Can Scientists Help Oysters Thrive Again?

Dnieving work and pollution destroyed the once rich reefs. Thorough science can help return them

Tim question, Cognized magazine

September 24, 2025

Chesapik Gulf – the largest on the air in the continental part of the United States – are used oysters, more than someone can imagine today. The indigenous Americans collected oysters more than 12,000 years before the arrival of Europeans, as evidenced by the piles of thrown shells left in garbage pits. In the late 1800s, annual crops from the bay, in which people of European origin dominated, amounted to about 600 million to 1.2 billion pounds.

In 2024, wild commercial crops were less than 5 percent of this.

Resurrection and pollution by deposits, sewer and fertilizers have been established since the 1700s, a century after the first English settlement, Jamstown, was created on James River This is eaten in the bay. Today, global warmingAn increase in sea level and acidification pose additional threats.

But the biggest destruction was from the method standing behind these record crops: the practice of dredging work, begun in the late 1800s, in which Havy -metallic columns or gears are dragged through the sea bottom to dig a bunch of oysters at the same time. This destroyed the majority of giant reefs formed by countless generations of oysters growing on each other.

Like Coral reefsThese oyster reefs played important environmental roles, providing habitats and nurseries for many other types and filtering of huge volumes of water. They also offered basic services to people protecting the coastal lines and supported fishing for millennia.

For decades, environmental organizations worked on the restoration of the population of oysters in the bay, accruing data on the way to study on successes and failures. Others turned to the distant past to understand what was lost, and evaluate what could be restored.

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Cliff is digging

A few years ago, a paleontologist of conservation Rowen Lokwood In the college of William and Mary in Williamsburg, Virginia, went to one of the few surviving fossil reefs, near Datton, Virginia. She had long wanted to find out what the Oystera of Chesapik Gulf reefs were before people started there a large -scale harvest.

When this reef was formed from 195,000 to 245,000 years ago, the sea level was higher, so today the fossil reef comes out of the water on the rock face along the Pinoktank River. “All oysters are in life positions, are still formulated,” says Lokwood. “They look like they died yesterday.” To interpret the fossils, she united with a marine biologist Roger MannAlso, from William and Mary, who for decades carefully monitored the Chesapik -Ustitz population.

On the basis of the fossil reef in the Daton area, as well as an extensive collection of shells in Museum of Natural History of Virginia taken from fossil reefs that no longer exists, Lockwood and Mann appreciated For a long time, local oysters lived four times longer (up to 21 years) and grow twice as much (up to about ten inches in diameter), almost ten times higher than the density of reefs in this area today.

This means that the oysters who suppress filters could go through all the water of the Chesapik Gulf through their gills in one day, calculated Mann and Lockwood. Today it can take about a year.

If these giant reefs magically appeared today, this can solve many problems of the bay. Agricultural and wastewater rich in nutrients cause huge flowers of algae, and when these algae die and plunge, bacteria bloom in turn, consuming so much oxygen that few other organisms survive at the lower depths. “Many oysters could turn most of this material into oyster fabric and sink,” says Lokwood.

Dnieving work

But how much recovery is realistic?

“It would be naive to think that we will be able to restore these systems to the point that they were similar before we put 18 million people in the watershed in the Gulf of Chesapic. This simply will not happen, ”Mann says. “What existed even several hundred years ago will never be recreated.”

And neither Mann nor Lokwood see great value in the current, large -scale practice of the release of living larvae or young oysters in the bay. They say that it is expensive and that the vast majority of the larvae released are probably quickly consumed by predators. “It's like washing them in the toilet,” says Lokwood.

But, inspired by the amazing size of many fossil sinks, Lokwood claims that recovery could be significant if the practice of dredging work was stopped, and the restoration efforts were aimed at protecting large oysters of adults, which filtered more water, produce more offspring and help rifs growing.

According to her, this would require the introduction of large, solid structures that imitate the reefs that were destroyed. They will not allow oysters to be covered with a large amount of precipitation, which are washed into the bay. They will also prevent dredging work, which would be useful for oysters, but not for fishermen. “The waters have been here for hundreds of years, and these are the means of generations that we need to save,” she says. “Thus, you must be careful where you put these structures.”

Mann, which is working closely with the Virginia Stage Commission on polls in order to scientifically inform about fishing management, contributes to a less controversial approach: Introducing empty oyster shells in elected areas Link naturally arrivating oysters arriving in order to settle. Vodka on board with this method, he says.

To date, this and other restoration efforts helped restore oyster reefs for almost 1800 acres in ten different tributaries in the bay. According to Mann, the harvesting once every three years minimizes the influence at the stage of early life, and the production of oysters increased about eight times.

Recovery rises

Chesapik Gulf is far from the only place where people are trying to restore oysters. Sea ecologist Jessica Pruett University of Southern Mississippi and Sea Ecologist Rachel Smith California University, Santa Barbara, are co-authors of 2025 article V Annual review of marine science that I found more than 2250 of the past and current recovery projects only for the Eastern Oyster (Crassostrea Virginica) and more than 200 for other species, with a steep increase since the 1990s.

The success of recovery depends on local circumstances, Smith says. For example, north of the mouth of the Chesapik Gulf, along the shores of Virginia, the restoration was quickly in the project, which has been working for about 20 years. The site is “another place than the bay, relatively untouched, with a small number of problems of water quality,” says Smith. “We had a great success by just releasing oyster shells or artificial concrete reefs.” A study published in 2022 He discovered that the density of oysters in reefs built from free shells reached the fruits of natural reefs in six years, and that dirty crabs that feed the oyster quickly entered. Meanwhile, the study of 2021 discovered that there were more oysters, and their density was greater where artificial reefs made of concrete were built above; Higher reefs also more effectively protected the shore from the waves.

However, in some places on the east coast of Virginia, oysters do not settle, despite supposedly favorable conditions.

The behavior of oysters can play a role. At the beginning of the larvae, very tiny and in the power of marine movements, explains the priest who studied them in the laboratory. But after a few weeks they are actively Look for a place for a settlementThe field “They have an impressive ability to swim,” says Pruett. “When they find a place that they like, they are like a“ dive bomb ”. And if this is not suitable, they can throw themselves back into the current. ”

Taking into account what attracts the larvae of oysters, it can be an important direction for future research – there is some evidence, for example, that artificial reefs in lighter colors can reduce the warming of sunlight on oysters, already emphasized by climate change, which would be useful in warming. But at least one species of oysters (Pacific oyster, Crassostrea Gigas) such reefs It seems to attract fewer larvae; Something in these reefs should be less attractive to them or even put them off.

Researchers say that there are many reasons to want to preserve or restore oyster reefs. In addition to the preservation of natural ecosystems and sustainable fishing, which depend on them, reefs can help protect the coastal lines from storms and floods, which will become more urgent, since climate change and increasing sea level lead to more dangerous storms.

And from the whole organic material that accumulates in reefs, the oysters themselves can also help absorb part of the carbon, which we radiate into the atmosphere. According to Putt, consumers can contribute, choosing oysters grown in cells that are collected without dredging and, therefore, without damage to reefs.

Oyster lovers can also ask employees in their favorite restaurant to make sure that empty shells are not in a landfill, she adds. “They can be processed as a result of restoration projects that return them back to the sea.” There they can help provide a substrate for oysters on which one could count on the fact that perhaps once our restless world can again become oyster.

Cognized magazine It is an independent journalistic effort from annual reviews.