Sockeye salmon estuary use in Puget Sound

For more information, view the original reports: The role of estuaries in the ecology of adult Pacific salmon and trout in Puget Sound and The role of estuaries in the ecology of juvenile Pacific salmon and trout in Puget Sound.

Overview

The vast majority of sockeye salmon from Puget Sound rivers (and others as well) feed in the open North Pacific Ocean (Farley Jr et al. 2018) and thus are not found in the Salish Sea as immature fish to any significant extent (Quinn and Losee 2022). There are only two major populations of sockeye salmon in rivers of Puget Sound (Baker River and Baker Lake, in the Skagit River system, and the Lake Washington basin), because the species tends to occupy lakes for a year or two prior to seaward migration. The primary Lake Washington population, spawning in the Cedar River, was established in the 1930s with a transplant from the Baker Lake population, though evidence indicates that the species existed in the basin prior to the stocking events (Hendry et al. 1996, Spies et al. 2007).

Adults

Adult sockeye arrive from the ocean, migrate through Puget Sound, and ascend their natal rivers. The Baker Lake and Lake Washington runs return in late spring and early summer, peaking in late June and early July (Figure 1). Like many sockeye populations towards the southern end of the species range (Hodgson and Quinn 2002), they enter freshwater well in advance of spawning, before the water temperatures in the outlet river get too warm. They hold in deep, cool water in the lake all summer, and spawn in the fall. These patterns are best known in the Lake Washington system, where they are counted at the Hiram Chittenden Locks and have been tagged and studied in some detail (Newell and Quinn 2005, Newell et al. 2007), revealing that they move quickly up the Ship Canal and into the lake (Liscom 1973, Newell and Quinn 2005), though the extent of holding in marine waters near the locks is not known. The Baker River population is a bit later than the Lake Washington population (Tillotson et al. 2019) but they are not counted the same way, so I am reluctant to over-interpret the difference. I surmise that the Baker River sockeye salmon also move upriver quickly but to my knowledge this has not been studied.

Rapid movement from marine water upriver, with little delay in estuaries, is common in sockeye salmon, though some of the Fraser River populations spend more time in the Strait of Georgia before moving upriver than others (Killick 1955, Crossin et al. 2007). Sonic tracking in Queen Charlotte Strait and the Strait of Georgia showed the fish swimming about 2 km/h (slower at night) and traveling about 20–30 km per day after considering the tidal currents and physical obstacles (islands, peninsulas, etc.) that they encountered (Quinn 1988, Quinn et al. 1989). There is evidence from passive acoustic monitoring that upriver migration is facilitated by use of tidal currents, as the salmon move up in the water column to take advantage of flooding tides and hold near the bottom of the estuary to avoid being pulled back on ebbing tides (Levy and Cadenhead 1995). This “selective tidal stream transport” is well known in larval fishes (McCleave and Kleckner 1982, Rowe and Epifanio 1994), invertebrates (Queiroga 1998) and adult fishes (Harden Jones et al. 1979, Parker and McCleave 1997) but has received surprisingly little attention among salmon scientists. This is a very fruitful area for future research. 

Juveniles

Unlike steelhead, which are produced in many Puget Sound rivers, sockeye salmon are more limited in distribution, in large part because they tend to occupy lakes for a year or two prior to seaward migration. The main Puget Sound populations are in the Baker River, part of the Skagit River system, and the Lake Washington basin. These populations predominantly migrate to sea after a full year of feeding in the lake at a rather large size. Data from the Baker River illustrate the timing of downstream migration (Figure 2). Like steelhead, sockeye salmon smolts tend to be large and migrate rapidly through estuaries on their way to the open North Pacific Ocean (Neville et al. 2016).

Both adults and juveniles generally do not seem to spend long periods of time in estuaries. However, this generalization may not apply to a lesser-known type of sockeye salmon that spawns in rivers not associated with lakes. The juveniles of this type may migrate to sea in their first year or second year of life. They are much less common in the Puget Sound region than the typical lake-rearing type of sockeye salmon, but they have been documented in several rivers and especially the Skagit and Nooksack rivers (Gustafson and Winans 1999). 

Based on data from the Fraser River system, the smaller and less abundant sockeye salmon that enter marine waters in their first year of life, later in the spring than the older smolts, remain longer than the others (Healey 1982, Freshwater et al. 2019). This type, that feeds for a few weeks or months in the natal river and then migrates to the ocean, occurs but is much less common in the Puget Sound region, and also much less well-known than the lake-type fish (Gustafson and Winans 1999). These ocean-type fish may rely more on estuaries, and their population status should be considered, despite their comparative scarcity. There is little to no information on the estuarine movements patterns of adults representing these sockeye types in Puget Sound.

References

Crossin, G. T., S. G. Hinch, S. J. Cooke, D. W. Welch, S. D. Batten, D. A. Patterson, G. Van Der Kraak, J. M. Shrimpton, and A. P. Farrell. 2007. Behaviour and physiology of sockeye salmon homing through coastal waters to a natal river. Marine Biology 152:905--918.

Farley Jr, E. V., T. D. Beacham, and A. V. Bugaev. 2018. Ocean ecology of Sockeye Salmon. Pages 319-390 in R. J. Beamish, editor. The Ocean Ecology of Pacific Salmon and Trout. American Fisheries Society, Bethesda.

Freshwater, C., M. Trudel, T. D. Beacham, S. Gautier, S. C. Johnson, C.-E. Neville, and F. Juanes. 2019. Individual variation, population-specific behaviours and stochastic processes shape marine migration phenologies. Journal of Animal Ecology 88:67-78.

Gustafson, R. G. and G. A. Winans. 1999. Distribution and population genetic structure of river- and sea-type sockeye salmon in western North America. Ecology of Freshwater Fish 8:181-193.

Harden Jones, F. R., G. P. Arnold, M. G. Walker, and P. Scholes. 1979. Selective tidal stream transport and the migration of plaice (Pleuronectes platessa L.) in the southern North Sea. Journal du Conseil International pour l'Exploration de la Mer 38:331-337.

Healey, M. C. 1982. Juvenile Pacific salmon in estuaries: the life support system. Pages 315-341 in V. S. Kennedy, editor. Estuarine Comparisons. Academic Press, New York.

Hendry, A. P., T. P. Quinn, and F. M. Utter. 1996. Genetic evidence for the persistence and divergence of native and introduced populations of sockeye salmon (Oncorhynchus nerka) within Lake Washington, WA. Canadian Journal of Fisheries and Aquatic Sciences 53:823-832.

Hodgson, S. and T. P. Quinn. 2002. The timing of adult sockeye salmon migration into fresh water: adaptations by populations to prevailing thermal regimes. Canadian Journal of Zoology 80:542-555.

Killick, S. R. 1955. The chronological order of Fraser River sockeye salmon during migration, spawning and death. International Pacific Salmon Fisheries Commission Bulletin 7:95 pp.

Levy, D. A. and A. D. Cadenhead. 1995. Selective tidal stream transport of adult sockeye salmon (Oncorhynchus nerka) in the Fraser River estuary. Canadian Journal of Fisheries and Aquatic Sciences 52:1-12.

Liscom, K. L. 1973. Sonic tags in sockeye salmon, Oncorhynchus nerka, give travel time through metropolitan water. Marine Fisheries Review 35:38-41.

McCleave, J. D. and R. C. Kleckner. 1982. Selective tidal stream transport in the estuarine migration of glass eels of the American eel (Anguilla rostrata) ICES Journal of Marine Science 40:262-271.

Neville, C. M., S. C. Johnson, T. D. Beacham, T. Whitehouse, J. Tadey, and M. Trudel. 2016. Initial estimates from an integrated study examining the residence period and migration timing of juvenile sockeye salmon from the Fraser River through coastal waters of British Columbia. North Pacific Anadromous Fish Commission Bulletin 6:45-60.

Newell, J. C., K. L. Fresh, and T. P. Quinn. 2007. Arrival patterns and movements of adult sockeye salmon (Oncorhynchus nerka) in Lake Washington: implications for management of an urban fishery. North American Journal of Fisheries Management 27:908-917.

Newell, J. C. and T. P. Quinn. 2005. Behavioral thermoregulation by maturing adult sockeye salmon (Oncorhynchus nerka) in a stratified lake prior to spawning. Canadian Journal of Zoology 83:1232-1239.

Parker, S. J. and J. D. McCleave. 1997. Selective tidal stream transport by American eels during homing movements and estuarine migration. Journal of the Marine Biological Association of the U.K. 77:871-889.

Queiroga, H. 1998. Vertical migration and selective tidal stream transport in the megalopa of the crab Carcinus maenas. Hydrobiologia 375/376:137-149.

Quinn, T. P. 1988. Estimated swimming speeds of migrating adult sockeye salmon. Canadian Journal of Zoology 66:2160-2163.

Quinn, T. P. and J. P. Losee. 2022. Diverse and changing use of the Salish Sea by Pacific salmon, trout, and char. Canadian Journal of Fisheries and Aquatic Sciences 79:1003-1021.

Quinn, T. P., B. A. terHart, and C. Groot. 1989. Migratory orientation and vertical movements of homing adult sockeye salmon, Oncorhynchus nerka, in coastal waters. Animal Behaviour 37:587-599.

Rowe, P. M. and C. E. Epifanio. 1994. Tidal stream transport of weakfish larvae in Delaware Bay, USA. Marine Ecology Progress Series 110:105-114.

Spies, I. B., E. C. Anderson, K. Naish, and P. Bentzen. 2007. Evidence for the existence of a native population of sockeye salmon (Oncorhynchus nerka) and subsequent introgression with introduced populations in a Pacific Northwest watershed. Canadian Journal of Fisheries and Aquatic Sciences 64:1209-1221.

Tillotson, M. D., H. K. Barnett, M. Bhuthimethee, M. E. Koehler, and T. P. Quinn. 2019. Artificial selection on reproductive timing in hatchery salmon drives a phenological shift and potential maladaptation to climate change. Evolutionary Applications 12:1344-1359.