In the 12 years since Dudgeon et al. (2006) reviewed major pressures on freshwater ecosystems, the biodiversity crisis in the world's lakes, reservoirs, rivers, streams and wetlands has deepened. While lakes, reservoirs and rivers cover only 2.3% of the Earth's surface, these ecosystems host at least 9.5% of the Earth's described animal species. Furthermore, using the World Wide Fund for Nature's Living Planet Index, freshwater population declines (83% between 1970 and 2014) continue to outpace contemporaneous declines in marine or terrestrial systems. The Anthropocene has brought multiple new and varied threats that disproportionately impact freshwater systems. We document 12 emerging threats to freshwater biodiversity that are either entirely new since 2006 or have since intensified: (i) changing climates; (ii) e-commerce and invasions; (iii) infectious diseases; (iv) harmful algal blooms; (v) expanding hydropower; (vi) emerging contaminants; (vii) engineered nanomaterials; (viii) microplastic pollution; (ix) light and noise; (x) freshwater salinisation; (xi) declining calcium; and (xii) cumulative stressors. Effects are evidenced for amphibians, fishes, invertebrates, microbes, plants, turtles and waterbirds, with potential for ecosystem-level changes through bottom-up and top-down processes. In our highly uncertain future, the net effects of these threats raise serious concerns for freshwater ecosystems. However, we also highlight opportunities for conservation gains as a result of novel management tools (e.g. environmental flows, environmental DNA) and specific conservation-oriented actions (e.g. dam removal, habitat protection policies, managed relocation of species) that have been met with varying levels of success. Moving forward, we advocate hybrid approaches that manage fresh waters as crucial ecosystems for human life support as well as essential hotspots of biodiversity and ecological function. Efforts to reverse global trends in freshwater degradation now depend on bridging an immense gap between the aspirations of conservation biologists and the accelerating rate of species endangerment.

Reproductive habitats are vital for sustaining fish populations, but their location and relative natal contributions are often unknown or poorly understood. We used otolith microchemistry to examine natal origins of Walleyes Sander vitreus in Missouri River reservoirs (i.e., Lake Oahe, Lake Sharpe, Lake Francis Case, and Lewis and Clark Lake) in North Dakota and South Dakota. Water Sr:Ca and Ba:Ca were spatially heterogeneous and temporally consistent in all impoundments. Otolith Sr:Ca and Ba:Ca from age‐0 Walleyes permitted the reclassification of fish to known natal habitats (i.e., tributary, embayment, main stem) and individual sites with 87% and 75% accuracy, respectively. Natal contributions were highest in tributaries, particularly those in Lake Oahe, where 32% of all adults and 77% of Lake Oahe adults hatched. Embayments and main‐stem environments had high natal contributions (67–78%) in Lakes Sharpe and Francis Case and Lewis and Clark Lake, where tributaries are less abundant. Our research demonstrates the utility of otolith microchemistry for measuring habitat‐ and site‐specific natal contributions and provides further information that can be used in managing Walleyes in Missouri River reservoirs, particularly for broodstock collection, habitat protection and restoration, and harvest regulations.Received April 17, 2015; accepted December 11, 2015 Published online March 30, 2016

In an increasingly interconnected world, human–environment interactions involving flows of people, organisms, goods, information, and energy are expanding in magnitude and extent, often over long distances. As a universal paradigm for examining these interactions, the telecoupling framework (published in 2013) has been broadly implemented across the world by researchers from diverse disciplines. We conducted a systematic review of the first five years of telecoupling research to evaluate the state of telecoupling science and identify strengths, areas to be improved, and promising avenues for future study. We identified 89 studies using any derivation of the term telecoupling. These works emphasize trade flows, information transfer, and species dispersal at international, national, and regional scales involving one or a few countries, with China, Brazil, and the United States being the most frequently studied countries. Our review showed a rising trend in publications and citations on telecoupling, with 63% of identified telecoupling studies using the framework’s specific language (e.g., “flows”, “agents”). This result suggests that future telecoupling studies could apply the standardized telecoupling language and terminology to better coordinate, synthesize, and operationalize interdisciplinary research. Compelling topics for future research include operationalization of the telecoupling framework, commonalities among telecouplings, telecoupling mechanisms and causality, and telecoupled systems governance. Overall, the first five years of telecoupling research have improved our understanding of human–environment interactions, laying a promising foundation for future social–ecological research in a telecoupled world.

The sustainability of freshwater fisheries is increasingly affected by climate warming, habitat alteration, invasive species and other drivers of global change. The State of Michigan, USA, contains ecologically, socioeconomically valuable coldwater stream salmonid fisheries that are highly susceptible to these ecological alterations. Thus, there is a need for future management approaches that promote resilient stream ecosystems that absorb change amidst disturbances. Fisheries professionals in Michigan are responding to this need by designing a comprehensive management plan for stream brook charr (Salvelinus fontinalis), brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) populations. To assist in developing such a plan, we used stream-specific regression models to forecast thermal habitat suitability in streams throughout Michigan from 2006 to 2056 under different predicted climate change scenarios. As baseflow index (i.e., relative groundwater input) increased, stream thermal sensitivity (i.e., relative susceptibility to temperature change) decreased. Thus, the magnitude of temperature warming and frequency of thermal habitat degradation were lowest in streams with the highest baseflow indices. Thermal habitats were most suitable in rainbow trout streams as this species has a wider temperature range for growth (12.0-22.5°C) compared to brook charr (11.0-20.5°C) and brown trout (12.0-20.0°C). Our study promotes resilience-based salmonid management by providing a methodology for stream temperature and thermal habitat suitability prediction. Fisheries professionals can use this approach to protect coldwater habitats and drivers of stream cooling and ultimately conserve resilient salmonid populations amidst global change.