Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and...
-
Upload
randolf-patrick -
Category
Documents
-
view
221 -
download
0
Transcript of Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and...
![Page 1: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/1.jpg)
Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA
Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State University
Spencer Peterson and John Van Sickle EPA NHEERL Corvallis, OR
![Page 2: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/2.jpg)
Questions
• What is the extent of mercury (Hg) contamination in fish tissue across all Western U.S. streams and rivers?
• What are the factors related to mercury levels in fish at this scale?
![Page 3: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/3.jpg)
Environmental Monitoring and Assessment Program (EMAP) Western U.S. Pilot Survey
• Sample sites were selected using the systematic, randomized EMAP sampling design from all perennial western U.S. streams/rivers– Additional hand-picked reference sites
• Samples selected off of the digitized version of the 1:100,000 scale USGS maps
• Inferences to the entire stream network can be made from probability survey data using site inclusion probabilities
![Page 4: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/4.jpg)
Field Methods
• Fish sampled by electrofishing
• Streams: backpack shocker on 40 channel width long sample reach
• Rivers: raft mounted shocker on 100 channel width reach
• Associated measurements of water chemistry, physical habitat, and watershed characteristics
![Page 5: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/5.jpg)
Tissue Samples
• Collect a big and small fish sample at each site if sufficient numbers available
• Big Fish: ≥ 120 mm total length– Up to 3 individuals of 3 different species of
varying size, individuals analyzed separately
• Small Fish: Adults < 120 mm– Single composite sample (50-200 g)
• Samples kept on ice, shipped overnight to laboratory and then frozen until analysis.
![Page 6: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/6.jpg)
Hg Laboratory Analysis
• Whole body analysis (µg Hg/g wet weight)• Fish ground up in blender (bass-o-matic)• Subsampled, frozen with no further sample
preparation • Subsamples thawed, rehomogenized, ≈0.25 g
analyzed by Combustion AAS (Milestone MDA80 direct Hg analyzer)
• Subsamples analyzed in duplicate, – repeat if > 5% difference
• Method Detection Limit = 0.0024 µg Hg/g wet wt.
![Page 7: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/7.jpg)
Most Common Species Analyzed
• Big Fish (2,707 fish, 626 sites)
• Non-Piscivores (85%)– Rainbow, Brown, Brook,
Cutthroat Trout– White, Largescale Sucker– Mountain Whitefish, Carp
• Piscivores (15%)– Smallmouth Bass– Northern Pikeminnow– Walleye, Northern Pike
• Small Fish (386 samples)– Mottled Sculpin– Common Shiner– Redside Shiner– Fathead Minnow– Creek Chub– Speckled Dace– Longnose Dace
![Page 8: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/8.jpg)
Three Aggregate Level III Omernik Ecoregions used in Analysis
![Page 9: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/9.jpg)
Mercury – Fish Length Relationship for Individual Big Fish
![Page 10: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/10.jpg)
Factors to Consider
• Fixed Factors– Ecoregion (Mountains, Xeric, Plains)– Site Disturbance Class (Low, Medium, High)– Trophic Group (Piscivore, Non-Piscivore)
• Covariates– Fish Age (Fish length)
• Analysis of Covariance using individual big fish
![Page 11: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/11.jpg)
Big Fish ANCOVA Results
• Effect F-value P - value df
Fish Length 330 < .0001 1
Trophic Group 120 < .0001 1
Ecoregion 1.8 0.17 2
Site Disturbance 3.7 0.03 2
Trophic x Ecoregion 11 < .0001 2
![Page 12: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/12.jpg)
Non-Piscivores
Piscivores
Fish Tissue Mercury in Trophic x Disturbance Class
![Page 13: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/13.jpg)
Fish Tissue Mercury in Ecoregion x Trophic Classes
Non-Piscivores
PiscivoresNon-Piscivores
Piscivores
![Page 14: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/14.jpg)
Correlation between Hg and environmental variables in Big Fish after partialing out the
effect of fish length • Piscivores (n=358)• Most strongly correlated with
– ANC (r = -0.57)– Conductivity (r = -0.56)– Watershed Slope (r = 0.52)– Precipitation (r = 0.51)– % Forested Watershed (r = 0.5)– Sulfate (r = -0.5)
• Non-Piscivores (n=1,964)– No variables
correlated with r > 0.3
![Page 15: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/15.jpg)
Various Fish Tissue Mercury Criteria Values
• Human Health– 0.5, 0.6, 1.0 µg/g – 0.35 µg/g (Oregon Health Div., 1997)– 0.30 µg/g (EPA, 2001)– 0.10 µg/g (Faroe Island Study, 1998)
• Wildlife protection values - Lazorchak et al. 2003
– 0.10 µg/g (Otter)– 0.07 µg/g (Mink)– 0.03 µg/g (Kingfisher)
![Page 16: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/16.jpg)
Relationship between Fish Tissue Filet and Whole body Hg
![Page 17: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/17.jpg)
Cumulative Distribution Function (CDF) of Mean Site Fish Tissue Mercury
Weighted population estimates from EMAP survey design
![Page 18: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/18.jpg)
Extent of Big Fish Hg Contamination by Family
Total Stream Length=305,000 km; 180,000 km with Big Fish
0 20,000 40,000 60,000 80,000 100,000 120,000 140,000
Salmonid
Ictalurid
Esocid
Cyprinid
Centrarchid
Catostomid
Estimated Stream Length (km)
Not Assessed
<0.1 ug/g
0.1-0.185 ug/g
>0.185 ug/g
![Page 19: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/19.jpg)
Summary
• Fish tissue mercury concentrations were most strongly related to trophic group and fish length not environmental factors, ecoregion, or site disturbance– Regional analyses must
consider trophic group and size
• In terms of % Stream Length exceeding criteria
• Big Piscivores– 93% > 0.1 µg/g – 57% > 0.185 µg/g
• Big Non-piscivores– 26% > 0.1 µg/g– 6% > 0.185 µg/g
![Page 20: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/20.jpg)
Summary (con’t)
• Fish tissue mercury concentrations in Western U.S. streams and rivers were found in a fairly narrow range, always above the detection limit (0.0024)– 90% of the small fish and non-piscivores had Hg
between 0.02 and 0.2 µg/g– High concentration “hot spots” (Hg > 0.5 µg/g) were
very rare (< 2% of stream resource)
• This strongly suggests a broad diffuse source of mercury from atmospheric deposition.
![Page 21: Mercury Concentrations in Stream Fish Throughout 12 Western States in the USA Alan Herlihy and Robert Hughes Dept. of Fisheries & Wildlife, Oregon State.](https://reader035.fdocuments.in/reader035/viewer/2022062309/56649eda5503460f94be9f7d/html5/thumbnails/21.jpg)
Study was funded by EPA’s Environmental Monitoring and Assessment Program
(EMAP)
EMAP Regional Hg Survey Citations• Oregon Streams: Peterson et al., 2002.
Environ. Toxicol. Chem. 21:2157-2164.
• Mid-Atlantic Streams: Lazorchak et al., 2003. Environ. Toxicol. Chem. 22:545-553.
• Northeast Lakes: Yeardley et al., 1998. Environ. Toxicol. Chem. 17:1875-1874.