ABSTRACT Increased anthropogenic delivery of nutrients to water bodies, both freshwater and estuarine, has caused detrimental changes in habitat, food web structure, nutrient cycling. Nitrogen‐stable isotopes may be suitable indicators such increased delivery. In this study, we looked at the differences response macrophyte δ 15 N values across different taxonomic groups geographic regions test a stable isotopic method for detecting impacts. Macrophyte with wastewater input water‐column...

Abstract Phototoxicity resulting from photoactivated polycyclic aromatic hydrocarbons (PAHs) has been reported in the literature for a variety of freshwater organisms. The magnitude increase PAH toxicity often exceeds factor 100. In marine environment phototoxicity to organisms not individual or complex mixtures PAHs. this study, larvae and juveniles bivalve, Mulinia lateralis , mysid shrimp, Mysidopsis bahia were exposed known phototoxic PAHs (anthracene, fluoranthene, pyrene), as well...

Stable nitrogen isotope ratios (δ 15 N) were measured in fish, mussel, and sediment samples taken from 17 small freshwater sites to examine food chain length trophic position across affected by differing levels of anthropogenic activity. Both shoreline development fish species composition varied greatly among sites, a range up 11.2‰ was found for the δ N values largemouth bass (Micropterus salmoides). Fish baseline corrected using unionid mussel (Elliptio complanata) values. Predators, such...

Per- and polyfluoroalkyl substances (PFAS) are anthropogenic, globally distributed chemicals. Legacy PFAS, including perfluorooctane sulfonate (PFOS), have been regularly detected in marine fauna but little is known about their current levels or the presence of novel PFAS seabirds. We measured 36 emerging legacy livers from 31 juvenile seabirds Massachusetts Bay, Narragansett Cape Fear River Estuary (CFRE), United States. PFOS was major perfluoroalkyl acid present, making up 58%...

The stable nitrogen isotope ratio in tissue of the ribbed mussel (Geukensia demissa) was investigated as an indicator source inputs to coastal salt marshes. Initially, mussels were fed a diet 15N-enriched algae laboratory determine how (δ15N) changed with time. Steady-state times calculated and found be size dependent, ranging from 206 397 d. This indicated that are long-term integrators δ15N their may reflect marsh. Next, indigenous collected 10 marshes similar hydrology geomorphology...

Abstract New Bedford Harbor (NBH) is a marine Superfund site contaminated with high concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and metals. Experiments were conducted to determine the causal toxic agent(s) in pore waters from sediments amphipods mysid shrimp. Chemical manipulations characterize toxicity revealed that pore-water was organic nature. Fractionation subsequent mass spectral identification peaks fraction indicated PCBs, PAHs,...

The highly productive coastal Mediterranean fishery off the Nile River delta collapsed after completion of Aswan High Dam in 1965. But has been recovering dramatically since mid-1980s, coincident with large increases fertilizer application and sewage discharge Egypt. We use stable isotopes nitrogen (delta(15)N) to demonstrate that 60%-100% current production may be from primary stimulated by nutrients runoff. Although establishment dam put Egypt an ideal position observe impact rapid...

Beaver-created ponds and dams, on the rise in northeastern United States, reshape headwater stream networks from extensive, free-flowing reaches to complexes of ponds, wetlands, connecting streams. We examined seasonal annual rates nitrate transformations three beaver Rhode Island under enriched nitrate-nitrogen (N) conditions through use N mass balance techniques soil core mesocosm incubations. recovered approximately 93% our Of added N, 22 39% was transformed during course incubation....

Stable isotope measurements of nitrogen and carbon (δ15N, δ13C) are often used to characterize estuarine, nearshore, open ocean ecosystems. Reliable information about the spatial distribution base-level stable values, represented by primary producers, is critical interpreting values in these While data generally readily available for estuaries, nearshore coastal waters, ocean, continental shelf less studied. To address this, as a first step towards developing surrogate isotopic signature...

In single bovine adrenal chromaffin cells loaded with fura-2, histamine, angiotensin II (AII) and caffeine elicited large transient increases of intracellular free Ca2+ concentration [( Ca2+]i) in the absence external Ca2+, peak amplitudes averaging 726 +/- 138 (n = 14), 710 102 21) 830 100 nM 30) respectively. A substantial portion agonist-induced rise [Ca2+]i depended on release from caffeine-sensitive stores, as pretreatment diminished subsequent agonist responses by 90-95%. Conversely,...

Over the past 50 years, mean annual water temperature in northeastern U.S. estuaries has increased by approximately 1.2°C, with most of warming recorded winter and early spring. A recent survey synthesis data from four locations Southern Rhode Island led us to hypothesize that this may be amplified shallow (<1 m), nearshore portions these estuaries. While intertidal areas are not typically selected as for long-term monitoring, we compiled published literature, theses, reports suggest...

Southern New England salt marsh vegetation and habitats are changing rapidly in response to sea-level rise. At the same time, fiddler crab ( Uca spp.) distributions have expanded purple Sesarma reticulatum ) grazing on creekbank has increased. Sea-level rise reduced predation pressure drive these populations but most studies focus one species; there is a need for community-level assessments of impacts from multiple species. There also identify additional factors that can affect populations....

We developed models to estimate the soft tissue content of benthic marine invertebrates that are prey for aquatic wildlife. Allometric regression wet weight with shell length 10 species had r 2 values ranging from 0.29 hermit crabs Pagurus longicarpus 0.98 green Carcinus maenas. As a class, bivalves highest (0.84) and crustaceans lowest (0.48). Energy nutrient is also presented species. The energy was in crabs, ranged within 2.20–4.71 kcal g ‐1 dry weight. Fat highly variable (range:...

Colloids have been shown to significantly affect the bioavailability and transport of anthropogenic contaminants in environment. In this study, three phase distributions (i.e., dissolved, colloidal, particulate) approximately 75 PCB congeners were measured a marine sediment core from New Bedford Harbor, MA. These are first report colloid−PCB interactions an environmentally contaminated sediment. <1.2 μm size isolated interstitial waters using reverse-phase chromatography with size-selected...

Abstract The toxicity that contaminated sediments may introduce into the water column has not been measured extensively. In order to quantify this potential toxicity, seawater overlying two uncontaminated and three marine was evaluated in laboratory with sea urchin Arbacia punctulata fertilization test. Concentrations of polychlorinated biphenyls (PCBs) copper, as representative contaminants, were also measured. To characterize sources samples chemically manipulated using reversed‐phase...