Hitchhikers Impacts Prevention Resources News Activities About Us Contact Us Frequently Asked Questions
Home Page
Welcome to Protectyourwaters.net Welcome to Protectyourwaters.net Welcome to Protectyourwaters.net Welcome to Protectyourwaters.net
Harmful Aquatic Hitchhikers: Plants: Hydrilla

What does Hydrilla look like?
University of Florida’s Center for Aquatic and Invasive Plants
University of Florida’s Center for Aquatic and Invasive Plants
Click image to enlarge
  • Hydrilla is a submersed freshwater herb. Being an invasive non-native weed, it often forms dense stands from the bottom to the top of the water, sprawling across the surface, although it may also be found as detached drifting mats.
Top of Page
Why is Hydrilla considered to be a nuisance?
University of Florida’s Center for Aquatic and Invasive Plants
University of Florida’s Center for Aquatic and Invasive Plants
Click image to enlarge
  • Once cultured and sold as an aquarium plant, it is hydrilla’s invasive qualities that make it a nuisance.
  • It has amazing reproductive capabilities that allow it to grow in almost any freshwater, in variable conditions with either low or high nutrient amounts, or a wide temperature tolerance: (68-86 F).
  • Hydrilla is an invisible menace until it fills the lake or river that it infests, "topping out" at the surface.
  • When hydrilla invades an area, ecologically important native, submersed plants are shaded out by hydrilla’s thick mats, or are simply out competed and eliminated.
  • Annually, millions of dollars are spent each year on herbicides and mechanical harvesters in Florida alone in an effort to place hydrilla under "maintenance control." Besides the impact to recreational fishing, Hydrilla greatly slows water flow and clogs irrigation and flood-control canals. In Florida, large mats of fragments collect at culverts and clog essential water control pumping stations. Hydrilla seriously interferes with boating, both recreational and commercial, and prevents swimming and fishing. Major infestations limit sportfish weight and size due to the plant’s ability to alter water chemistry and oxygen levels.
Top of Page
How does Hydrilla affect recreational users?
  • Due to its nuisance impacts, Hydrilla affects all recreational users of our aquatic resources. Its amazing reproduction capabilities can turn quality waters into areas that are choked with vegetation, which will essentially make them unusable.
Top of Page
Where is Hydrilla currently found?
USGS/Florida Caribbean Science Center
USGS/Florida Caribbean Science Center
Click image to enlarge
  • Currently, this plant is found primarily in two regions, the southeastern and the southwestern parts of the U.S.
Top of Page
What is Hydrilla’s potential to spread elsewhere in U.S.?
  • Hydrilla spreads to new waters mainly as fragments on boats and trailers. Conservationists in the U.S. need to learn from Russia experience because hydrilla has been found to grow in 50o N latitude range, which is the equivalent to the US/Canadian border.
Top of Page
Short term benefits of hydrilla don’t override the long term impacts
  • Some anglers originally thought that plants such as hydrilla and water hyacinth provided positive habitat. However, anglers now realize that these plants can take over a good fishing spot, consume the oxygen and cause fishkills. Also, when hydrilla creates mats, it can make it very difficult for anglers to access fishing spots.
Top of Page
How can I prevent the spread of Hydrilla?
University of Florida’s Center for Aquatic and Invasive Plants
University of Florida’s Center for Aquatic and Invasive Plants
Click image to enlarge
  • Be vigilant in cleaning your equipment.
Top of Page
What else can I do?
Top of Page
References
  • Plant species information provided by a collaborative effort involving the University of Florida’s Center for Aquatic and Invasive Plants and the Sea Grant College Programs of the University of Connecticut, University of Florida, University of Minnesota, University of Illinois, North Carolina State University and Purdue University. (http://aquat1.ifas.ufl.edu/)
  • Center for Aquatic and Invasive Plants, University of Florida. The information contained herein is based on the literature found in the APIRS database, the world's largest collection of scientific literature about aquatic, wetland and invasive plants.
  • USGS Florida Caribbean Science Center. http://nas.er.usgs.gov/plants/docs/hy_verti.html
Top of Page

Back to Harmful Aquatic Hitchhikers

Protectyourwaters.net Home Search Link To Us Site Map



The Stop Aquatic Hitchhikers web site is part of the ANS Task Force public
awareness campaign and is sponsored by the U.S. Fish and Wildlife Service
and the U.S. Coast Guard.

Visit Stop Aquatic Hitchhikers on Facebook
Like SAH! and Share

Partnership Opportunities

Become a Partner


Current Partners


State Info Pages

New Hampshire
Missouri
South Carolina
Arizona

News

Check out the Latest News about the Stop Aquatic Hitchhiker Campaign and the aquatic hitchhiker problem.

Common Hitchhikers

Zebra Mussels
Hydrilla
Whirling Disease
Spiny Water Fleas
Round Gobies
Water Hyacinth

Video Clips
Asian Carp in the Upper Mississippi River
(Real Video format)

Round Goby
(Quicktime Format)
New Audio Messages for Traveler Information Systems
Zebra Mussel (mp3)
Zebra Mussel #2 (mp3)