Anthropogenic markers for source tracking of fecal contamination in Bayou Lafourche: a major drinking water source in Southeast Louisiana, USA

Bayou Lafourche, which is the sole drinking water source for 300,000 people in Louisiana, has failed to consistently meet its designated use criteria set by the Louisiana Department of Environmental Quality (LDEQ). This resulted in a total maximum daily load to be imposed on the Bayou by the Environmental Protection Agency (EPA). These designated use water quality criteria include fecal coliform (FC) levels for drinking water source, primary contact recreation, and secondary contact recreation. The goal of this study was to identify and enumerate anthropogenic nonpoint source FC contamination from malfunctioning home sewage systems in the Bayou's watershed. Thirty-four sites along the Bayou were selected for the study. Samples were analyzed for optical brightener ratios, FC CFU/100 mL (mFC), Escherichia coli, and three human markers, including human polyomavirus BK, the Archaeon Methanobrevibacter smithii, and the human-associated Brevibacterioides HF 183 eubacteria. Frequencies of sites with all three anthropogenic molecular markers are considered positive for human fecal contamination. This study provided data to address the problem of malfunctioning on-site sewage systems in the Bayou Lafourche watershed.

Efficacy of pest control strategies in Louisiana sugar cane: a preliminary survey

SummaryAlthough the first or second clonal cuttings of heat-treated sugar cane were widely used for seed, differences were not detected among crop years or locations in the incidence of ratoon stunting disease. Sugar-cane mosaic virus (SCMV) disease was widespread in all areas surveyed; however, the plant cane crop had a lower incidence of SCMV than the first or the second ratoon crop. The estimated cane yield was increased approximately 19·4 t/ha by heat treatment during the 2-year survey period.The management system used to control the sugar-cane borer (SCB), Diatraea saccharalis (F.), was effective regardless of the crop year or area surveyed. Season-long SCB control was achieved by the use of two (1981) or three (1982) properly timed applications of insecticide and the use of a SCB moderately resistant variety resulting in an average of 6–9% bored sugar-cane internodes.Poor weed management, particularly with johnsongrass (Sorghum halepense(L.) Pers.), accounted for much of the reduction in cane yield (P < 0·01); the estimated yields of the second ratoon crop were substantially altered, particularly those of farms surveyed in the Bayou Lafourche area.