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.

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.

Background: There is growing evidence of the potential negative consequences of altered flow regimes, in terms of magnitude, frequency, timing, duration or season pattern, on fluvial ecosystems and the fisheries they support. The scientific and policy communities have acknowledged the need for a better understanding of the effects of flow alteration on fish productivity. We conducted a systematic map to provide an overview of the existing literature base on the effects of flow-regime changes on direct outcomes of freshwater or estuarine fish productivity in temperate regions to inform stakeholders and policy makers. Methods: To identify relevant articles for inclusion in this systematic map, we searched six bibliographic databases, 29 organizational websites, one search engine, and 297 reviews, and solicited grey literature through relevant sources. We screened articles at title and abstract, then by full-text using predefined inclusion criteria. Included studies were coded for key variables of interest, along with a very basic critical appraisal for internal validity (i.e., susceptibility to bias). The quantity and characteristics of the available evidence, knowledge gaps and subtopics with sufficient coverage for full systematic reviewing are reported in a narrative synthesis. The distribution and frequency of examined effects of flow-regime changes on fish productivity outcomes are presented in visual heatmaps. Review findings: A total of 1368 studies from 1199 articles were included in the systematic map database and used to identify a number of interesting themes in the evidence base: (1) large evidence bases were found in temperate regions of United States of America (USA), Canada, and Australia; (2) most studies either used a temporal or spatial trend design i.e., lacking a 'true' before intervention time period, or no intervention control sites; (3) the most studied causes of altered flow regime were natural (e.g., floods, droughts, climate change), hydroelectric facilities (hydro), and dams with no hydro; and (4) there were clear clusters of studies evaluating effects of changes in magnitude and surrogate measures (e.g., velocity, water depth) on fish productivity outcomes, in particular abundance and diversity metrics. A number of potential knowledge gaps were identified: including geographic (Northern Africa, and possibly parts of Asia), causes of altered flow regime (restoration, land-use change, and water abstraction/extraction/diversion), interventions (flow duration, frequency, rate of change, or timing), outcomes (population viability) and specific intervention/cause/outcome groups (e.g., changes in flow magnitude due to hydro or natural causes and fish survival,

Anthropogenic waterways and canal systems have been part of the cultural and natural landscape for thousands for years. As of the late 20th century, more than 63,000-km of canals exist worldwide as transport routes for navigation, many with barriers (e.g., locks, dams) that fragment the system and decrease connectivity. Fragmentation alone can have negative implications for freshwater biodiversity; by isolating populations and communities, other human-mediated disturbances associated with canals like poor water quality and invasive species can exacerbate these negative effects. As such, the capacity of these interconnected freshwater systems to support biodiversity is continuously degrading at a global level. One critical, highly complex issue that unites canals worldwide is the challenge of governing these systems in a holistic, unified way to both protect biodiversity and preserve historical elements. Managing historic canals involves multiple objectives across many agencies and stakeholders, often with different or conflicting objectives. Here, we use the Rideau Canal, a UNESCO World Heritage Site and National Historic Site of Canada, as a case study to demonstrate the importance of considering canals as social-ecological systems for effective and efficient governance. Historic canals are integrated systems of both humans (social) and the environment (ecological), linked by mutual feedbacks and coevolution, and must be managed as such to achieve conservation goals while maintaining commemorative integrity. We discuss the history of the Rideau Canal and its current governance, biodiversity in the waterway, different threats and issues (user conflicts, aquatic pollution, shoreline development, water management, species at risk, and invasive species), and conclude by outlining ways to address the challenges of managing it as a coupled social-ecological system. We present different research needs and opportunities that would enable better management, though above all, we propose a shift from the current governance structure – which at best can be considered “patchwork” – to a coordinated, multi-scalar and multi-stakeholder governance regime such that the Rideau Canal can be maintained for its historical integrity without compromising biodiversity conservation. Given that canals are now pervasive worldwide, this article is not only topical to the Rideau Canal, but also to other waterways in Canada and beyond.

The study provides evidence of some parental misconceptions around eye care for young children and some barriers to access. Possible solutions to this are discussed.