Accession Number : ADA189281

Title :   Mussel Survey, Locks 12, 15, 16, 17, and 19, Mississippi.

Corporate Author : STANLEY CONSULTANTS MUSCATINE IA

PDF Url : ADA189281

Report Date : Nov 1987

Pagination or Media Count : 90

Abstract : A qualitative mussel survey was performed in the Mississippi River upstream of Locks 12, 15, 16, 17 and 19 between August 19 and September 19, 1987 to determine the presence of absence of mussels at each of the five locations. The area surveyed at each site was directly upstream of the primary lock chamber. The survey area extended from the upstream end of the landward lock wall for a distance of 2,000 feet upstream and was bounded by the bank on one side and by a line, 20 feet riverward of the outside lock wall on the other. All survey work was performed by divers using a surface air supply and umbilical cord. Significant concentrations of mussels were found only near Locks 15 and 17. Only scattered individuals were encountered at the remaining three sites. All individuals recovered were identified, recorded and returned to the river. Where beds were encountered, their limits were defined and located, and density measurements performed. No endangered, threatened or rare species were found. Substrates encountered included bedrock, scattered rocks, riprap, gravel, fine and coarse sand, and silt. Keywords: Population surveys.

Descriptors :   *MUSSELS, *POPULATION(MATHEMATICS), AIR, DENSITY, DIVERS, GRAVEL, MEASUREMENT, MISSISSIPPI RIVER, POPULATION, ROCK, SAND, SCATTERING, SILT, SUBSTRATES, SURFACES, SURVEYS, LOCKS(WATERWAYS)

Subject Categories : Biology
      Biological Oceanography

Distribution Statement : APPROVED FOR PUBLIC RELEASE