Sediment and benthic response to wastewater solids in a marine mesocosm

Abstract

zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Wastewater solids were added to a series of marine mesocosms at the Marine Ecosystem Research Laboratory (MERL), University of Rhode Island. There was a range of sludge addition simulating 1, 4, and 8 times the average nitrogen enrichment of Narragansett Bay. Three other mesocosms received inorganic nutrients at similar levels, and three mesocosms were maintained as controls. In systems receiving nutrients or sludge, primary production was initially increased. Respiration of the increased loading in the sludge treatment generally resulted in decreased dissolved oxygen concentrations. In the highest level of sludge treatment, the benthic respiration resulted in anoxic conditions in the fourth month of the experiment. The benthos seemed to be the area primarily affected by wastewater disposal. Species feeding at or near the sediment-water interface showed a strong positive density response to sludge addition because of the increase in available food. Based on the findings of this experiment and comparison with marine areas of wastewater disposal, the condition of the benthic community can be generally defined based on organic loading rates. Organic loading rates less than approximately 0.1 g/m 2 • d C had little effect on the sediment community. Loading rates between 0.1 and 1.0 g/m 2 «d C resulted in an enriched sediment community, while loading over 1.5 g/m 2 -d C produced degraded conditions. The quantification of the relationship between organic loading and benthic response presented here can be useful in evaluating wastewater treatment and disposal options.zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Water Environ. Res., 65, 879 (1993).

Molecular typing of Escherichia coli strains associated with threatened sea ducks and near‐shore marine habitats of south‐west Alaska

“…Escherichia coli strains (n = 13) tested from the water samples belonged to a potentially pathogenic serogroup O8, or were mostly O negative (Table 3). An outfall site may produce enhanced foraging conditions through eutrophication (Maughan and Oviatt, 1993;Grall and Chauvaud, 2002;Macdonald et al, 2003). Relatedness among 58 strains was first determined by enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC PCR), and was found to be 42.4-100%.…”

“…A habitat may represent an ecological trap if it is preferred over another optional habitat, and if there is a difference in measure of fitness or fitness outcome between these habitats (Battin, 2004;Robertson and Hutto, 2006). An outfall site may produce enhanced foraging conditions through eutrophication (Maughan and Oviatt, 1993;Grall and Chauvaud, 2002;Macdonald et al, 2003). Nutrient enrichment may lead to increased benthic biomass and food resources for benthic foragers, such as sea ducks.…”

Organic pollution and its effects: a short-term transplant experiment to assess the ability of biological endpoints to detect change in a soft sediment environment

“…Gray et al 1990, Warwick & Clarke 1991, Ferraro et al 1994, there has also been a call for more experimental studies to test the proposed links between pollutants and changes in faunal assemblages , Keough & Quinn 1991, Gray 1992. To this end, mesocosms have been used as experimental test systems of responses to pollutants, for meiofauna and macrofauna (Oviatt et al 1987, Gray et al 1988, Maughan & Oviatt 1993. Manipulative field studies aimed at detecting links between a putative pollutant and established soft sediment assemblages are rarer; although Morrisey et al (1996) investigated the effect of copper on macroinfaunal assemblages and Eleftheriou (1982) looked at the effects of dosing sediments with sewage sludge.…”

Aquatic sediments

“…Wastewater. Wastewater solids were added to marine mesocosms to evaluate the condition of the benthic community (Maughan and Oviatt, 1993). The quantification of the relationship between organic loading and benthic response presented could be useful in evaluating wastewater treatment and disposal options.…”