THE COST
Approximately $70 million annually (2005) is spent managing plant invaders in
Florida's lakes, rivers, canals, marshes and swamps. (This includes expenditures by state
agencies, water
management districts, counties and cities; this does not include private company and individual
efforts such as plant management in retention and condo ponds or in agricultural canals, nor does
it include
costs of upland invasive plant management.)
INTUITIVELY, MOST PEOPLE
WOULD PREFER TO USE MEANS OTHER THAN
HERBICIDES
to fight
invading plants, means such as machines to collect the plants, or
fish and insects to eat the plants. Our intuition is bolstered by the
fact that well-meant, but ultimately unwise, use of certain chemicals in decades past resulted in
environmental problems such as bioaccumulation of compounds in birds and
other animals, and direct killing of fish, cattle and other animals.
Environment managers today, including aquatic weed managers, have learned from the
past, and are determined to conduct their necessary work in well-considered ways using
compounds that are registered for use and regulated by the U.S. EPA as well as by state
agriculture and environment authorities.
Continuing research by chemists, agronomists and other scientists, as well as education and
training of personnel, make invasive plant management using herbicides
increasingly more of a science than an art. However, today's environment agency employees as
well as citizens are, and ought to be,
vigilant against pesticide mis-use; whether herbicide, insecticide or any-cide; whether by
agencies, companies or
individuals.
So please read on, and learn more about the use of aquatic herbicides in the fight against
invasive plants.
CONSIDERING ALL, today's
invasive plant managers, more often than not, must rely on
herbicides to turn back rapidly invading plants. When circumstances make herbicidal control
the method of choice, invasive plant managers take special care to:
a) use only herbicides approved by the U.S.
Environmental Protection Agency;
b) apply the herbicides at the proper, legal, rates, according to the plant, location,
etc.;
c) apply the herbicides selectively to the target plant(s); and
d) apply the herbicides as carefully as possible.
MANAGEMENT AGENCIES
More than 100 government agencies and even more companies in Florida
employ workers to detect and remove unwanted plants that are invading our
wetlands, lakes and rivers. Federal, state and local governments have been involved in plant
management in Florida for more than 100 years. Here is a map and
list of agencies in Florida that conduct aquatic plant management.
MAINTENANCE CONTROL
Because it is impossible to eliminate every single invader plant, "maintenance control" has become the mantra of today's
invasive plant manager. Simply stated, maintenance control means keeping the invading
plants down to the lowest levels possible. In fact, maintenance control is part of Florida law.
Reduced aquatic weeds and reduced herbicide use prove this guiding principle. More about maintenance control...
HERBICIDE HISTORY
Since the late 1800s, various chemicals have been applied to our
freshwaters to help stem the tide of invading aquatic and wetland plants. Of course,
some of them we wouldn't use today for plant management, any more than we'd use leaches to
treat headaches. This brief history of aquatic herbicide
development tells the tale, from sea-salt and sulfuric acid used in the early years; to 2,4-D
beginning in the 1940s; to endothall, fluridone and other newer compounds that were discovered
and developed and are in use today.
FLORIDA'S AQUATIC HERBICIDES
In 2005, there are eight herbicides registered for use in
Florida waters for plant management. That is, there are eight herbicidal active
ingredients registered for use by the U.S. EPA and the Florida Department of Agriculture
and Consumer Services. These active ingredients include:
1) chelated copper;
2) diquat;
3) endothall;4) fluridone;
5) glyphosate;6) 2,4-D;
7) triclopyr; and
8) imazapyr.
Here are their descriptions.
CHOOSING HERBICIDES
Public and private plant managers in Florida choose their aquatic herbicide for each job according to target plant, water body type, uses of the water body,
wind, temperature, water depth, and other factors such as efficiency and cost-effectiveness. Here are
things managers take into account when choosing which aquatic herbicide(s) to use for each
plant species in each aquatic or wetland site.
Read the Aquatics article "HOW TO BUILD WEIGHTED TRAILING HOSES" by Dr. William Haller, et al 
