[1] Support for low-carbon energy and opposition to new large dams encourages global development of small hydropower facilities. This support is manifested in national and international energy and development policies designed to incentivize growth in the small hydropower sector while curtailing large dam construction. However, the preference of small to large dams assumes, without justification, that small hydropower dams entail fewer and less severe environmental and social externalities than large hydropower dams. With the objective to evaluate the validity of this assumption, we investigate cumulative biophysical effects of small (<50 MW) and large hydropower dams in China's Nu River basin, and compare effects normalized per megawatt of power produced. Results reveal that biophysical impacts of small hydropower may exceed those of large hydropower, particularly with regard to habitat and hydrologic change. These results indicate that more comprehensive standards for impact assessment and governance of small hydropower projects may be necessary to encourage low-impact energy development.

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1.Oyster reef living shorelines have been proposed as an effective alternative to traditional coastal defence structures (e.g. bulkheads, breakwaters), with the benefit that they may keep pace with sea-level rise and provide co-benefits, such as habitat provision. However, there remains uncertainty about the effectiveness of shoreline protection provided by oyster reefs, which limits their broader application. 2.We draw evidence from studies along the east and gulf coasts of the United States, where much research and implementation of oyster reef restoration has occurred, to better define the existing gaps in our understanding of the use of restored oyster reefs for shoreline protection. 3.We find potential disconnects between ecological and engineering functions of reefs. In response, we outline how engineering and ecological principles are used in the design of oyster reef living shorelines and highlight knowledge gaps where an integration of these disciplines will lead to their more effective application. Synthesis and applications.This work highlights the necessary steps to advance the application of oyster reef living shorelines. Importantly, future research should focus on appropriate designs and conditions needed for these structures to effectively protect our coasts from erosion, while supporting a sustainable oyster population, thereby providing actionable nature-based alternatives for coastal defence to diverse end-users. How to cite this article: Morris RL, Bilkovic DM, Boswell MK, et al. The application of oyster reefs in shoreline protection: Are we over-engineering for an ecosystem engineer? J Appl

As the decommissioning of dams becomes a common restoration technique, decisions about dam removals must be based on sound predictions of expected outcomes. Results of past and ongoing dam removal monitoring are an important source of information that practitioners may utilize to evolve predictive and decision-making tools, emphasizing the need for thorough and defensible documentation of dam removal outcomes. However, as dam removals challenge many basic assumptions of conventional experimental designs and data analysis techniques, the quality of information available to aid decision-making may be questionable or misleading.Nevertheless, some study design principles and analysis procedures may be robust to the challenges presented by dam removal research. To assist managers in undertaking dam removal monitoring, this article discusses the assets and limitations of monitoring and analysis options available for dam removal studies, with emphasis on selecting a rigorous experimental design and determining significance of results.As the chosen monitoring design will influence the appropriateness of applying standard analytical methods, particularly statistical hypothesis testing, researchers should carefully consider constraints inherent to dam removal studies when designing a monitoring plan and assigning significance to observed changes. Ecological significance is often the most justifiable method for framing significance of dam removal outcomes, though it may be complicated by identification of environmentally significant thresholds. Another alternative is evaluation of the practical significance of results, when observed changes exceed measurement error and background variability. Establishing practical significance may be informative when statistical and ecological significance is inappropriate or impossible to determine.