Toxic contaminants in embryonic and adult Pacific Herring (Clupea pallasii) from Port Gamble Bay, Washington: extent and magnitude of contamination by polycyclic aromatic hydrocarbons (PAHs) and other toxic contaminants

In this study, we deployed manually spawned herring embryos in Port Gamble Bay to evaluate polycyclic aromatic hydrocarbon (PAH) contamination and the potential related health effects related to exposure of developing herring eggs to PAHs.  We confirmed the suspicion from previous studies that PAHs are the most widespread and abundant of potentially harmful chemicals spawned embryos may encounter in the bay.  In particular, PAHs were measured in greatest concentration in herring embryos from the two Mill Sites and the Former Lease Area, areas which had previously been identified as PAH-contaminated areas.  High PAH levels and the induction of cytochrome P4501A (an enzyme associated with PAH exposure) in some of the embryos from these locations suggests that eggs spawned in these areas face a greater risk of lethal and sublethal effects than eggs spawned elsewhere in Port Gamble Bay.  Although contaminant levels and hatching success were not correlated in this study, herring embryos survived significantly better outside Port Gamble Bay than inside the bay.  Deployment, retrieval, and analysis of the polyethylene membrane devices (PEMDs) were highly successful.  PAH profiles in PEMDs were largely congruent with their co-deployed eggs, with a few exceptions.  The concentration of PAHs in PEMDs correlated well with PAHs in embryos, although PAH concentrations were approximately 30 times greater than embryos.  Further lab-controlled studies are needed to more accurately calibrate this relationship, and evaluate its full potential.  Although some other (non-PAH) chemical contaminants such as PCBs, PBDEs, DDTs, dioxins, and furans occurred in some embryo samples, their levels were largely low enough to conclude lower risk regarding embryo health.  The relative abundance, or fingerprint, of PAHs suggested a pyrogenic or highly weathered petroleum signal.  This is consistent with the putative sources of PAHs in the bay, namely creosote pilings, and a long history of burning wood in the area.  The contaminant levels described herein have provided an in situ, broad-spatial-scale, and real-time observation of the potential chemical exposure naturally spawned herring may experience in Port Gamble Bay.  These results can be used as a baseline for monitoring the success of cleanup or remediation efforts in Port Gamble Bay.