Diagnosis of potential stressors adversely affecting benthic invertebrate communities in Greenwich Bay, Rhode Island, USA

Abstract

Greenwich Bay is an urbanized embayment of Narragansett Bay potentially impacted by multiple stressors. The present study identified the important stressors affecting Greenwich Bay benthic fauna. First, existing data and information were used to confirm that the waterbody was impaired. Second, the presence of source, stressor, and effect were established. Then linkages between source, stressor, and effect were developed. This allows identification of probable stressors adversely affecting the waterbody. Three pollutant categories were assessed: chemicals, nutrients, and suspended sediments. This weight of evidence approach indicated that Greenwich Bay was primarily impacted by eutrophication-related stressors. The sediments of Greenwich Bay were carbon enriched and low dissolved oxygen concentrations were commonly seen, especially in the western portions of Greenwich Bay. The benthic community was depauperate, as would be expected under oxygen stress. Although our analysis indicated that contaminant loads in Greenwich Bay were at concentrations where adverse effects might be expected, no toxicity was observed, as a result of high levels of organic carbon in these sediments reducing contaminant bioavailability. Our analysis also indicated that suspended sediment impacts were likely nonexistent for much of the Bay. This analysis demonstrates that the diagnostic procedure was useful to organize and assess the potential stressors impacting the ecological well-being of Greenwich Bay. This diagnostic procedure is useful for management of waterbodies impacted by multiple stressors. Environ Toxicol Chem 2017;36:449-462. © 2016 SETAC.

A novel method for assessing microplastic effect in suspension through mixing test and reference materials

“…Many suspension- and filter-feeders frequently face turbid environments with high concentrations of non-caloric materials generated by natural processes, such as terrestrial runoff, currents, and weather-induced bottom sediment resuspension 55 , but also by anthropogenic activities, such as dredging and capping of contaminated sediments using various technologies. In aquatic ecology, conditions with elevated suspended solids are commonly acknowledged as stressful 56 and regulated by water quality standards 21,57 . The quality standards vary across regions and types of aquatic systems, e.g., lotic and lentic, as well as systems with different natural levels of suspended solids.…”

Functional plasticity in oyster gut microbiomes along a eutrophication gradient in an urbanized estuary

“…The head of the Bay, located in a highly urbanized area, is highly eutrophic while trophic levels at the mouth are more similar to those found over the continental shelf [ 12 , 13 ]. Previous studies have shown that eutrophication in the headwaters of Narragansett Bay affects many local communities and ecosystem processes at locations downstream, including nitrification rates [ 14 ], primary productivity [ 15 ], animal physiology, and benthic biodiversity [ 16 , 17 ]. Over the last 20 years, Narragansett Bay has undergone dramatic changes as a result of targeted efforts to reduce nutrient loading, providing a dynamic model for the study of gradients in estuarine eutrophication [ 18 ].…”

Six decades of change in pollution and benthic invertebrate biodiversity in a southern New England estuary

“…Regional factors may be more important than local factors in driving changes at North Jamestown while local pollution factors may be a stronger influence in driving changes at Spar Island. The two sites we used complement studies of benthic community trends in two other impacted areas of upper Narragansett Bay -Greenwich Bay and the Providence and Seekonk Rivers (Calabretta and Oviatt, 2008;Pelletier et al, 2017). Like Mount Hope Bay, Greenwich Bay is another sub-embayment that has shown few signs of ecosystem recovery (Pesch et al, 2012;Pelletier et al, 2017).…”

“…Additionally, the Kruskal-Wallis test indicated that variance of Δ* was influenced by eutrophication (water column chlorophyll a, sediment TOC) and by sediment contaminants. Although correlations do not prove causation, these stressors are known to affect community composition (Jeon and Oviatt, 1991;Snelgrove et al, 2004;Diaz et al, 2008;Tweedley et al, 2015;Hale et al, 2016;MERL, 2017;Pelletier et al, 2017). Although moderate levels of nitrogen and sediment TOC support secondary production, too-high levels can lead to seasonal hypoxia and degraded sediment habitat, as exists in much of the upper third of the bay (Saarman et al, 2008).…”

“…Although moderate levels of nitrogen and sediment TOC support secondary production, too-high levels can lead to seasonal hypoxia and degraded sediment habitat, as exists in much of the upper third of the bay (Saarman et al, 2008). There, eutrophication and hypoxia are strong enough to overcome the effect of sediment grain size on the distribution of benthic animals (Pelletier et a., 2017). Using data from the UK National Marine Monitoring Program of estuaries and coasts, Tweedley et al (2015) found that taxonomic distinctness was unaffected by natural differences between the two environments, but was significantly correlated with heavy metal concentrations in sediments.…”