Prespawning, Spawning, and Postspawning Behavior of Striped Bass in the Miramichi River

Abstract

Acoustic telemetry was used to describe the behavior of individual striped bass Morone saxatilis and their use of the Miramichi River estuary during two consecutive spawning seasons in 2004 and 2005. In both years, prespawning striped bass staged in the lower and middle sections of the Miramichi River estuary downstream from the spawning area. Males and females moved in synchrony from the staging area to the spawning grounds in the Northwest Miramichi River. The dates of arrival at the spawning grounds were similar between sexes in both years, but significantly later (by about a week) in 2005. There were no significant differences in average daily water temperature on the dates of arrival at the spawning grounds for male and female striped bass, but water temperatures on the arrival dates were significantly cooler in 2005. Increases in temperature rather than the absolute temperature was the apparent cue initiating the movements of striped bass onto the spawning grounds. Females occupied the spawning grounds for 12 and 7 d in 2004 and 2005, respectively, significantly less than the approximately 15 d for males in each year. The shorter occupation of the spawning grounds by female striped bass was determined by their significantly earlier departure dates than males. Staging downstream of the spawning area by males and females, rapid ascent by both sexes to the spawning area, and the longer residency of male striped bass on the spawning grounds are important characteristics that must be considered when developing management actions to protect and rebuild the spawning stock of this northern population of striped bass.