Master of Science (MS)


Renewable Natural Resources

Document Type



Riverine fisheries management programs often do not focus on non-sport and non-commercial fishes, such as catostomids, yet many suckers have become threatened or endangered throughout river systems in the United States because of habitat alterations. In the Pearl River, sedimentation, dam construction, and other hydrologic modifications have negatively impacted habitats used by southeastern blue suckers Cycleptus meridionalis, a species of concern in both Louisiana and Mississippi. The principal objective of this project was to investigate habitat use of likely historically abundant southeastern blue suckers in the lower Pearl River. During electrofishing surveys in 2010 and 2011, we observed no southeastern blue suckers in the west branch of the Pearl River, and significantly lower catch rates in the main branch of the Pearl River (Mean Catch Per Unit Effort (CPUE) = 0.053/minute) relative to three other common benthic Pearl River fishes, including smallmouth buffalo Ictiobus bubalus (P< 0.0018), channel catfish Ictalurus punctatus (P< 0.0001) and flathead catfish Pylodictus olivaris (P< 0.0017). However, CPUE for southeastern blue suckers was similar to quillback Carpiodes cyprinus (P=0.999) and highfin carpsucker Carpiodes velifer (p=0.999). A mark and recapture population analysis was unable to generate a reasonable population estimate for southeastern blue suckers in this section of the Pearl River. The low CPUE values for other non-buffalo catostomids indicates that the availability of suitable habitat may be limiting populations of benthic suckers in the southern portions of the river. Habitat use of radio-tagged southeastern blue suckers indicated a strong affinity for deeper, outside river bends with accumulations of large woody debris and gravel, with high habitat specificity indicated by extended periods of little movement from these areas. Limited movements suggest a low potential for colonization of new areas or recolonization of abandoned habitats within the river. Raising the threat status for southeastern blue suckers, both globally and in Louisiana, may be warranted given their high habitat specificity, low recolonization potential, and susceptibility to the continuing degradation of their preferred habitats from sedimentation.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

William E. Kelso