Mercury in the Great Salt Lake Ecosystem

1
Mercury in the Great Salt Lake Ecosystem

• Jodi Gardberg
• Utah DEQ, Division of Water Quality

2
The Mercury (Hg) Cycle
3
Toxic Effects of Hg to Humans

• Methylmercury is the most toxic form of Hg
• Neurotoxin damage to the brain and nervous
  system
• Impacts the immune system
• Alters genetic and enzyme systems
• Particularly damaging to developing embryos

4
Toxic Effects of Hg to Birds

• Adults
• Decreased nesting effort
• Increased nest abandonment
• Decreased survival rates
• Direct mortality
• Young
• Anemia
• Feather abnormalities
• Neurological and immunological changes
• Decreased growth rates
• Eggs
• Decreased egg weight
• Malformations
• Lowered hatchability

5
Duck Advisories
Northern Shoveler
Common Goldeneye
Cinnamon Teal
www.waterfowladvisories.utah.gov/advisories.htm
6
Are avian species at risk from Mercury exposure
associated with the Great Salt Lake?
7
GSL Mercury Workplan

• 2007 Workplan Assessment of Hg in the GSL
  Ecosystem
• Assess Hg concentrations in the sediment, water
  column, avian tissues and food-chain biota
• Project Team UDWR, UDWQ, USU, USGS, GSL Alliance
  and USFWS
• 66,000 from DEQ Restricted Account One time
  FY2007 appropriation
• 87,000 from EPA RGI grant
• 53,000 from EPA WPDG grant
• 213,000 Total to Date

8
Mercury in the Water Column and Sediment

• Hg in the Water Column Dave Naftz, USGS
• Hg in the Sediment Dave Naftz, USGS

9
Great Salt Lake Food Web
Birds
Adult Brine Flies
Brine Shrimp
Brine Fly Larvae
Detritus
Blue-green and benthic algae
Nutrients from watershed
Decay
10
Mercury in the Avian Diet

• Hg in Brine Shrimp and Brine Shrimp Cysts Clay
  Perschon, UDWR
• Hg in Brine Fly Larvae and Pupae Wayne
  Wurtsbaugh, USU

11
Mercury in the Avian Species

• Hg in waterfowl tissues Clay Perschon, UDWR

12
Mercury in the GSL Wetlands and Farmington Bay

• Hg in Cinnamon Teal - Clay Perschon, UDWR
• Hg in Plants and Macroinvertebrates Theron
  Miller, UDWQ
• Hg in the Water Column and Sediments Dave
  Naftz, USGS

13
Future Data Needs

• Sulfur Reducing Bacteria (SRB)
• Hg interaction with Selenium
• Rates of Mercury Methylation in sediments
• Historical Mercury Methylation and
  bioaccumulation rates
• Physiological fate and transport of Hg in avian
  species
• Ecological exposure potential