientist with the Smithsonian Environmental Research Center, predicts a rapidly rising acidity level for our oceans over the next 100 years. And therein lies the trouble. We have a potentially cataclysmic situation on our hands, all because of acidifying ocean water.

Canary in the Coal Mine: Pacific Northwest Oyster Farms
Are you skeptical of the risks? Just look at the extraordinary lengths one oyster farm has already gone in an attempt to combat the problem. The Seattle Times recently chronicled the plight of oyster farms in the Pacific Northwest including the Nisbet family of Goose Point Oyster Co in a three part expose on Sea Change. Since 2005 oyster farms in Washington state have seen billions of oyster die offs. The Nisbets had such trouble with acidic water at their Washington state oyster hatchery, they decided to build an entirely new hatchery operation in Hawaii. That’s right, the situation was so dire that rather than growing baby oysters right next to their farm in Washington state, they built a state of the art nursery more than 2,600 miles away to avoid the corrosive water of the Pacific Northwest. Here the Hawaiian oysters are raised until the Nisbets transport their precious oyster babies with hardened, calcified shells back to the mainland. Sound expensive? Well it is. And if this proves to be the prerequisite of successfully growing oysters in the Pacific Northwest, oyster prices are set to rise dramatically. Already commanding retail prices of $2-5 an oyster, one naturally wonders how much higher oyster prices can realistically go and still have a market.

Is the Chesapeake Bay Next?
With the trouble our Pacific cousins are having, we naturally ask: Is the Chesapeake Bay next? Recent articles speculate we might already be seeing the early warning signals. When we talk to the oyster hatcheries that keep our Chesapeake Bay oyster nurseries supplied with baby oysters, we realize how little we know. This is not due to lack of smarts. The scientists who support our fishery are brilliant. However, the Chesapeake Bay is wildly complex. The Bay’s acidity levels naturally ebb and flow in seasonal, estuarine patterns. In order to gauge the true difference, we must take numerous readings over time. So far the signs are concerning, as acidity appears to be on the rise.

What to do?
If the Atlantic waters that mix in the Chesapeake Bay continue to see rising acidity levels similar to the Pacific, drastic action will be necessary. Oyster shell is missing in the Bay. If it was present, it would help moderate acidity levels. But because oyster shell has been strip mined away over the centuries, no modifying base substrate exists. Add in historically high levels of carbonic acid borne by man’s demand for fossil fuels, and we have a disaster in the making. The state of the remaining one percent of historical oyster stocks in the bay is fragile at best. Unless we invest vast sums to reintroduce oyster shell to the bay, or some other form of artificial base regulator, we could quickly surpass an acidic tipping point.

If shellfish are impacted, one naturally asks what happens to all the other sea faring animals that rely on shellfish for nourishment? Surely, they will also suffer from acidic water and a lack of food. How little we know about this problem and how to potentially combat it is startling. One could argue our ignorance is downright irresponsible. Imagine a life with no oysters, clams, mussels, or any other animals that rely upon shellfish for food. It’s time to take action by committing the monetary resources to charge our best scientific minds with finding solutions. Unfortunately, time is not on our side.