Dear MARMAM colleagues, We are pleased to announce that the following paper is now available online: Enrico Pirotta, Len Thomas, Daniel P. Costa, Ailsa J. Hall, Catriona M. Harris, John Harwood, Scott D. Kraus, Patrick J. O. Miller, Michael J. Moore, Theoni Photopoulou, Rosalind M. Rolland, Lori Schwacke, Samantha E. Simmons, Brandon L. Southall and Peter L. Tyack. Understanding the combined effects of multiple stressors: A new perspective on a longstanding challenge. Science of the Total Environment 821, 153322. Abstract: Wildlife populations and their habitats are exposed to an expanding diversity and intensity of stressors caused by human activities, within the broader context of natural processes and increasing pressure from climate change. Estimating how these multiple stressors affect individuals, populations, and ecosystems is thus of growing importance. However, their combined effects often cannot be predicted reliably from the individual effects of each stressor, and we lack the mechanistic understanding and analytical tools to predict their joint outcomes. We review the science of multiple stressors and present a conceptual framework that captures and reconciles the variety of existing approaches for assessing combined effects. Specifically, we show that all approaches lie along a spectrum, reflecting increasing assumptions about the mechanisms that regulate the action of single stressors and their combined effects. An emphasis on mechanisms improves analytical precision and predicti! ve power but could introduce bias if the underlying assumptions are incorrect. A purely empirical approach has less risk of bias but requires adequate data on the effects of the full range of anticipated combinations of stressor types and magnitudes. We illustrate how this spectrum can be formalised into specific analytical methods, using an example of North Atlantic right whales feeding on limited prey resources while simultaneously being affected by entanglement in fishing gear. In practice, case-specific management needs and data availability will guide the exploration of the stressor combinations of interest and the selection of a suitable trade-off between precision and bias. We argue that the primary goal for adaptive management should be to identify the most practical and effective ways to remove or reduce specific combinations of stressors, bringing the risk of adverse impacts on populations and ecosystems below acceptable thresholds. Keywords: adaptive management, climate change, combined effects, mechanistic modelling, multiple stressors, population consequences. A PDF copy of the paper can be downloaded for free from: https://doi.org/10.1016/j.scitotenv.2022.153322 Please do not hesitate to contact me for any question regarding our work. Best Regards, Enrico Pirotta