Nutrient pollution from agricultural and urban runoff and municipal waste water is one of the biggest threats to aquatic ecosystems. Many water bodies across the globe suffer from loss of biodiversity, oxygen depletion, and harmful algal blooms because of nutrient pollution. The Chesapeake Bay – the largest estuary in North America- is no exception.
Although many efforts have been taken to clean up the bay, nutrient pollution is still at unacceptable levels.
A recent study suggests that commercial oyster farms might be the solution to the Bay’s water quality issues.
As oysters feed on phytoplankton, they take up nutrients like nitrogen and phosphorus. The pollutants are then stored in their shells and tissue – a process known as bioassimulation.
Researchers found that allowing oysters to grow an additional 2.5 cm beyond the regular “cocktail” harvest size enabled them to remove 2.2 times more nutrients. An oyster farm harvesting 1 million of these larger oysters could remove 132 kg of nitrogen and 19 kg of phosphorus from the Bay.
If farms were to adopt the practice of growing larger oysters, expansion of the oyster aquaculture industry might significantly improve water quality in the Bay.
Image courtesy of Allerina & Glen via a Creative Commons license.