A new study suggests rising levels of maritime traffic could affect the biodiversity of oceans and lead to a rise in invasive and pestiferous species.
The study, published in the Nature Sustainability journal by researchers from Canada’s McGill University, found that the increased proliferation of “non-indigenous pests” owed more to global shipping traffic than to climate change; and that as the world’s shipping industry continues to grow, bio-invasion could increase to between three and 20 times current levels by 2050. Shipping is currently responsible for around 80 per cent of global trade and between 60 and 90 per cent of bio-invasions in the ocean; Brian Leung, an associate professor in McGill’s Department of Biology and School of Environment and senior author of the paper, said: “Biological invasions are believed to be a major driver of biodiversity change, and cause billions of dollars in economic damages annually.”
In some of the cases studied, researchers found that invasive organisms travelled out of their indigenous habitat in ships’ ballast water; while in others, non-native species were found to have attached to the outside of ships as they travelled. The McGill team also modelled future shipping traffic and bio-invasion growth scenarios based on socioeconomic projections created by the International Panel on Climate Change. The scenarios showed that, as global demand for non-local goods and services increases in line with international economic growth, the need for shipping – and by extension the risk of transferring non-indigenous species to new habitats – increases concomitantly.
Graduate student Anthony Sardain, a lead author on the paper, said: “To understand how biological invasions will change, we need to understand how shipping patterns could change. Our study suggests that, unless appropriate action is taken, we could anticipate an exponential increase in such invasions, with potentially huge economic and ecological consequences…all scenarios point to an increase in both shipping and invasions. That should alert us to the gravity of the situation, and the importance of measures to curtail biological invasions.”