Habitat Program Manager:
Stanley D. Rice
- Summer increases in PAH loads of a small Alaskan lake used by personal water
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Traditionally, organisms (mussels) that
bio-concentrate organic contaminants such as Polyaromatic Hydrocarbons (PAH)
are used to determine if these compounds are present in specific water
bodies. This presents several problems. Separating the organic compounds
from tissue lipids is an expensive process, and there is variation in
uptake do to the variations in lipid content. There are also
difficulties identifying species that can be used along salinity
gradients such as found in estuaries.
Recently semi-permeable membrane devices (SPMD) have been used to
detect PAH contamination. They are polyethylene bags filled with a lipid
which mimics how an aquatic organism such as mussels would concentrate
organic contaminants. This provides a time integrated sample in which
the lipid in the SPMD can be easily extracted for analysis. Although the
SPMDs are cheaper than traditional methods, they are patented and
currently only manufactured by one laboratory.
We are currently developing the use of cost
effective, low density polyethylene strips (LDPE) without the lipid for
monitoring water quality. We have been comparing the results observed in
LDPEs & SPMDs deployed side by side. Initial results indicate
that LDPEs perform identically to SPMDs in locations where contaminants
are present in low concentrations.
Employing the use of LDPEs has many advantages for habitat
management. They allow for an inexpensive survey of a broad area, a
standardized matrix for sampling transects across different estuarine
habitats, the ability to monitor contaminant dispersal from mixing
zones, and contaminant source identification without biometabolism.
These devices could easily be deployed to monitor contamination in boat
harbors, urban runoff, lakes, streams, and industrial discharge.
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