AsianScientist (Dec. 20, 2018) – Scientists in China have developed modified clay to prevent dangerous algal blooms, a boon for Chile’s aquaculture industry.
Algal blooms can take a severe toll on the health of marine organisms as their sudden rapid growth can deplete oxygen and nutrients in water bodies. If left unchecked, the vast amounts of algae can cause water to become discolored, resulting in what is known as a ‘red tide.’
As the main production country of salmon and trout in the world, Chile’s aquaculture industry provides incomes for thousands of families. However, toxic red tide has become a fatal threat to fishes and the livelihood of fish farmers. Between 2015 and 2016, the red tide caused economic losses of US$100 million in Chile’s aquaculture industry.
To inhibit algal blooms, scientists at the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS) developed ‘magic soil’—modified clay that causes algae to sink to the sea bottom. Based on field studies, 70 to 80 percent of harmful algae can be removed by modified clay.
Laboratory investigations also revealed that the collision between modified clays and algae resulted in the release of large amounts of reactive oxygen species which inhibited the growth and proliferation of algae.
The researchers further analyzed the impact of the modified clay on other marine organisms, such as shellfish and other filter-feeding organisms. They found that the modified clay did not pose any acute or chronic toxicity concerns.
“As agreed, we developed special modified clays in full consideration of its application in Chile and tested its effect on salmon and shellfish many times. It turns out that the new modified clay does no harm to the cultured species,” said Professor Yu Zhiming of IOCAS, who led the development of modified clay.
Finally, laboratory and field tests revealed that the appropriate dosage of modified clay could achieve marked improvement in water quality while mitigating algal blooms. The researchers intend to disperse 27 tons of modified clay onto the red tide in Chilean waters.
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Source: Chinese Academy of Sciences; Photo: Institute of Oceanology of the Chinese Academy of Sciences.
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