ALBERT

Description: Vazella pourtalesi presence and absence data were obtained from several different sources: DFO's multispecies trawl survey conducted in the Maritimes Region between 2007 to 2017 (presences and absences), DFO optical (in-house camera/video and remotely operated vehicle) benthic surveys conducted between 2001 and 2017 (presences only), and commercial bycatch records from the Fisheries Observer Program (FOP) from 1997 to 2007, and 2010 to 2015 (presences only). The DFO multispecies trawl survey is stratified random (by depth) and conducted using primarily Western IIA trawl gear. The average distance of these tows is ~ 3.17 km. Absence records were created from null (zero) catches that occurred in the same surveys. Commercial bycatch data between 1997 to 2007 from the Fisheries Observer Program was further post-processed and validated for accuracy, while the data from 2010 to 2015 was extracted directly from the Maritimes Fishery Science Database managed by DFO. Commercial trawls are much longer in duration and may follow bottom contours and/or retrace their footprint through the course of a 10+ km tow. For both the DFO multispecies trawl survey and FOP data, start coordinates were used to represent the tow, whereas for the DFO benthic imagery survey data the actual location of the V. pourtalesi record in situ was used. A 1 x 1 km grid matching that of the environmental data was placed over the study area and the presence-absence data were reduced to one record per cell, with a presence taking precedence over an absence if both occurred in the same cell. This gave a total of 215 presences (102 from the DFO trawl surveys, 47 from DFO benthic science surveys, and 66 from the FOP) and 2867 absences for the model.