Each oyster can clean up to 227 liters of water a day, helping to remove harmful chemicals that pollute the ocean. They are truly the diligent “cleaners” of the ocean. However, oyster populations around the world are being destroyed.
Oysters play a huge role in reducing marine pollution, preventing erosion and helping other marine life thrive. However, the current decline in their numbers globally is changing the ocean.
According to research, the number of oysters and coral reefs in the world has decreased by 85% since their peak. This makes them the most endangered marine species in the world. The severe decline of wild oysters means that their purifying effect on the ocean is also lost. Meanwhile, water pollution is a more serious problem than ever.
According to the National Oceanic and Atmospheric Administration (NOAA), a single oyster can filter 50 gallons (227 liters) of water per day. They remove pollutants and release clean water to sustain ocean life. Small animals also live on oyster shells, which attract larger creatures and are the foundation for the entire ecosystem.
Oysters are on the brink of extinction due to pollution and overfishing. When they disappear, the ocean life that depends on oysters is also in danger.
Pacific Oysters – Ecosystem Engineers
Oysters act like the “kidneys” of the ocean. They filter out pollutants and leave behind clean water. They remove chemicals like nitrogen and phosphorus, which are often released into the ocean from industrial activities.
A study by Stanford University looked at the impact of oysters. Researchers put clams, mussels, and oysters into a tank of contaminated wastewater. Within 72 hours, the animals appeared to remove up to 80 percent of the contaminants in the water. These included herbicides, pesticides, and more. Oysters can also make water clearer, allowing more sunlight to enter, helping marine plants grow and promoting life.
Oyster shells also provide a home for many invertebrates, providing them with shelter from weather fluctuations and predators.
Some species rely on the shells to thrive, according to researchers at the University of Maryland. “These humble creatures are much more than just having a rock-hard shell and not being able to walk,” said Luke Helmer, a researcher at the University of Portsmouth who works to conserve oysters. Their importance is comparable to coral reefs.”
He also revealed that seahorses have been found off the coast of Scotland thanks to oyster cages. Jacob Kean-Hammerson, a large-scale conservation project coordinator in the Solent, a sea area in southern England, describes oysters as “ecosystem engineers”. They have the ability to create new life in their habitats.
They act like coral reefs, providing safe habitats for other creatures such as shrimp, anchovies and herring, which in turn attract more creatures.
“The marine environment affects all living things (including humans) on this planet, and a healthy ocean makes for a healthy planet,” Helmer asserts. “Our climate, our food supply and our survival are all dependent on and linked to the ocean in some way.”
“Not only do oysters provide habitat, the diverse populations of organisms that rely on oysters become limitless as they form complex three-dimensional structures similar to coral reefs or shoals. “
Some species that rely on oysters also help clean the ocean. “Oysters are an essential part of the health of the global ocean, providing food, jobs and habitat,” the US National Oceanic and Atmospheric Administration (NOAA) says. It also notes that oysters help prevent erosion and create a barrier to protect land from storms and tides. NOAA has declared oyster restoration a “conservation priority.”
A chance for new life
Conservationists looking to save oysters are focusing on the Solent. An area between southern England and the Isle of Wight, the Solent was once the largest oyster fishing area in Europe. However, oyster fishing was banned there after the harvest fell from 200 tonnes in 2008 to 20 tonnes in 2013.
The National Fisheries and Conservation Agency has deemed the oyster resource “non-renewable.” Helmer, a Portsmouth oyster researcher, said the impact of oysters can be seen through the reduction of water quality and fish stocks.
This in turn impacts the local economy, and threatens the cultural heritage of the residents. Scientists want to prevent the situation in the Solent from getting worse. The government has also identified it as an area of special conservation need.
A five-year project funded by the Blue Marine Foundation has been set up. The aim is to restore the oyster reef, which biologists hope willto make a huge impact. Millions of oysters will be re-grown each year for five years running. Starting in 2019, it promises to restore the vast biota that once covered the land.
“In 1978, there were about 15 million oysters harvested in the Solent,” says Kean-Hammerson, who runs the project in the Solent. “That’s 600 million gallons of water that’s not being filtered.” The Solent project was inspired by an oyster conservation project in the Chesapeake Bay.
Oysters had almost disappeared from the strait between Maryland and Virginia before a conservation project in the 1990s brought them back. Helmer says this is particularly relevant to the Solent: “We need to look at larger projects, like the Chesapeake Bay, to get some guidance and a sense of the scale of what we should be aiming for.”
According to The New York Times, at its peak around 1875, 20 million bushels of wild oysters were taken from the bay in a single year. It’s impossible to calculate the exact bushel weight, but that equates to about 450,000 tons. By the 1990s, that number had dropped to about 20,000 bushels, about a thousandth of the historic high.
“The native oyster population in the Chesapeake Bay is about one percent of what it was in its history,” said Sean Corson, executive director of the NOAA Chesapeake Bay Office.
Organizations like NOAA have partnered with the Chesapeake Bay Campaign, a project aimed at large-scale oyster conservation. The 2014 Chesapeake Bay Basin Agreement calls for oyster conservation in 10 tributaries—five in Maryland and five in Virginia—by 2025.
An urgent project
Corson insists that this is essential if we are to continue to enjoy the positive effects that oysters provide. “You can’t have timber or wildlife in the forest without healthy trees,” he says. “The same goes for oysters. If we want to benefit from them, we have to have the right environment for them to thrive.”
According to Helmer, an oyster researcher in Portsmouth, “We’ve lost 85 percent of the global oyster population, and the few that remain are in poor condition. If projects like mine don’t happen, the entire ecosystem is at risk of being destroyed.”
Source: Vietnam Seafarming Association
