In the delicate ecosystems of the world, invasive species are akin to cancer. They arrive where they're not wanted, spread aggressively, and they damage the very system in which they live. Kudzu, zebra mussels and Africanized honeybees are some of the more well-known invasive species, but a team of international scientists says those are just the beginning. In a recently released report they warn that a new wave of biological invaders is on its way.
The report, which has been published in the journal Trends in Ecology & Evolution and is the result of a meeting of 17 global experts at Cambridge University, found 14 major issues related to the management and spread of invasive species in the next two decades. "We have identified some potential game-changers" said professor Anthony Ricciardi from McGill University, who led the study.
The report makes mention of the spread of invasive species from both animal and plant kingdoms and talks about the way human activities will be affecting them. For example, modern farming techniques that encourage the use of soil bacteria and fungi might have consequences beyond improving crop yields. "The cultivation and distribution of 'growth enhancing' microbes could cause some crop plants or plant species residing near agricultural fields to become invasive pests" says professor Daniel Simberloff from the University of Tennessee.
Our work in the lab is also impacting invasive species, especially when it comes to genetic modification. A report about the work from Cambridge University points to the release of mosquitos in the Florida Keys meant to interrupt the disease-carrying bug's reproductive lifecycle. "The push to use genetically modified agents to control invasive species will continue to grow," said professor Hugh MacIsaac from the University of Windsor, "and with it will come public opposition and the view that we are opening Pandora's Box."
Also, in terms of human impact on invasive species, the authors of the study site our influence on the Arctic as a major factor. "The gold rush has begun for major expansion of human activities in the Arctic, with the potential for large-scale alien species transfers" says Dr. Greg Ruiz from Smithsonian Environmental Research Center, referring to the way in which melting sea ice has opened up this part of the world to increased human activity. The researchers say that the Arctic was once protected from rampant human exploration, but the melting ice has expanded our forays into the region for fishing, tourism, mining and the development of shorelines. And with increased human activity comes an increase in the likelihood invasive species will be introduced.
Of course, some invasive species will do just fine on their own without human influence in the next two decades – particularly bacteria, water molds, fungi and viruses. In terms of their spread, the report points to the "Bsal" fungus wiping out salamanders in Europe; the fungus that causes the bat-destroying white-nose syndrome; and sea star wasting disease which the Cambridge report says is one of the worst wildlife die-offs ever observed.
The report also makes mention of the fact that efforts meant to downplay the impact of invasive species have altered the public's perception of the threat they pose, and such a trend needs to be reversed if their influence is to be moderated.
"Denialism in science is not new, but its growth in the context of invasive species is especially worrying for people trying to conserve unique native biodiversity" said professor Tim Blackburn of University College London. "Manufacturing doubt about the negative impacts of invasive species can delay mitigating action to the point where it is too late."