Toxic contaminants are pollutants like polychlorinated biphenyls (PCBs), DDT and other legacy pesticides, current use pesticides, pharmaceuticals (and other consumer products), polycyclic aromatic hydrocarbons (PAHs), trace elements, and polybrominated diphenyl ethers, (PBDEs, or flame retardants).These contaminants can impair water quality, affect aquatic organisms like insects and salmon, and impair environmental and human health.
Because the presence of toxics in the lower Columbia River is a priority issue for the Estuary Partnership, we collaborate with our monitoring partners to assess toxics contaminants in the ecosystem.
Estuary Partnership’s Ecosystem Monitoring Project
In collaboration with USGS and NOAA Fisheries, we sampled for contaminants in water, sediment, and juvenile Chinook salmon in the lower river.
Key Monitoring Products
See our report of 2004-2007 Ecosystem Monitoring Project results, map of sampling sites, and data from this project and the Bi-State Program.
Foundation of the Ecosystem Monitoring Project: The Bi-State Program
The Lower Columbia River Bi-State Water Quality Program (1990-1996) was the first comprehensive, large-scale study of toxics in the lower river.
Development of Three Toxics Models
Models are being developed to identify toxic contaminant sources and describe likely modes and routes of transport (e.g., sediment transport and deposition, trophic processes), potential exposure and uptake, and possible effects on survival and productivity on listed salmon species, based on existing scientific information.
Estuary Partnership’s Ecosystem Monitoring Project
The Estuary Partnership’s Ecosystem Monitoring Project (2004-2007) in collaboration with USGS and NOAA Fisheries sampled for contaminants in water, sediment, and juvenile Chinook salmon in the lower river. This monitoring effort provides a comprehensive picture of how toxics (particularly bioaccumulative ones) are moving through the lower river and food chain and ultimately affecting juvenile salmon.
Key findings from the Ecosystem Monitoring Project included:
- PCBs, PAHs, and PBDEs are widespread in the lower river, both geographically and in the food web.
- Urban and industrial portions of the lower river contribute significantly to contaminants levels in juvenile salmon.
- Juvenile salmon originating from elsewhere in the Columbia Basin (like the Snake River and middle and upper Columbia) are absorbing toxic contaminants during their time rearing and feeding in the lower Columbia River.
- Juvenile salmon are accumulating DDT in their tissue and are exposed to estrogen-like compounds in the lower river (likely associated with pharmaceuticals and personal care products).
- Concentrations of the trace element copper were present at levels that could interfere with crucial salmon behaviors (like imprinting, homing, schooling, predator detection, predator avoidance) and spawning.
- The most frequently detected pesticides in water were atrazine, simazine, and metolachlor, which are suspected hormone disruptors.
Key Monitoring Products
See our Lower Columbia River and Estuary Ecosystem Monitoring Project: Water Quality and Salmon Sampling Report for more details on the study, including a discussion of the contaminants, sampling methods, and next steps for addressing toxics in the lower river. Report hard copies are available from the Estuary Partnership office.
The Estuary Partnership’s Monitoring Map provides locations and key results for our water and salmon monitoring sites.
Compare the Ecosystem Monitoring Project sites with the Bi-State Program sites and view data collected by both programs on the Toxics Monitoring Interactive Map!
Foundation of the Ecosystem Monitoring Project: The Bi-State Program
The Lower Columbia River Bi-State Water Quality Program (1990-1996) was the first comprehensive, large-scale study of toxics and other ecosystem components in the lower river and provided crucial background for the Estuary Partnership’s Ecosystem Monitoring Project.
The Bi-State Program (Tetra Tech, Inc. 1996) found that:
- Dioxins and furans, metals, PCBs, PAHs, and pesticides impair water, sediment, and fish, and wildlife in the lower river.
- Many toxic contaminants are moving up the food chain and accumulating in the bodies of animals that eat fish. Reproductive abnormalities were observed in river otters, some of whom had concentrations of PCBs that exceeded threshold levels. Nesting bald eagles showed signs of accumulating DDE and PCBs at levels high enough to impair reproduction.
- Arsenic, a human carcinogen, exceeded both the US EPA ambient water quality criteria for protection of human health and the US EPA human health advisories for drinking water (Fuhrer et al. 1996).
- Sediment contamination was highest near urban and industrial areas, with contamination in excess of levels of concern for DDE (a breakdown product of DDT), PCBs, dioxins and furans, and PAHs.
- The amount of riparian habitat and tidal swamps and marshes has decreased by as much as 75 percent from historical levels.
- Beneficial uses such as fishing, shellfishing, wildlife, and water sports were impaired.
- Lastly, the Bi-State Program concluded that people who eat fish from the lower Columbia over a long period of time are exposed to health risks from arsenic, PCBs, dioxins and furans, and DDT and its breakdown products (Tetra Tech, Inc. 1996).
Development of Three Toxics Models
Models are being developed to identify toxic contaminant sources and describe likely modes and routes of transport (e.g., sediment transport and deposition, trophic processes), potential exposure and uptake, and possible effects on survival and productivity on listed salmon species, based on existing scientific information. Existing data continues to be reviewed to determine which types of quantitative information are available on contaminant releases, transport and sedimentation processes, relevant salmon life history characteristics, and contaminant concentrations in sediment and biota that could be used for more quantitative assessments. Three models are currently in development:
Conceptual Model of Contaminant and Endangered Salmonid Species Interactions within the Columbia River Estuary
Models of Contaminant Uptake and Bioaccumulation in Juvenile Salmon from the Columbia River Estuary - PCB Case Study
Modeling Impacts of Chemical Contaminant on Salmon Populations in the Columbia River Estuary
Conceptual Model of Contaminant and Endangered Salmonid Species Interactions within the Columbia River Estuary
The Estuary Partnership contracted with NOAA in 2005 to develop three models related to toxics and salmonids in the lower Columbia River and estuary. The Conceptual Model of Contaminant and Endangered Salmonid Species Interactoins within the Columbia River Estuary (conceptual model) will be used in conjunction with GIS layers, as a basis for informed decision making regarding efficient environmental monitoring. The first component of the conceptual model is exposure analysis in which contaminant distribution patterns are combined with the abundance and distributions of listed salmon species to generate an exposure profile for salmon and their habitat that identifies the major contaminants of concern for different populations and ESUs. The second component is ecological response analysis, where the potential effects of contaminants on salmon and their habitat, including the species with which they interact (i.e. predators, pathogens, and prey), are identified. In summary, the conceptual model provides a qualitative description of contaminant exposure and associated risks to listed salmon in the Columbia, and identifies the chemical stressors that salmon encounter throughout their life-histories, the likely sources of exposure, and the physical and biological factors that influence their exposure, and the potential effects of these contaminants on their health and survival. The conceptual model also provides a framework for a quantitative assessment of contaminant exposure levels and responses in salmon, which is being conducted through the contaminant uptake and bioaccumulation and chemical contaminants impacts on salmon population models.
Models of Contaminant Uptake and Bioaccumulation in Juvenile Salmon from the Columbia River Estuary - PCB Case Study
The Estuary Partnership is also funding NOAA’s development of a contaminant uptake and bioaccumulation model, which is building on the work of the conceptual model and is being developed to assist in determining the potential sources of contaminant uptake by juvenile salmon in the lower Columbia River and estuary. This model is utilizing data collected through the Ecosystem Monitoring Project on contaminant concentrations in water, bed and suspended sediments, salmon prey, and juvenile salmon to develop quantitative exposure profiles for the different salmon stocks that utilize the estuary, and to identify major contaminant sources and locations where exposure may occur (e.g., freshwater vs. estuary; hatchery feed vs. prey in the environment). Various uptake mechanisms and scenarios will be explored with the model, and results for bioaccumulative contaminants will be compared to actual contaminant body burdens measured in juvenile salmon from the Columbia to identify the scenarios that best account for exposure patterns observed in the field. For this and the chemical contaminants impacts on salmon populations model (see below), NOAA selected PCBs and copper as the model contaminants since these contaminants are known to be historically present, accumulate in biotic tissues through water column, sediment and dietary exposures, and produce effects in salmonids that are well-characterized. Moreover, they represent two different classes of contaminants in terms of exposure pathways and effects. PCBs accumulate in biotic tissues primarily through sediment and dietary exposures, and effects are associated with long-term exposure. With copper on the other hand, exposure may occur through sediment and dietary pathways, but short-term exposure to copper in the water column is also very important, and associated with acute impacts on olfactory function and behavior. Other contaminants (e.g., DDTs, PAHs, organophosphate pesticides) and mixtures will be considered as data permit.
Modeling Impacts of Chemical Contaminants on Salmon Populations in the Columbia River Estaury
Finally, the Estuary Partnership is contracting with NOAA to develop a Chemical Contaminants Impact Model to provide a quantitative measure of the impact of contaminant exposure on population numbers of salmonids in the Columbia River Basin. Two complementary modeling approaches are being used for this work: a Leslie Matrix-based model that will compare impacts of contaminants on salmon from different populations or ESUs based on average exposure characteristics for the group, and an individually-based model that can capture variability in exposure levels in salmon based on their specific migration patterns and residence time in the estuary. The models will link predicted or measured contaminant body burdens or exposure levels in specific salmon stocks based on field data collected as part of this project to potential adverse health effects in individuals, and model the consequences of those impacts on population growth rates and related parameters associated with stock viability. Information on health impacts of contaminants will be derived from past and current laboratory studies conducted by NOAA and other research groups that explicitly link the dose of a contaminant to specific health outcomes. As noted above, PCBs and copper are the model contaminants to be considered first in these analyses, since their effects in salmonids are well-characterized.
All three of the models will be updated with emerging data during 2007 and the details of each will be provided in the final report of the Estuary Partnership's Ecosystem Monitoring Project available in September 2007. Overall, the models will characterize how contaminants may contribute to the risk of extinction of ESA-listed salmonids. This analysis can then be used to guide potential management actions that could mitigate this risk.