BY JOSHUA JONES
The world of invasive species can be a bewildering place for pet owners. Sensational media reports abound about environmental devastation, economic losses, and both human and animal health problems. Burmese pythons in the Florida Everglades and red lionfish established across the Caribbean and Gulf of Mexico remind us that unintended consequences can occur when exotic species find their way into new lands and waters.
Invasive species experts agree that a multi-faceted prevention approach is far more cost-effective than coping with ecological and economic disruption after introduced animals and plants are well-established. But this “ounce of prevention is better than a pound of cure” approach must be based upon sound scientific principles. In the invasive species world, these key cogs to prevention are risk assessment, regulations and education.
It is important to keep in mind that most non-native species are not invasive; many are innocuous, and many others are beneficial. Most species introduced to a new place do not become established. They are unable to survive inhospitable climate or unsuitable habitat in a foreign land, like piranhas that freeze in Maine winters. Of the non-native plants and animals that successfully reproduce and spread, only a small number go on to cause serious problems, i.e., become invasive.
The challenge, then, is to continue to refine the methods with which scientists can predict the chances of a species becoming invasive, and then to take steps to prevent their introduction and establishment. Scientists have been refining methods that can predict whether a non-native species will become problematic. These methods first consider the climate where a species naturally occurs to determine where similar temperature and humidity profiles are found in the U.S. For example, many ornamental fish are from tropical regions of South America and Asia; similar climate in the United States is limited to a relatively small area, primarily in central and south Florida. Therefore, it is not surprising that aquarium fish have not established populations in most of the continental U.S.
A second stage in risk assessment examines the invasion history for species that might become established. Factoring this history together with various biological traits produces an estimate of the overall risk of a species in a location.
PIJAC has been cooperating with the U.S. Fish and Wildlife Service (USFWS) in using a science-based approach to identify invasive species among animals not in the U.S. trade with the understanding that the industry will voluntarily refrain from importing these potentially problematic species.
A final note on risk assessment is in order. Estimating the invasive risk of animals and plants is an educated guess and not an exact science. To one degree or another, risk assessment relies on expert opinion to fill these gaps. Risk assessors should therefore aim to work with pet breeders, who are frequently an untapped resource.
For the minority of pets assessed as high risk species, regulations to reduce risk may be appropriate. For example, restrictions on possession in vulnerable areas, bio-security requirements such as cage locks and limited access, microchipping or other identification techniques and experience requirements may be effective in reducing the chance of an animal’s escape and establishment to an acceptable level.
Notably, while it is common to prohibit the personal ownership of certain very large or dangerous zoo and museum animals, such restrictions are unnecessary for the vast majority of pets.
At the federal level, injurious wildlife is a legal subset of invasive species. To quote the federal Lacey Act, which is the basis for federal regulation of invasive and injurious wildlife policies, wild animals found to be harmful or potentially harmful “to human beings, to the interests of agriculture, horticulture, forestry, or to wildlife or the wildlife resources of the United States” are included in this category.
With only a few exceptions, injurious wildlife may not be imported into the U.S. or transported across state lines, though injurious wildlife under the Lacey Act does not affect legal possession or movement inside a state. Many states have restrictions on the possession of various exotic species, some of which are also listed under the Lacey Act, that pose a threat within their borders. Some states list species for which possession is prohibited or allowed by permit, a so-called “black list” or “dirty list.” Other states have adopted a “clean list” approach, listing only species that may be imported or possessed. It’s not uncommon for state and local regulations to have elements of both, listing species that require permits along with those that may be possessed without restrictions.
Many invasive species get their start when well-meaning owners release their pets into the wild, unaware of the potential problems. Other pets escape poorly maintained or inadequate habitats and go on to cause problems. Even though most pets are not high-risk, invasive species predictions are not guaranteed, emphasizing the importance of responsible pet ownership in preventing the escape and release of all companion animals.
PIJAC has partnered with the federal Departments of Interior (USFWS) and Commerce (National Marine Fisheries Service) in the development of Habitattitude, a website designed to diminish the chances of releasing invasive animals into the wild. Habitattitude provides information on invasive species and the importance of responsible pet ownership to protect the environment. Recently, PIJAC has also assumed the responsibility for www.MyRightFish.com, a website targeting the beginner saltwater aquarium owner to provide information on making wise choices related to marine fish, and thus lessening the chance of release into our coastal waters.
Although social media has become an increasingly prominent medium, word-of-mouth and personal contact remain remarkably effective in communicating the right message. We encourage pet owners to visit the PIJAC website, as well as those above, and use your own networks to greatly expand the scope of our outreach.