Data used in: Propagule Pressure in the Presence of Uncertainty: Extending the Utility of Proxy Variables with Hierarchical Models (D.A.R. Drake, O. Casas-Monroy, M.A. Koops, and S.A. Bailey), Methods in Ecology and Evolution, Accepted June 2015. Data provided by D. Andrew R. Drake, email: andrew.drake@utoronto.ca The files 'PACDENS.txt', 'GLDDENS.txt', and 'ATLDENS.txt' are text files that describe the density of zooplankton (organisms/m3) sampled from ballast water. In each text file, columns represent a single ship sample and rows represent individual species (column sums represent the total density of the sample). The column headings (e.g., 71, 51, etc.) have been coded to represent the source and recipient region of each trip, with the first digit representing the source region, and the second digit representing the destination region within Canadian waters. Region codes are as follows: 1 - Arctic Canada, 2 - Atlantic Canada, 3 - Great Lakes St. Lawrence River, 4 - Pacific Canada, 5 - US Ballast Water Exemption Zone, East Coast, 6 - US Ballast Water Exemption Zone, West Coast, 7 - All global regions not covered in digits 1 through 6. The field 'SpeciesID' is a unique identifier, and 'Nonindig' describes whether the species of interest is (1) or is not (0) nonindigenous for each source region. The file 'rtrips.txt' is a text file that describes the ship-trips and corresponding ballast water volume (Mt) between source and recipient regions. The column 'Identifier' is a unique identifier, 'ArrivalRegion' and 'SourceRegion' are geographic codes as described above, 'ArrivalObj' and 'SourceObj' are unique identifiers, and 'DisVol' is the estimated ballast water discharge volume.