Under the Fisheries Act of Canada (2012), proponents of development projects are responsible for offsetting the destruction of freshwater and marine habitat if “serious harm” is expected to occur to fish supporting a commercial, recreational or Aboriginal fishery. One method of offsetting lost fish habitat in the coastal marine environment is the creation of artificial reefs. Artificial reefs are constructed with ships, rock or other hard substrate that creates surfaces upon which marine life can grow and seek shelter. We examine the conditions under which an artificial rock reef is equivalent to lost marine habitat and can satisfy the legislated requirement of maintaining or enhancing the productivity of a fishery impacted by a development project. To help achieve the objective of maintaining the productivity of the fisheries impacted by development projects, we recommend that coastal engineering plans for offsetting works incorporate the environmental requirements of the relevant fishery species during the critical juvenile stage of its life history.