Arctic Grayling were collected at designated stations on the Oksrukuyik from 1990 to current time. Phosphorus addition has occurred from 1991 to 1996; station sites are relative distance from the original 1991 dripper. Grayling were caught, pit tagged, weighed, measured, and then released back into the river.
Adult Arctic Grayling were caught and tagged in the Kuparuk River. A second fishing campaign occurred later in the summer, and any fish that was recaptured was remeasured to determine growth. Phosphorus addition has occurred since 1983; station sites are relative distance from the original 1983 phosphorus dripper. Stations include sites in a reference, recovery, and fertilized reach. Reaches were defined based on the location of phosphorous addition (see methods). Arctic Grayling were caught early in the field season, tagged, and recaptured late in the field season.