Global introductions of salmon and trout in the genus Oncorhynchus: 1870–2007

Abstract

The purpose of this review is to provide a global perspective on Oncorhynchus salmonine introductions and put-and-take fisheries based on modern stocking programs, with special emphasis on freshwater ecosystems. We survey the global introductions of nine selected salmonines of the genus Oncorhynchus: golden trout, cutthroat trout, pink salmon, chum salmon, coho salmon, masu/cherry salmon, rainbow trout/steelhead, sockeye salmon/kokanee, and chinook salmon. The information is organized on a geographical basis by continent, and then by species and chronology. Two different objectives and associated definitions of 'success' for introductions are distinguished: (a) seed introduction: release of individuals with the purpose of creating a wildreproducing, self-sustaining population; and (b) putand-take introduction: release of individuals with the purpose of maintaining some level of wild population abundance, regardless of wild reproduction. We identify four major phenomena regarding global salmonine introductions: (1) general inadequacy of documentation regarding introductions; (2) a fundamental disconnect between management actions and ecological consequences of introductions; (3) the importance of global climate change on success of previous and future introductions; and (4) the significance of aquaculture as a key uncertainty in accidental introductions. We conclude this review with a recognition of the need to terminate ongoing stocking programs for introduced salmonines worldwide.

Seasonal age distributions and maturity stage in a naturalized rainbow trout (Oncorhynchus mykissWalbaum) population in southern Chile reveal an ad-fluvial life history

“…Similar patterns of habitat use have been reported in both native and introduced populations, with adults using inlet streams to spawn and juveniles occupying streams as nursery areas before they emigrate to the lake (Youngs and Oglesby, 1972;Hayes, 1988;Rosenau, 1991;Seelbach, 1993;Sakai and Espinos, 1994;Graynoth, 1996;Dedual et al, 2000;Riva-Rossi et al, 2007). However, naturalized populations currently exist across a diverse array of habitats (Crawford and Muir, 2008). In many cases, such as southern Chile (Soto et al, 2006;Arismendi et al, 2009), there is a lack of information about how rainbow trout use these habitats.…”

“…Rainbow trout (Oncorhynchus mykiss Walbaum) is one of the most popular game species that has been introduced all over the world (Crawford and Muir, 2008). Similar patterns of habitat use have been reported in both native and introduced populations, with adults using inlet streams to spawn and juveniles occupying streams as nursery areas before they emigrate to the lake (Youngs and Oglesby, 1972;Hayes, 1988;Rosenau, 1991;Seelbach, 1993;Sakai and Espinos, 1994;Graynoth, 1996;Dedual et al, 2000;Riva-Rossi et al, 2007).…”

The impact of non-native rainbow trout within Afro-montane streams in eastern Zimbabwe

“…Non-native trout species, especially of the genera Oncorhynchus and Salmo, are among the most globally widespread within freshwater ecosystems (Welcomme, 1988;Cambray, 2003;Crawford & Muir, 2008). Non-native trout species have become established within both previously fishless habitats as new functional groups and within habitats that already contain fish (Simon & Townsend, 2003;Strauss et al, 2006;Strayer, 2010).…”

‘Neo-Europe’ and its ecological consequences: the example of systematic degradation in Australia's inland fisheries

“…Inland fisheries species in other neo-Europes have also been depleted; for example, Pacific salmon in the USA and Canada have deteriorated dramatically since settlement, and populations occurring inland have been disproportionately more impacted than those in coastal areas [19]. In addition, it is well known that European settlers consistently introduced comparable non-native fish species to geographically distinct locations [3,6,7].…”

“…Between 1820 and 1930, more than 50 million European people migrated to distant colonies-the United States, Canada, Australia, New Zealand, Argentina, Uruguay-which have been called the 'neo-Europes' [3]. When settlers arrived, they initiated unprecedented changes in ecosystems, including the intentional introduction of exotic species [4][5][6] to 'renovate the biota' [7]. The behaviours of settlers have been shown to have been vested in their ability to acclimatize to new surroundings [3,4].…”