Prospects for the future of pink salmon in three oceans: From the native Pacific to the novel Arctic and Atlantic

Abstract

While populations of other migratory salmonids suffer in the Anthropocene, pink salmon (Oncorhynchus gorbusca Salmonidae) are thriving, and their distribution is expanding both within their natural range and in the Atlantic and Arctic following introduction of the species to the White Sea in the 1950s. Pink salmon are now rapidly spreading in Europe and even across the ocean to North America. Large numbers of pink salmon breed in Norwegian rivers and small numbers of individuals have been captured throughout the North Atlantic since 2017. Although little is known about the biology and ecology of the pink salmon in its novel distribution, the impacts of the species' introduction are potentially highly significant for native species and watershed productivity. Contrasts between pink salmon in the native and extended ranges will be key to navigating management strategies for Atlantic nations where the pink salmon is entrenching itself among the fish fauna, posing potential threats to native fish communities. One key conclusion of this paper is that the species' heritable traits are rapidly selected and drive local adaptation and evolution. Within the Atlantic region, this may facilitate further establishment and spread. The invasion of pink salmon in the Atlantic basin is ultimately a massive ecological experiment and one of the first examples of a major faunal change in the North Atlantic Ocean that is already undergoing rapid changes due to other anthropogenic stressors. New research is urgently needed to understand the role and potential future impacts of pink salmon in Atlantic ecosystems.

Evidence of successful recruitment of non‐native pink salmon Oncorhynchus gorbuscha in Iceland

“…The spawning time of O. gorbuscha (August‐September) overlaps with that of some native salmonids: S. alpinus (September), S. salar (October–December), and S. trutta (October–December; starts in northern rivers in September). However, strong selection of O. gorbuscha to Atlantic conditions may result in changes in the future (Lennox et al ., 2023 and the references therein). Among potential implications, the aggressive behavior of O. gorbuscha (Quinn, 1999) may disrupt the normal behavior (by wounding, killing, or forcing the latter species to use less suitable positions prior to and during spawning) of both native salmonid parr and spawners, which enter the river earlier than, but spawn after, O. gorbuscha (Armstrong et al ., 2018; Hindar et al ., 2020, and the references therein).…”

“…The spawning time of O. gorbuscha (August-September) overlaps with that of some native salmonids: S. alpinus (September), S. salar (October-December), and S. trutta (October-December; starts in northern rivers in September). However, strong selection of O. gorbuscha to Atlantic conditions may result in changes in the future (Lennox et al, 2023 and the references therein).…”

Recreational anglers in Norway report widespread dislike of invasive pink salmon

“…Whether these perceptions can be expected to remain stable in the coming years is uncertain, but we suggest that perceptions will change as new knowledge about pink salmon emerges. Many anglers may not know whether pink salmon will remain in their rivers or continue to spread, and there are almost no scientific studies on the impacts of pink salmon on native European fishes (Lennox et al, 2023). As such information becomes more available, and perhaps as media narratives or social norms begin to shift towards catching and consuming pink salmon, the change in perception towards pink salmon may be of great interest to follow in these Norwegian fisheries.…”

“…The findings suggest that perceptions may be primarily influenced by factors at the level of the angler and at the level of the effects imposed by the species rather than at the level of the species . These findings are complicated by a lack of biological data on the potential impacts of pink salmon on native ecosystems in Norway (Jonsson & Jonsson, 2018;Lennox et al, 2023), such that concepts of impact rely on hearsay, conjecture and own observations rather than scientific evidence for certain impacts. The predominant negative perceptions may also be influenced by factors at the governance and policy level (as described by , which can shape angler values, attitudes and behaviours.…”

“…Atlantic salmon fisheries are facing a major state change in parts of the northeast Atlantic Ocean where pink salmon (Oncorhynchus gorbuscha) have rapidly begun colonizing rivers in Russia, Norway, Iceland, Scotland and beyond (Lennox et al, 2023). For half a century following the introduction of pink salmon to White Sea rivers in Russia, pink salmon were observed in variable numbers in Norway, primarily in northern regions, and with more frequent sightings during odd-numbered years due to their 2-year life cycle (Sandlund et al, 2019).…”