Modeling round goby Neogobius melanostomus range expansion in a Canadian river system

摘要

We applied a gamma transit time model to predict the rate of range expansion of the round goby (Neogobius melanostomus Pallas, 1814) in the Trent-Severn Waterway (Ontario, Canada). Gamma distributions were fit to actual transit times of the population front from 2009 to 2011. A lack of model fit in the second year is thought to be indicative of an upstream bait bucket introduction, and this model may be useful for identifying such events. Range expansion predictions were highest in high quality habitats at 9.3 km/year, with a 5% probability that highly mobile individuals may disperse 27 km/year. The model also predicts the arrival time of the population at any distance from the population front with a given confidence interval. The estimation of a timeline for range expansion and determining underlying factors affecting the spread of invasive species could inform preventative strategies. This model is potentially useful in predicting transit times of other invasive species expanding their range in linear space, and in separating natural population expansion from additional human-assisted movement in the same system.