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In the Yangjiang profile, a total of 29 (27 groundwater samples and 2 surface water samples: seawater and aquaculture wastewater) and 32 (29 groundwater samples and 2 surface water samples: seawater and aquaculture wastewater) samples were collected on August 12, 2020 (wet season) and November 8, 2020 (dry season), respectively. The measurement procedures for the trace metals (As, Ba, Cd, Cr, Fe, Mn, Pb, and Zn) in groundwater samples were described elsewhere (Luo et al., 2021). In brief, the samples with high salinity (>1) were first diluted and then analyzed using inductively coupled plasma mass spectrometry (ICP–MS) (Agilent 7900 Series, USA). The detection limits (μg/L) of trace metals were 0.12, 0.20, 0.05, 0.11, 0.82, 0.12, 0.09, and 0.67 for As, Ba, Cd, Cr, Fe, Mn, Pb, and Zn, respectively. A mixed standard solution and two standard reference materials were used to construct the calibration curve and control the analytical quality, respectively. The recoveries of the standard reference materials were 105.4%, 101.7%, 102.6%, 104.0%, and 103.4% for As, Cd, Cr, Pb, and Zn, respectively, indicating that the measured results were within the range of the certified values (Luo et al., 2021). Reagent blanks were determined for each sample analysis and trace metals were undetectable therein.