2009 Maine Water Conference
Tuesday, March 24, 2009
Holiday Inn, Portland, Maine

POSTER AWARDS

High School l Undergraduate l Graduate

High School Competition Winner

Carin P. King, Waterville Senior High School, Waterville, ME

Detection of Arsenic in Ground Water Using Surface Plasmon Resonance: Field Verification of a New Analytical Technique for Arsenic

Arsenic is a known toxin found in water throughout the world. Arsenic contamination is a particular problem in 38 developing countries where drinking water is often drawn from shallow, unmonitored wells. The WHO has determined that “simple, reliable, low cost equipment for field measurements” is an urgent requirement for arsenic detection (WHO 2001). Our past work developed a single beam surface plasmon resonance method for detecting arsenic at 20 ppb in pure water. We now describe the extension of this method to lower arsenic detection limits in a ground water sample matrix. Arsenic samples were obtained from ground water wells at over 20 locations in central Maine. An analytical intercomparison study was performed on these samples using SPR and an ICP- optical emission spectroscopy. This work provides the next step towards an analytically robust method for
detecting arsenic in ground water using a single beam SPR instrument.

Undergraduate Competition Winner

Spencer Blair-Glantz, University of Southern Maine, Portland, ME

Zooplankton Population Analysis and Body Length Measurement in Damariscotta Lake, Maine in Relation to Alewife Populations

The purpose of the study was to analyze the impact of predation from juvenile alewives (Alosa) on zooplankton population numbers and overall body size, to determine if predation primarily affects the larger-bodied zooplankton groups, driving down their populations and allowing other groups to flourish. Zooplankton groups in Damariscotta Lake, Maine, collected on 5 monthly sampling dates (June to October 2008) and identified, counted,
and measured for body length. Eight zooplankton groups were identified and measured: Cyclopoida, Calanoida, Daphniidae, Bosmina, copepod nauplii, Asplanchnidae, Conochilus, and Holopedium spp. All zooplankton groups changed in abundance over the duration of the study period. Daphniidae in particular were affected by alewife predation; initially abundant, their populations dropped dramatically soon after the appearance
of alewife juveniles. Average body length also dropped somewhat over the five month span. Copepod nauplii had a large population increase, as well as a small increase in average body size. Interestingly, zooplankton dynamics in Damariscotta Lake varied by lake basin, with zooplankton consistently more abundant and
larger in the main (north) basin than in the Muscongus basin (south). Changes in zooplankton abundance and length correspond to the time of the summer that juvenile alewives would be expected to consume larger zooplankton. Differences between basin may be related to basin morphology, differential usage by juvenile alewives, or productivity.

Graduate Competition Winner

Jennifer C. Meyers, University of Maine, Orono, ME

Developing Non-lethal Biomarkers for Waterborne Organic Contaminants

Expression of cytochrome P4501A (CYP1A) in the liver is a well-established, but lethal biomarker for organic contaminant
exposure in vertebrate species. A non-lethal biomarker using scales and gill filaments to measure CYP1A enzyme activity (measured as ethoxyresorufin o-deethylase, EROD) would present an alternative method for detection of water-borne contaminant exposure in endangered or threatened fish species. This analysis would also provide an inexpensive technique (compared to whole body chemical analysis) to determine acute organic contaminant
exposure and help identify specific geographical areas for chemical analysis to aid in implementing restoration plans for contaminated sites.

We are evaluating the sensitivity, reliability, and time course of the induction and duration of CYP1A activity in gills, scales, and livers in Atlantic salmon (Salmo salar). Atlantic salmon are indigenous to Maine and are currently listed as an endangered species. We exposed salmon parr to two aqueous concentrations of PCB-126 (0.01 μM & 0.001 μM, static exposure), acetone (32.25 ppm, vehicle), and untreated water for 24 h before transferring the fish to clean, flow-through water. Throughout several time points (during and post exposure) we collected gill filaments and scales (non-lethally) and whole livers (lethally).
Gill EROD activities in fish treated with 0.01 μM PCB-126 were elevated at 6 h during exposure and remained significantly elevated (compared to untreated and acetone controls) throughout the experiment. The 0.001 μM PCB-126 treated fish showed an elevated gill EROD activity at 6 h which declined at 24 h exposure before reaching untreated activity levels by 48 h post exposure. Scale EROD activities were elevated for 0.001 μM PCB-126 treated fish at 6 h, but not significantly elevated in the 0.01 μM PCB-126 treated fish until 24 h. After 48 h post exposure, scale EROD activities became highly variable in all groups.

Gill and scale CYP1A activity show encouraging results as non-lethal biomarkers of contaminant exposure and response for use with endangered fish species. Liver EROD activities are currently undergoing analysis. Future investigations include optimizing scale and gill EROD protocols to reduce variability.