Concentrations of sea pens, small and large gorgonian corals and sponges on the east coast ofCanada have been identified through spatial analysis of research vessel survey by-catch datafollowing an approach used by the Northwest Atlantic Fisheries Organization (NAFO) in theRegulatory Area (NRA) on Flemish Cap and southeast Grand Banks. Kernel density analysiswas used to identify high concentrations. These analyses were performed for each of the fivebiogeographic zones of eastern Canada. The largest sea pen fields were found in theLaurentian Channel as it cuts through the Gulf of St. Lawrence, while large gorgonian coralforests were found in the Eastern Arctic and on the northern Labrador continental slope. Largeball-shaped Geodia spp. sponges were located along the continental slopes north of the GrandBanks, while on the Scotian Shelf a unique population of the large barrel-shaped sponge Vazella pourtalesi was identified. The latitude and longitude marking the positions of all towswhich form these and other dense aggregations are provided along with the positions of all tows which captured black coral, a non-aggregating taxon which is long-lived and vulnerable tofishing pressures.