Fall Spawning of Atlantic Sturgeon in the Roanoke River, North Carolina

Abstract

In 2012, the National Oceanic and Atmospheric Administration (NOAA) declared Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus to be threatened or endangered throughout its range in U.S. waters. Restoration of the subspecies will require much new information, particularly on the location and timing of spawning. We used a combination of acoustic telemetry and sampling with anchored artificial substrates (spawning pads) to detect fall (September–November) spawning in the Roanoke River in North Carolina. This population is included in the Carolina Distinct Population Segment, which was classified by NOAA as endangered. Sampling was done immediately below the first shoals encountered by anadromous fishes, near Weldon. Our collection of 38 eggs during the 21 d that spawning pads were deployed appears to be the first such collection (spring or fall) for wild‐spawned Atlantic Sturgeon eggs. Based on egg development stages, estimated spawning dates were September 17–18 and 18–19 at water temperatures from 25.3°C to 24.3°C and river discharge from 55 to 297 m3/s. These observations about fall spawning and habitat use should aid in protecting critical habitats and planning research on Atlantic Sturgeon spawning in other rivers. Received April 14, 2014; accepted September 9, 2014

Annual Spawning Migrations of Adult Atlantic Sturgeon in the Altamaha River, Georgia

“…Most information regarding the timing of spawning has been obtained from populations at the northern end of the range, where spawning typically occurs from May to August (Bain 1997;Dadswell 2006). In rivers south of the Hudson, however, adults are often observed in riverine habitats during both spring and fall (Smith and Dingley 1984;McCord et al 2007), and there is strong empirical evidence of fall spawning runs in Virginia (Balazik et al 2012), South Carolina , and North Carolina (Smith et al 2015).…”

“…The adhesive eggs are broadcast over hardbottom substrates composed of gravel and cobble (Gilbert 1989;Smith and Clugston 1997;Sulak and Clugston 1998). Previous research, including both laboratory and field studies, suggest that water temperatures of 13-25°C are optimal for egg survival and hatching (Borodin 1925;Smith 1985;Kieffer and Kynard 1993;Hatin et al 2002;Smith et al 2015).…”

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“…In northern populations, spawning occurs in the spring (Bain, 1997), whereas the results of recent studies indicate that at least some central and southern populations spawn in the fall (Hager et al, 2014;Smith et al, 2015;Ingram and Peterson, 2016). During the first several years of life, the young fish, known as river-resident juveniles (RRJs), occupy estuarine habitats near the freshwater-saltwater interface.…”

“…Historically, this species occurred in the rivers and estuaries of the Atlantic Ocean along the North American coast from the St. Lawrence River, Canada, to the St. Johns River, Florida, United States (ASSRT, 2007). Commercial fisheries of both the United States and Canada exploited populations of Atlantic sturgeon throughout much of the 19th and 20th centuries (Smith and Clugston, 1997); however, most of these fisheries collapsed during the early 20th century because of gross overharvesting, industrial development, and damming and pollution of Atlantic coast rivers (Smith and Clugston, 1997;ASSRT, 1998;Secor, 2002;ASSRT, 2007).…”

Estimating Sturgeon Abundance in the Carolinas Using Side‐Scan Sonar

“…Additionally, presence of adult sturgeon in rivers during summer may be related to fall spawning (Smith et al 1984;Balazik et al 2012;Smith et al 2015).…”