Never mind that it couldn’t really walk, couldn’t really live out of water for long in 90-degree temperatures. Never mind it that would not attack humans (or other land mammals).

From the New York Times to the BBC it grabbed headlines, becoming late-night fodder for Leno, Letterman, et. al. faster than you could say O.J.

If you spent your summer on the planet Earth, you know about the snakehead: the northern Chinese snakehead fish that reared its ugly head in an Anne Arundel County pond last June and changed the world as we knew it.

Its eradication took a panel of scientific experts, a team of fishery biologists and technicians, pesticide consultants, law enforcement officers and attorneys. Ninety days and more than 1,000 expired snakeheads later the alien invaders are no longer.

Yet for all the trouble it caused, the snakehead may have done something of a public service, by focusing international attention on the havoc non-native species can wreak when introduced where they don’t belong.

Here in our area, the issue crosses disciplines, challenging land managers, fish and wildlife biologists, and water quality experts alike.

On the Eastern Shore nutria are devouring critical marsh habitat.

Nutria

Mute Swan

Water Chestnut

In the Bay mute swans are eating their way through 9 million pounds of submerged aquatic vegetation annually, driving native waterfowl from their homes and eliminating vital habitat for crabs and fish.

In the Bird and Sassafras Rivers volunteers (myself included) are waging war on water chestnut, pulling by hand the spiney pods that, if left unchecked, can overtake native vegetation and choke off waterways, making them uninhabitable for aquatic species, unsafe for people, impassable for boats.

This summer, the only thing competing with the snakehead for the front-page was another exotic: a six-foot long, cholera-carrying, fluorescent pink nuclear worm from Vietnam.

Yet, in the complex world of non-indigenous species, it’s not always so easy to identify the bad guys. Alien species are not always invasive -- they don’t always colonize, spread rapidly or displace indigenous plant and animal life. There are also “good” non-natives. Wheat, cattle, brown trout and honeybees are just a few of the many introduced species that have been embraced by - and become cornerstones of - our culture.

Finally, there are species where the verdict is still out, as in the case of the Asian oyster. If introduced into the Bay, (as is being promoted in some arenas), it may be able to resist the diseases responsible for the decline in our native oyster populations. Unknown is the impact it might have on Chesapeake Bay natives, oysters and others.

The issue of introduced species is also high on the national agenda. A report to the Pew Oceans Commission, an independent leadership group studying marine life in the U.S., calls them “a growing and imminent threat to living marine resources,” with hundreds of introductions having already taken place from Hawaii to New England, and more arriving daily via ships’ ballast water, fishing activities and other means. (In the San Francisco Bay alone, it is estimated that from 1961 to 1995 one inadvertent introduction became established every 14 weeks.)

Beyond the ecological threat, is economic impact. The cost of research, control, management, and loss of native species can be staggering. To what extent? Currently before Congress is a bill to regulate ballast discharge from commercial vessels, screen imports of live organisms, create a national database to monitor invasives and provide for rapid-response funding. If passed, the legislation will spend about $140 million a year to tackle a problem estimated to cost the U.S. $135 billion annually.

While regulatory controls will certainly help, prevention will continue to be hampered by the seemingly infinite occasion for introduction, intentional or not. The opportunity to act most often comes only after the horse is out of the barn, and, snakeheads aside, we’re not about to become the department of killing resources.

The truth is that even as public awareness grows and regulations become more stringent, we remain at the mercy of our biosphere and our civilization. It is the nature of nature to adapt, evolve and migrate. Today, that nature exists in an ever-shrinking world where humans -- by far the most effective, inexhaustible introducer of invasives -- can move around the globe almost effortlessly to even the most remote areas.

With no one solution imminent the most prudent course of action seems to be to continue what we’re already doing. Expand regulatory controls. In the case of new introductions, where eradication seems feasible - as in the case of the snakehead - act quickly to eliminate the interloper. In the face of already established species such as mute swans, measured action to manage the population and minimize its impact is more realistic.

As in any effort to manage a species -- plant or animal, harmful invasive or native in trouble - science must guide our decision-making.

And as for the snakehead? It really was just a fish. But what a fish story...

The Pew Oceans Commission’s policy recommendations will be presented to Congress early next year. The report, Introduced Species in U.S. Coastal Waters: Environmental Impacts and Management Priorities by Dr. James T. C Carlton of Williams College and Mystic Seaport is available at www.pewoceans.org To learn more about invasive species in Maryland, visit www.dnr.state.md.us