"Marine Movements of Dolly Varden in Northern Alaska, Evaluated Using Satellite Telemetry"

In northern Alaska, Dolly Varden char Salvelinus malma is highly valued as a subsistence food and thousands are harvested each year. However, little is known about oceanic dispersal or feeding ecology.  Our research attempts to addresses this knowledge gap, by using pop-up satellite archival tags (PSATs).  We attached 52 PSATs to Dolly Varden in a river in northwestern Alaska, and 41 PSATs to Dolly Varden in or near North Slope drainages, to examine the marine dispersal, behavior and habitat occupancy of this species.  Dolly Varden that went to sea demonstrated both offshore and nearshore dispersal. The offshore type was the first documented northerly and westerly dispersal and occupancy of outer continental shelf areas.  While occupying these areas, tagged Dolly Varden demonstrated affinity for the first five meters of the water column, diel patterns in depth occupancy, and dives of up to 50 m.  During the nearshore dispersal type, Dolly Varden transited in coastal areas, likely returning to their natal rivers to spawn. While in nearshore areas, Dolly Varden occupied shallow waters (< 6 m), including some waters with temperatures below -1ºC. These results demonstrate that PSATs offer an effective method with which to study Dolly Varden ecology in marine waters.