Scaphirhynchus Conference: Alabama, Pallid, and Shovelnose Sturgeon

St. Louis, Missouri, 11-13 January 2005

22.  HABITAT AND POPULATION ATTRIBUTES OF PALLID STURGEON IN THE LOWER MISSISSIPPI RIVER

K. Jack Killgore*, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, EE-A, Vicksburg, MS 39180-6199; Phone 601-634-3397; Fax 601-634-2398; Jack.Killgore@erdc.usace.army.mil

Jan Jeffrey Hoover, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, EE-A, Vicksburg, MS 39180-6199; Phone 601-634-3996; Fax 601-634-3560; Jan.J.Hoover@erdc.usace.army.mil

Steven G. George, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, EE-A, Vicksburg, MS 39180-6199; Phone 601-634-2897; Fax 601-634-3560; Steven.G.George@erdc.usace.army.mil

Bradley R. Lewis, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, EE-A, Vicksburg, MS 39180-6199; Phone 601-634-3481; Fax 601-634-3560; Bradley.R.Lewis@erdc.usace.army.mil

Catherine E. Murphy, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, EE-A, Vicksburg, MS 39180-6199; Phone 601-634-4233; Fax 601-634-3560; Catherine.E.Murphy@erdc.usace.army.mil

The Corps of Engineers is evaluating life history, habitat, and population attributes of pallid sturgeon (Scaphirhynchus albus) in the lower Mississippi River (LMR), which extends 950 miles from the mouth of the Mississippi River up to the mouth of the Ohio River.  To date, 123 pallid and almost 2,781 shovelnose sturgeons have been captured, tagged and released in the LMR, representing a ratio of pallid:shovelnose sturgeon of 1:23.  Despite low returns, our tagging program has yielded valuable information on sturgeon movements and growth.  A notable recapture was a pallid sturgeon collected near Greenville, MS (RM 527) that had been released into the Mississippi River near New Madrid, MO (RM 889) four years earlier as part of hatchery releases by the Missouri Department of Conservation (MDC).  Pallid sturgeon collected in the LMR ranged in age from 3 to greater than 14 years.  Average age (±SD) of pallid sturgeon vulnerable to trotlines and gill nets was 7 ± 3 years with an average fork length of 709 ±108 mm. Smaller sturgeon (<200 mm) were captured by trawls, but positive identification is pending. Demographic data suggests that pallid sturgeon growth is highly variable among individuals but that annual mortality does not appear to be high.  Habitat studies have been variable, but there are indications that pallid sturgeon prefer steep, sloping banks and dike tips during lower river stages, and flooded sandbars during higher stages. Habitat use, movement, and gear efficiency is correlated to river stage and particularly water temperature. Sturgeon locations have been superimposed on GIS maps of the LMR and a tiered approach to habitat classification (geomorphic, spatial, and structural criteria) is used to identify potential restoration opportunities.