An SPMD can even be used to concentrate contaminants efficiently from the air, soil, and sediment. If a spill happened in the first week of an SPMD deployment, we will still find hydrophobic contaminants from the spill in the device when we come back in a month. With fish, we might not. Also, we can use SPMDs to back-calculate a waterborne contaminant concentration, and we usually can't do that with fish. An SPMD is not a perfect model of a fish.
Fish can depurate some contaminants and pick up other pollutants through their diet.
Some of these contaminants reach their highest concentrations in animals that are high on the food chain. An SPMD cannot model biomagnification, but it can alert us to the presence of contaminants that can be biomagnified. An SPMD is a useful tool that assesses environmental contamination by hydrophobic chemicals. In addition, the Overview discusses SPMD technology in greater detail. It's a device that mimics parts of aquatic animals that cause bioconcentration.