Hq40d multiparameter meter

Pore water temperature (PWT), dissolved oxygen (DO), pH, electrical conductivity (EC), and oxidation–reduction potential (ORP) were measured in situ using an HQ40d multiparameter meter (HACH, Loveland, CO, United States). DOC in the water samples was analyzed with an Aurora 1030W TOC Analyzer (OI Analytical, College Station, TX, United States) after filtration with 0.22-μm membrane.

We selected the bacterial species pools from Shidou Reservoir, which is one of largest sources of drinking water in Xiamen, China [34 (link)] and is therefore under governmental protection from pollution originating from household drainages and a nearby dam (Fig. S1). Unlike other contaminated aquatic environments [18 (link), 35 (link), 36 (link)], the concentrations of BPA, BPS, TCS, and TCC in Shidou Reservoir (China) are very low (<1 ng/L), such that the reservoir’s waters provide an ideal system to investigate the influence of persistent micropollutants on an aquatic microbiome. Surface water (100 L) from Shidou Reservoir (24˚41ʹ39ʹʹN, 118˚0ʹ37ʹʹE) was collected at 0.5 m depth on June 1, 2017 (Fig. S1). Temperature, pH, conductivity, dissolved oxygen (DO), and DO saturation, measured in situ using a HACH HQ40d multi-parameter meter (HACH, Loveland, CO, USA), were 29.0 °C, 8.90, 54.4 μs/cm, 8.84 mg/L and 116.7%, respectively. The concentrations of BPA, BPS, TCS, and TCC in the reservoir water were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) (ABI 3200QTRAP, Framingham, MA, USA) with solid-phase extraction and all were <1 ng/L at the time of sampling (details of the measurements are provided below). The collected water was transported from the field to the laboratory within 2 h after sampling.

The water sampling procedures for the surf zone, watershed, groundwater, nearshore, offshore, and WWTP ocean outfall diffuser are described in the SI Methods. Dissolved oxygen, electrical conductivity, and temperature of water samples were recorded in the field using an HQ40d multiparameter meter (Hach, Loveland, OH). The sampling details for watershed sediments, intertidal sands, and nearshore sediments, and the analyses of particle grain sizes, moisture, and total organic content are described in the SI Methods. Total coliform (TC), E. coli (EC) and enterococci (ENT) in water and solid samples were quantified using the IDEXX Quanti-Tray/2000 method, following the manufacturer’s protocols (IDEXX Laboratories, Westbrook, MA), with details in the SI Methods. FIB exceedances were based on California single sample surf zone criteria for TC (10,000 MPN/100 ml), EC (400 MPN/100 ml), and ENT (104 MPN/100 ml) (Sikich et al., 2018 ).