What’s the best way of predicting the range of an invasive marine species? This study points to the simplest of explanations: time since introduction. Researchers compiled a database of GBIF-mediated occurrences as well as traits and environmental variables for 138 invasive, coastal marine invertebrates in either Australia, New Zealand, or the United States. Estimating the total length of coastal range for each species, they found time since introduction to be the most important variable in predicting the range. On average, invasive species expand their range at about 400 km per decade. But since time after introduction can only be measured after an invasion occurs, the calculation doesn’t help in avoiding or managing invasions. The message is clearly that identifying vulnerable areas is the best means protecting against invasion.
Byers, J. E., Smith, R. S., Pringle, J. M., Clark, G. F., Gribben, P. E., Hewitt, C. L., … Bishop, M. J. (2015). Invasion Expansion: Time since introduction best predicts global ranges of marine invaders. Scientific Reports, 5, 12436. doi:10.1038/srep12436