Dispersal Patterns and Summer Ocean Distribution of Adult Dolly Varden from the Wulik River, Alaska, Evaluated Using Satellite Telemetry

In northwest Alaska, Dolly Varden charr Salvelinus malma is highly valued as a subsistence fish and local residents harvest thousands of these fish each year. Because the Chukchi Sea is biologically productive in the summer, we hypothesized that Dolly Varden inhabit this sea, including offshore areas, during the summer. Therefore, we attached 52 Pop-up Satellite Archival Transmitting (PSAT) tags to Dolly Varden in the Wulik River, which flows into the Chukchi Sea, to examine their oceanic dispersal and behavior. PSAT tags provided the first evidence of a northwesterly offshore dispersal of Dolly Varden (n=8) to the Russian Chukchi Sea north of the Chukotka Peninsula, demonstrating that some Dolly Varden from northwest Alaska occupy offshore areas of the Chukchi Sea during the summer feeding season. While at sea, they dispersed up to 60 km ·day-1 and frequently occupied relatively shallow water (<15 m). Two of the fish likely occupied this area of the Chukchi Sea for at least 45 days; therefore, we infer that offshore areas of the continental shelf of the Chukchi Sea may be an important feeding area for Dolly Varden. Other dispersal patters are discussed as well.