NontargetedBiomonitoring of Halogenated Organic Compoundsin Two Ecotypes of Bottlenose Dolphins (Tursiops truncatus) from the Southern California Bight

摘要

Targeted environmental monitoring reveals contamination by known chemicals, but may exclude potentially pervasive but unknown compounds. Marine mammals are sentinels of persistent and bioaccumulative contaminants due to their longevity and high trophic position. Using nontargeted analysis, we constructed a mass spectral library of 327 persistent and bioaccumulative compounds identified in blubber from two ecotypes of common bottlenose dolphins (Tursiops truncatus) sampled in the Southern California Bight. This library of halogenated organic compounds (HOCs) consisted of 180 anthropogenic contaminants, 41 natural products, 4 with mixed sources, 8 with unknown sources, and 94 with partial structural characterization and unknown sources. The abundance of compounds whose structures could not be fully elucidated highlights the prevalence of undiscovered HOCs accumulating in marine food webs. Eighty-six percent of the identified compounds are not currently monitored, including 133 known anthropogenic chemicals. Compounds related to dichlorodiphenyltrichloroethane (DDT) were the most abundant. Natural products were, in some cases, detected at abundancessimilar to anthropogenic compounds. The profile of naturally occurringHOCs differed between ecotypes, suggesting more abundant offshoresources of these compounds. This nontargeted analytical frameworkprovided a comprehensive list of HOCs that may be characteristic ofthe region, and its application within monitoring surveys may suggestnew chemicals for evaluation.