In aquatic systems, biological invasions can result in adverse ecological effects. Management techniques available for non-native fish removal programs (including eradication and population size control) vary widely, but include chemicals, harvest regimes, physical removal, or biological control. For management agencies, deciding on what non-native fish removal program to use has been challenging because there is little reliable information about the relative effectiveness of these measures in controlling or eradicating non-native fish. We conducted a systematic review, including a critical appraisal of study validity, to assess the effectiveness of different non-native fish removal methods and to identify the factors that influence the overall success rate of each type of method. We found 95 relevant studies, generating 158 data sets. The evidence base was dominated by poorly documented studies with inadequate experimental designs (76% of removal projects). When the management goal was non-native fish eradication, chemical treatments were relatively successful (antimycin 89%; rotenone 75%) compared with other interventions. Electrofishing and passive removal measure studies indicated successful eradication was possible (58% each) but required intensive effort and multiple treatments over a number of years. Of these studies with sufficient information, electrofishing had the highest success for population size control (56% of data sets). Overall, inadequate data quality and completeness severely limited our ability to make strong conclusions about the relationships between non-native fish abundance and different methods of eradication and population control and the factors influencing the overall success rate of each method. Our review highlights that there is considerable scope for improving our evaluations of non-native fish removal methods. It is recommended that programs should have explicitly stated objectives, better data reporting, and study designs that (when possible and appropriate) incorporate replicated and controlled investigations with rigorous, long-term quantitative monitoring. Future research on the effectiveness of non-native fish removal methods should focus on: (i) the efficacy of existing or potentially new removal measures in larger, more complex environments; (ii) a broader range of removal measures in general; and (iii) phenotypic characteristics of individual fish within a population that fail to be eradicated or controlled.

Throughout its distribution in North America, the threatened eastern massasauga rattlesnake (Sistrurus c. catenatus) persists in a series of habitat-isolated disjunct populations of varying size. Here, we use six microsatellite DNA loci to generate information on the degree of genetic differentiation between, and the levels of inbreeding within populations to understand how evolutionary processes operate in these populations and aid the development of conservation plans for this species. Samples were collected from 199 individuals from five populations in Ontario, New York and Ohio. Our results show that all sampled populations: (i) differ significantly in allele frequencies even though some populations are < 50 km apart, and may contain genetically distinct subpopulations < 2 km apart; (ii) have an average of 23% of alleles that are population specific; and (iii) have significant FIS values (mean overall FIS = 0.194) probably due to a combination of Wahlund effects resulting from fine-scale genetic differentiation within populations and the presence of null alleles. Our results imply that massasauga populations may be genetically structured on an extremely fine scale even within continuous populations, possibly due to limited dispersal. Additional information is needed to determine if dispersal and mating behaviour within populations can account for this structure and whether the observed differentiation is due to random processes such as drift or to local adaptation. From a conservation perspective, our results imply that these massasauga populations should be managed as demographically independent units and that each has high conservation value in terms of containing unique genetic variation.

Integrating knowledge from across the natural and social sciences is necessary to effectively address societal tradeoffs between human use of biological diversity and its preservation. Collaborative processes can change the ways decision makers think about scientific evidence, enhance levels of mutual trust and credibility, and advance the conservation policy discourse. Canada has responsibility for a large fraction of some major ecosystems, such as boreal forests, Arctic tundra, wetlands, and temperate and Arctic oceans. Stressors to biological diversity within these ecosystems arise from activities of the country's resource-based economy, as well as external drivers of environmental change. Effective management is complicated by incongruence between ecological and political boundaries and conflicting perspectives on social and economic goals. Many knowledge gaps about stressors and their management might be reduced through targeted, timely research. We identify 40 questions that, if addressed or answered, would advance research that has a high probability of supporting development of effective policies and management strategies for species, ecosystems, and ecological processes in Canada. A total of 396 candidate questions drawn from natural and social science disciplines were contributed by individuals with diverse organizational affiliations. These were collaboratively winnowed to 40 by our team of collaborators. The questions emphasize understanding ecosystems, the effects and mitigation of climate change, coordinating governance and management efforts across multiple jurisdictions, and examining relations between conservation policy and the social and economic well-being of Aboriginal peoples. The questions we identified provide potential links between evidence from the conservation sciences and formulation of policies for conservation and resource management. Our collaborative process of communication and engagement between scientists and decision makers for generating and prioritizing research questions at a national level could be a model for similar efforts beyond Canada.Generación de Preguntas de Investigación Prioritarias para Informar a las Políticas y Gestión de la Conservación a Nivel Nacional

The recognition that we are in the distinct new epoch of the Anthropocene suggests the necessity for ecological restoration to play a substantial role in repairing the Earth's damaged ecosystems. Moreover, the precious yet limited resources devoted to restoration need to be used wisely. To do so, we call for the ecological restoration community to embrace the concept of evidence-based restoration. Evidence-based restoration involves the use of rigorous, repeatable, and transparent methods (i.e. systematic reviews) to identify and amass relevant knowledge sources, critically evaluate the science, and synthesize the credible science to yield robust policy and/or management advice needed to restore the Earth's ecosystems. There are now several examples of restoration-relevant systematic reviews that have identified instances where restoration is entirely ineffective. Systematic reviews also serve as a tool to identify the knowledge gaps and the type of science needed (e.g. repeatable, appropriate replication, use of controls) to improve the evidence base. The restoration community, including both scientists and practitioners, needs to make evidence-based restoration a reality so that we can move from best intentions and acting with so-called "purpose" to acting for meaningful impact. Doing so has the potential to serve as a rallying point for reframing the Anthropocene as a so-called "good" epoch.

This study investigated how demographic characteristics of black rat snakes Elaphe obsoleta are affected by the length of the active season, and also used the resulting demographic data to determine the proximate factors responsible for male-biased sexual size dimorphism (SSD) in the species. Demographic data collected from 1981 to 1998 in Ontario (ON; 583 males and 588 females) and from 1942 to 1976 in Maryland (MD; 180 males and 150 females) were used to develop growth models with the von Bertalanffy growth equation. Instantaneous growth rates declined signi®cantly with increasing snout±vent length (SVL) in males and females of each population. The growth models predicted age using SVL satisfactorily, but the accuracy of the model decreased signi®cantly with increasing SVL. As predicted, based on the brevity of their active season (ON % 135 days, MD % 190 days), rat snakes of both sexes from Ontario had lower and more variable instantaneous growth rates and matured at a more advanced age (ON % 9 years, MD % 4 years) than snakes from Maryland. However, the rapid growth and early maturation in Maryland snakes occurred at the expense of longevity (maximum: ON % 30 years, MD % 20 years). Slower growth and later maturation will make rat snakes in Ontario less capable of recovering from population declines. Within each population, males grew faster than females. Survivorship for Ontario snakes did not vary by sex, but increased signi®cantly with increasing SVL. The demographic consequence of sex differences in growth was a male-biased sex ratio among larger snakes. Because SSD is a function of males growing faster than females, SSD in black rat snakes is probably a product of sexual selection, suggesting that large size confers a mating advantage in males.