|A single hydrilla plant. Photo Credit: NCSU|
|Hydrilla actively growing in the water column|
Hydrilla also has excellent survival and dispersal strategies. Hydrilla spreads via fragmentation meaning that the plant breaks apart (either by natural breaking or disturbance from boat propellers) and can produce entirely new plants! If that’s not bad enough, Hydrilla also produces special survival structures called tubers and turions. The turions break off the stems in the fall and can drift for long distances before sinking to start a new plant. The tubers grow on the plants roots and detach in the fall producing new plants. A single tuber can lead to the production of several hundred others in the course of one season! Recent research at North Carolina State University has shown that tubers can survive for up to seven years in the sediment before sprouting. The long survival time of the tubers creates the major challenge in management of the plant.
|Hydrilla tubers. Photo Credit: NCSU Aquatic Weeds Program|
Once sprouted, Hydrilla’s speed of growth is fast and furious. Hydrilla plants can double their biomass every two weeks during optimal growing conditions. Recent research has shown that hydrilla can produce alarming amounts of biomass during the year. Click here for a summary of that research. Once Hydrilla reaches the surface, it will expand horizontally covering the entire water surface while rapidly producing new stem growth through branching. It also doesn’t help that when Hydrilla was introduced into the U.S., it came without any of it’s natural enemies like herbivorous fish and insects. The voracious nature of Hydrilla and tangled mats that it forms has a number of environmental, economic and cultural impacts impeding recreation, decreasing property value, and even potentially harboring cyanobacteria which produce deadly toxins. For more information on such toxins, click here.
|Hydrilla in a North Carolina reservoir. Photo Credit: NCSU Aquatic Weeds Program|
Stay tuned next week for more of the latest in aquatic plant science, management, and innovation!