Impact ID |
Scientific Name
|
Impact Type
|
Study Type
|
Study Location
|
Impact Description
|
Geographic Location
|
Reference
|
2978
|
Hydrilla verticillata
|
Competition
|
Anecdotal
|
Field
|
Hydrilla verticillata grows faster than native plants in the Potomac River/Chesapeake Bay area and may reduce their seasonal abundance.
|
|
10138
|
3071
|
Hydrilla verticillata
|
Competition
|
Observational
|
Field
|
Hydrilla impacted four lakes in New Zealand, forming dense mono-specific stands that have displaced native plants.
|
|
33834
|
3077
|
Hydrilla verticillata
|
Competition
|
Anecdotal
|
Field
|
Hydrilla are considered to cause the loss of native species through competition and displacement.
|
|
33837
|
4055
|
Hydrilla verticillata
|
Competition
|
Experimental
|
Laboratory
|
Hydrilla verticillata grew in biomass and density at a faster rate than Elodea canadensis when planted in various ratios.
|
|
33834
|
7038
|
Hydrilla verticillata
|
Competition
|
Anecdotal
|
N/A
|
Hydrilla verticillata is not easy to detect until it fills the lake it infests and tops out at the surface; it grows in thick mats, and shades out or outcompetes ecologically important native submersed plants including Potamogeton pondweeds, tapegrass (Vallisneria americana), and coontail (Ceratophyllum demersum).
|
|
10285
|
7039
|
Hydrilla verticillata
|
Competition
|
Anecdotal
|
N/A
|
Hydrilla verticillata grows aggressively and competitively, spreading through shallower areas and forming thick mats in surface waters that block sunlight penetration to native plants below.
|
|
10285
|
7040
|
Hydrilla verticillata
|
Competition
|
Observational
|
Field
|
In the southeast, hydrilla effectively displaces beneficial native vegetation.
|
Southeastern U.S.
|
10135
|
7041
|
Hydrilla verticillata
|
Competition
|
Observational
|
Field
|
Research found that sportfish reduced in weight and size when Hydrilla verticillata occupied the majority of the water column, suggesting that foraging efficiency was reduced as open water space and natural vegetation gradients were lost.
|
Lake Wales, Polk County, Florida
|
10511
|
7042
|
Hydrilla verticillata
|
Competition
|
Anecdotal
|
N/A
|
Hydrilla verticillata infestations can cause a reduction or the extirpation of populations of native aquatic species. Hydrilla forms a dense mat of vegetation at the water surface and limits light penetration degrading or eliminating all layers below.
|
|
42106
|
7043
|
Hydrilla verticillata
|
Competition
|
Observational
|
Field
|
Hydrilla verticillata is highly adaptive to the environment and competitive with most other aquatic plants. The growth habit of hydrilla enables it to compete effectively for sunlight. It can elongate up to 1 inch per day, and produces the majority of its stems in the upper 2–3 feet of water. This mat of vegetation intercepts sunlight and leads to exclusion of other aquatic plants.
|
Orange County, Florida
|
42107
|
9223
|
Hydrilla verticillata
|
Competition
|
Experimental
|
Field
|
Hydrilla verticillata was able to reach greater depths with increased water clarity. It was able to grow at lower depths than native Egeria najas, mostly likely allowing it to escape wave disturbance
|
Itaipu Reservoir, Paraná River, Brazil
|
42764
|
9224
|
Hydrilla verticillata
|
Competition
|
Observational
|
Field
|
Research from South America, indicate Hydrilla verticillata invaded sites regardless of species diversity and whether dominant native macrophytes were already present.
|
Rosana Reservoir, Brazil
|
42772
|
9225
|
Hydrilla verticillata
|
Competition
|
Experimental
|
Field
|
Invasive Hydrilla verticillata reduced the growth of native Egeria najas regardless of sediment type. Researchers believe this indicated E. najas will be unable colonize sites where H. verticillata is abundant.
|
Paraná River, Brazil
|
42771
|
9226
|
Hydrilla verticillata
|
Competition
|
Experimental
|
Field
|
Hydrilla verticillata had a higher capacity to take up and assimilate nitrate than native Vallisneria neotropicalis, giving it a competitive advantage during the growing season. Vallisneria neotropicalis
|
Lake Stone, Florida, USA
|
42767
|