Autumn Migration and Overwintering of Arctic Grayling in Coastal Streams of the Arctic National Wildlife Refuge, Alaska

Abstract

During 1984 and 1985, 67 adult Arctic grayling Thymallus arcticus with surgically implanted radio transmitters were released at their summer feeding areas in three river systems of the Arctic National Wildlife Refuge, Alaska. We tracked the fish from aircraft to determine patterns of autumn migration to overwintering locations. During August or September in each area, fish left the small tundra streams where they were tagged and migrated into larger streams. Migration rates peaked at 5–6 km/d about 1 September and averaged 1 km/d. Fish in two river systems moved into adjacent rivers after passage through estuarine waters. Migration distances from spawning or summer feeding areas to overwintering sites were as great as 101 km. Potential overwintering areas determined from transmitter relocations included deep pools, spring‐fed areas, and lakes. Management problems associated with these extensive seasonal migrations may include the maintenance of the species migratory circuit in a region that may face future development.

Seasonal cues of Arctic grayling movement in a small Arctic stream: the importance of surface water connectivity

“…These observations suggest small stream confluences may serve as a predictable source of late season prey subsidies to fish in larger tundra rivers. The period of spring flooding represents a peak in aquatic connectivity across the ACP, and may be of great importance in facilitating the dispersal of fish from overwintering habitats and the colonization of new habitats (Craig and Poulin 1975;West et al 1992). Floods can increase habitat access to foraging areas (Winemiller and Jepsen 1998), and serve an important role in metapopulation dynamics by facilitating dispersal from source habitats to sink habitats (Schlosser and Angermeier 1995).…”

“…Floods can increase habitat access to foraging areas (Winemiller and Jepsen 1998), and serve an important role in metapopulation dynamics by facilitating dispersal from source habitats to sink habitats (Schlosser and Angermeier 1995). The role of floods in fish ecology is often explored in the context of dryland watersheds and drought conditions (Labbe and Fausch 2000;Falke et al 2012), though the relationship of Arctic fishes to ice is strikingly similar to the relationship of dryland fishes to drought (West et al 1992). The long Arctic winter effectively isolates freshwater fishes into scattered and limited overwintering habitats for up to 9 months, while the thawing of winter ice and associated flooding re-connects these habitats.…”

“…Permafrost soils create extensive surface-water storage in the form of lakes and wetlands, creating a vast mosaic of shallow habitats with changing connectivity as snowmelt drains, the surface active layer above permafrost thaws, and water evaporates (Woo and Winter 1993). Timed with snowmelt and ice breakup, migratory fish move into productive seasonal habitats to forage and spawn (Morris 2003); however, fish must time migrations out of such habitats before freeze-up or low stream flow threaten to leave them isolated in habitats that will eventually freeze (Craig and Poulin 1975;West et al 1992).…”

Distribution and biophysical processes of beaded streams in Arctic permafrost landscapes

“…At least some alluvial streams in the Arctic foothills of Alaska have experienced prolonged periods of no flow over certain reaches during drought conditions when only minimal flow through interstitial gravels disrupt migration of the Arctic grayling (Betts and Kane, 2011). In some instances, individual Arctic graylings have been observed traveling over 160 km within a year visiting different key habitats within a "migratory circuit" (West et al, 1992). Thus, connectivity among spatially separated habitats is critical to this life history strategy, and beaded streams may function in maintaining hydrologic connectivity and fish passage between alluvial rivers, tundra lakes and ponds.…”

Comparative biology and management of Arctic and European grayling (Salmonidae, Thymallus)

“…After local summer readjustment of stream feeding habitats as the territorial young grow larger, many populations have to leave their summer feeding habitats because these may freeze solid, dry up or be subject to severe frazil ice formation. Suitable wintering habitat is reached by refuge migrations of distances varying froma few kilometres up to 160 km (Wilson et al, 1977;Tack, 1980;Hop et al, 1986;West et al, 1992), usually downstream to larger river mainstems but sometimes upstream to particular areas in stream upper reaches. In spring, trophic migrations occur to highly specific, but regionally variable feeding habitats (Tack, 1980;Armstrong, 1986;Fleming, 1991;Ridder, 1991a).…”