I am Nithmi Jayasundara, a fourth-grader at Korematsu Elementary School. I am a member of Korematsu’s Nature Bowl third- and fourth-grade environmercials team.
I want to tell you about a big problem caused in the Sacramento-San Joaquin Delta recently. An invasive aquatic weed called South American spongeplant has been spreading in the past few years. Spongeplant is native to South America. It was noticed in the San Joaquin River and the delta in 2008.
No one knows the real reason it has spread in California but not in other states, but there are many ways it could’ve happened. One way is probably that people saw how beautiful it was and wanted it in their aquariums and water gardens. That way, it spread through aquarium and water garden trades. When they cleaned the tanks, the plant escaped into ponds and streams, and it spread.
Spongeplant is a problem because it blocks canals, pumps and dams. It can increase risk of flooding by blocking canals and streams and it also spoils water quality. Spongeplant is also a great place for mosquitoes to hide, and mosquitoes can spread disease. So as you can see, spongeplant is a big problem to us and the environment.
The effects caused by spongeplant are similar to the results of water hyacinth, which was a serious problem some time ago, yet this plant is harder to control. This is still a big problem because soon after an area is cleared, it grows back. Water hyacinth plants could only spread vegetatively, or by their roots, but spongeplant spreads vegetatively and through seed dispersal.
We have to stop the spread of this invasive plant. Since it is spread through aquarium and water garden trades, the most you can do to help stop infestations is to not buy it and grow it in aquatic gardens.
Spongeplant looks a lot like duckweed, yet it is slightly bigger, and it has small, white flowers. If you see this in your area, inform the United States Department of Agriculture Research Services as soon as possible.