Water hyacinths have invaded the Valsequillo reservoir. Today’s Image of the Day from NASA Earth Observatory shows the Valsequillo reservoir in central Mexico, where the water has been transformed by floating plants called water hyacinths.
The reservoir was once filled with clear water, but nearly half of its surface is now covered with water hyacinths, according to NASA.
These invasive plants, which are native to the Amazon, can quickly spread across and waterways, blocking sunlight and causing obstruction.
In a recent study, scientists at ETH Zürich demonstrated that water hyacinth invasions have increased in reservoirs across the globe.
“There’s some irony to the situation. Water hyacinths are brought in for their beauty, but then can quickly grow into a monster,” said study co-author Scott Winton. “You can look at reservoirs throughout the world and see a similar pattern.”
“Rapid urbanization often comes along with untreated sewage water that gets into service waters, which provides nutrients that allow the plants to thrive,” explained study co-author Fritz Kleinschroth. “We interpret the floating vegetation invasions as an issue of an underlying water pollution problem.”
Among 20 reservoirs examined for the study, Valsequillo showed one of the most widespread increases in water hyacinth coverage over the last ten years.
The team noted that water hyacinths can also play an important role in cleaning polluted water.
“Water hyacinths are vilified because of the problems they cause, but you would have a suite of different problems if those rivers did not contain those plants,” said Winton. “If water hyacinths were not absorbing the excess nutrients, they would most likely be picked up by some other micro-organism or algae that could potentially cause much worse problems.”
Image Credit: NASA Earth Observatory
By Chrissy Sexton, Earth.com Staff Writer