Evaluation of Shortnose Sturgeon Spawning in the Pinopolis Dam Tailrace, South Carolina

Abstract

Fifty egg mats and up to five D‐shaped plankton nets were deployed in the tailrace of Pinopolis Dam at river kilometer 77 on the Cooper River, South Carolina, to evaluate the spawning activity of shortnose sturgeon Acipenser brevirostrum. Spawning times were estimated by back‐calculation based on developmental phase. Eggs were collected on 17 of 21 d sampled continuously from March 4 through March 25, 2002, when water temperatures were 10–16°C. A total of 31 shortnose sturgeon eggs were collected from egg mats. An additional 338 shortnose sturgeon eggs and 1 newly hatched yolk sac larva were collected from plankton nets. A minimum of 20 spawning events occurred in the tailrace during the 2002 spawning season. No relationship between mean daily discharge and spawning date was observed. Shortnose sturgeon spawned more often during the night than at any other time of day independent of generation.

Early Life Stage Mortality Rates of Lake Sturgeon in the Peshtigo River, Wisconsin

“…Eggs naturally deposited on substrate egg mats have been used to locate and describe spawning habitat for many sturgeon species (e.g., Fox et al 2000;Paragamian et al 2001;Duncan et al 2004); however, only a single study has produced estimates of total egg deposition using this sampling gear. Sulak and Clugston (1998) estimated that total deposition of Gulf sturgeon eggs in the Suwannee River, Florida, ranged between 404,600 and 711,000 eggs/spawning event.…”

Delineation of discrete population segments of shortnose sturgeon Acipenser brevirostrum based on mitochondrial DNA control region sequence analysis

“…It is also likely that a remnant population of shortnose sturgeon of Santee River ancestry persisted in the Santee-Cooper Lakes when this occurred. The past decade has witnessed considerable spawning activity immediately below the Pinopolis Dam on the Cooper River (Duncan et al 2004) either by descendants from the original Santee River population that could not gain access to traditional upriver spawning grounds on tributaries of the Santee River, or by migrants from elsewhere.…”

“…Some of these populations continue to flourish (Saint John) while others may be at historically low levels (Merrimack and Cape Fear; Kynard 1997). The difference in status may result from where these dams were situated, i.e., whether they are upriver or downriver from historical spawning locales and in the case of the latter, to the suitability of the habitat below these dams for spawning (Kynard 1997;Duncan et al 2004).…”

“…Spawning activity has been confirmed by the presence of fertilized eggs (Duncan et al 2004), although an almost total absence of larval and juvenile life stages casts doubt on whether reproduction is successful. Both the Santee and Cooper River populations were recommended as individual DPS by the SSRT (NMFS 1998).…”

Modification of a Passive Gear to Sample Paddlefish Eggs in Sandbed Spawning Reaches of the Lower Yellowstone River

“…Artificial substrate mats have proven to be an effective technique for determining the fine-scale location of spawning sites for various sturgeon populations (Marchant and Shutters 1996;Sulak and Clugston 1998;Fox et al 2000;Paragamian et al 2001;Perrin et al 2003;Duncan et al 2004). Similar to paddlefish eggs, the highly adhesive sturgeon eggs sink after they are broadcast by spawning adults.…”