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The objective of this paper is to determine whether contaminant data on mussels and sediments can be used interchangeably, or not, when assessing the degree of anthropogenic contamination of a water body. To obtain adequate coverage of the entire Gulf of Maine, Bay of Fundy sediment samples were collected, analyzed and combined with similar data from four coastal monitoring programs. This required careful interpretation but provided robust results consistent with published literature. A strong correspondence was found between sediment and mussel concentrations for polycyclic aromatic hydrocarbons, moderate to weak correspondence for polychlorinated biphenyls, and except for mercury and zinc, little to no correspondence was found for metals. We conclude that mussel contaminant data are likely sufficient for providing information on the spatial and temporal distribution of chemical contaminants, in coastal waters, under a broad range of environmental conditions and contaminant levels, and unlike sediments, provide direct information on contaminant bioavailability.

We analyzed surface sediments from 23 northeast USA estuaries, from Maine to Delaware, and nine estuaries from Prince Edward Island (PEI, Canada), to determine how dinoflagellate cyst assemblages varied with nutrient loading. Overall the abundance of cysts of heterotrophic dinoflagellates correlates with modeled nitrogen loading, but there were also regional signals. On PEI cysts of Gymnodinium microreticulatum characterized estuaries with high nitrogen loading while the sediments of eutrophic Boston Harbor were characterized by high abundances of Spiniferites spp. In Delaware Bay and the Delaware Inland Bays Polysphaeridium zoharyi correlated with higher temperatures and nutrient loading. This is the first study to document the dinoflagellate cyst eutrophication signal at such a large geographic scale in estuaries, thus confirming their value as indicators of water quality change and anthropogenic impact.

These proceedings contain the abstracts, manuscripts, and posters of presentations given at the Fifth Interagency Conference on Research in the Watersheds—Headwaters to estuaries: advances in watershed science and management, held at the Trident Technical College Conference Center in North Charleston, South Carolina, March 3-5, 2015. The conference was hosted by the USDA Forest Service, Southern Research Station, Center for Forested Wetlands Research.The conference theme was selected to recognize the focus of many natural resource agencies and universities in understanding how ecosystems are connected from interior upland habitats to the estuaries, as land use in the upper portion of watersheds often affect hydrological, ecological, and sociological processes downstream. This theme builds on past ICRW programs held in Arizona, North Carolina, Colorado, and Alaska by delivering a strong southeastern coastal plain theme while maintaining a broad national focus that highlights ongoing interagency research and management initiatives.The conference was structured to focus on key issues faced by managers and scientists throughout the US, with many of these issues having a strong coastal watershed focus. Thematic areas included managing forested wetlands and agricultural catchments, identifying research advances from experimental watersheds, tracking the fate of contaminants through landscapes, advancing restoration ecology of connected ecosystems, and understanding the role of climatic perturbations (e.g., drought, severe storms) on watersheds. In addition, the role that ecosystems play in water use and management was a focal point, including modeling and measuring evapotranspiration associated with land use change.

Seagrasses provide important ecological services that directly or indirectly benefit human well-being and the environment. Excess nitrogen inputs are a major cause of eelgrass loss in the marine environment. Here we describe the results of a study aimed at quantifying the extent of eelgrass as a function of predicted watershed-derived nitrogen loading for small-to-medium-sized shallow estuaries in New England. Findings confirm that reduced extent of eelgrass corresponds to increased loading of nitrogen to this class of estuary. At lower levels of nitrogen loading (≤50 Kg ha−1 yr−1), eelgrass extent is variable and is likely controlled by other ecosystem factors unrelated to water quality. At higher loading rates, eelgrass coverage decreases markedly, with essentially no eelgrass at loading levels ≥100 Kg ha−1 yr−1.

Excess nitrogen inputs to estuaries have been linked to deteriorating water quality and habitat conditions which in turn have direct and indirect impacts on aquatic organisms. This paper describes the application of a previously verified watershed loading model to estimate total nitrogen loading rates and relative source contributions to 74 small-medium sized embayment-type estuaries in southern New England. The study estuaries exhibited a gradient in nitrogen inputs of a factor of over 7000. On an areal basis, the range represented a gradient of approximately a factor of 140. Therefore, all other factors being equal, the study design is sufficient to evaluate ecological effects conceptually tied to excess nitrogen along a nitrogen gradient. In addition to providing total loading inputs rates to the study estuaries, the model provides an estimate of the relative contribution of the nitrogen sources from each watershed to each associated estuary. Cumulative results of this analysis reveal the following source ranking (means): direct atmospheric deposition (37%), ≈wastewater (36%), >indirect atmospheric deposition (16%) > fertilizer (12%). However, for any particular estuary the relative magnitudes of these source types vary dramatically. Together with scientific evidence on symptoms of eutrophication, the results of this paper can be used to develop empirical pressure-state models to determine critical nitrogen loading limits for the protection of estuarine water quality.

Few biogeographic studies of dinoflagellate cysts include the near‐shore estuarine environment. We determine the effect of estuary type, biogeography, and water quality on the spatial distribution of organic‐walled dinoflagellate cysts from the Northeast USA (Maine to Delaware) and Canada (Prince Edward Island). A total of 69 surface sediment samples were collected from 27 estuaries, from sites with surface salinities >20. Dinoflagellate cysts were examined microscopically and compared to environmental parameters using multivariate ordination techniques. The spatial distribution of cyst taxa reflects biogeographic provinces established by other marine organisms, with Cape Cod separating the northern Acadian Province from the southern Virginian Province. Species such as Lingulodinium machaerophorum and Polysphaeridinium zoharyi were found almost exclusively in the Virginian Province, while others such as Dubridinium spp. and Islandinium? cezare were more abundant in the Acadian Province. Tidal range, sea surface temperature (SST), and sea surface salinity (SSS) are statistically significant parameters influencing cyst assemblages. Samples from the same type of estuary cluster together in canonical correspondence analysis when the estuaries are within the same biogeographic province. The large geographic extent of this study, encompassing four main estuary types (riverine, lagoon, coastal embayment, and fjord), allowed us to determine that the type of estuary has an important influence on cyst assemblages. Due to greater seasonal variations in SSTs and SSSs in estuaries compared to the open ocean, cyst assemblages show distinct latitudinal trends. The estuarine context is important for understanding present‐day species distribution, the factors controlling them, and to better predict how they may change in the future.

The United States Environmental Protection Agency (U.S. EPA) and other environmental authorities regulate concentrations of dissolved oxygen (DO) as a measure of nutrient-related eutrophication in estuarine and coastal waters. However, in situ DO concentrations are extremely variable, and their characterization requires an extensive sampling program to provide data over meaningful scales of time and space. In contrast, benthic faunal communities integrate the impacts of low DO over time, and can be rapidly assessed using benthic imaging. The goal of this study was to quantify the relationships between near-bottom dissolved oxygen and measures derived from benthic imaging with a sediment profile camera. We monitored three stations in Narragansett Bay (Rhode Island, USA) for DO and other water quality parameters 15–20 cm above the sediment surface on 15-minute intervals between July and November 2002, and regularly sampled these stations with a sediment profile camera throughout this time period. These soft-sediment stations encompassed several DO environments. We tested for relationships between near-bottom DO and several camera measures, including Nilsson and Rosenberg's Benthic Habitat Quality (BHQ) index, the apparent Redox Potential Discontinuity (aRPD) depth, and various faunal features that can be identified in sediment profile images. Camera measures were examined against a variety of methods of characterizing DO (including mean DO, and the percent of time under various DO thresholds), over a span of time scales from 1 day to 49 days. The best relationship (highest r 2 ) between near-bottom DO and BHQ was found when DO was evaluated as the percent of time under a hypoxic threshold of 2.6 mg l − 1 over a 28-day time scale (by examining DO records over the 28 days preceding each camera deployment). We found that, over several benthic settings, the BHQ index was successful at identifying environments that had experienced relatively high or low DO over the preceding four weeks. Our sediment profile data showed more variability with DO in the intermediate values of BHQ. We conclude that sediment profile camera measures correlate to DO in areas where low DO is the primary stressor, integrate DO over ecologically relevant time scales, and enable sampling over spatial scales that are meaningful for mapping by virtue of rapid deployment and analysis. We submit that sediment profile camera imagery is a useful assessment and mapping tool for environmental managers interested in benthic condition and in first-order quantitative estimates of near-bottom DO regimes in areas where low DO is the primary benthic stressor.

Both surface and core studies from two highly impacted estuaries (New Bedford Harbor, Massachusetts, USA and Halifax Harbour, Nova Scotia, Canada) were carried out to determine if benthic foraminifera could be used to detect changes through time in these areas. New Bedford Harbor is in a highly industrialized area that has undergone severe environmental stresses from a variety of sources for almost 400 years, and has been declared an U.S. Environmental Protection Agency (EPA) Superfund site (i.e., a site so impacted that a special EPA fund is set up to clean it up in designated time frame). Halifax Harbour has been subjected mostly to domestic pollution (i.e., organic carbon produced by human wastes), rather than industrial (chemical) pollution since the founding of the city in 1749. Although many geochemical studies have been done in both estuaries, there are few baseline data on the biota. In this paper we use benthic foraminiferal assemblages retrieved from sediment cores to reconstruct biotic changes of the recent past. It is then possible to correlate faunal changes with already known geochemical parameters. The character of the pollution has changed in New Bedford Harbor as remediation efforts have taken hold. This change was detected with the foraminifera. One outcome is that deformities among one species, Haynesina orbiculare, appear to occur simultaneously with high polychlorinated biphenyls (PCB's) in the sediments. In Halifax Harbour, where the largest impact is due to high organic input from domestic sources, species tolerant of low-oxygen conditions are most prominent at present. Core studies show that prior to the rapid growth of Halifax (in the 1960s) the organic input was much lower than at present. The higher input of organic carbon (OC) at present is indicated by foraminiferal species tolerant of high OC in cores since 1960, generally those with agglutinated as opposed to calcareous tests. We define industrial vs. OC pollution in sediments using foraminifera as proxies, and further, the environmental history is accurately depicted without original baseline data. Data from these two estuaries can be compared to other sites where degradation may be in different stages, which can be assessed by looking at foraminiferal faunas in those areas.

Analysis of the spatial distribution of the dinoflagellate cyst assemblages in 19 surface sediment samples collected from 3 Buzzards Bay (Massachusetts, USA) embayments revealed the potential applicability of dinoflagellate cysts as biological indicators of environmental conditions in estuarine systems. Sites with the highest levels of toxic pollution and hypertrophic conditions are characterized by the lowest dinoflagellate cyst species-richness and concentrations. Among the abi- otic factors influencing the distribution of dinoflagellate cysts, nutrients and toxic pollution are the major controls, as in these embayments salinity and temperature variability is low. Principal compo- nent analysis, based on the proportions of cyst taxa, indicated that cyst assemblages gradually change when moving away from the sources of nutrient pollution, sewage outfalls in particular.

In this study we present a novel comparison of three proxy indicators of paleoproductivity, pigments, biogenic silica (BSi), and cysts of autotrophic dinoflagellates measured in cored sediments from New Bedford Harbor, Massachusetts. In addition to detailed historical reports we use palynological signals of land clearance, changes in the ratio of centric and pennate diatoms, sedimentary organic carbon and stable carbon isotopes to constrain our interpretations. Our study spans the period from prior to European settlement to approximately 1977, during which watersheds were cleared, port development occurred and much of the coastal property became industrialized. The combined effects of nutrient loading from watershed clearance and urban sewage on the estuarine ecosystem shifted not only levels of primary production, but also the nature of the production. Our proxies show that when European colonists first arrived the estuarine production was benthic-dominated, but eventually became pelagic-dominated. Importance of water column production (by diatoms and dinoflagellates) rapidly increased as soil nitrogen was released following forest clearance. Stabilization in rates of forest clearance is reflected as a decline in production. However, population increases in the urbanizing watershed brought new sources of nutrients through direct sewage discharge, apparently again stimulating primary production. We assume that early 20th century changes in sewage discharge and introduction of heavy metals into Harbor waters caused a temporary reduction in primary production. The introduction of a new sewer outfall near the core site and changes in estuarine hydrography due to construction of a hurricane barrier across the mouth of the harbor are reflected by renewed water column production, but decreases in the population of diatoms and dinoflagellates. Fossil pigments suggest renewed water column production in the latest years recorded by our sediment core.

Sediments record the history of contamination to estuaries. Analysis of the concentrations of toxic organic compounds, contaminant and crustal metals, organic carbon content and isotopic composition in sediment cores from two estuarine systems in Buzzards Bay allowed reconstruction of human impacts over 350 years. Vertical distributions of the contaminants correlate with changes in the nature of watershed/estuarine activities. All contaminants were highly enriched (tens to hundreds times background) in modern New Bedford Harbor sediments. Enrichment began around the turn of the 20th century for all but PCBs, which were first synthesized in the 1930s. An increase in organic carbon content and a shift of carbon isotopes toward a more terrestrial signature illustrates increasing anthropogenic impact in New Bedford as population grew along with the industrial base. Institution of environmental protection measures in the late 20th century was reflected in decreased, although still substantially elevated, concentrations of contaminants. A lack of industrial development in Apponagansett Bay resulted in much lower concentrations of the same indicators, although specific contaminants related to the early whaling industry increased significantly above background as early as the late 18th century. The similarity of indicators in older portions of cores from NBH and unimpacted Apponagansett Bay demonstrates that cores can be used to establish reference conditions as successfully as using separate sites judged a priori to represent the reference state. The historical reconstruction approach provides the basis for establishing relationships between environmental stressors and factors that drive the stressors, as well as a framework for the assessment of ecological response(s) to environmental stressors over a range of time and/or exposure scales.

Ecological conditions in the Potomac Estuary are affected by a variety of natural and anthropogenic stressors. Natural climatic factors combined with anthropogenic activities affect fluxes of material through Potomac River watersheds and cause changes in ecological conditions in the Potomac Estuary. A basic premise of this ongoing study is that effects of anthropogenic and natural stressors can be distinguished. The investigation involves: 1) analysis of existing data using time series methods, 2) retrospective modeling to link the response of estuarine water quality to changes in stressors, and 3) new measurements on sediment cores from the Potomac Estuary. Estuarine effects being considered include changes in the distribution and abundance of chlorophyll a, diatoms, dinoflagellates, ostracods, submerged aquatic vegetation, benthic fauna, dissolved oxygen, and foraminifera. Since current conditions may be due to the accumulation of effects over many years, our research considers variability and changes during the past century in the context of long-term changes during the past 500 years. The availability of large data sets from the past century, long-term information on variability in precipitation from tree ring data from the past 300 years, and paleoecological studies by other investigators in the Potomac Estuary and main stem of Chesapeake Bay make the Potomac Estuary an ideal place to develop methods to distinguish between effects of natural and anthropogenic stressors in estuaries, in the context of a varying, and perhaps changing, climate.

The U.S. Environmental Protection Agency has released a report entitled Condition of the Mid-Atlantic Estuaries. That report summarizes the findings of several studies conducted by federal and state agencies and academic institutions in Chesapeake Bay, Delaware Estuary, and the coastal bays of Delaware, Maryland, and Virginia, and simultaneously addresses two distinct audiences: environmental managers and the general public. This paper documents the process of preparing the Estuaries Report, emphasizing the lessons learned in merging information from a wide-variety of sources and in reporting the results to multiple audiences. The major difficulties in preparing the report included: 1) choosing a format and topics that adequately addressed both environmental managers and the public, 2) resolving spatial and temporal disparities in the assembled data sets, and 3) establishing threshold values that distinguished between acceptable and unacceptable conditions in indicators. Our solutions to these challenges and alternatives are discussed. We conclude that a small team of knowledgeable scientists can effectively merge the information of diverse sources into a document that is useful to both environmental managers and the interested public. However, considerable interaction between the team and other scientists was necessary to resolve ambiguities and assure relevancy and accuracy. These findings support the proposition that the vast sources of existing environmental information can be easily and effectively used to assess the ecological condition across large regions.

On 19 January 1996, the barge North Cape spilled more than three million liters of No. 2 fuel oil into Rhode Island Sound near Matunuck, Rhode Island. The toxicity and chemistry of this oil in two subtidal sediments were followed for more than 9 months. Maximum concentrations of polycyclic aromatic hydrocarbons (PAHs) in the sediments reached 730 μg / g dry weight (DW). Water samples taken immediately after the spill were phototoxic to embryos of the bivalve Mulinia lateralis. Total PAHs and toxicity to the amphipod Ampelisca abdita were high immediately after the spill, decreasing to background values ( 10 μg / g DW and

Sediments collected and examined for total aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) were used to assess current inputs, as well as historical trends in Narragansett Bay. The historical trends in contaminants were dominated by three distributions: (a) a subsurface maximum with decreased contaminant levels both to the surface and with depth in the cores; (b) maximum contaminant concentration at the surface, decreasing with depth; and (c) relatively homogeneous contaminant concentrations with depth. Sedimentation rates ranged from 0.11 to 5.5 cm yr-1 in the Providence River area. From this, three different depositional zones were postulated that approximately correlate with water depth and degree of human impact. The Providence River sediments accumulated organic toxicants at a much greater rate than the remainder of the estuary, comprising nearly 90% of the accumulation, but only about 9% of the surface area. By using a box model, it was establis...

A geochemical study of coprostanol (5β-Cholestan-3β-ol) was undertaken, to examine the transport and fate of a compound of moderate polarity and reactivity in the marine environment, and also because of the interest in coprostanol for use as a sewage tracer. During 1985–86, 20 sites in Narragansett Bay, including the major point sources and rivers discharging into the bay estuary, were sampled at four different times. In addition, surface sediments from 26 stations in the bay were collected. The large number and diversity of samples allowed for an assessment of major inputs of sewage into the bay as well as the recent fate of sewage-derived particles in surface sediments. Results from the study revealed that 50% of the total particulate coprostanol entering the bay was discharged into the Providence River, primarily due to inputs from the wastewater treatment facility (WWTF) at Fields Point, as well as input from the Pawtuxet and Blackstone Rivers. In the lower bay, the Newport WWTF was the largest single source of coprostanol (37% of the total particulate coprostanol) to the bay. Effluent concentrations of coprostanol from secondary WWTFs were consistently lower than those of primary treatment facilities, demonstrating the usefulness of corporstanol as an indicator of treatment plant efficiency. The distribution of coprostanol in waters and surface sediments showed a gradient of decreasing concentration downbay. When coprostanol concentrations in surface sediments were normalized to organic carbon (OC) concentrations, elevated levels were seen only in the Providence River, with a more or less even distribution throughout the rest of the bay. Results also suggest that coprostanol degrades more rapidly in the water column compared to the petroleum hydrocarbons (PHCs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), however, it is relatively stable once it is buried in the sediments. Coprostanol concentrations in waters (0·02–0·22 μg 1 −1 ) and surface sediments (0·22–33 μg g −1 ) were as high or higher than values reported in the literature, indicating that the estuary is impacted by sewage.

The major rivers and municipal treatment facilities that discharge directly into Narragansett Bay have been surveyed to determine the amount of PCBs associated with their discharges under dry weather conditions. The Blackstone River, which empties into the northernmost sector of the bay system, was the largest source of riverine PCBs, contributing ∼ 70% of the 12 kg of Ar 1254 transported by the evaluated rivers per year. An additional 2.5 kg, annually, may be coming from freshwater inputs not explicitly measured in this study, giving a total fluvial input of ∼ 14 kg Ar 1254 per year. A single wastewater treatment facility, the Fields Point plant, which also discharges into the northern sector of the bay, contributed 70% of the 5.9 kg year−1 of Ar 1254 attributable to municipal inputs. Therefore, an estimated 20 kg of particulate Ar 1254 enters the bay, annually, from these sources, under dry weather conditions. Ar 1254 inputs represented ∼ 70% of the total Aroclors present in the samples (i.e., Ar 1242, Ar 1254, and Ar 1260). Of note was the almost exclusive presence of decachlorobiphenyl in the river samples.

The dinoflagellate cyst records in sediments from New Bedford Harbor and Apponagansett Bay demonstrate sensitivity to environmental change caused by human activity in the watersheds over the last 500 years. Changes in the species richness, as well as absolute and relative abundance of dinoflagellate cyst taxa reflect recent periods of development around the estuaries. Cyst taxa sensitive to these changes include Dubridinium spp., Polykrikos schwartzii, Lingulodinium machaerophorum, Operculodinium israelianum and Selenopemphix quanta. The greatest changes in the dinoflagellate cyst record occur during the 20th century, when New Bedford Harbor was exposed to both toxic pollution and heavy nutrient loading from point and non-point sources. Apponagansett Bay was not subject to industrial pollution and nutrient enrichment has been lower (from non-point sources). In Apponagansett Bay there is an increase in the dinoflagellate cyst species richness while species richness first increased, then declined in New Bedford Harbor. During the same period, the total dinoflagellate cyst concentration in New Bedford Harbor fluctuated over a wide range. The decline of species richness and the large fluctuations in the total cyst abundances signal the intensified anthropogenic disturbance in the watershed, notably a high degree of eutrophication and toxic pollution.

The U.S. EPA has prepared a State of the Region Report for Mid-Atlantic Estuaries to increase knowledge of environmental condition for improved environmental management. Sources of information included the National Estuary Programs, the Chesapeake Bay Program, the state monitoring programs in Delaware, Maryland, and Virginia, Federal programs such as National Status & Trends, National Shellfish Register, National Wetlands Inventory, the Environmental Monitoring and Assessment Program, and other primary literature sources. The state of the estuarine environment was summarized using indicators for water and sediment quality, habitat change, condition of living resources, and aesthetic quality. Each indicator was briefly discussed relative to its importance in understanding estuarine condition. Wherever possible, data from multiple programs were used to depict condition. Finally, an overall evaluation of estuarine condition in the region was determined. The usefulness of monitoring programs that collect consistent information with a well-defined sampling design cannot be overemphasized.

The resuspension - deposition continuum plays a significant part in the distribution of fine grained sediments and associated organic pollutants in aquatic systems. The chemistry of resuspension was investigated during a year long study by submitting a variety of sediments, including relatively contaminated homogenized dredge spoils and moderately contaminated stratigraphically intact sediments, to artificial resuspension using a particle entrainment simulator. Fine grained sediments were entrained into the test cylinder under conditions that are similar to the resuspension energy that would be expected in a typical estuary. Samples of the resuspended material were collected under a variety of experimental conditions, for the evaluation of organic contaminants such as polycyclic aromatic hydrocarbons (typically associated with oil pollution as well as petrogenically derived) and PCBs (a mixture of toxic organic constituents associated with industrial pollution) as well as for geotechnical parameters such as grain size and particle number and organic carbon content. Results thus far indicate that the volume weighted resuspended sediment load is proportional to the shear stress energy applied for any given core. Moreover, each core has a relatively characteristic erodibility pattern, apparently depending upon the distinctive characteristics of the sediment, for example, grain size composition, biological density, homogeneity, etc. Resuspension, deposition, organic contaminants, PES, hydrocarbons Poly chlorinated biphenols, estuaries, fine sediments, shear stress energy, erodibility.

In an effort to provide a better understanding of the sources of petroleum hydrocarbons in urban runoff, petroleum products as well as probable source materials were analyzed for hydrocarbons and trace metals and then compared to urban runoff samples from four different land use areas. The petroleum products considered were No. 2 and No. 6 fuel oils, used and virgin crankcase oils, and gasoline. Source materials included street dust, roadside soil, roadside vegetation, and atmospheric fallout; and the land use categories were commercial, residential, interstate highway, and industrial areas. The samples were compared on the basis of hydrocarbon (saturated and aromatic) and trace metal (Cd, Pb, Mn, Cu, Fe, Zn) loadings and distributions. Results indicated that the hydrocarbon content in runoff at all four land use sites originated primarily from used crankcase oil, with a small amount of No. 2 fuel oil detected at the industrial site. Only a small portion of the crankcase oil component came from the sources surveyed, and the majority of this oil probably came from: (1) oil drops within the driving lanes on the road surfaces or deposits in parking areas, and/or (2) direct dumping of waste crankcase oil down storm drains.

The temporal variability of hydrocarbon inputs from rivers discharging into Narragansett Bay under dry weather conditions, as well as the elucidation of the types and sources of hydrocarbons found in urban rivers, has been investigated. The rivers studied, the Blackstone, the Pawtuxet, the Moshassuck, and the Woonasquatucket, constitute the majority of river flow to the estuary. The unfiltered river water samples were extracted and analyzed for total aliphatic hydrocarbons, including natural and petroleum-derived species. The results of the year-long study revealed consistent oil pollution in all of the rivers sampled. Crankcase oil was ubiquitous, but the presence as well of fuel oils and, particularly in the Moshassuck River, gasoline (or kerosene), demonstrate that these rivers are subject to considerable oil pollution stress. The average concentration of hydrocarbons was ≈37 μg l−1 which, according to some toxicologists, indicates that sensitive organisms may be under stress. In addition, most samples showed evidence of small amounts of terrigenous plant wax hydrocarbons. Hydrocarbon concentrations are comparable to those in other urban rivers but are higher than in rivers from rural areas; moreover, they did not vary in any systematic way with season. The mass transport of hydrocarbons in each of the rivers generally mimicked trends in river discharge, thereby emitting the lowest mass to the estuary in the summer and increasing throughout the remainder of the year. Moreover, due primarily to relative discharge differences, the Blackstone and Pawtuxet rivers constitute 90% of the total calculated flux of hydrocarbons from all four rivers. By combining the results from this investigation with those from previous studies, it was possible to obtain an estimate of the total annual inputs of these contaminants to Narragansett Bay. Total annual loads from rivers and wastewater treatment facilities were approximately 240 mt. When sources such as wet weather inputs were included, the total increased to 420 mt yr−1. This value represents direct current inputs to the system and is considerably lower than previously published estimates. The current direct input estimate, while indicative of an improving situation, differs from previous estimates in that the latter were based upon calculations that approximated the long-term loadings from the watersheds, most of which are likely accumulating above the fall-lines of rivers throughout the watershed. Nevertheless, the current loadings represent a significant chronic flux of hydrocarbons to Narragansett Bay. For example, this estimate indicates that an amount equal to approximately 43% of the oil discharged into Narragansett Bay from the recent World Prodigy oil spill enters the estuary from chronic sources every year.

This text contains techniques for chemical and biological monitoring of estuaries and coastal waters, which have been applied successfully in field stations. The detection of man-made effects upon estuarine and coastal waters, caused by, for example, organic and inorganic pollutants and sedimentation, are discussed, and their effects on different forms illustrated. Each chapter considers a specific area of monitoring and presents a review of techniques currently in use. World-wide case studies illustrate the use of the technique in practical situations.

To compile an oil pollution budget for Narragansett Bay, Rhode Island, urban runoff samples were collected at four storm drains each serving a different land use. Three to six storm events with different rainfall amounts were monitored at each drain, and the samples were analyzed for petroleum hydrocarbons using glass capillary gas chromatography. The hydrocarbon (HC) load for each storm (mass HC/area) varied systematically with total rainfall, and the storm event load–rainfall relationship was different for each land use. Using rainfall records, the load for each storm was calculated and then summed to predict an annual input rate of hydrocarbons to receiving waters in terms of mass HC/area for each land use. Industrial and interstate highway land gave the highest loads followed by commercial and residential land, respectively. Finally, an estimate of the total hydrocarbon annual input to Narragansett Bay via urban runoff was compiled using land use data from cities and towns in the drainage basin.

Storm generated runoff pollution in urban areas is a significant problem for water quality planners. Previous studies have characterized the inorganic and organic constituents in urban runoff, and it was shown that many of these pollutants are susceptible to quiescent settling and removal from the water column. Detention basins, either natural or manmade, are comparatively inexpensive management practices for the control of urban runoff pollution. The present study assessed a detention basin for its effectiveness in treating petroleum hydrocarbons, polycyclic aromatic hydrocarbons and suspended solids from runoff at a shopping center parking lot.

A mesocosm experiment to assess the fate and effects of sewage sludge in the coastal marine environment was conducted over 4 mo during the summer of 1984 with 9 different treatments of sewage sludge and nutrient addtions. Evidence from setthng rate studes, accumulahons of carbon and pollutant organics and rahos of in the sediment indicated up to 83 O/O of the sludge particulate inputs settled to the bottom and up to 51 % accumulated there. While no toxicity due to organics or metals was apparent, prolonged hypoxia and even anoxia occurred in upper treatment levels. At summer temperatures, sludge particulate inputs in excess of 1 g C m-2 d-' caused these hypoxic conditions. In contrast to low primary production in low and medium sludge treatments during the last 2 mo of the experiment, the highest sludge treatment had high production. We attribute these patterns to excessive grazing pressure from zooplankton and benthlc fauna in the lower 2 treatments and hypoxia-retarded grazing in the upper treatment. In the upper treatments, peaks of produchon stimulated peaks of excessive respiration suggesting that respiration of sludge particulates was enhanced or CO-metabolized with the production of fresh organic material.

The Pawtuxet River flows from a relatively rural area through some of the more highly industrialized sections of Rhode Island. During its journey, the river receives many municipal, industrial, and ground water sources of metal constituents. The present report is the first in a two part series in which the water quality of this urban river was evaluated by a chemical monitoring study of the sources, transport mechanisms, and fate of cadmium, chromium, copper, lead, and nickel in the river. The second paper will use the chemical data to derive and calibrate a steady-state water quality model for this river. The metal concentrations In the river tended to increase from the headwaters to the mouth with river stations nearest to point source outfalls showing elevated values. In some sections of the river, levels of a few of the metals could not be explained by the point sources; and other inputs, including sediment resuspension, axe proposed to make up this apparent unbalance. The ability of a municipal secondary treatment plant to remove metals was demonstrated, and the tie-in of the effluent from a major chemical company to the plant did not cause any observable deterioration in treatment efficiency.

During four rain events, stormwater runoff samples from Interstate Highway 95 in Rhode Island were collected and analyzed for petroleum hydrocarbons, 14 polycyclic aromatic hydrocarbons (PAHs) and a variety of trace metals. The concentrations were variable throughout the storm events and some of the components responded similarly and others differently depending on the source and form of the component in the runoff. Loading factors as a function of area and traffic volume were developed from the concentration and flow data. Application of the highway runoff loading factors to the Pawtuxet River adjacent to this interstate highway suggests that highway runoff could be the source of over 50% of the annual pollutant loads of solids, PAHs, Pb, and Zn entering this river. It is recommended that highways as a source of non-point pollution to receiving waterbodies should be included as a part of any river and estuarine water quality management planning exercise.