Wildfires Fuel Ocean Algae Blooms

A few years ago, a massive algae bloom grew in the southern Pacific Ocean, growing over four months to cover an area larger than Australia. Such blooms are often caused by agricultural runoff, which is loaded with the nitrogen that these tiny plantlike organisms love to feed on. But there are no farms in this remote stretch of water between New Zealand and South America. Instead, a new study has found that the bloom was caused by a natural disaster thousands of miles to the west: the wildfires in Australia in 2019 and 2020. Those blazes consumed an area of forest larger than West Virginia and sent plumes of smoke 20 miles into the air. The ash and smoke that blew out to sea contained trace amounts of iron, which algae need to live and reproduce, and which is scarce in the southern Pacific. Using satellite images, the researchers found that the blooms peaked in places where large amounts of soot landed.
At sea, algae can poison other organisms by releasing toxins and can suffocate marine life by sucking up oxygen as they decompose. But algae also absorb carbon from the atmosphere – and the researchers say the blooms were so massive that they might have soaked up 50 to 150 percent of the carbon released by the Australian wildfires. The only question is, “How much did it offset?”, study co-author Nicolas Cassar from Duke University told Popular Science. “But we don’t know.” Hopefully further research will answer this question.
Our earth keeps trying to preserve itself in surprising ways, but humans have created so much carbon that we now need to make some drastic changes to help it heal.