scholarly journals Seasonal changes in habitat suitability for adult shovelnose sturgeon in the lower Mississippi River

2017 ◽  
Vol 35 (1) ◽  
pp. 11-21
Author(s):  
D. A. Hann ◽  
H. L. Schramm
Keyword(s):  
Mississippi River ◽  
Habitat Suitability ◽  
Seasonal Changes ◽  
Shovelnose Sturgeon ◽  
Lower Mississippi River

Age, Growth, and Mortality of Shovelnose Sturgeon in the Lower Mississippi River

1998 ◽  
Vol 18 (3) ◽  
pp. 725-730 ◽  
Author(s):  
James V. Morrow ◽  
James P. Kirk ◽  
K. Jack Killgore ◽  
Steven G. George
Keyword(s):  
Mississippi River ◽  
Shovelnose Sturgeon ◽  
Lower Mississippi River

scholarly journals Entrainment of Endangered Sturgeon by a Large Water Diversion: Rescue, Enumeration, and Conservation Opportunities

2021 ◽  
Author(s):  
Kenneth Jack Killgore ◽  
Jan Jeffrey Hoover ◽  
William Todd Slack ◽  
Steven G. George ◽  
Christopher G. Brantley
Keyword(s):  
Mississippi River ◽  
Total Population ◽  
Water Diversion ◽  
Lake Pontchartrain ◽  
Operational Parameters ◽  
Shovelnose Sturgeon ◽  
Pallid Sturgeon ◽  
Structure Conservation ◽  
Lower Mississippi River ◽  
Large Water

The Bonnet Carre’ Spillway diverts water from the Mississippi River through a floodway into Lake Pontchartrain to reduce river stages at New Orleans and prevent flood damages. Pallid Sturgeon, a federally listed species under the Endangered Species Act, and Shovelnose Sturgeon, listed under the Similarity of Appearance rule, are entrained through the Spillway structure and become trapped in the Spillway canals and other waterbodies. Five openings and corresponding rescue operations occurred between 2008 and 2019 after each Spillway closure. Operational parameters spanned a range of water temperatures and seasons with magnitude and duration of discharge varying across all openings. A total of 70 days with crew number ranging from 6 to 12 were expended to rescue 57 Pallid Sturgeon and 362 Shovelnose Sturgeon after the five openings that spanned 240 total days. More sturgeon were entrained at higher water temperatures, with greater numbers of bays opened, and for longer periods of time. Recovery of sturgeon is initially high but over time declines as sturgeon are depleted from the floodway, stranded in isolated waterbodies in the floodway, and/or displaced further downstream into Lake Pontchartrain during longer openings. Sturgeon that cannot find their way back to the floodway are unlikely to be rescued. Recent population studies indicate that less than 1% of the total population size in the Lower Mississippi River are entrained. However, this does not take into account those individuals entrained but not captured and the potential impacts of more frequent openings of the structure. Conservation recommendations are provided to increase catch efficiency and recovery of the endangered sturgeon.

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