Aquatic Invasive Species

Oxygen Needed

By: David Lung

Giant salvinia is an invasive aquatic fern that quickly covers the water surface, outcompetes native aquatic plants, and kills other aquatic organisms due to a decrease of dissolved oxygen. Flores and Carlson (2006) worked with the salvinia weevil to figure out if there was a correlation between the control effects of the weevils on giant salvinia and also dissolved oxygen levels after the release of the weevils. Flores and Carlson (2006) reared the salvinia weevil in tanks with giant salvinia and released the weevils at 6 sites in Texas waterways. Insect population densities were sampled monthly to make sure that the insects were dispersing. Dissolved oxygen levels were then measured after a little over a year. Flores and Carlson (2006) observed a significant increase in dissolved oxygen levels following successful control. More research is needed to understand the relationship between the weevil and the fern in order to understand the difference in the amount of time needed for complete control.

Journal of Aquatic Plants Management. 44: 115-121