Toxicity persistence to the nontarget amphipod Hyalella curvispina in runoff events following chlorpyrifos applications to soy experimental plots was compared in conventional and no-till management. Two application scenarios were compared: an early-season application with the soil almost bare and a late-season application after the foliage had attained complete soil cover. H. curvispina was exposed to chlorpyrifos using two different test systems: a short-term (48 h) runoff water exposure and a long-term (10 days) soil exposure. Both commonly used crop management practices for soybean production resulted in runoff toxicity following pesticide applications and represent a toxicity risk for adjacent inland waters. Toxicity persistence was longer after the earlier than the late season application, likely because of higher volatilization and photodecomposition losses from the soy canopy than from the soil. For the early-season application, toxicity persisted longer in the no-till plots than in the conventional tillage plots. Suspended matter was higher in the conventional treatment. Chlorpyrifos sorption to suspended matter likely contributed to the shorter persistence. For the late-season application, toxicity persisted longer in the conventional treatment. The causes remain conjectural. The soil organic carbon content was higher in the no-till treatment. Sorption to organic matter might have contributed to the shorter chlorpyrifos toxicity persistence in no-till management. Late applications are more frequent and prevail longer throughout the soy growing season. Overall, the no-till management practice seems preferably because shorter toxicity persistence in runoff represents a lower environmental risk for the adjacent inland waters.

Within the next five years the manufacture of large quantities of nanomaterials may lead to unintended contamination of terrestrial and aquatic ecosystems 1 . The unique physical, chemical and electronic properties of nanomaterials allow new modes of interaction with environmental systems that can have unexpected impacts 2,3 . Here, we show that gold nanorods can readily pass from the water column to the marine food web in three laboratory-constructed estuarine mesocosms containing sea water, sediment, sea grass, microbes, biofilms, snails, clams, shrimp and fish. A single dose of gold nanorods (65 nm length 3 15 nm diameter) was added to each mesocosm and their distribution in the aqueous and sediment phases monitored over 12 days. Nanorods partitioned between biofilms, sediments, plants, animals and sea water with a recovery of 84.4%. Clams and biofilms accumulated the most nanoparticles on a per mass basis, suggesting that gold nanorods can readily pass from the water column to the marine food web.The transport of contaminants to oceans through estuaries is often mediated by chemical and physical processes associated with mixing fresh water with sea water. As this region is also the habitat for many commercially and ecologically important shellfish and finfish, it could also be a critical point of nanomaterial contaminant entry into the marine food web. For example, salinity gradients, such as those found in tidal mixing zones, typically promote the flocculation and precipitation of organic matter and naturally occurring particulates 4,5 . Organic matter and particulates can be consumed by detritivores or shellfish, and they can also be a sink for anthropogenic material through burial in sediments 6 . At present little is known about the physicochemical behaviour of nanomaterial in the mixing zone, precluding prediction of their eventual environmental distribution. Measurement of nanomaterial distributions in model estuarine systems is a necessary first step towards the evaluation of the effects of nanoparticles on the environment.This study used a series of three replicate estuarine mesocosms as laboratories for measuring the behaviour of nanoparticles in complex environments. These systems are representative of Spartina (cordgrass) dominated estuaries and have been successfully used for estimating the coastal impact of several other contaminants, including atrazine, fipronil, endosulfan and nutrients (Fig. 1) [7][8][9][10] . In this study, three replicates of a complex ecosystem were constructed to model the edge of a tidal marsh creek. The systems were made up from natural, unfiltered sea water from Cherry Point Boat Landing on Wadmalaw Island, South Carolina, USA (salinity determined by conductivity and adjusted to 20‰ by the addition of deionized water) and contained a periodically submerged sediment tray in the primary tank and an attached reservoir for water storage (isolated with a screen) to simulate a tidal cycle [9][10][11] . Sediments were planted with Spartina alterniflora, 100 juvenile Mercenari...

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Benzophenone-2 (BP-2) is an additive to personal-care products and commercial solutions that protects against the damaging effects of ultraviolet light. BP-2 is an "emerging contaminant of concern" that is often released as a pollutant through municipal and boat/ship wastewater discharges and landfill leachates, as well as through residential septic fields and unmanaged cesspits. Although BP-2 may be a contaminant on coral reefs, its environmental toxicity to reefs is unknown. This poses a potential management issue, since BP-2 is a known endocrine disruptor as well as a weak genotoxicant. We examined the effects of BP-2 on the larval form (planula) of the coral, Stylophora pistillata, as well as its toxicity to in vitro coral cells. BP-2 is a photo-toxicant; adverse effects are exacerbated in the light versus in darkness. Whether in darkness or light, BP-2 induced coral planulae to transform from a motile planktonic state to a deformed, sessile condition. Planulae exhibited an increasing rate of coral bleaching in response to increasing concentrations of BP-2. BP-2 is a genotoxicant to corals, exhibiting a strong positive relationship between DNA-AP lesions and increasing BP-2 concentrations. BP-2 exposure in the light induced extensive necrosis in both the epidermis and gastro dermis. In contrast, BP-2 exposure in darkness induced autophagy and autophagic cell death.The LC50 of BP-2 in the light for an 8 and 24 hour exposure was 120 parts per million (ppm) and 165 parts per billion (ppb), respectively. The LC50s for BP-2 in darkness for the same time points were 144 parts per million and 548 parts per billion [corrected].