Key Findings and Next Steps
During Phase 1 contaminants of concern were measured in samples along the B.C. coast. Phase 2 will expand the project’s spatial coverage and continue to lay the foundation for a coast-wide temporal trend analysis.
Phase 1 of PollutionTracker provides a high quality coast-wide baseline dataset. The pollutants detected in Phase 1 samples are a reflection of a variety of sources, including local urban and industrial inputs to the marine environment (e.g., wastewater and effluent discharges, road run-off, stormwater inputs, shipping activities, pesticide use), external inputs (e.g., contaminants carried from other places via oceanic and atmospheric transport), and oceanographic factors (e.g., currents, water depth, bottom substrate). More detailed assessments of contaminant sources and distributions (e.g., hydrocarbon fingerprinting analysis) will be conducted in the months to come.
PollutionTracker was designed to determine the relative state of pollution in coastal B.C., but not to determine the specific risks to human health. Customized risk assessments conducted by health authorities are required to determine the safety of seafood consumption. A pollution-free coastal environment is important to wildlife and people who rely on seafoods. Ongoing PollutionTracker monitoring in coastal B.C. will help inform human health risk studies by identifying hotspots, the presence of contaminants of concern, and trends over time. The relative importance of seafoods to coastal indigenous communities highlights the relevance and timeliness of PollutionTracker as a monitoring framework in support of mitigation and source control.
Polychlorinated biphenyls (PCBs) were detected in all sediment and mussel samples, with the highest levels found in industrialized and port areas. In some locations, PCB levels in sediment were above the environmental quality guideline protective of marine benthic invertebrates. The highest coast-wide levels of PCBs in sediment and mussels were found in Victoria Harbour, reflecting historical activities and discharges to the marine environment, as well as a vulnerable receiving environment. Given that British Columbia’s killer whales are among the most PCB-contaminated marine mammals in the world, it is important that we give further attention to PCBs in their ocean habitat.
Dioxins/furans (PCDD/Fs) were detected in all sediment and mussel samples, with the highest levels found in industrialized and port areas. The highest coast-wide levels of PCDD/Fs in sediment were found in Victoria Harbour. In some locations, dioxin/furan levels in sediment were above the environmental quality guideline protective of marine benthic invertebrates. In mussels, levels were relatively high in Victoria Harbour and Burrard Inlet, as well as in Howe Sound and Fraser River estuary samples, possibly due to past pulp mill discharges in and near these areas.
Polycyclic aromatic hydrocarbons (PAHs) were detected in all sediment and mussel samples. PAH levels were highest in industrialized and urban areas, reflecting the multitude of PAH sources in these areas. Levels were relatively high in both sediment and mussels collected from Prince Rupert Harbour and Victoria Harbour, and in mussels from Howe Sound, Patricia Bay, and Fulford Harbour. Additional fingerprinting analysis of PAH data will establish a valuable baseline and help distinguish between different sources.
Polybrominated diphenylethers (PBDEs) were detected in all sediment and mussel samples. PBDE levels were highest in industrialized and port areas (Prince Rupert Harbour and Victoria Harbour). Levels were also relatively high in mussels collected from less industrialized areas of the coast (Dixon Island, Indian Arm, and Howe Sound), reflecting the tendency of PBDEs to bioaccumulate in marine foods webs.
Tetrabromobisphenol A (TBBPA) was not detected in mussels, and was detected in only one sediment sample collected from Victoria Harbour. These results suggest that despite its widespread use, TBBPA is not found in appreciable quantities in sediment or mussels.
Hexabromocyclododecane (HBCD) was detected in a handful of sediment and mussel samples along the coast, with some of the highest levels in industrialized and port areas (Prince Rupert Harbour, Victoria Harbour, and Burrard Inlet). These results suggest that this flame retardant is generally localized around urban areas where it is likely to be used in the construction and materials sectors.
Metals (Cadmium, Lead, Mercury)
Cadmium, lead, and mercury were detected in all sediment and mussel samples. Levels measured in many sediment samples exceeded environmental quality guidelines protective of marine benthic invertebrates.
- Cadmium levels in sediment from Prince Rupert, and two locations in Haida Gwaii (Bischof Islands and Haswell Bay) exceeded the probable effects level for marine benthic invertebrates, the level above which adverse effects are likely. Cadmium concentrations in mussels were comparable coast-wide, with the highest concentrations measured in Haida Gwaii (Wiah Point, Bischof Islands, Haswell Bay). This may reflect a wide geological (natural) source of this metal, rather than human activities.
- Lead levels were highest in sediment and mussels collected from Prince Rupert and Victoria Harbour. This may reflect historical localized urban and industrial activities.
- Mercury levels in sediment from the Strait of Georgia, Howe Sound, Burrard Inlet, Fraser River, and Victoria Harbour were above the probable effects level for benthic marine invertebrates. In mussels, mercury levels were similar coast-wide. While some of this mercury can be attributed to natural geological sources, human activities both locally (e.g., pulp mills) and internationally (coal-fired generating stations) likely contribute.
Perfluorinated compounds (PFCs) were found in sediment from Burrard Inlet, Victoria Harbour, as well as Haida Gwaii (Armentieres Channel), Howe Sound, and the Fraser River estuary. In mussels, PFCs were only detected in Victoria Harbour. While only detected at a few sites at the time of sampling, the high persistence of PFCs underscores concerns about their effects in the environment and the need to monitor this contaminant class.
Alkylphenols were detected in most sediment samples, with the highest levels reported in Burrard Inlet and Victoria Harbour. In mussels, alkylphenols were detected in all samples, with the highest levels reported in both industrialized and more remote areas. These findings indicate that alkylphenols are released from a large number of sources in coastal British Columbia.
Organotins were only detected in a few sediment samples, with the highest levels in Victoria Harbour. In mussels, organotins were only detected in one sample (Victoria Harbour). These results suggest that while tributyltin (TBT) and other organotins continue to persist in the marine environment, the ban on TBT-based anti-fouling paints implemented in Canada in 2002 has proven largely successful.
Legacy organochlorine pesticides were detected in sediment and mussel samples coast-wide. In sediment, the highest levels were found in Victoria Harbour, Burrard Inlet, and Prince Rupert. In general, dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) were dominant in sediments, and hexachlorobenzene (HCB) was also abundant in Burrard Inlet samples. In mussels, overall levels were more comparable among sites coast-wide, with the highest levels measured in Victoria Harbour. DDT, chlordane, and HCH were dominant at most sites. These results highlight the persistence of organochlorine pesticides in the marine environment long after being banned in Canada, as well as possible new inputs from other parts of the world via atmospheric and oceanic transport.
Current Use Pesticides
Only one or two individual current use pesticides (CUPs) were detected in sediment or mussels at any given site, and concentrations often could not be quantified (these were reported as estimated maximum levels by the laboratory). Different CUPs were detected in sediments versus mussels.
In sediments, CUPs were detected in samples from Haida Gwaii (Armentieres Channel, Bischof Islands), Bella Bella, and southern coastal areas (Howe Sound, Burrard Inlet, Fraser River, Tsawwassen, Saturna Island), but were not detected in Prince Rupert Harbour or Victoria Harbour. Overall CUP levels in sediment were highest in Burrard Inlet and Tsawwassen. Pendimethalin was most common on the south coast, while alachlor was the most widely detected CUP coast-wide. Both are herbicides used to control grasses and broadleaf weeds in crops. Alachlor has been banned in Canada since 1985 but is still one of the most widely used herbicides in the United States.
In mussels, CUP levels were highest in Prince Rupert Harbour and Indian Arm. The herbicide trifluralin was the most widely detected CUP in mussels coast-wide.
Triclocarban, an antibacterial agent used in soaps, was the only pharmaceutical or personal care product detected in sediment and mussel samples. The highest levels of triclocarban were measured in sediment from Prince Rupert Harbour and Victoria Harbour, and triclocarban was also detected in Burrard Inlet, Strait of Georgia, Howe Sound, and Fraser River estuary sediments. Triclocarban was only detected in mussels from Prince Rupert Harbour and Victoria Harbour. Its presence in the coastal environment is troubling because it has been shown to accumulate in marine food webs.
The analysis of microplastics in sediment and mussels is in progress. These results will be reported in early 2018.
Phase 2 of PollutionTracker will launch in early 2018. It will build on Phase 1 results at dedicated PollutionTracker sites, expand the project’s spatial coverage with additional new sites, and continue to lay the foundation for a coast-wide temporal trend analysis.