A call for global action to conserve native trout in the 21st century and beyond

Trout and char (hereafter, trout) represent some of the more culturally, economically and ecologically important taxa of freshwater fishes worldwide (Kershner, Williams, Gresswell, & Lobón‐Cerviá, 2019a). Native to all continents in the Northern Hemisphere (as well as western Mediterranean Africa), trout belong to seven genera (Oncorhynchus, Salvelinus, Salmo, Hucho, Parahucho, Brachymystax and Salvethymus), which are distributed across more than 60 countries (Muhlfeld et al., 2019). Despite their broad importance as indicators of biodiversity in cold‐water ecosystems (Haak & Williams, 2013), as well as cultural icons for food and recreation, nearly half of the world's recognised trout species (IUCN, 2018) are imperilled or at risk of global extinction (Muhlfeld et al., 2018, 2019). The root causes of their vulnerability include broad‐scale alteration of landscapes and watersheds, dams, overharvest, pollution, interactions with hatchery‐bred conspecifics and non‐native species. However, emerging threats such as climate change and related problems such as the spread of diseases and parasites pose significant challenges and uncertainties to native trout and their habitats (Kovach et al., 2016; Muhlfeld et al., 2018). Ultimately, conservation of native trout depends on understanding their diversity, a willingness to address threats at their root causes and implementing progressive conservation solutions that promote persistence of these iconic species in the face of growing human pressures.