Invasoras clandestinas a bordo

Um novo estudo vem comprovar como algumas espécies invasoras marinhas se estão a disseminar usando as rotas marítmas. O trabalho, realizado por investigadores da Universidade de Bristol (Reino Unido) e Oldenburg (Alemanha), estabelece uma relação entre as rotas marítimas comerciais e o fluxo de animais e plantas invasoras, que apanham boleia nos tanques de lastro e nos cascos dos navios até novos destinos.

Some regions, such as the San Francisco Bay or Chesapeake Bay, have even reported several new exotic species per year. The knock-on effects to fishermen, farmers, tourism and industry create billions of US dollars in damage every year.  Conservationists and ship engineers are now trying to prevent the next big invasion. But without knowing when and where it may occur, their possibilities remain limited.

As part of the research project, funded by the Volkswagen Foundation, the team obtained detailed logs of nearly three million ship voyages in 2007 and 2008. Depending on the particular route travelled by each ship, the researchers estimated the probability that a species survives the journey and establishes a population in subsequent ports of call. Although this probability is tiny for any single voyage, the numbers quickly add up because modern cargo traffic volumes are enormous.

(…)Bioinvasion is, as the researchers admit, a complex process, and records of past invasions are far from comprehensive. Facing these uncertainties, they simulated various different scenarios. Interestingly, the key results are comparable for different models, predicting the same hotspots and global highways of bioinvasion. The traffic on the main shipping routes plays the greatest role for the calculation.

Researchers calculate the global highways of invasive marine species


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