Chironomids as Environmental Indicators:Heavy Metals and Deformities Chaleen Shephard May 6, 1999

Pollutants Often manmade materials Excesses occur naturally

Bioaccumulation Build-up of toxic materials in tissues Magnify in food chain

Heavy Metals Chromium Copper Manganese Nickel

Chironomids Non-biting Midges Aquatic Insect Larvae 1/2 Inch Two Small Prolegs Found In Sediment Detritivores

a b c d e f g Chironomids

Indicator Species Large distribution area Variety of habitats Primary food source for many organisms

Morphological Testing Deformities in mouthparts, antennae, mandibles Effect of chemical contaminants

Flow Line Division, New Castle, Pennsylvania Five sites, Five Subsamples at Each Site Sediment Sample: AA, ICP spectrometry Chironomid Samples Sampled on 10/28/98 and 1/30/99 Sampling

Microwave Digester

AAICP

Mounting Head CapsuleCMCP-9/ CMCP-9AF Medium

Classification Normal

Classification Class I

Classification Class II

Classification Class III

Statistical Analysis At each site the five subsamples were combined to produce a sufficient sample size

Percent Deformity = chironomids at each site with deformed mouthparts divided by the total number of chironomids at that site

Toxic Score [No. Class I+2(No. Class II)+3(No. Class III)] X 100 Total Number Of Larvae

Concentration of Metals Kruskal-Wallis test (nonparametric alternative to Analysis of Variance) Followed by a distribution- free Multiple Comparisons Test

Results p= 0.010

Results p= 0.012

Results p= 0.013

Results p= 0.008

Results Correlation

Conclusions High concentrations of metals, especially at the outflow pipe No correlation between deformities and concentrations of heavy metals Low numbers of chironomids Lethal concentrations of heavy metals

Future Studies Tissue Analysis Laboratory tests Identification of species More samples, more chironomids, quantitative sampling Similar locations