Northern California’s Clear Lake is anything but that in an image taken from space that shows the extent of algae blooms in the water.
NASA’s Landsat 9 satellite recorded an image on May 15 that showed bright green denoting algae over much of the lake, according to the National Aeronautics and Space Administration website.
The algae bloom is linked to substances such as phosphorus and other chemicals that NASA said are due to “runoff from nearby farms, vineyards, faulty septic systems, gravel mines, and an abandoned open-pit mercury mine.”
Clear Lake was anything but clear in May!
The lake in California is prone to algal blooms, like the green swirls seen in this #Landsat image. But blooms have become more frequent in recent years due to increased nutrient inputs. https://t.co/v3dRdNqQF9 pic.twitter.com/iERl4HFMP5
— NASA Earth (@NASAEarth) May 29, 2024
“These excess nutrients can cause harmful algal blooms,” said Ian Hendy, a senior scientific officer at the Institute of Marine Sciences of the University of Portsmouth in England, according to Newsweek.
“This is a bust or boom scenario whereby blue-green algae, for example, will proliferate and utilize all of the available dissolved oxygen.”
When the algae use the oxygen, there is none left for other forms of life.
“This process creates very low oxygen levels in the water, making life for aquatic organisms such as fish and invertebrates very dangerous,” Hendy said.
NASA warned that the bloom may contain blue-green algae, which is also called cyanobacteria.
Have you ever been to Clear Lake?
Some cyanobacteria produce microcystin, which can irritate the skin and cause liver and kidney damage.
Clear Lake is about 60 miles north of San Francisco Bay. Covering 68 square miles, it is a popular spot for outdoor activities like boating and fishing, according to the Los Angeles Times. It has also long battled algae blooms.
NASA reported that the latest blooms are increasing and that “three species of blue-green algae can cause adverse human health effects under certain conditions.”
NASA’s analysis of the lake said levels of chlorophyll-a, which can help approximate cyanobacteria levels, hit some of their highest values of the month on May 15, when the image was taken.
NASA cautioned that an actual water sample needs to be taken to be sure of what is going on.
“Even if toxins were not present, the abundance of algae could still harm aquatic life; bacteria consume oxygen as they break down dead phytoplankton, which can cause hypoxia and dead zones,” NASA cautioned.
The level of the algae bloom could impact boating, fishing and swimming at the lake, one of the most-visited lakes in the country, for several weeks, according to the Los Angeles Times.
A May 8 analysis of the lake did not show the bloom. The next testing is scheduled for Tuesday, the Times reported.