Demographic information and phthalate metabolite concentrations (µg/L) detected in bottlenose dolphins (Tursiops truncatus) urine sampled from Barataria Bay, LA during 2011-2023 and Sarasota Bay, FL during 2010-2019, 2022-2024

Exposure to phthalate esters has previously been documented in bottlenose dolphins (Tursiops truncatus) inhabiting an urban estuary (Sarasota Bay, FL, USA; 2010-2019). Phthalates are chemicals commonly added to plastic products and consumer goods to enhance qualities such as flexibility, fragrance, and stability. These chemicals are known to leach out of plastic products and into the marine environment, leaving wildlife vulnerable to reproductive, developmental, and metabolic health effects. Environmental phthalate exposure has been shown to vary relative to human activity and urbanization. To evaluate potential differences in dolphin exposure risk, urinary phthalate metabolite concentrations were compared between free-ranging bottlenose dolphins from an urban (Sarasota Bay, FL, USA; 2010-2023; n= 71 ) and rural estuary (Barataria Bay, LA, USA; 2011-2023; n = 45). The magnitude of MEHP detection did not differ significantly between sampling sites (p = 0.97); however, MEHP was detected m..., Each urine sample was screened for seven phthalate metabolites (MEP, MEHP, MEHHP, MEOHP, MBzP, MiBP, and MBP). Urine samples (1 mL) were spiked with isotopically labeled internal standards for each metabolite before proceeding to a glucuronidation step to release monoesters from their conjugated forms (Blount et al., 2000). Following glucuronidation, samples were extracted via SPE (Agilent Bond Elute Nexus) then separated and quantified using high-performance liquid chromatography (HPLC; Agilent 1100; WatersXBridge BEH C18, 2.5 μm, 2.1 x 50 mm analytical column) coupled to a triple quadrupole mass spectrometer (MS; Applied Biosystems Sciex API 4000) with electrospray ionization (ESI negative) interface. Sample integrations were performed using Analyst software (Sciex ver 1.5). Prior to the acquisition of sample data, the instrument was calibrated (standard reference material (SRM) 3060: monoester phthalates in acetonitrile); coefficients of determination (r2) for all metabolites were ≥ ..., , # Demographics and phthalate metabolite concentrations (µg/L) detected in bottlenose dolphins (Tursiops truncatus) urine sampled from Barataria Bay, LA during 2011-2023 and Sarasota Bay, FL during 2010-2024.

[https://doi.org/10.5061/dryad.pc866t20f](https://doi.org/10.5061/dryad.pc866t20f)

## Description of the data and file structure

Bottlenose dolphins (*Tursiops truncatus*)* *sampled for this study were from the Barataria Bay Estuarine System Stock occupying Barataria Basin in Louisiana, and the National Marine Fisheries Service (NMFS) stock that includes dolphins using Sarasota Bay, and Little Sarasota Bay (Tyson and Wells, 2016) in Florida. Catch-and-release health assessments of the dolphins in Barataria Bay, LA were conducted in 2011, 2013-2014, 2017-2019, and 2023, and in Sarasota Bay, FL during 2010-2019, 2022-2024 in which dolphins of interest were encircled by a net and lifted onto a veterinary examination boat where urine and other biological sampling was conducted. Urine..., , **Changes after May 30, 2025:** A value for F155 MEOHP concentration was retained in error. The concentration (when blank corrected), was below the detectable limit, and the file has been updated to reflect the change.