“Profiles in Environmentalism” is a recurring segment on our blog where we shine a light on the dedicated people who are working to preserve the world around them. Big or small, local or national, every environmental organization works towards the same goal: providing a greener world for future generations.

It used to be that the only way for a species to make the jump from one continent to another was to swim, walk, or fly there themselves. But all that has changed with the advent of ocean-going vessels and air travel. Species that once spent generations slowly expanding across seas and continents can now find themselves in entirely new environments within the span of months, weeks, or even days. And in those cases where they have no natural predators, these species can precipitate the demise of native species and the collapse of whole ecosystems.

It is estimated that North America is home to some 50,000 different species of non-native plants and animals. Altogether, these species cost the US economy $137 billion through agricultural losses, infrastructure maintenance, and decreased property values; not to mention the millions of dollars spent by state and federal agencies to contain and eradicate these species. Though invasive species are found in almost all fifty states, there are some parts of the country that have been hit harder than most by these interloping plants and animals.

On the Front Lines

The state of Texas is a virtual battleground for invasive species; a state locked in constant battle on land and water against a myriad number of non-native trees, insects, and aquatic species. The northern plains are constantly under threat from invasive buffelgrass and king ranch bluestem, two species of introduced grass that are rendering whole acres of Texas unsuitable for wildlife. In the east, the lakes and rivers of the Lonestar State are continuously clogged by Zebra Mussels and Giant Salvinia, a species of floating fern that was originally imported from Brazil for home aquariums and water gardens.

The growing pressure exerted by these species on local ecosystems and economies served as the impetus for the creation of TexasInvasives.org, an online hub managed by the Lady Bird Johnson Wildflower Center that pulls together a number of resources for the benefit of the public; including databases, reports, fact sheets, and case studies. The site is part of a far-reaching partnership between the Lady Bird Johnson Wildflower Center, the Texas Invasive Plant and Pest Council, the Texas Parks and Wildlife Department, the US Forest Service, Texas A&M, the USDA Animal and Plant Health Inspection Service, and many other regional groups that lend their own knowledge and expertise to both the site and the numerous programs maintained by the organization.

One of the most effective programs organized by the Wildflower Center is the Invaders of Texas program. The program provides training for volunteers who wish to become citizen-scientists for the organization. These volunteers learn to identify and catalog invasive species through the Texas Invaders app (iPhone version here, Android version here), as well as receiving training in basic field work. The data collected by these volunteers is essential to the large-scale programs employed across the state to monitor and halt the spread of harmful species. Those who participate in the program are able to log sightings of invasive species into a statewide database that is used by resource managers to coordinate removal projects.

The current extent of the Texas Invaders' citizen-scientist network.

The current extent of the Texas Invaders’ citizen-scientist network.

The Invaders program graduated its 2,000th citizen-scientist just last year; adding to the program’s already sizable network of volunteers. Together, these volunteers form Texas’ first line of defense; alerting the state to new invasive species and keeping tabs on those that are known to inhabit Texas. Since its inception, the program has helped identify 18,000 invasive species and contributed over 12,000 volunteer hours to the effort. With their invaluable reporting data, they’ve helped organize over 500 removal projects targeted at trees and insects that threaten the natural biodiversity of Texas’ ecosystems.

A Plurality of Pests

One species that has been on the Invader’s radar for the last few years is the Emerald Ash Borer, a species of beetle that has already devastated forests throughout the Eastern U.S. It was first identified in Michigan in 2002 after a prolonged wave of ash tree deaths left much of Detroit and points north stripped of their tree cover. Before long, these little green beetles were showing up in over two dozen states, killing off millions of trees throughout the Midwest and along the East Coast.


Tunnel marks left behind by the larvae of an Emerald Ash Borer. Photo Credit: John Hritz, Creative Commons License

Though adult Ash Borers Beetles are easy to spot, they are not the actual culprit behind the tree deaths. Instead, it is their larvae that are responsible for killing ash trees. As soon as these tiny grubs are laid inside a tree they start digging through the bark, creating intricate tunnels that slowly deprive the tree of nutrients. If the infestation continues unabated, the tree eventually dies leaving behind a bare husk and one less potential habitat for local wildlife.

Though Texas has yet to see signs of the Ash Borer, there are growing concerns that it could find its way in from states such as Arkansas, where it has already become entrenched in the regional ash tree population. Fortunately, the Texas Invaders are on alert. Regular samples are taken from ash trees in North Texas, the region closest to known Ash Borer territory, and so far none of these samples have shown infestation. But in order to hedge its bets, the Wildflower Center has also created a seed bank to store seedlings from those ash trees native to Texas in the event that they are wiped out by the beetles.

Zebra Mussels are no bigger than a fingernail, but they can cling to virtually any surface and can accumulate to such a degree that they have been known to sink buoys.

Besides the looming threat of the Emerald Ash Borer, there are a number of other species that have plagued Texas for years, such as the Zebra Mussel. Possibly the most insidious species to ever stalk the waters of North America; the Zebra Mussel is barely the size of a fingernail and yet has caused hundreds of millions of dollars worth of damage since its arrival. These tiny, striped mollusks were originally introduced to North America 20 years ago after stowing aboard cargo ships hailing from the ports of Western Europe. Their first landfall in North America occurred up north in the Great Lakes, a region that is still struggling to combat the decline of native species and infrastructure damage caused by these minuscule mollusks.

The Zebra Mussel can be found in lakes and rivers on either coast, and have become endemic to a number of waterways within Texas. For the Texas Invaders, these mussels have become a regular sticking point in their outreach to boaters, one of the primary means that the species spreads from one body of water to another. The larvae of the zebra mussel are microscopic, allowing them to slip into the bilge water of a motorboat where they can remain dormant for long stretches. One the boat is placed in another lake or river, the larvae can easily slip into the water and begin churning out even more larvae.

Zebra Mussels have spilled out of the Great Lakes region, extending as far south as Texas and branching out to the coasts.

Once zebra mussels settle in a body of water they begin propagating in such large numbers that buoys, docks, boats, and even water pipes become completely encrusted with them. This poses a serious problem for power plants, especially nuclear plants, which rely on freshwater intake to keep their cooling systems functional. Millions of dollars are spent annually by utility companies to keep their pipes free of mussels, a process that requires vigilant cleaning to prevent shutdowns.

In order to prevent their spread, Texasinvasives.org instructs boaters to thoroughly clean their boats in between outings. This requires scrubbing the boat, trailer, and all gear with warm water, as well as draining any water remaining in the boat, live wells, or the motor. It is also crucial to let it dry for at least a week before use in order to ensure that all the larvae are killed. These procedures are enforced at the state level, with fines imposed on individuals who fail to properly clean and drain their boats, jet skis, and other freshwater vehicles.

Future Battle Lines

Groups like Texsinvasvies.org have made tremendous progress in halting the advance of invasive species, but the battle is far from over. Many of the species that have been transplanted to Texas and parts beyond are here to stay unless new methods of eradication are developed. Some groups have tried implementing novel, yet unorthodox, strategies such as encouraging the consumption of invasive wildflowers and animals, and introducing the fashion industry to the fur of the invasive Nutria rodent. But the most effective strategies remain those espoused by Texasinvasives.org, and others, that ask for constant vigilance on the part of industries and members of the public. The best way to keep the invaders at bay is to keep them in their own bays.