Comparative impacts of two major hurricane seasons on the Neuse River and western Pamlico Sound ecosystems

Abstract

Ecosystem-level impacts of two hurricane seasons were compared several years after the storms in the largest lagoonal estuary in the U.S., the Albemarle-Pamlico Estuarine System. A segmented linear regression flow model was developed to compare mass-water transport and nutrient loadings to a major artery, the Neuse River Estuary (NRE), and to estimate mean annual versus storm-related volume delivery to the NRE and Pamlico Sound. Significantly less water volume was delivered by Hurricane Fran (1996), but massive fish kills occurred in association with severe dissolved oxygen deficits and high contaminant loadings (total nitrogen, total phosphorus, suspended solids, and fecal bacteria). The high water volume of the second hurricane season (Hurricanes Dennis, Floyd, and Irene in 1999) delivered generally comparable but more dilute contaminant loads, and no major fish kills were reported. There were no discernable long-term adverse impacts on water quality. Populations of undesirable organisms, such as toxic dinoflagellates, were displaced down-estuary to habitats less conducive for growth. The response of fisheries was species-dependent: there was no apparent impact of the hurricanes on commercial landings of bivalve molluscs or shrimp. In contrast, interacting effects of hurricane floodwaters in 1999 and intensive fishing pressure led to striking reductions in blue crabs. Overall, the data support the premise that, in shallow estuaries frequently disturbed by hurricanes, there can be relatively rapid recovery in water quality and biota, and benefit from the scouring activity of these storms.estuaries ͉ fisheries ͉ resilience ͉ volume delivery ͉ water quality

Ecosystem Responses to Extreme Natural Events: Impacts of Three Sequential Hurricanes in Fall 1999 on Sediment Quality and Condition of Benthic Fauna in the Neuse River Estuary, North Carolina

“…Approximately 17,000 km 2 were inundated by Hurricane Floyd floodwaters, resulting in the drowning of over two million poultry livestock and 30,000 hogs, as well as damage to or failure of animal-waste lagoons, croplands, dams, and wastewater treatment systems (Bales, 2003). The influx of freshwater into the NRE caused vertical stratification and periods of bottom-water hypoxia in parts of the estuary for several weeks (Burkholder et al, 2004;Paerl et al, 2001;ModMon, 2004).…”

“…Burkholder et al (2004) also assessed comparative impacts of these hurricanes relative to those of Hurricane Fran (1996) on water quality and commercial fisheries in the Neuse River and western Pamlico Sound. To our knowledge, no prior studies have investigated potential effects of the 1999 hurricanes on benthic fauna and sediment quality.…”

Comprehensive trend analysis of nutrients and related variables in a large eutrophic estuary: A decadal study of anthropogenic and climatic influences

“…Moderate to high precipitation has also led to bypassing of raw sewage from municipal wastewater treatment plants (WWTPs); flooding of WWTPs in the aftermath of Hurricanes Fran (1996) and Floyd (1999) led to sustained treatment bypasses and the release of large amounts of raw sewage for weeks following the storms (Bales 2003). Although such major storms can cause acute short-term adverse effects on estuarine systems, they can also function beneficially in system flushing and renewal (Bales 2003;Burkholder et al 2004). …”

The effect of Hurricane Katrina on the mussel assemblage of the Pearl River, Louisiana

“…Effects on the benthos are less clear, and benthic production often recovers quickly after hurricanes (Burkholder et al 2004;Cebrain et al 2007). The effects of hurricane disturbances on unionid mussel assemblages occurring in coastal plain rivers have not as yet been studied.…”