Did you know that shellfish can clean water by filter feeding?
A single oyster can clear over 30 gallons a day, retaining particles as small as 2 microns. As they feed, shellfish is able to remove microscopic plants. Recent studies reveal that shellfish aquaculture can improve species abundance and diversity. Oysters are a keystone species, meaning they control the environment in which they live by cleaning the water, while the spaces between their shells provide habitat for juvenile fish, crabs, and the organisms on which they feed. When hundreds and thousands of shellfish grow, they have the power to clean our polluted rivers.
There was a report back in 2008 stating that in Charles River, oysters are used for cleaning the river. 150,000 of oysters were installed in the river for their sole purpose: "to eat sewage." The Massachusetts Oyster Project installed these oysters in the river as a solution for water pollution project. These "shellfish potentially stand to process 3 million gallons of sewage-tainted liquid every 24-hours, slowly purifying the Charles," says James, who wrote about this news in 2008. Oysters that filter sewage have been found to contain salmonella and other harmful bacteria, which makes them dangerous to eat. There will be signs posted to ban people from attempting to harvest these shellfish. They are solely sowed for the purpose of purifying the river to help revitalize the ecosystem.
Another report stated that oysters cleaned the oil spill at an unprecedented rate. The oysters can filter out toxins in the water. The oil spill triggered four conservation organizations (the Alabama Coastal Foundation, Mobile Baykeeper, the Nature Conservancy, and the Ocean Foundation) to propose a restoration idea that is to "create 100 miles of oyster reef in the region, and 1000 miles of replanted marshlands." The report stated that "the cleaner water leads to more seagrass growth, creating new habitats for fish."
In the past, people spent so much money and time to develop technologies to treat sewage waters when nature can do it better and cheaper. As these projects take nature as solutions, other regions with polluted waters should invest their time and money to resolve water pollution naturally like oysters rather than trying to build big and expensive water treatment plants that cleans water expensively.