They are an important link in the aquatic food chain and a food source for several predators, including fish and various invertebrates. Tiny Hyalella offer many advantages as a biological indicator of environmental quality. The organisms are easy to raise, reproduce readily, and are representative of species of invertebrates found in most water systems. The tiny crustaceans provide biological measurements of water quality so researchers don't have to rely solely on chemical and physical measurements. Hyalella are collected with other small animals common to water systems and are examined to determine whether an ecosystem is functioning properly.
Scientists can then focus their research on the areas that are potentially problematic.
Hyalella are also used in laboratory experiments. Cooper and ecologist Scott S. Knight expose them to various concentrations of chemicals to evaluate and model responses to actual exposures in streams and lakes. They run toxicity tests using known and controlled mixtures of multiple chemicals to determine critical levels of contamination. Then they compare their lab results to those obtained in outdoor bodies of water to determine if the lab data reflect what is happening in the real world. Monitoring water quality through chemical and physical measures reveals the effects of improved conservation farming practices.