Dieldrin%20in%20Cyprinus%20Carpio%20from%20the%20Des%20Moines%20River:%201977-2003

1
Dieldrin in Cyprinus Carpio from the Des Moines
River 1977-2003
INTRODUCTION Dieldrin concentrations have been
measured over a span of 26 years in common carp
(Cyprinus carpio) from the Des Moines River below
two reservoirs. Saylorville Reservoir is located
11 miles upstream from the city of Des Moines
while Red Rock Reservoir is located 60 miles
downstream. The Des Moines River watershed is
primarily agriculturalcorn and soybean cropland.
Dieldrin vs Fat
Data Summary

• Quick Facts on Aldrin Dieldrin
•  
• Aldrin (C12H8Cl6) and Dieldrin (C12H8Cl6O)
• Organochlorine insecticides
• Persistent, Bioaccumulative and Toxic (PBT)
  pollutants
•  
• Use History
• Agricultural use Corn and cotton crops
• Prophylactic use and timber treatment for
  termites
• Early 1950s until 1989 when manufacture in US
  discontinued
• Peak use in 1966
• Food crop use cancelled 1974
• Last registered use termiticide, cancelled
  1987-1989
•  
• Environmental Profile
• Aldrin converts rapidly to dieldrin by
  microsomal oxidation reaction
• Half-life of dieldrin in temperate soils, 5
  years
• Solubility 0.01-0.11 mg/L, very soluble in
  organic solvents
• Partition Coefficients

• RESULTS
• Uniformity of fish
• Std deviation of sample fish lengths ranged from
  3 to 5 of mean
• Condition factor weight(g)x105 / Length(mm)3
• Ave fillet fish condition factors
  Saylorville1.23 Red Rock 1.29
• Ave whole fish condition factors Saylorville
  1.26 Red Rock 1.30
• Ave fat in fillets Saylorville 0.8, Red Rock
  0.9
• Ave fat in whole fish Saylorville 4.0, Red
  Rock 3.7
• Statistical Analysis
• Time Trends
• Sens Slope
• no time trend in whole fish data
• significant (P0.05) downward trend in fillet
  concentrations
• Saylorville fillet concentration 0.77 ppb/yr
• Red Rock fillet concentration 0.69 ppb/yr
• Parameter interaction Dieldrin vs. Fish length,
• fat, River Flow, Annual Precipitation
• Correlation

Significant Trends
Dieldrin vs Annual Precipitation

• DISCUSSION
• Note 1993 fish were collected during high flow
  but before the record-breaking floods of 1993
• Fillet Fish Data
• Highest fillet conc. seen in 1977, then declined
  sharply until 1987, after which they leveled off
• Fillet concentrations below Saylorville Dam
  (more urban) were higher than below Red Rock Dam
• In general, concentrations are low, fillet conc.
  well below FDA action level
• However, not until after 1993 were fillet conc.
  below EPA screening value for recreational
  fishers
• In fillet samples after 1990, the variations in
  fat, despite the uniformness of samples,
• attributed to variations in dieldrin
  concentrations
• Whole Fish Data
• Trends are easier to distinguish in fillet vs
  whole fish samples because the fat in whole fish
  varied more
• Dieldrin in whole fish below Sayl Dam have been
  below 10 ppb since 1997
• Dieldrin in whole fish below RR Dam have been
  more variable
• Below RR Dam peaks in 1991 and 1998 were not
  explained by fat data

• METHODS
• Sampling Protocol
• Annual collections in May, June or July
• Target age class III Cyprinus carpio
• Fish length 312-351 mm
• 2 subsamples of 5 fish each per sample
• Smallest fish gt75 of largest
• Std deviation of fish lengths lt10 mean length
• Difference in fish lengths between subsamples
  lt10 of mean
• Analytical Methods
• Grind, homogenize sample
• Extract with petroleum ether, concentrate
• Partition w/ acetonitrile, cleanup w/ Florisil,
  reconcentrate
• Analyze w/ gas chromatograph w/ electron
  capture detector
• Results on wet weight basis
• fat (lipid)-gravimetric

The Des Moines River Water Quality Network
(DMRWQN) is a long-term monitoring project
sponsored by the Rock Island District COE and
performed by ISUs Department of Civil,
Construction Environmental Engineering. For
more information visit http//www.cce.iastate.edu