MBL, WOODS HOLE, MAIn a new study documenting the microbial landscape of New Orleans and Lake Pontchartrain in the wake of Hurricanes Katrina and Rita, scientists report that sediments in interior portions of the city appear to be contaminated with fecal microbes, a chronic condition they say persisted in the area before the hurricanes, and that the resulting water quality in the city and in nearshore waters of the lake continues to be impacted by discharges from this contamination.
According to the study authors, including Marine Biological Laboratory (MBL) Assistant Research Scientist, Dr. Linda Amaral Zettler, while floodwaters pumped from New Orleans back into Lake Ponchartrain following the Hurricanes showed higher-than-normal levels of bacteria and pathogens, fecal indicator microbe and pathogen concentrations in the lake returned to pre-hurricane levels within two months. However, the sediments left behind in the flooded regions of the city appear to contain microbes commonly found in sewage treatment and remain a cause for concern because they may serve as a potential source of ongoing microbial exposure.
The report, which appears this week's Online Early Edition of The Proceedings of the National Academy of Sciences, maintains that further investigation is needed to evaluate the microbial quality of floodwater sediments deposited in the New Orleans area and highly recommends epidemiologic studies to determine whether there is an elevated risk of exposure to human pathogens through contact, ingestion, and inhalation of these sediments.
The study was a collaborative response of several institutions, including the Woods Hole Center for Oceans and Human Health, of which the MBL and Amaral Zettler are a part. The researchers began collecting water and sediment samples from the interior canals and shoreline of New Orleans and the offshore waters of Lake Pontchartrain in October 2005 after the floodwaters had receded. They examin
Contact: Gina Hebert
Marine Biological Laboratory