The restoration of abalone (Haliotis spp.) populations through supplementation with the offspring of hatchery-spawned wild parents has been attempted in several species, with variable results. Between 2002 and 2005, the Bamfield Huu-ay-aht Community Abalone Project released 4.5 million larvae and 152,000 juveniles of the northern abalone (Haliotis kamtschatkana) into Barkley Sound, BC. The purpose of this study was to estimate the long-term survival of outplanted abalone 3-7 years after their release and thus determine their contribution to local population densities at three different outplanting sites. We identified outplanted abalone by genotyping epipodal tentacles sampled from wild-caught abalone for seven microsatellite loci. We then used three different pedigree reconstruction programs: one that used genotypes from hatchery-reared siblings (PEDIGREE 2.2), one that used the wild parent genotypes that were available (CERVUS 3.0), and one that used both sources of information (COLONY 2.0). Each program identified different but partially overlapping subsets of hatchery-outplanted offspring. From this we inferred that up to 26% of the individuals sampled at the main outplanting site were from hatchery spawnings. Despite this large contribution of hatchery-reared stock, the density of mature abalone at each site was below the level required for successful fertilization. More intensive outplanting efforts might increase population densities of this broadcast spawner above this minimum sustainable level. However, for supplementation to be successful, other factors that could reduce outplanted juvenile survival, including the low genetic diversity of hatchery-produced offspring and the low habitat quality of some outplanting sites, need to be monitored.
Although the negative impacts of roads on herpetiles are well documented, broad-scale implementation of effective mitigation measures to address these impacts remains limited. Here, we evaluated whether a novel, cost-effective, retrofit ecopassage design can reduce road mortality of herpetiles in the Lake Simcoe Watershed, using a before-after-control-impact study. We also examined whether the ecopassages impacted the movement of turtles across the landscape using wildlife cameras. Our study indicated that the ecopassages significantly reduced turtle road mortality at the treatment sites but were not effective at mitigating road mortality of other herpetiles. Most turtle road-kill at the ecopassages sites occurred at fence ends, highlighting the need for solutions to address fence-end effects for herpetiles. There was no evidence that the ecopassages reduced turtles' ability to move between habitats as individuals were observed crossing through the ecopassages. Our results suggest that inexpensive solutions can effectively mitigate road mortality for turtles and taller fencing could improve the design for other species. Ecopassages, such as the ones tested in this study, should be widely implemented in road-kill hotspots across all regions, especially in habitats of rare or at-risk species, in order to protect turtles and other wildlife from the increasing threat of roads.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.