Freshwater biodiversity is in decline globally, and this includes declines in native trout and char. Of 124 recognized trout and char species, only 67 have had their status assessed by the International Union for Conservation of Nature (IUCN), and 73% of these 67 are considered to be threatened with global extinction (Muhlfeld et al. 2018).
In 2019 at the international symposium “Advances in the Population Ecology of Stream Salmonids V” held in Granada, Spain (2023 symposium is May 8-12 in Mallorca, Spain) a special session was held on “The Status and Conservation of Trout and Char Worldwide." The session was followed by an interactive forum for attendees to identify solutions for the sustainability of native trout at local to global scales. One of the identified solutions was to: Establish place-based conservation protections for native trout: propose adding “Outstanding Coldwater Rivers” to the World Heritage List. A summary of this forum was published by an international slate of authors in the journal Ecology of Freshwater Fish (see here).
In 2013, Amy Haak and Jack Williams of Trout Unlimited's Science program proposed a systematic approach to conservation planning, published in the Journal of Conservation Planning, that could be jumpstarted by focusing on native trout (and char). Their approach focused on the 3-Rs: representation, redundancy, and resiliency. That is, focusing management on ensuring representative elements of life history, geographic, and genetic diversity remain within the historical range of a species or subspecies, and that there is redundancy in these representative elements. Their approach of a balanced portfolio of conservation for a species included ensuring that some populations occupied large enough patches of habitat to ensure long-term population persistence.
Establishing large, interconnected habitats facilitates migratory life history strategies, including the use of mainstem rivers and lakes where prey resources are often more abundant and temperatures may be more optimal for growth in fall, winter, and spring (highlighted by Jonny Armstrong's work here). Focusing conservation at the watershed scale, including in downstream areas that may afford growth advantages for cold-water obligates like trout and char, also benefits other non-game fishes and aquatic organisms of conservation concern. And since we know more about trout (and char) because they are a sportfish managed, in part, for recreational angling.
Haak and Williams highlighted Muddy Creek in south-central Wyoming as an example where there are native Colorado River Cutthroat Trout in the headwaters and native Bluehead Sucker, Flannelmouth Sucker, and Roundtail Chub in Muddy Creek further downstream. Watershed-scale conservation, jumpstarted with native trout management, can benefit entire native aquatic communities - often called a native fish conservation area.
Trout and char are economically and ecologically important taxa that are important indicators of aquatic ecosystem health and are important icons for food and recreation. Seven genera of trout and char (Oncorhynchus, Salvelinus, Salmo, Hucho, Parahucho, Brachymystax and Salvethymus) are native to all continents in the Northern Hemisphere (as well as western Mediterranean Africa) across 60 countries. Their presence in watersheds can be used to jumpstart conservation planning and implementation because we know more about them and their ecological needs, but conservation work done to benefit trout and char that can have positive downstream impacts on other aspects of aquatic biodiversity. Haak and Williams illustrated this with examples of Cutthroat Trout in the United States, but these same concepts have relevancy to Brown Trout in Spain, Softmouth Trout in the Balkans, and beyond. Where might these watersheds be, and are they the type of places that could be listed as an Outstanding Coldwater River?
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