Quantifying the probability of a successful marine bioinvasion due to
source-destination risk factors
Abstract
The increasing spread of marine non-indigenous species (NIS) due to the
growth in global shipping traffic is causing widespread concern for the
ecological and economic impacts of marine bioinvasions. Risk management
authorities need tools to identify pathways and source regions of
priority concern in order to better target efforts for preventing NIS
introduction. The probability of a successful NIS introduction is
affected by the probability that a marine species entrained in a
transport vector will survive the voyage between origin and destination
locations, and establish an independently reproducing population at the
destination. Three important risk factors are voyage duration, range of
environmental conditions encountered during transit, and environmental
similarity between origin and destination. In this study, we aimed for a
globally comprehensive approach of assembling quantifications of
source-destination risk factors from every potential origin to every
potential destination. To derive estimates of voyage-related marine
biosecurity risk, we used computer-simulated vessel paths between pairs
of ecoprovinces in the Marine Ecoregions Of the World biogeographic
classification system. We used the physical length of each path to
calculate voyage duration risk, and the cross-latitudinal extent of the
path to calculate voyage path risk. Environmental similarity risk was
based on comparing annual average sea surface temperature and salinity
within each ecoprovince to those of other ecoprovinces. We derived three
separate sets of risk quantifications, one each for voyage duration,
voyage path, and environmental similarity. Our quantifications can be
applied to studies that require source-destination risk estimates. They
can be used separately or combined, depending on the importance of the
types of source-destination risks that might be relevant to particular
scientific or risk management questions or applications.