Invasive species : solutions to the economic burden

To date, there are 544 spe­cies lis­ted as inva­sive in France. Among them, the Asian hor­net deci­mates domes­tic bees, the tiger mos­qui­to spreads dengue fever and chi­kun­gu­nya, the prim­rose willow causes the disap­pea­rance of aqua­tic plants that are close to it… This phe­no­me­non is cal­led ‘bio­lo­gi­cal inva­sion’ and these spe­cies have cer­tain cha­rac­te­ris­tics in com­mon. First, they have been dis­pla­ced by humans, often as unex­pec­ted pas­sen­gers in the trans­port of goods and people. Once intro­du­ced, they have sur­vi­ved in their new envi­ron­ment, spread, and had various impacts, such as eli­mi­na­tion of local spe­cies, spread of diseases, alte­ra­tion of eco­sys­tems or devas­ta­tion of crops. 

Inva­sive spe­cies are not only a threat to bio­di­ver­si­ty, but also a major eco­no­mic bur­den. We have recent­ly demons­tra­ted this by sum­ma­ri­sing all exis­ting glo­bal eco­no­mic costs due to inva­sions since 1970, which total $1,288bn¹. This is only a tiny frac­tion of the actual costs, as it is only what has been esti­ma­ted and publi­shed. As such, the majo­ri­ty of the costs have not as yet been asses­sed. This figure has been gro­wing stea­di­ly, tri­pling eve­ry ten years until it rea­ched an esti­ma­ted $163 bil­lion in 2017 alone. A new stu­dy just publi­shed in France spe­ci­fi­cal­ly shows that inva­sions cost bet­ween 1.1 and 10.2 bil­lion euros bet­ween 1993 and 2018².

These costs are asso­cia­ted with many socio-eco­no­mic sec­tors (agri­cul­ture, health, tou­rism, real estate…), and thus affect a varie­ty of pri­vate and public actors. The bur­den of bio­lo­gi­cal inva­sions the­re­fore appears to be sys­te­mic and requires a strong and concer­ted poli­cy rather than one-off efforts. Below, we present three ways of tack­ling this burden.

The eco­no­mic costs gene­ra­ted by inva­sive spe­cies can be divi­ded into damage costs (loss of agri­cul­tu­ral yields, tou­rism reve­nues, etc.) and mana­ge­ment costs (control or era­di­ca­tion of inva­sive popu­la­tions, etc.). All stu­dies show that invest­ment in pre­ven­tive mea­sures is the most cost-effec­tive and effi­cient stra­te­gy against bio­lo­gi­cal inva­sions. For example, ear­ly detec­tion and rapid era­di­ca­tion of new inva­sions is much less cost­ly and has a much higher suc­cess rate than late action, which often amounts to damage control.

It is the­re­fore essen­tial to streng­then ear­ly detec­tion and moni­to­ring pro­grammes for alien spe­cies, so that an effec­tive res­ponse can be ini­tia­ted at the first sign of nega­tive impacts. The varie­ty of these impacts cou­pled with the com­plexi­ty of imple­men­ting research recom­men­da­tions requires inter­dis­ci­pli­na­ry and inter­sec­to­ral approaches – still too rare – invol­ving eco­lo­gists, eco­no­mists, ana­lysts, socio­lo­gists and sta­ke­hol­ders (e.g. bio­di­ver­si­ty managers). 

To raise awa­re­ness of bio­lo­gi­cal inva­sions among the gene­ral public and pri­vate and public sta­ke­hol­ders. It is cru­cial to raise awa­re­ness of public and pri­vate sta­ke­hol­ders who are res­pon­sible for the trans­lo­ca­tion of living orga­nisms on an international/regional scale (e.g. acti­vi­ties lin­ked to trade or live­stock far­ming) and/or who are vic­tims of their effects (e.g. far­mers). It is also essen­tial to raise awa­re­ness among the gene­ral public through various media and edu­ca­tio­nal chan­nels (e.g. in school cur­ri­cu­la). Empo­we­ring consu­mers by pro­vi­ding infor­ma­tion on the ori­gin and risks of the orga­nisms they buy, for example in the orna­men­tal trade [i.e. trade in exo­tic ani­mals or plants], would be an excellent way to reduce the risks of uncon­trol­led intro­duc­tions into the wild.

In this context, buil­ding bridges bet­ween science and socie­ty is the­re­fore the key ele­ment. These bridges include (i) the for­ma­li­sa­tion of inter­sec­to­ral net­works dedi­ca­ted to research and mana­ge­ment of bio­lo­gi­cal inva­sions, (ii) the orga­ni­sa­tion of dis­cus­sion work­shops and spe­ci­fic and conti­nuous trai­ning, and (iii) the deve­lop­ment of par­ti­ci­pa­to­ry science pro­grammes, which represent a major asset due to their triple edu­ca­tio­nal, scien­ti­fic and mana­ge­ment role. For example, there is now an appli­ca­tion deve­lo­ped by Europe (Inva­sive Alien Spe­cies Europe³) that allows any citi­zen to send pho­tos of new pre­su­med spe­cies with a view to deploying rapid res­ponses in terms of mana­ge­ment. Des­pite its inter­est, this appli­ca­tion is not wide­ly publicised. 

There is also great poten­tial in par­ti­ci­pa­to­ry science tools based on arti­fi­cial intel­li­gence to iden­ti­fy spe­cies, such as the Pl@ntNet appli­ca­tion, which is a great tool for the ear­ly detec­tion of inva­sions⁴, but is lar­ge­ly under-exploi­ted at present. We the­re­fore empha­sise the need for deci­sion-makers to be invol­ved to achieve concer­ted and effi­cient mana­ge­ment of these bio­lo­gi­cal invasions. 

Des­pite the increase in natio­nal and inter­na­tio­nal laws to com­bat bio­lo­gi­cal inva­sions, the magni­tude of their damage conti­nues to acce­le­rate, which sug­gests that these laws remain insuf­fi­cient. There is a need to streng­then spe­cies bla­ck­lists by rapid­ly upda­ting them once impacts are pro­ven, and to consi­der a shift in the legal para­digm towards whi­te­lists, i.e. the deli­be­rate intro­duc­tion of new alien spe­cies must be autho­ri­sed in advance on the basis of an inva­sion risk assess­ment. Those res­pon­sible for deli­be­rate intro­duc­tions should be held cri­mi­nal­ly liable as a deterrent. 

Bio­se­cu­ri­ty, which consists of the inter­cep­tion of alien spe­cies prior to their intro­duc­tion, is the most effec­tive and cost-effi­cient tool to com­bat the impacts of bio­lo­gi­cal inva­sions. For example, some coun­tries seve­re­ly affec­ted by bio­lo­gi­cal inva­sions, such as New Zea­land and Aus­tra­lia, have put in place high­ly effec­tive bio­se­cu­ri­ty pro­to­cols for both tou­rism and inter­na­tio­nal trade. These mea­sures require sub­stan­tial staf­fing, par­ti­cu­lar­ly for the imple­men­ta­tion of sur­veillance, qua­ran­tine and disin­fec­tion pro­to­cols ; but they offer insu­rance and a very signi­fi­cant net bene­fit com­pa­red to the exces­si­ve­ly high costs of damage and mana­ge­ment of invasions. 

In France, this legal fra­me­work and bio­se­cu­ri­ty mea­sures still appear to be lacking, as sug­ges­ted by the recent his­to­ry of inva­sions in France such as the Asian hor­net⁵, the tiger mos­qui­to⁶, the mug­wort⁷, gar­den flat­worms⁸, or the Xylel­la fas­ti­dio­sa bac­te­rium⁹. As island sys­tems are even more fra­gile to inva­sions than conti­nen­tal ones, rein­for­ced bio­se­cu­ri­ty mea­sures should be imple­men­ted, par­ti­cu­lar­ly in the French over­seas ter­ri­to­ries, inclu­ding tra­vel bet­ween over­seas territories.

Bio­lo­gi­cal inva­sions cause enor­mous eco­no­mic losses for socie­ty. This loss of ear­nings that we have esti­ma­ted is only the hid­den face of an ice­berg whose total amount is cur­rent­ly unquan­ti­fiable, given the diver­si­ty and scale of the impacts of inva­sions – and we are only tal­king about the mone­ta­ry cost here, igno­ring the irre­pa­rable eco­lo­gi­cal and health costs. Never­the­less, we do have the keys to fight this bur­den since the pro­blem does not lie with the dis­pla­ced spe­cies, but rather with our acti­vi­ties that cause these dis­pla­ce­ments, over which we do have control.