Control is better
Trust is good, but not too much of it. At least not when it comes to trading exotic creatures. The attractive ornamental palm tree or the cute turtle soon becomes a nuisance for the new home. Control is therefore necessary - and sometimes saves enormous follow-up costs.
The rangers in Everglades National Park could hardly believe their eyes when they encountered a special victim-perpetrator relationship in the middle of Florida's swamps in the fall of 2005. Only a few days earlier, a python apparently wanted to feast on an alligator between the sedges, but in this case animal eyes were bigger than the stomach - with a bitter end for both of them: the lizard died by strangulation, but she took revenge posthumously the snake, which simply tore it apart while devouring the prey that was too plentiful.
However, the game wardens were less shocked by the horrible scenario than by the aggressive behavior of the enormously dimensioned python, which, moreover, should not exist in American swamps. It originally came from tropical Southeast Asia, where it was trafficked into the United States by pet traders. There, young, and thus still really small, constrictor snakes can sometimes be sold for less than twenty dollars and easily get into the hands of inexperienced people. Within a year, the scale carriers increase in weight by up to ten times, they devour enormous amounts of warm-blooded food and quickly outgrow their owners. Their countermeasure: uncompromising disposal in the nearest swamp, where the pythons can survive thanks to the usually mild temperatures here, even in winter - and are now really prospering.
Because what were only isolated cases a few years ago is slowly growing into a constrictor snake plague, which endangers the native fauna as well as individual domestic animals and is now resulting in high costs for control measures. However, the invasive snakes are not alone in this and certainly not in the first place. In the United States alone, the ecological and economic damage caused by so-called neozoa and neophytes – animals and plants that have just been introduced and are problematic – is estimated at 137 billion dollars a year. There are similar estimates for Australia and New Zealand. For example, Asian longhorned beetles (Anoplophora glabripennis) are destroying North American forests, Brazilian water hyacinths (Eichhornia crassipes) are clogging African canals and polluting fishing grounds, European rabbits are grazing Australian grasslands bare, and the Pacific alga Caulerpa taxifolia at times threatened coastal fisheries in the Mediterranean.
So wouldn't it be cheaper to take strict measures against and controls in the trade in natural products in order to nip these dangers in the bud - even if this doesn't go well with globalized trade at first glance? Or does its economic benefit so clearly outweigh the possible follow-up costs of limiting damage to a few less invasive species that these could be risked for the benefit of flourishing free trade? In fact, the globalized exchange of ornamental plants, wild animals, fruits, vegetables and wood products generates billions of dollars, as scientists around Reuben Keller from the University of Notre Dame in Indiana concede. On the other hand, strict, scientifically backed reviews and market restrictions have been proven to cause high expenditure at first with no benefit at first glance.
For this reason, governments have often already rejected new risk assessments or introduced them only hesitantly. It was feared that too many exotic species, whose trade might have increased gross national product, would be rejected compared to correctly identifying species that are actually highly dangerous. Keller and his colleagues therefore developed a simple cost-benefit analysis with which they wanted to determine the framework conditions for long-term profitable access controls in a market economy that was unbridled on this point.
As a practical example, they used Australia's ornamental plant quarantine program to keep potential problem species out of the fifth continent. After all, almost 1,400 invasive species have entered the country through their import alone, which now cause at least 1.7 billion euros in damage every year. On the other hand, in 2004, the trade in ornamental plants, including the invasive greenery that had already been brought into the country, corresponding accessories and associated services, generated revenues of around EUR 2.1 billion. However, while the sales of many ornamental plants fell again in the long term due to typical consumer interest, the expenses for repairing damage and combating escaped exotic plants remained high in the long term - only very few of them can be successfully completely removed from the environment again.
With each additional dangerous neophyte, the costs rose disproportionately in the long run, while their economic benefit only lasted for a short time. In contrast, the already strict Australian surveillance system only costs around 200,000 euros a year – so it hardly weighs against the expenditure and income. As a result, the efforts to keep critical plants away pay off after just a few years and the savings in the state budget from the lack of control measures outweigh the potential benefit for the economy.
This calculation applies to an even greater extent for foreign animal species, which establish themselves in a new home faster than plants and therefore cause damage earlier. In addition, according to the researchers, new surveys show that successful invasions occur much more frequently than previously known, while new evaluation criteria can be used to identify critical species with high accuracy and thus exclude them from the movement of goods: all arguments in favor of trade restrictions.
Keller's team, however, admits a problematic point in their calculation, which is less of an economic than of a political nature: the period from which an invasive species starts to cost a lot of money is in most cases significantly longer than the term of office of the responsible decision-makers – a mismatch that, as is well known, not only affects ecological issues.