NRC Handelsblad | By Wouter van der Weijden | September 7, 2003
The World Trade Conference which begins next week in Mexico initiates a new round in the debate on globalisation. This debate, says Wouter van der Weijden, pays scant regard to the biological dimension of globalisation. Biological globalisation puts humans, agriculture and nature at risk and every effort must be made to curb it.
The globalisation debate focuses on economic, social and cultural issues. But there is little discussion about biological globalisation, the dispersal of plant, animal and microbe species around the planet. Some organisms, such as livestock, pets and ornamental plants, are transported intentionally. Others are transported unintentionally: rats hitch a ride on ships and lorries; microbes are carried on people, animals and plants. This has been going on for thousands of years, but the process is speeding up as more and more people and goods travel at greater speeds over longer distances. The SARS virus even spread across three continents in a matter of weeks.
Biological globalisation, like other forms of globalisation, has both beneficial and dangerous consequences. Of clear benefit has been the spread of highly productive agricultural crops from Asia and America to other regions of the world. Relieved of their native pests and diseases, many of these crops flourished even better in their new homes than in their areas of origin. The result has been a worldwide increase in agricultural productivity. Dutch agriculture, for example, now relies on cereals and beets from the Middle East and potatoes and maize from America.
A dangerous consequence of biological globalisation is the spread of epidemics, some of which have proved disastrous. In the fourteenth century the transport of hides from Asia led to the outbreak of bubonic plague, which killed a quarter of the European population. After the First World War an Asian flu virus took the lives of 20 to 40 million people. This virus reached Europe on an American navy ship that docked in Spain (the origin of the misleading name `Spanish flu'). In the preceding centuries European settlers to America brought bubonic plague, smallpox, measles and typhoid fever, which wiped out no less than 95% of the native population. And the suffering is not over yet. The US has recently been exposed to two new pathogens from Africa, the West Nile virus and monkeypox, and new viruses regularly crop up on Asian livestock farms. Virologists predict new pandemics that will make SARS look like child's play.
Globalisation also takes its toll in the farming sector. The dramatic foot and mouth epidemic that recently afflicted the UK and the Netherlands was probably caused by an infected piece of meat from India. In 1991 the American Corn Rootworm Beetle succeeded in crossing the Atlantic Ocean in an aircraft to Bosnia and has spread throughout Europe, reaching the Netherlands last summer.
The Netherlands plays a pivotal role in the spread of plant diseases. Huge volumes of flowers are imported to Schiphol airport for auction in Aalsmeer and then shipped on to other countries. This is a recipe for bio-invasions because pathogens and weeds may be brought in with the flowers and subsequently sent out to all corners of the earth. The border controls may be strict, but they are not watertight.
Biological globalisation also threatens nature and biodiversity. Bio-invasions often displace native species. Remote islands are most vulnerable because although they are home to few species, a relatively large proportion of these are endemic species found nowhere else. Goats, rats, plants and parasites introduced onto these islands have caused biological havoc. The classic example is Hawaii, which used to have many colourful endemic finches. In 1827 a British ship travelling from Mexico arrived in Hawaii, where the crew emptied out a barrel of drinking water which contained mosquito larvae infected with smallpox and avian malaria. Sixteen bird species were wiped out as a result. A recent example is the island of Guam, also in the Pacific, where nine species of bird, five lizard species and two bat species have been lost in the last ten years. They were defenceless against a tree snake presumed to have arrived on a ship from New Guinea at the end of the 1940s. Similar unseen battles between native and introduced species are raging on a growing number of islands, a conflict that has even made the pages of The Economist. Almost half the flora of New Zealand now consists of exotics.
Continents are not exempt, either. A notorious example is the enormous damage caused by rabbits in Australia. At the moment the US is involved in a trade dispute with China about wooden pallets which were found to harbour a species of beetle. Trees in New York and Chicago are already infested. Eurasia is less troubled by such exotics, perhaps because - as Darwin proposed - selection pressure is greatest on large continents and so their native species are more resilient. Despite this, forests in the Netherlands are under attack from Black Cherry, a native of North America, arable crops are afflicted by the Colorado beetle and greenhouse crops by the Californian Thrip. Aquatic species are not exempt either. Nile Perch introduced into Lake Victoria have exterminated 200 endemic fish species. In the Netherlands, mussel farming is threatened by the introduced Japanese oyster. Meanwhile, oil tankers transport freshwater animals around the globe in the ballast water they carry as return freight.
On a worldwide scale, bio-invasions are the second most important cause of declining biodiversity after habitat loss. Can such invasions be checked in a globalising world? Not entirely, but the rate at which it goes on must be drastically reduced. Even rapidly spreading organisms can be checked, as we have seen in the case of SARS. We will have to make a much clearer distinction in world trade regulations between living and non-living material. Trade in non-living material may expand; but trade in living material must be regulated more strictly, and where necessary cut back. East-West shipments are often riskier than North-South shipments because tropical species tend not to thrive in temperate climates, and vice versa. What is most urgently needed is a more effective way of preventing organisms being transported with agricultural and forestry products, fresh food and ballast water.
The World Trade Organisation (WTO) allows countries to stop risky living material crossing international borders. Ironically enough, the countries that make most use of this are the USA and Australia, the champions of free trade. Where economics are concerned they argue for the rights of the strong; where biology is concerned they defend the rights of the weak. After the foot and mouth crisis, the EU also decided to check incoming travellers for possession of ham and other food. Poor countries, though, often lack the capacity to carry out such checks.
The WTO regulations chiefly deal with organisms posing a threat to agriculture and with endangered animal species, but pay little attention to invasive species that threaten biodiversity. New Zealand has introduced a new policy based on the precautionary principle which bans the import of organisms unless express permission is given. Like the US, they have banned the import of ballast water.
Regarding the position of the Netherlands, we would be well advised to help poor countries (including island states) develop systems to prevent bio-invasions. At home, we must take a more critical look at our flower auctions. They may be an economic success, but they are also a recipe for biological globalisation.
Wouter van der Weijden is an environmental biologist worlking for the Centre for Agriculture and Environment in Utrecht, the Netherlands.NRC Handelsblad:
