Type 1 Pacific lamprey habitat on the Klickitat River near Glenwood, WA. Type I (preferred) lamprey habitat that consists of a mixed substrate of silt, clay, organic matter, and sand.
Trend and source identification of mercury contamination in Mid-Columbia Basin Pacific lamprey larvae Active
By Washington Water Science Center
September 25, 2023
The Issue:
Mercury contamination and toxicity threaten Pacific lamprey recovery in the Columbia River basin. Methylmercury concentrations in larval Pacific lamprey from tributaries in the mid-Columbia were measured to be as high as 4.0 µg/g wet weight. At these concentration levels, injury is predicted to occur in more than 50% of larval and adult fish and more than 90% of early-life stage fish. An understanding of mercury sources and concentrations in larval lamprey is needed to address the water quality threats identified in the Mid-Columbia 2021 Regional Implementation Plan.
How USGS will help:
This study will use a suite of lamprey tissue and streambed mercury analyses to understand trends and identify potential sources of elevated mercury tissue concentrations in juvenile Pacific lamprey.
Background
Pacific lamprey (Entosphenus tridentatus) is an ecologically and culturally important species throughout western North America. First Nations and Indigenous peoples have harvested the fish for subsistence, medicinal, and ceremonial purposes for thousands of years. Owing to the lamprey's anadromous life history, the fish is an essential source of marine-derived nutrients that drive primary production in their natal freshwater streams, filling an essential ecological niche that supports productive ecosystems.
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While historically abundant, the number of adult Pacific lamprey returning to the Columbia River basin has declined dramatically, concurrent with lamprey declines observed along the West Coast. These declines are primarily attributed to dams and other human-constructed barriers, though other threats, such as exposure to contaminants, may also impact the Pacific lamprey population in the Columbia River basin.
Pacific lampreys are anadromous, spawning and rearing in freshwater habitats and then migrating to the ocean to grow. Most of their life cycle is spent in freshwater, first as larvae and then as adult migrants. The total life span of Pacific Lamprey is 4-13 years, with only up to 3.5 years spent as a marine parasite. Lamprey burrow into sediments and slowly transition to their parasitic juvenile phase during the prolonged microphagous feeding larvae phase. Little is known about potential environmental impacts during this larval stage and the subsequent impacts on outmigration success. Previous work in the Columbia River basin has identified elevated levels of persistent pollutants in both adult and larvae lamprey, including mercury and polychlorinated biphenyls (PCBs).
Problem
Previous work by the Pacific Northwest National Laboratory (PNNL) and the USGS, documented high levels of mercury and methylmercury in Pacific lamprey throughout the Columbia River Basin. The concentrations in larvae were generally higher than returning adults on a per mass basis, suggesting that fish were accumulating mercury after hatching. The USGS and PNNL studies were conducted more than a decade ago. Repeat measurements of tissue concentrations are needed to understand if mercury contamination in lamprey larvae is reducing or increasing. Additionally, the source of these high mercury levels remains to be determined.
Objectives
This project will build on the initial work conducted by the USGS and PNNL by collecting modern data on mercury tissue concentrations in Pacific lamprey larvae to assess potential trends in tissue concentrations. Additionally, the project will attempt to use mercury isotope ratios to understand the relative contribution of different mercury sources to the overall body burden of mercury in lamprey. The additional data collected to apportion sources will also inform mercury concentrations in returning adult lamprey, returning adult salmon, and sediments.
Relevance and Benefits
The study serves a local need to understand better the relationship between sources, processes, and mercury concentrations in Columbia River tributaries. The study will inform the Pacific lamprey mid-Columbia regional management unit's Regional Implementation Plan, which ranked water quality, including contaminants, as a "high threat." Collecting and disseminating new information on contaminants in larval lamprey and tracing their source and mechanism for uptake will provide a much-needed road map for mitigating these impacts and restoring key local subpopulations within the Mid-Columbia subbasins. The adult mercury concentration data also may support future risk assessments related to the human health risk of adult lamprey consumption.
Sources/Usage: Public Domain. View Media Details
Approach
The USGS is partnering with Yakama Nation Fisheries to collect Pacific lamprey larvae from the four stream tributaries to the Columbia River during the summer and fall of 2023. The tributaries include Rock Creek, Wind River, White Salmon River, and up to four locations on the Klickitat River. Sampling will target type I (preferred) lamprey habitat that consists of a mixed substrate of silt, clay, organic matter, and sand. Additionally, Yakama Nation Fisheries staff will organize the collection of adult lamprey and salmon tissue. USGS staff will collect streambed sediments alongside larval lamprey collection on the four Columbia River tributaries.
Tissue and sediment samples will be analyzed at the USGS Mercury Research Laboratory in Madison, WI for total mercury, methylmercury, and isotopic mercury concentrations. Additionally, tissue will be analyzed for stable isotopes to better understand larval diets. The investigation will compare isotopic ratios to known end members, including returning adult spawners, to better understand mercury sourcing and uptake in juvenile lamprey.
Pacific Lamprey Habitat
Type 1 Pacific lamprey habitat on the Klickitat River near Glenwood, WA. Type I (preferred) lamprey habitat that consists of a mixed substrate of silt, clay, organic matter, and sand.
Pacific Lamprey ammocoetes
Pacific Lamprey ammocoetes in a measurement tank. Tissues collected from the lamprey will be analyzed for mercury as part of a study on mercury contamination in the Columbia River Basin.
Pacific Lamprey ammocoetes in a measurement tank. Tissues collected from the lamprey will be analyzed for mercury as part of a study on mercury contamination in the Columbia River Basin.
The Issue:
Mercury contamination and toxicity threaten Pacific lamprey recovery in the Columbia River basin. Methylmercury concentrations in larval Pacific lamprey from tributaries in the mid-Columbia were measured to be as high as 4.0 µg/g wet weight. At these concentration levels, injury is predicted to occur in more than 50% of larval and adult fish and more than 90% of early-life stage fish. An understanding of mercury sources and concentrations in larval lamprey is needed to address the water quality threats identified in the Mid-Columbia 2021 Regional Implementation Plan.
How USGS will help:
This study will use a suite of lamprey tissue and streambed mercury analyses to understand trends and identify potential sources of elevated mercury tissue concentrations in juvenile Pacific lamprey.
Background
Pacific lamprey (Entosphenus tridentatus) is an ecologically and culturally important species throughout western North America. First Nations and Indigenous peoples have harvested the fish for subsistence, medicinal, and ceremonial purposes for thousands of years. Owing to the lamprey's anadromous life history, the fish is an essential source of marine-derived nutrients that drive primary production in their natal freshwater streams, filling an essential ecological niche that supports productive ecosystems.
Sources/Usage: Public Domain. View Media Details
While historically abundant, the number of adult Pacific lamprey returning to the Columbia River basin has declined dramatically, concurrent with lamprey declines observed along the West Coast. These declines are primarily attributed to dams and other human-constructed barriers, though other threats, such as exposure to contaminants, may also impact the Pacific lamprey population in the Columbia River basin.
Pacific lampreys are anadromous, spawning and rearing in freshwater habitats and then migrating to the ocean to grow. Most of their life cycle is spent in freshwater, first as larvae and then as adult migrants. The total life span of Pacific Lamprey is 4-13 years, with only up to 3.5 years spent as a marine parasite. Lamprey burrow into sediments and slowly transition to their parasitic juvenile phase during the prolonged microphagous feeding larvae phase. Little is known about potential environmental impacts during this larval stage and the subsequent impacts on outmigration success. Previous work in the Columbia River basin has identified elevated levels of persistent pollutants in both adult and larvae lamprey, including mercury and polychlorinated biphenyls (PCBs).
Problem
Previous work by the Pacific Northwest National Laboratory (PNNL) and the USGS, documented high levels of mercury and methylmercury in Pacific lamprey throughout the Columbia River Basin. The concentrations in larvae were generally higher than returning adults on a per mass basis, suggesting that fish were accumulating mercury after hatching. The USGS and PNNL studies were conducted more than a decade ago. Repeat measurements of tissue concentrations are needed to understand if mercury contamination in lamprey larvae is reducing or increasing. Additionally, the source of these high mercury levels remains to be determined.
Objectives
This project will build on the initial work conducted by the USGS and PNNL by collecting modern data on mercury tissue concentrations in Pacific lamprey larvae to assess potential trends in tissue concentrations. Additionally, the project will attempt to use mercury isotope ratios to understand the relative contribution of different mercury sources to the overall body burden of mercury in lamprey. The additional data collected to apportion sources will also inform mercury concentrations in returning adult lamprey, returning adult salmon, and sediments.
Relevance and Benefits
The study serves a local need to understand better the relationship between sources, processes, and mercury concentrations in Columbia River tributaries. The study will inform the Pacific lamprey mid-Columbia regional management unit's Regional Implementation Plan, which ranked water quality, including contaminants, as a "high threat." Collecting and disseminating new information on contaminants in larval lamprey and tracing their source and mechanism for uptake will provide a much-needed road map for mitigating these impacts and restoring key local subpopulations within the Mid-Columbia subbasins. The adult mercury concentration data also may support future risk assessments related to the human health risk of adult lamprey consumption.
Sources/Usage: Public Domain. View Media Details
Approach
The USGS is partnering with Yakama Nation Fisheries to collect Pacific lamprey larvae from the four stream tributaries to the Columbia River during the summer and fall of 2023. The tributaries include Rock Creek, Wind River, White Salmon River, and up to four locations on the Klickitat River. Sampling will target type I (preferred) lamprey habitat that consists of a mixed substrate of silt, clay, organic matter, and sand. Additionally, Yakama Nation Fisheries staff will organize the collection of adult lamprey and salmon tissue. USGS staff will collect streambed sediments alongside larval lamprey collection on the four Columbia River tributaries.
Tissue and sediment samples will be analyzed at the USGS Mercury Research Laboratory in Madison, WI for total mercury, methylmercury, and isotopic mercury concentrations. Additionally, tissue will be analyzed for stable isotopes to better understand larval diets. The investigation will compare isotopic ratios to known end members, including returning adult spawners, to better understand mercury sourcing and uptake in juvenile lamprey.
Pacific Lamprey Habitat
Type 1 Pacific lamprey habitat on the Klickitat River near Glenwood, WA. Type I (preferred) lamprey habitat that consists of a mixed substrate of silt, clay, organic matter, and sand.
Type 1 Pacific lamprey habitat on the Klickitat River near Glenwood, WA. Type I (preferred) lamprey habitat that consists of a mixed substrate of silt, clay, organic matter, and sand.
Pacific Lamprey ammocoetes
Pacific Lamprey ammocoetes in a measurement tank. Tissues collected from the lamprey will be analyzed for mercury as part of a study on mercury contamination in the Columbia River Basin.
Pacific Lamprey ammocoetes in a measurement tank. Tissues collected from the lamprey will be analyzed for mercury as part of a study on mercury contamination in the Columbia River Basin.