Species of plants and animals that are not native (natural) to an area are known as:
Established ecosystems have
developed their own natural balance and controls over time, and the
plants and animals within those systems find this balance suitable for
survival, or they have been able to adapt in order to survive within those
non-native species from other ecosystems are introduced, they can upset
that balance and bring harm to the established plants and animals, and
the whole ecosystem.
species come from somewhere else and they are not natural to the
ecosystem they have been introduced to. They may be harmless and
beneficial in their natural surroundings, but they can totally devastate
different environments. When alien species enter into an ecosystem, they can disrupt the natural balance, reduce
biodiversity, degrade habitats, alter native genetic diversity, transmit exotic diseases
to native species, and further jeopardize endangered plants and animals.
When there are no established natural controls, such as predators to
keep the non-native harmful species in check, there can be a population
explosion of the invasive non-native species causing an ecological
Not all non-native species
are invasive and harmful. But many can completely take over and entirely change
whole established ecosystems. These are the non-natives that invade
an established environment; therefore, they are invasive.
species may be as
harmless looking as green plants or a frog. They
don't have to be vicious looking to bring harm to an area. They
may even be beautiful to look at. This could have a detrimental
effect on native species if bees or other pollinators preferred the
flowering displays of the invasive species over the native species. Many humans want to design their
own ecosystems to fit their needs. They bring in ornamental
flowering trees, non-native fish, specialty seeds, and unusual
animals. This can wreak havoc on the natural species and the
Ornamental exotic plants,
flowers and trees, or animals that are brought into an ecosystem may
increase the diversity of species locally; but, then the introduced
species can take over, crowd out or kill the native indigenous species,
and in some cases cause extinctions of particular species of plants and
animals. This has happened in island ecosystems where alien species caused
the total destruction of local species that existed nowhere else on the
planet. Therefore, the species became extinct and the biodiversity
of our planet further reduced.
damage can occur from
an insect species that bores holes in trees, or weeds that take over, or zebra mussels
that clog up water systems (i.e., Great Lakes). There are many species that
are not native to an area which can be very dangerous and cause harm and
even death to humans (i.e., brown tree snake). A non-native species could be
something that brings disease to an area or to people through introduced
bacteria or viruses (i.e., Ebola), or possibly a
plant that would crossbreed with other plants and cause major changes to
plant life. When natural habitat or food supply
is destroyed, by alien species or from other circumstances, animals have to leave to find
shelter and food in an ecosystem which will sustain them. Some
native animals cannot leave. Without proper habitat and food
supplies, they die.
Many non-native species
have been transported in the ballast water of ships and then are
released into the waters in ports of call. Many more non-native
species arrive in the products that are imported from other countries. Inspecting shipments of
goods is overwhelming our human resources, such as in Florida where they
have approximately 12,000 shipments of animals per year and only 8
inspectors. There has been an ever-increasing amount of international world
trade in exotic species in exporting and importing of plants and animals
(such as ornamental tropical fish, rainforest birds, exotic plants, and
various species introduced for a purpose). This lines the pockets
of the traders, shippers and sellers of these goods with huge profits of millions
of dollars. But, who pays to manage and control the global
transport of invasive species with regard to prevention of negative
impacts? What and where are the controls, rules and environmental
regulations to protect ecosystems, habitats and species from alien
invasive species? Who pays for risk assessments prior to the importation of products and species? Who compensates those who
have been negatively affected or lost their livelihood because a harmful
species hitchhiked a ride in a plane wheel, a cargo container, in
agricultural products, or in ships' ballast water? Those who
originally gained the monetary benefits from the invasives pay virtually none of the
costs for environmental protection, nor are they generally held
accountable for the negative environmental impacts they cause.
The general public, future
generations, and the planet's environment and biodiversity end up paying dearly from the
negative impacts of the exploitation of species, the loss of
biodiversity in both the country of origin and the importing country,
and for the environmental damage that occurs. Huge sums of money
have to be expended to try and rectify the damage to species and
ecosystems from the introduction of non-native species into the
ecosystems. Once massive damage is done, there are cases where it
is impossible to bring the ecosystem back to its "natural"
don't necessarily come from far away. They may come from
neighboring areas, but from different ecosystems. If you
have ever crossed a border between countries, you may have passed
through an inspection point where inspectors ask if you are bringing any
fruit, plants or animals into the country. The reason for this is
to keep non-native species out of their particular ecosystems.
"Super-highways for non-indigenous
species" have occurred in such places as South Florida, where natural
aquatic habitats have been drained or diverted and modified to
accommodate for new development. A network of man-made canals has
allowed for the expansion of non-indigenous species that could result in
altering established natural systems and cause significant economic
harm. The Everglades, which has suffered serious decline over the
years, is already in a threatened state. This once-vibrant and
massive wetland ecosystem of many habitats, is now even further
threatened by many fishes that have been introduced that are
out-competing native species.
Other occurrences of non-native
species being introduced to an area have been from aquaculture escapes,
aquarium releases, state government bio-control, planting fish for sport
fishing, and individuals that bring in species for various reasons,
accidentally or on purpose.
And there are other Alien Species
Did you ever think of yourself as an Alien Species? When we
venture out into the wilderness to enjoy nature we are an invasive
species. As "eco-tourism" has
expanded worldwide, many thousands of people yearly invade pristine areas and
change the natural balance of nature. Tourism has been thought to
be a savior for financially poor, but biologically rich regions of the
Earth. Tourists spend money; in fact, millions of dollars are
spent on "eco-tourism." But, who are the major
benefactors of all that money? - the
tourism industry. Many of the companies associated with
"eco-tourism" are located in countries far removed from the
eco-regions they send vacationers to. They are not impacted by the environmental
changes which occur from the human alien species they ship off and fly
off to the
ecologically important hotspots of our planet.
Along with tourists and related activities
comes environmental destruction. Tourism brings in ships and
jets carrying supplies and people, and the carriers and supplies
in more alien species (i.e., non-native plants, animals and organisms) which threaten and devastate native habitat and
species. More people must also come to the tourist resort area to fill the jobs of the
expanded tourism industry, such as in hotels, restaurants, and
transportation fields. As
more and more people take up residence, there is more construction and
The Galapagos is one very special place on our
planet where they are striving to protect the biodiversity and
ecosystems from the activities of humans. 60,000 people visit the
Galapagos Islands each year. The Galapagos is considered to be a
laboratory of evolution - a living library of genetic information.
95% of the known species
that ever existed on the Galapagos Islands are still alive today.
These creatures have had to come up with some major adaptations to solve
problems in order to have survived as species for this long of a period
of time. How can this biological heritage be protected from 60,000
visitors a year? 60,000 alien species who want to see this
remarkable place. Strict rules have been set up as to where people
and their animals can live. Off-limit areas have been set aside,
such as the National Park, and guides must accompany people who wish to
tour the area. They are trying very hard to keep environmental
damage to a minimum, but accidents can happen that can totally destroy
what species have taken many lifetimes to build. Accidents like
oil spills from ships bringing fuel in to accommodate the tourism
industry and the additional residents working for the tourist trade.
There can be many
benefits from eco-tourism, if handled in an environmentally responsible
way. The millions of dollars that are generated from the tourist
trade could greatly benefit the ecosystems which are impacted by the
tourism industry. Funds from monies generated by tourism need to
be set aside, and certain monies specified for conservation of species
and restoration of habitat in those areas which incur the tourism
impact. This will greatly help in our efforts to preserve
biological diversity on our planet.
Strict rules for
environmental compliance are good and necessary. Much more needs
to be done to protect our planet and its biodiversity from the invasion
of alien species.
on our Earth, lest you be a harmful alien species.
NON-NATIVE PETS AND PLANTS
Don't Release Non-Native Species - Escapees are Harmful
Sometimes people tire of their aquariums and the care that is necessary
to maintain them. Then there is a problem with what to do with the
fish, animals and plants from the aquarium. Some people think they
are being kind by releasing the fish and animals into the environment,
such as in local waters. This is not the kind thing to do and it is
the wrong thing to do!
Water gardeners who have ponds and garden pools many times have
non-native plants and fish in these waters. Care must be taken to
avoid release of these non-natives into the environment.
Take a look at this National Geographic article to find out
how non-native fish and aquarium plants can wreak devastation if
released into the environment.
Tries to Eat Alligator, Explodes
The problem arises when people buy pets they are not prepared to care
for. An introduced population of non-native Burmese Pythons has
been growing over the past 20 years in the Florida Everglades, from
people who have released them after being unable to care for them, or
become afraid of keeping them. These Asian snakes can grow 6
feet in length in one year, and reach 10-20 feet in length as adults!
Zoos and attractions won't take them, so they are just let out into the
wild and end up killing and eating the natural native animal species
that are important to ecosystems, and endangered species that are
important for biodiversity. An $8 billion restoration project
could even be jeopardized from the encroachment of these snakes.
Other non-native species have also been causing problems in South
Florida, such as discarded Iguanas that are gobbling up tropical plants
at a rapid rate. Speaking of gobbling, when you read this story
you will realize that non-native species can be a real danger:
This is important advice regarding all non-native species, whether they
be animals you have kept as pets or plants that are not natural to the
environment. Do not release them into the environment.
Photo courtesy of
Staff CDFA, California Dept of Food and Agriculture, Integrated
Pest Control Branch
Photo courtesy of
Douglas Barbe, California Dept of Food and Agriculture, Botany
Water Hyacinths - Beautiful, aren't they?
However, some are listed as the
worst aquatic weeds in the world, growing so rapidly they double
in 12 days - and seeds can survive for 30 years!
Imagine then, how one plant can cause ecological and
economic disaster as it rapidly spreads. In a lake such as
the one above, as you can see, the water hyacinths are so dense they prevent sunlight and oxygen from reaching the
water and submerged plants, they crowd out other native aquatic
plants, and severely reduce the biological diversity in aquatic
ecosystems. They also can block waterways, cause
rivers and streams to change course, and interfere
with human activities such as boating, swimming and
fishing. Millions of dollars have been spent to try and
correct the damage caused by these beautiful plants. Water hyacinths were brought to China from South
America as ornamental
plants, to provide livestock food, and to control pollution by absorbing heavy
metals in the water. A lake in China has suffered a
decline in fish species, and reduced water levels which brought
on notable local climate changes - all because of water hyacinths.
The good news...experiments
are being conducted and technology developed which could change
the image of water hyacinths from a destructive weed to a useful
and beneficial plant. Some of the experiments showing
purification system: Using water hyacinths to absorb and
digest wastewater pollutants (they thrive on sewage!)
Harvesting these pollution-gorged water hyacinths and turning
them into fertilizer.
producer: Heat-treating water hyacinths in combination
with other products to produce methane gas for consumer
feed: Harvesting and solar drying water hyacinths for
livestock feed, saving agricultural lands to grow food for
New Image for the Water Hyacinth (NASA)
LINKS TO MORE
INFORMATION ON NON-NATIVE SPECIES
As you visit websites
pertaining to non-native species, keep in mind that specific information
pertains to specific regions or ecosystems throughout the world.
As an example, a
non-native species in the southeastern U.S. may not be non-native in
Official U.S. reference gateway to information, programs, organizations,
and services about invasive species. You can learn about the
impacts of invasive species and the Federal government's response, as
well as read select species profiles and find links to agencies and
organizations dealing with invasive species issues.
Invasive Species Bills - 109th Congress
List of bills for the U.S. 109th
Congress (2005-2006) relating to invasive species, including links to
information and current status of bills. (U.S. invasive species site)
Center for Plant Conservation defines the terms “native” and
"exotic" as follows:
Native species - as referring to the "approximately 20,000 plants
that have been growing in the United States since before human
Exotic species - those species that have been introduced by
people and are “alien” to our native ecosystems.
an Invasive Species? (Audubon)
Nonindigenous Aquatic Species (U.S. Geological Survey)
A central repository for accurate and spatially referenced biogeographic
accounts of nonindigenous aquatic species. Animal and plant
queries, general taxa information for plants, vertebrates and
invertebrates, alert system, report a species, resource links.
(Ecological Society of America)
invasive species, how they are transported, and the negative impacts
that can result.
of Invasive/Exotic to North America Species
World Conservation Union -
Management of Invasive Alien Species
Alien Species Invade the Planet (also en español)
"Invading alien species are driving untold numbers of native plant
and animal species to extinction worldwide," species that are
crucial to the natural functioning of their ecosystems.
Among them are the gray squirrel, domestic cat, Indian myna bird, Asian
longhorned beetle, sweet potato whitely, Asian tiger mosquito, yellow
Himalayan raspberry, Koster's curse, starling, mimosa, shoebutton
ardisia, red-vented bulbul, erect pricklypear, small Indian mongoose,
Nile perch, brown tree snake, strawberry guava, brushtail possum, crazy
ants, and mile-a-minute weed.
Invasive Species Specialist Group (World Conservation Union)
The ISSG is a global group of 146 scientific and policy
experts on invasive species from 41 countries.
100 of the World's Worst Invasive Alien Species
- the tip of the iceberg
We only know a tiny fraction of what is being destroyed. Species
are becoming extinct that we haven't
even discovered yet.
"We do not know
today which plant and animal species are useful for the future of
humanity, so the protection of biodiversity is obviously
Species - U.S. Environmental Protection Agency
EPA discusses the vast "bioinvasion" of exotic species.
Invasive Species - National Wildlife Federation
"Society pays a great price for invasive species - costs measured not
just in dollars, but also in unemployment, damaged goods and equipment,
power failures, food and water shortages, environmental degradation,
increased rates and severity of natural disasters, disease epidemics,
and even lost lives." NWF presents some facts and discusses the
pathway of these virulent "hitchhikers."
Introduced Species of South Florida (Florida Museum of Natural
Non-indigenous fishes are continuing to spread across the Everglades
region, out-competing native species. These species have been
introduced primarily through aquarium and aquaculture facilities..."
Native and Exotic Species - Florida (South Florida Water
Great Reshuffling: How Alien Species Help Feed the Global
An examination of the history and ecology of
the global trade in species of plants and animals. Non-native
species have been introduced to countries by early colonists, and for
such reasons as increasing the economy, for food, for energy, and for
biological control of pests. While possibly succeeding in the
original purpose for introducing the exotic species, some have caused
more devastating economic and/or environmental damage than the original
problem they were introduced to solve. What currently is
"naturalness"? Differences in species introductions, how
climate change affects global economy and alien species, and suggestions
for the global community in dealing effectively with harmful alien
species. It is a global problem significant of a global response.
Vexing, Virulent Varmint (Los
Angeles Times 5/25/01)
"It is furry and cute--and has the power to devastate ancient forests."
That's why New Zealanders are saying the only good one is a flat one!
to increase the fur trade and now defoliating the country.
"3:1 rule: For every year you delay controlling an
invasive plant infestation, it will take three years to regain control."
Caulerpa Taxifolia - a classic example of a non-native species that just
takes over everything. Read about this tropical plant that has
invaded the northern Mediterranean, advancing an inch a day turning
ecosystems into biological deserts. It was thought Caulerpa had no
natural enemies; however, recent research has shown that there is a kind
of slug that sucks the toxins and life out of the invading plant. Read
about this highly specialized slug and how biologists are weighing the
biological risk factors of releasing this non-native slug into the
waters of the Mediterranean to control the invading Caulerpa before it
colonizes the whole Mediterranean Sea. (PBS/Scientific American Frontiers
- scroll down to The Green Invader for
Invasive Species Program
- From The Nature Conservancy
Invasive species alerts are posted on the main page.
Click on "What are invasive species?" and find a clickable map
of the 48 contiguous states. Click on various states to see what
the worst weeds are which have invaded the natural native plant
ecosystems in different areas. Learn about different types of
control methods and how you can help in your area.
Click on "Links" in left frame for a great list of website
U.S. Fish and
Wildlife Service Invasive Species Program
See Threats from Invasive Species, Impacts and
Examples. Learn what preventive measures are being taken.
Species Resource Links
U.S.G.S. Biological Resources Division
for Aquatic and Invasive Plants and the Aquatic, Wetland and Invasive
Plant Information Retrieval System (APIRS)
Read about the Invasive
Non-indigenous Plants of Florida
and find out why they are harmful to Florida's forests and wetlands.
What You Can Do to Prevent Species Invasion (Union of Concerned
Exotics, Clean Your Boat - (Environmental News
Video available from the University of
Minnesota Sea Grant Program shows the simple steps boaters across North America can take to
prevent the spread of nasty nuisance species of plants and animals in
both marine and freshwater environments. The video is designed to be shown at visitor centers, environmental learning centers, boating
retail outlets, and at boater training sessions.