Wild Oysters Deemed ‘Functionally Extinct’

by | 2.10.2011 at 11:09am | 2 Comments
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Oysters have become a quintessential part of romantic dinners. Sadly, the oysters themselves get no love: global oyster populations have fallen dramatically in recent years due to overharvesting and destructive fishing techniques. (Source: Will Innes on Flickr)

A recent Valentine’s Day-inspired article in the Grist pointed out that oysters are the only delicacy that enhances The Mood and water quality. Don’t get too excited, though: a new study published this week in BioScience revealed that oysters are “functionally extinct” in many parts of the world where they were once abundant, and nothing kills The Mood (or mollusks) like functional extinction.

Today about 95% of all oysters served in restaurants and sold in markets are farmed, a result of the fact that overfishing has destroyed more than 85% of global oyster reefs. In places that were once famed oyster harvesting spots, only 1% of reefs remain; in fact, five locations in North America contain 75% of remaining global oyster reefs.

Estimates indicate that at the current rate of decline, wild oysters could disappear within decades if nothing is done to remedy the situation. This possibility is so alarming because oysters play a crucial role in the coastal ecosystems they inhabit. Not only do the mollusks filter impurities from the water and support fish populations, but they also prevent coastal erosion: over time, shells of deceased oysters form reefs, which mitigate the erosion of shorelines.

The importance of oysters for coastal waters and aquatic communities led Dr. Michael Beck (University of California, Santa Cruz) to conduct a study examining the decline of oyster populations worldwide. Dr. Beck and his team of marine biologists studied 144 former oyster beds in 40 regions around the world, making theirs the largest study to date of wild oysters.

Louisiana oyster reefs, such as the one pictured above, were severely damaged last spring following the BP oil spill in the Gulf of Mexico. (Source: www.creoleneworleans.com)

Dr. Beck and his team found that oyster reefs are at less than 10% of their prior abundance in 70% of bays and 63% of eco-regions studied and less than 1% of prior abundance in 37% of bays and 28 % of eco-regions. These numbers led Beck to conclude that oysters have become “functionally extinct,” meaning “they lack any significant ecosystem role”.

This is a shocking finding considering the historic dominance of oysters in temperate coastal waters. Like lobsters, oysters were once so abundant they were considered peasant food. In recent decades, however, their status as a culinary delicacy has led to intensive harvesting and many populations have been destroyed by modern fishing methods, especially dredging and trawling, which disturb the ocean floor.

In an ironic twist, the only native oyster populations in the world that had remained at historic abundance levels were devastated last spring. Yes, the healthiest oyster beds in the world (in fact, the only oyster beds in the world deemed healthy by Dr. Beck and his team) were in the Gulf of Mexico, site of the BP Deepwater Horizon oil spill. While in the early stages of the spill it was determined that the oil had not significantly harmed Gulf oyster reefs, subsequent decisions by politicians only made the environmental disaster worse for the oysters.

Only days after the explosion that sent a steady torrent of oil into the Gulf, Louisiana officials and Governor Bobby Jindal decided to open giant valves on the Mississippi River in an attempt to push incoming oil out of the state’s coastal marshes and back out to sea. Although the intentions behind the decision weren’t bad, the deliberation (and consequently the outcome) was poor: state bureaucrats didn’t consider the delicacy of coastal ecosystems or the specific conditions marine organisms need to survive.

The Davis Pond Diversion structure flows at capacity, pushing water into the upper Barataria Basin to try and curb the possible intrusion of oil into coastal marshes and bays west of the Mississippi River. (Source: Louisiana Coastal Protection and Restoration)

The impact of the freshwater diversions from the Mississippi was far more severe than the damage done by the oil. Following his study, Dr. Beck estimates that half of the Gulf’s most productive oyster reefs were destroyed by the decrease in salinity; immediately following the river releases, oyster fishermen along the Louisiana coast reported mortality rates of 80% for thousands of acres of oyster beds. While oyster harvesters are being compensated for their losses through the $20billion BP compensation fund, the oysters themselves aren’t so lucky.

At the end of the grim report, Dr. Beck offered hopeful suggestions, recommending that all areas where less than 10% of former oyster reefs remain be closed to harvesting, dredging and any activity that could harm remaining oyster stocks. Dr. Beck was quoted in a NY times article as saying that although oysters “are already functionally extinct [in many places]… if we act now with reasonable measures, we can get them back”.

So what measures should be taken?  One possibility is re-introducing oysters into waters that they once inhabited, as suggested by one New York artist. Last year, Kate Orff presented her idea to reintroduce oysters into the waters around New York City as part of the MoMA’s “Rising Currents” exhibit. Orff proposed creating oyster farms in New York harbor and the Gowanus Canal; the oysters would filter (and thus improve) polluted waters and the rope structures that would comprise their beds would mitigate storm surge.

While initially presented as part of an art exhibit, Orff’s design has real potential. Students at the New York Harbor School have already begun experimenting with oyster farms in city waters. More important than the physical outcome of Orff’s idea, however, is the way in which it demonstrates and promotes innovative thinking. Orff’s New York oyster beds may not be the type of measure Dr. Beck had in mind for revitalizing oyster stocks but, the idea of finding a single solution for multiple problems may be the type of approach necessary for revitalizing the global environment.

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2 Responses to “Wild Oysters Deemed ‘Functionally Extinct’”

  1. Jeremy says:

    “… oyster harvesters are being compensated for their losses through the $20 billion BP compensation fund…”

    I find this type of thinking — that people can somehow be compensated for the devastation of the environment — appalling. You can’t put a price tag on the health of an ecosystem, and the environment belongs to everyone, not just the people (or companies) who exploit it to make a buck. Thinking of complex ecosystems simply as resources to be economically exploited will only pave the way for the continued ecological degradation of the planet. Will we be able to wake up and realize what is truly priceless before we have a barren planet?

  2. Katie Horner says:

    While I hate to say this, we live in a capitalist society. Consquently, I think the answer to your question is no, we won’t ever be able to conceive of the earth and its natural resources as ‘priceless’ – they have a monetary value simply by constituting the world we humans (resource users and inventors of that all-powerful system, capitalism) live in.

    In the particular instance discussed in my post, however, I’d argue that it is not the environment or a specific ecosystem that is being assigned a monetary value but rather, the oyster industry. It’s true that oyster harvesters make their money by exploiting marine ecosystems but I think it’s important to acknowledge that all people make their living (both figuratively and literally) by exploiting the environment, be it directly or indirectly.

    To say that the oyster harvesters and fishermen whose livelihoods were destroyed by the BP oil spill should not be compensated is something that many people would find as appalling as you find their compensation to be. Your line of thinking seems like a slippery slope to me. You say that placing an economic value on natural resources will “pave the way for continued ecological degradation of the planet.” However, if companies that pollute the environment on the magnitude that BP did and are not held accountable won’t that also pave the way for continued ecological degradation by removing all consequences of doing so?

    I certainly admire your purity of thought regarding the environment. On a personal level, I do think it’s important to have a valuation of the natural world that does not have a monetary basis. On a societal level, however, I think it’s important to acknowledge certain realities regarding how industries, nations, and other individuals view the environment and natural resources, for if we choose to ignore or merely judge as “appalling” these realities, we will never succeed in changing them.

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