Budy, P., K.B. Rogers, Y. Kanno, B. Penaluna, N.H. Hitt. J. Dunham, C. Mellison, and W.L. Somer. 2019 Distribution and Status of Trouts and Chars in North America. Invited Chapter 8 in: Diversity and Status of Trouts and Chars of the World. Editors: J.L. Kershner, J. E. Williams, R. E. Gresswell. American Fisheries Society. Symposium Book. USGS FSP: IP-088494.
Abstract
Trout and char are a celebrated group of fishes and char hold a distinct place in the culture, nutrition, and economy of indigenous people. Their connections to ecosystems and people are profound and complex, and, in the United States, many are the state fish! Trout and char are speciose, and most taxa have evolved in response to major geological events. Today, relative to their historical distribution and abundance, the status of most trout and char in the United States is considered poor, and distributions have been dramatically reduced. In Canada, some of these fishes are depressed, while others are secure and support commercial and subsistence harvest. In the USA, for example, of the lineages of Oncorhynchus that we described, two are already extinct, five are listed as Threatened under the ESA, three are protected under Conservation Agreements or are considered ‘Species of Concern’, and those that remain have all undergone or are currently undergoing status assessments due to declines in abundance and distribution (Table 1). In contrast, of the four Salvelinus species we reviewed, only one is listed as Threatened under ESA, one is declining across its native range, and the other two have no range-wide legal conservation status and are considered stable. Arctic Char are even considered a sustainable food fish and are “of least concern” on the IUCN list.
Most species or sub-species face similar threats, although the most important limiting factors varied. Habitat degradation, genetic introgression, and the negative effects of non-native fishes (often by other trout) are the most influential threats to persistence. However, because all trout are obligate cold-water species, climate warming is also a ubiquitous threat. In addition, due to their extreme popularity as a game fish and recreational and economic value, trout and char enjoy broader management support than most species of fish and wildlife, particularly among those that are imperiled. As a consequence, there is a long history of trout and char management in North America. That history has changed over time from management focused on improving recreational angling opportunities to management that also emphasizes conservation and restoration of native populations. Common management strategies include hatchery propagation, harvest restrictions, habitat restoration (riparian, in-stream), improving passage and connectivity, and minimizing the impacts of non-natives (via removal, sterilization). Despite their imperiled status and persistent threats, the outlook is promising for many species, sub-species, and populations, largely because the most important limiting factors have been identified and because they are, in sum, a wildly celebrated group of fishes.
Most species or sub-species face similar threats, although the most important limiting factors varied. Habitat degradation, genetic introgression, and the negative effects of non-native fishes (often by other trout) are the most influential threats to persistence. However, because all trout are obligate cold-water species, climate warming is also a ubiquitous threat. In addition, due to their extreme popularity as a game fish and recreational and economic value, trout and char enjoy broader management support than most species of fish and wildlife, particularly among those that are imperiled. As a consequence, there is a long history of trout and char management in North America. That history has changed over time from management focused on improving recreational angling opportunities to management that also emphasizes conservation and restoration of native populations. Common management strategies include hatchery propagation, harvest restrictions, habitat restoration (riparian, in-stream), improving passage and connectivity, and minimizing the impacts of non-natives (via removal, sterilization). Despite their imperiled status and persistent threats, the outlook is promising for many species, sub-species, and populations, largely because the most important limiting factors have been identified and because they are, in sum, a wildly celebrated group of fishes.