Diel activity of Gulf of Mexico sturgeon in a northwest Florida bay

Abstract

In this paper, we assess patterns in activity of Gulf of Mexico sturgeon Acipenser oxyrinchus desotoi over a 24-h period in the Pensacola bay system, Florida. Although seasonal migration of sturgeon is well documented, little information is available pertaining to daily variation in activity. We surgically implanted 58 Gulf sturgeon with acoustic transmitters in the Escambia (n = 26), Yellow (n = 8), Blackwater (n = 12) and Choctawhatchee rivers (n = 12) in June, July, September and October 2005. Gulf sturgeon location was monitored using an array of 56 fixed-station acoustic receivers. The relationship between frequency of Gulf sturgeon observations recorded on all acoustic receivers and time of day for all seasons combined indicated a strong diel activity pattern. Gulf sturgeon were frequently detected at night in all seasons with the exception of summer. Consecutive hourly observations indicated lateral movement of Gulf sturgeon between independent acoustic receivers on 15% of all observations of individuals. The use of an acoustic receiver array not only provides continuous data within a defined area, but also provides insight into nocturnal behavior of Gulf sturgeon not previously identified.

Dispersal and survival of stocked juvenile hatchery-reared Atlantic sturgeon (Acipenser oxyrinchus)

“…The results of the present study indicated that juvenile Atlantic sturgeon were active at night, with a peak around sunset; so the nocturnal migration of A. oxirinchus could be common. Similar diel migration patterns were observed in Gulf sturgeon (A. oxyrinchus desatoi) in the Pensacola bay system in northwest Florida (Wrege et al 2011).…”

Status of scientific knowledge, recovery progress, and future research directions for the Gulf Sturgeon,Acipenser oxyrinchus desotoiVladykov, 1955

“…That is, sturgeon can forage as effectively at night as in the day. Indeed, there is evidence of increased GS foraging activity at night during the winter feeding period (Wrege et al., ).…”

Activity patterns of Gulf Sturgeon (Acipenser oxyrinchus desotoi) in the staging area of the Pascagoula River during fall outmigration

“…The importance of TOD as a predictor of Gulf Sturgeon activity is supported by the total sum of weights among three candidate models and indicated that Gulf Sturgeon were more likely to be captured at night or during the evening crepuscular period. In fact, nocturnal movement of early developing Gulf Sturgeon (Kynard & Parker 2004), adult Gulf Sturgeon (Wrege et al 2011), and 15-day-old Atlantic Sturgeon (Gessner et al 2009) have been observed in field and laboratory studies. Diel changes in movements and activity (diel plasticity) of anadromous fishes may be a common strategy when moving along habitat gradients.…”

“…In fact, nocturnal movement of early developing Gulf Sturgeon (Kynard & Parker ), adult Gulf Sturgeon (Wrege et al. ), and 15‐day‐old Atlantic Sturgeon (Gessner et al. ) have been observed in field and laboratory studies.…”