Scientists Introduced Oysters Into Water Tank Polluted With Toxic Algae for 90 Minutes. Here’s What Happened
The role of oysters in preserving the marine ecosystem might be underappreciated. They provide sustenance and economic value to thousands of creatures while acting as natural water purifiers for water bodies. Oysters have significant water filtering capacities and remove pollutants within short periods. Researchers at the University of Hong Kong conducted an experiment and introduced oysters into a tank of polluted water for 90 minutes and were surprised by the results, as documented in a YouTube video posted on YouTube by South China Morning Post (@SouthChinaMorningPost) in 2019.
Two tanks of polluted water that contained toxic microscopic algae were placed adjacent to each other and observed for 90 minutes. The only difference was one tank had a few oysters in it. A gradual color change was observed in the tank with oysters indicating that the molluscs were at work. They filtered the water causing a decrease in the pollutant concentration in compassion to the adjacent tank which still had the same water. The tank in question showcased conspicuous changes and a clear bluish water was obtained within one and a half hours. The video description revealed that these toxic algae exist in large concentrations in the red tides of Hong Kong often killing fish and causing harm to marine life.
Therefore, it is evident how oysters significantly impact the overall health of a water body. A single oyster can filter up to 50 gallons of water in a day, according to a report by One Earth. They help remove the excess nitrogen from the water by absorbing it to form their shells and tissues for growth. It is estimated that oyster reefs remove nitrogen amounts equal to 20,000 bags of fertilizers, saving the government about $1.7 million worth of sewage treatment. The oysters also cluster on older shells and fuse as they grow to form hard reefs which are inhabited by small fish and marine plants for survival.
On the other hand, nitrogen is also important for all marine plants and animals, pollution from sewage, fertilizer runoffs, and factories has caused an increase in nitrogen concentration. This concentration benefits a toxic algal bloom in the water that sucks up all the oxygen and deprives other creatures of it, ultimately, killing the marine ecosystem of that water body. This is a major problem in the Bay waters in the United States.
Oysters tend to consume these pollutants or merge them into small structures that sink into the bottom of the sea while not taking up too much space. However, scientists are worried about the rapidly depleting populations of oysters. The report suggests that 80% of their reefs have been destroyed due to overfishing activities and warming climates. The reduced numbers are in turn affecting the net filtering capacity of the oyster community making more and more water bodies polluted and inhabitable.
The constant advocacy has created awareness around the significance of oysters and their populations are reportedly growing. Oyster reefs in Harris Creek on Maryland’s Eastern Shore have been restored and could potentially filter the entire volume within 10 days in summer days. Cities have taken initiatives for seeding and growth of shellfish and, more importantly, to reduce the nitrogen concentrations in coastal waters, according to marine specialist Joshua Reitsma. He is associated with the Woods Hole Sea Grant Program and Cape Cod Cooperative Extension.
You can follow @SouthChinaMorningPost on YouTube for more videos.