Occurrence and distribution of marine natural organic pollutants: Lipophilic marine algal toxins in the Yellow Sea and the Bohai Sea, China

Abstract For the first time, the composition, concentration and distribution characteristics of typical lipophilic marine algal toxins (LMATs) are investigated in surface seawater, suspended particulate matter (SPM) and sediments from the Yellow Sea and the Bohai Sea, China. Pectenotoxin-2 (PTX2) and okadaic acid (OA) were detected in offshore surface seawater samples ( n  = 67) of the Yellow and Bohai Seas, and PTX2 was found in higher concentrations than OA. The concentrations of PTX2 were between 0.49 and 14.14 ng/L. OA, dinophysistoxin-1(DTX1), PTX2 and gymnodimine (GYM) were detected in the nearshore surface seawater samples ( n  = 20) of the Haizhou Bay of the Yellow Sea. OA concentrations were between 11.47 and 55.85 ng/L. There was a large degree of variation in the concentrations of DTX1, from n  = 13) obtained from the Longdao area of the Bohai Sea mainly contain OA (5.00–24.14 ng/L) and DTX1 (1.52–49.39 ng/L), with PTX2 concentrations being less than the LOQ. Several LMATs were also detected both in the SPM and sediment samples of each study area. In summary, the LMAT composition and concentration levels in the surface seawater found in nearshore samples were substantially different from those of samples from the distant shore, which indicated the obvious regional characteristics of LMATs according to their spatial distribution in the Yellow Sea and the Bohai Sea.