Arrival and departure windows of Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) in Chesapeake Bay in Virginia

Atlantic sturgeon (Aci-penser oxyrinchus oxyrinchus) has been listed under the Endangered Species Act since 2012, with the Chesapeake Bay distinct population segment listed as endangered. We tracked the tim-ing of occupancy and movement in Chesapeake Bay of adult Atlantic stur-geon from the York River to best iden-tify when Atlantic sturgeon are likely to interact with anthropogenic threats. We monitored 84 adult (40 male and 44 female) Atlantic sturgeon from August 2013 through January 2020 by using acoustic telemetry. Both spawn-ing and non-spawning fish regularly utilized Chesapeake Bay, with females and males arriving as early as 27 Feb-ruary (when the mean water tempera -ture was 7.7degree celsius) and 4 March (6.5degree celsius) and departing as late as 24 January (6.3degree celsius) and 27 January (6.5degree celsius), respectively. Peak occupation of the bay by Atlan-tic sturgeon occurred from 1 April to 31 August and again from 15 October to 1 December. Females of above average size (>1880 mm in fork length) spent significantly longer in the bay (>113 d) than smaller females and all males before spawning; therefore, the females capable of producing the most eggs were disproportionately exposed to anthro-pogenic threats. Although changes in arrival and departure dates are not sta-tistically significant, during the 7 years of this study, both males and females generally arrived earlier and departed later each year than the previous year, increasing residency in Chesapeake Bay by a month in that time.

Automated summary

This study tracked the occupancy and movement of Atlantic sturgeon in Chesapeake Bay and found that the sturgeon regularly utilized the bay for both spawning and non-spawning periods, with females staying longer. The study also observed that the arrival and departure dates of the sturgeon became earlier and later each year, resulting in a longer residency in Chesapeake Bay by a month.