Author: Corey J. SchwankePublisher:
ISBN:
Category : Arctic grayling
Languages : en
Pages : 32
Book Description
Gulkana River Arctic grayling Thymallus arcticus were radiotagged in fall 2016 and tracked for the following 14 months to describe seasonal distributions, migration patterns, and to identify spawning areas. Radio tags were surgically implanted into 126 Arctic grayling ≥320 mm fork length (FL) in a 64.5 river kilometer (rkm) reach of the Gulkana River mainstem from the confluence of the Middle Fork Gulkana River down to a point approximately 5 rkm above Sourdough Creek. A total of 15 aerial tracking surveys were flown from 7 November 2016 through 3 November 2017. Arctic grayling located during tracking surveys exhibited migratory behavior. Fish that survived a full year had a mean home range of 60.9 rkm and 8 fish had home ranges >100 rkm. Migrations for spawning were generally upstream and began in early May. Most fish made post spawning movements upriver to summering locations in June and July, then downstream migrations to overwintering areas starting in August. Several new spawning areas were documented with Stump Creek and the West Fork Gulkana River being the most significant. Radiotagged fish were also present in other smaller unnamed tributaries around the West Fork Gulkana River confluence during the spawning period. Already recognized spawning tributaries such as the Middle Fork Gulkana River, Twelvemile Creek, and Sourdough Creek had radiotagged Arctic grayling in them during the spawning period, but Poplar Grove did not.