First juvenile chum salmon confirms successful reproduction for Pacific salmon in the North American Arctic

Abstract

The distributional extent of Pacific salmon Oncorhynchus spp. in the North American Arctic is unresolved. While adult Pacific salmon have a recurring presence across the Alaskan North Slope and into the Canadian Arctic, it is uncertain if these fish are part of established Arctic populations, vagrants from outside sources reproducing unsuccessfully, or both. Here we present the first confirmed record of a juvenile Chum Salmon O. keta captured in the nearshore marine ecosystem in the North American Arctic. This provides the first scientific evidence of successful spawning and early marine survival of Pacific salmon in the North American Arctic. It was caught near Kaktovik, Alaska in August 2017 with a group of similarly sized age-0 Mackenzie River Arctic Cisco Coregonus autumnalis. Stable isotope and otolith microchemistry analyses are consistent with use of the nearshore estuarine corridor from the Mackenzie River west along the northern coast. This contributes critical information needed to identify, manage, and conserve biodiversity at the northern range edge, and will help to clarify the status of Pacific salmon as potentially emerging fisheries develop in the North American Arctic due to climate warming.

Hatcheries to high seas: climate change connections to salmon marine survival

“…Pacific salmon are distributed throughout the international waters of the North Pacific, Bering Sea, Gulf of Alaska, and Sea of Okhotsk (Walker et al 2000; Myers et al 2007; Urawa et al, 2018). Early juvenile chum salmon have recently been found in the North American Arctic (Dunmall et al, 2022). Environmental conditions such as SST at regional spatial scales largely determine salmon survival and are better predictors of survival than large-scale climate indices such as PDO (Mueter et al, 2002).…”

Local environmental conditions structured discrete fish assemblages in Arctic lagoons

“…In recent sampling, this species has been found less often in lagoons during late summer, and access to suitable lagoon habitat may be restricted as waters continue to warm during summer months (Marsh et al 2020;von Biela et al 2023). Certainly, small climate change induced increases in lagoon summer water temperatures (to > 10 °C) may affect the presence or distribution of fishes-promoting higher species richness in Arctic estuaries by way of range expansions or migrations of boreal species (Roux et al 2016;Barton et al 2020;Dunmall et al 2022).…”

Fisheries Volume 48 Number 7 July 2023

“…Elevated stream temperature could delay migration timing, which could reduce harvest rates, especially if run timing begins to overlap with other subsistence activities such as hunting or berry picking. Pacifi c salmon currently are harvested in small quantities compared to nonsalmon fi shes (<1%), but this could increase with climate change as Pacifi c salmon may continue to expand their range and establish spawning populations in the Arctic (Nielsen et al 2013 ;Carothers et al 2019 ;Dunmall et al 2022 ). Additionally, if freshwater productivity increases, Dolly Varden could shift from anadromy to a semi-anadromous or freshwater foraging pattern (Nordeng 1983 ), which could reduce the number of fi sh migrating through the lower river and, consequently, decrease harvest rates.…”