Ship biofouling is a major vector for the introduction and spread of harmful marine species globally, however, its importance in Arctic coastal ecosystems is understudied. The objective of this study was to provide insight regarding the extent of biofouling (i.e., percent cover, abundance, and species richness) on commercial ships operating in the Canadian Arctic. A questionnaire was used to collect information on transit history, anti-fouling practices, and self-reported estimates of biofouling extent from a sample of ships operating in the region during 2015 – 2016.

A questionnaire was distributed electronically to all commercial ships entering the Northern Canada Vessel Traffic Services zone by the Canadian Coast Guard as part of the standard entry clearance communications, though participation in the survey was voluntary. Information was collected on ships’ operational profile (travel history, typical sailing speed, port residence time, and time at sea), information on antifouling systems installed, general characteristics (ship type, year built, gross tonnage, length, and wetted surface area), and self-reported estimates of percent cover of biofouling. The travel history of ships was requested for the last 10 ports-of-call preceding arrival at a Canadian Arctic port as well as the planned stops in the Arctic. The last 10 ports-of-call were categorized into biogeographic realms following the largest spatial units in the Marine Ecoregions of the World (MEOW) system; the Laurentian Great Lakes was included as an additional biogeographic realm. Self-reported estimates of percent cover of biofouling were based on a Captain’s general knowledge of the ship (i.e., best guess) and results from the latest underwater inspection (i.e. opportunistic observations on biofouling from the most recent underwater inspection as part of regular cleaning, repair, and/or maintenance of the hull conducted by ship owners).

Data are self-reported by vessel Captains that participated in the voluntary study. Missing values (marked as 'N/A') were not submitted by vessel Captains. Self-reported data have not been verified against any independent dataset.